spermatogenesis of male patients with congenital

Received: Mar 19, 2020 Revised: Jun 10, 2020 Accepted: Jun 16, 2020 Published online Jul 14, 2020Correspondence to: Xiaming Liu https://orcid.org/0000-0002-1194-8791 Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Qia-okou District, Wuhan 430030, Hubei, China. Tel: +86-27-83665308, Fax: +86-27-83665308, E-mail: [email protected]*These authors contributed equally to this work as co-first authors.

Copyright © 2021 Korean Society for Sexual Medicine and Andrology

Spermatogenesis of Male Patients with Congenital Hypogonadotropic Hypogonadism Receiving Pulsatile Gonadotropin-Releasing Hormone Therapy Versus Gonadotropin Therapy: A Systematic Review and Meta-Analysis

Chao Wei1,* , Gongwei Long1,* , Yucong Zhang1,2 , Tao Wang1 , Shaogang Wang1 , Jihong Liu1 , Delin Ma3 , Xiaming Liu1

Departments of 1Urology, 2Geriatric, and 3Endocrine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China

Purpose:Purpose: Pulsatile gonadotropin-releasing hormone (GnRH) therapy and gonadotropin therapy (GT) were widely used for male patients with congenital hypogonadotropic hypogonadism (CHH), but their efficacy was not well compared before. We conducted this meta-analysis to compare the efficacy of restoring fertility using these two therapies.Materials and Methods:Materials and Methods: PubMed, Web of Science, and Scopus were systematically searched for comparative studies evaluat-ing the efficiency of GnRH therapy and GT for male patients with CHH. For continuous outcomes, the weighted mean dif-ference (WMD) was used to measure the difference, whereas the risk ratio with 95% confidence interval was calculated for binary variables.Results:Results: Overall, eight articles from seven studies with 420 patients enrolled were included in the analysis. Patients from the two different groups were determined to be comparable in age, proportion with Kallmann syndrome, percentage of cryptor-chidism and pretreatment hormones (follicular-stimulating hormone, luteinizing hormone, and testosterone). GnRH therapy was related to a larger testicular volume (standardized mean difference=-1.43; p=0.01) and earlier spermatogenesis (WMD=-5.30 months; p=0.004) compared to GT. However, the difference in the rate of positive sperm detection (p=0.08), sperm concentration (p=0.37), and pregnancy rate (p=0.11) were not significant. Allergic reactions mostly occurred during GnRH therapy, while GT was related to a higher incidence of gynecomastia and acne.Conclusions:Conclusions: Compared to GT, GnRH was related to earlier spermatogenesis and less estradiol-related adverse reactions, al-though there were no significant differences in spermatogenesis rate, sperm concentration, and pregnancy rate. High-quality randomized controlled trials are needed for future research.

Keywords:Keywords: Chorionic gonadotropin; Gonadotropin-releasing hormone; Idiopathic hypogonadotropic hypogonadism; Kall-mann syndrome; Spermatogenesis

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Original Article

pISSN: 2287-4208 / eISSN: 2287-4690World J Mens Health 2021 Oct 39(4): 654-665https://doi.org/10.5534/wjmh.200043

Male reproductive health and infertility

http://crossmark.crossref.org/dialog/?doi=10.5534/wjmh.200043&domain=pdf&date_stamp=2021-10-01

https://orcid.org/0000-0001-9205-5030

https://orcid.org/0000-0001-8008-2306

https://orcid.org/0000-0002-2991-5066

https://orcid.org/0000-0002-2614-4913

https://orcid.org/0000-0003-0211-4303

https://orcid.org/0000-0002-3649-9734

https://orcid.org/0000-0002-0860-0129

https://orcid.org/0000-0002-1194-8791

Chao Wei, et al: GnRH Therapy Versus Gonadotropin Therapy for CHH

655www.wjmh.org

INTRODUCTION

Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder caused by gonadotropin-releasing hormone (GnRH) deficiency or resistance [1]. Based on olfactory dysfunction, patients can be categorized into two subtypes, Kallmann syndrome (KalS), which is an-osmic, and idiopathic hypogonadotropic hypogonadism (IHH), which maintains normal olfactory function [2]. Because of the GnRH secretion deficiency or resistance, children with CHH display absent or arrested puberty, and their development of sex characteristics and fertil-ity are severely impeded.

Injections of testosterone can improve the devel-opment of sex organs and secondary sexual charac-teristics, but it can also inhibit spermatogenesis [3]. To restore fertility, gonadotropin therapy (GT) was developed, and the treatment of human chorionic go-nadotropin (HCG) alone or in combination with human menopausal gonadotropin (HMG) was confirmed to be effective in the induction of spermatogenesis in CHH patients [4-6]. However, the HCG/HMG therapy was conducted by intramuscular or subcutaneous injection 2–3 times weekly and the long duration of therapy and inconvenience of frequent injections result in poor compliance.

In 1978, the mechanism of pulsatile secretion of GnRH was clarified by Belchetz et al [7]. In 1982, pul-satile GnRH was first applied to six IHH patients and successfully induced spermatogenesis in three patients [8]. Through a subcutaneously placed butterfly needle, GnRH was administrated in 90- or 120-minute intervals using a portable pump, and the pulsatile administra-tion of medication more closely mimics the physiologi-cal conditions. Both pulsatile GnRH therapy and GT were recommended for the induction of male fertility [9]. However, although pulsatile GnRH therapy is closer to physiological conditions theoretically, whether it is superior to GT remains unclear. Several studies sug-gested that GnRH therapy enlarged testicular volume more efficiently [10-12], and the rate of spermatogenesis was significantly higher than GT [13]. Importantly, GnRH therapy was related to earlier spermatogenesis than GT [12-14]. However, several studies indicated that there was no difference between the two therapies [15,16]. In addition, several studies reported related side effects with highly inconsistent results [10,12,14,16].

Due to the controversial results regarding the ef-

ficacy of GnRH and GT, we performed this systematic review and meta-analysis to directly compare the effi-cacy and safety of these two therapy modalities.

MATERIALS AND METHODS

No previous protocol was published for this system-atic review and meta-analysis.

1. Literature searchA comprehensive literature search was conducted

for studies published from the inception of databases to February 10, 2020, in PubMed, Web of Science, and Scopus to identify studies comparing GnRH therapy to GT in CHH treatment.

Separate searches were carried out using diagnosis (hypothalamic hypogonadism, hypogonadotropic hypo-gonadism, CHH, IHH, Kallmann’s syndrome) and inter-vention terms (GnRH, follicular-stimulating hormone [FSH], HCG, HMG). The detailed search string was listed in Supplement Table 1.

Titles and abstracts of articles identified by the key-word search were screened against the study selection criteria. Potentially relevant articles were evaluated of the full text. An additional manual search of refer-ences from identified studies was performed. Two in-dependent reviewers screened all studies according to inclusion and exclusion criteria, and all disagreements were resolved by discussion with a third author.

2. Study selection criteriaStudies that met the following criteria were included

in this meta-analysis:1) The diagnosis of CHH was based on reliable evi-

dence including history, hormone tests, and imag-ing tests.

2) The efficacy or safety of GnRH and GT in male patients was compared.

3) The therapy protocol was documented with de-tailed regimens.

4) The articles were written in English or Chinese with English abstracts.

5) The required data should be complete with confi-dence intervals (CIs), standard deviation (SD), or standard error.

Studies that met the following criteria were exclud-ed:

1) The study was a review with no original data.

https://doi.org/10.5534/wjmh.200043

656 www.wjmh.org

2) The study was a case report that reported the efficacy of GnRH therapy or GT with a limited sample size (less than 5).

3. Data extraction and quality assessmentTwo reviewers independently extracted data from

every study and evaluated methodological quality. The following information was extracted from each study: number of cases; proportion of KalS; proportion of cryptorchidism; age at initial treatment; duration of therapy and follow-up; pretreatment and posttreatment FSH, luteinizing hormone (LH), estradiol, testosterone, testicular volume; rate of spermatogenesis at the end of study; time to the first sperm detection; sperm concen-tration; rate of pregnancy; and events of side effects.

The quality of each study was determined using the ROBINS-1 tool, a tool recommended by Cochrane for assessing risk of bias in non-randomised studies of in-terventions [17]. The graph for risk of bias was gener-ated with robvis tool [18].

4. Data analysisA formal meta-analysis of studies comparing the

efficacy (testosterone, testicular volume, rate of sper-matogenesis, time to first sperm detection, sperm count, and rate of pregnancy) of GnRH therapy to GT for CHH was conducted (primary outcomes). Successful spermatogenesis was defined as the appearance of at least one sperm cell in the semen. Additionally, the side

effects of the two treatments were compared (secondary outcomes). Besides, a subgroup analysis of the rate of spermatogenesis according to the presence of cryptor-chidism was performed.

For outcomes of continuous variables, the weighted mean difference (WMD) was used to measure the dif-ference, whereas the risk ratio (RR) with 95% CI was calculated for binary variables. Standardized mean dif-ference (SMD) was used if the results were measured using different scales or the reported outcomes varied greatly. For studies reporting medians and ranges, a validated mathematical model was used to convert the median (range) to mean±SD [19].

When two publications reported the same study, rel-evant parameters were only counted once for the scope of the present analysis. For example, this approach was employed for the study published by Schopohl et al [12] and Schopohl [20]. When two studies reported by the same group contained overlapping patients, we only used the relevant data of the higher-quality study.

A fixed-effects model was used to calculate the pooled estimates if no significant heterogeneity was identified (I2<50%). Otherwise, a random-effects model was used. Additionally, a sensitivity analysis was also performed by changing effect model. Due to the limited number of included studies, the publication bias was evaluated by using Egger linear regression. All statisti-cal analyses were performed by using Review Manager 5.3 (Cochrane Collaboration, Oxford, UK), except for

Records excluded afterreview of titles and abstracts

(n=1,902)

Full-text articles excluded, withreasons (n=28):

Review, case report (n=13)Not HH (n=6)No comparison (n=9)

Additional records identifiedthrough reference list

(n=1)

Records after duplicates removed(n=1,937)

Records screened(n=35)

Full-text articles assessedfor eligibility

(n=7)

Studies included in meta-analysis

(n=8)a

Records identified throughdatabase searching

(n=2,490)

Fig. 1. PRISMA flow chart of the screen-ing of eligible studies. aOf the eight ar-ticles included, two articles reported the outcomes of the same study [12,20].


657www.wjmh.org

Tabl

e 1.

Cha

ract

erist

ics o

f inc

lude

d st

udie

s in

the

met

a-an

alys

is co

mpa

ring

GnRH

and

GT

for m

ale

CHH

patie

nts

Stud

ySt

udy

desi

gnSt

udy

orig

inGn

RH

regi

men

sGT

regi

men

GnRH

/GT

Repo

rted

ou

tcom

e

Test

icul

ar

volu

me

mea

sure

men

tTo

tal

case

s (n)

Case

s of

KalS

(n)

Mea

n

age

(y)

Med

ian

FU

(mo)

Büch

ter e

t al (

1998

) [15

] RT

P, SC

Germ

any

5–20

μg

ever

y 12

0 m

inut

esHC

G 1,

000–

2,50

0 IU

twic

e a

wee

k an

d HM

G 75

–150

IU th

ree

times

a w

eek

( i.m

. or s

.c.)

6/18

2/9

30.1

/29.

1N

STV

, Rat

eS, T

imeS

, Ra

teP

Palp

atio

n or

US

Gong

et a

l (20

15) [

10]

PRP,

SCCh

ina

8–10

μg

ever

y 90

min

utes

HCG

1,00

0–2,

000

IU tw

ice

a w

eek

or e

very

ot

her d

ay (i

.m.)

12/2

28/

1513

.39/

13.8

9N

ST,

FSH,

TV,

AR

Orc

hido

met

er

Huan

g et

al (

2015

) [13

] RT

P, SC

Chin

a10

μg

ever

y 90

min

utes

HCG

3,00

0 IU

and

HM

G 75

IU tw

ice

a w

eek

(i.m

.) HC

G do

se w

as a

djus

ted

acco

rdin

g to

T le

vel.

40/5

220

/29

22.4

/20.

58.

2/9.

2T,

FSH,

TV,

Rat

eS,

Tim

eS, R

ateP

Orc

hido

met

er

Klie

sch

et a

l (19

94) [

16]

RTP,

SCGe

rman

y5–

20 μ

g ev

ery

120

min

utes

HCG

1,00

0–2,

500

IU tw

ice

a w

eek

and

HMG

75–1

50 IU

thre

e tim

es a

wee

k (i.

m. o

r s.c.

)6/

112/

730

.7/3

1.0

14.5

/15.

7FS

H, T

V, R

ateS

, Ti

meS

, SpC

, Ra

teP,

AR

Palp

atio

n or

US

Liu

et a

l (19

88) [

11]

PRP,

SCUS

A10

–20 μg

ev

ery

120

min

utes

HCG

2,00

0 IU

and

HM

G (7

5 IU

FSH

and

75

IU

LH) t

hree

tim

es a

wee

k (i.

m.)

5/10

0/0

23.1

/30.

620

.8/2

4.0

T, FS

H, T

V, R

ateS

Orc

hido

met

er

Mao

et a

l (20

17) [

14]

RTP,

SCCh

ina

10 μ

g ev

ery

90 m

inut

es

HCG

2,00

0 IU

and

HM

G 75

IU tw

ice

a w

eek

(i.m

.)HC

G do

se w

as a

djus

ted

acco

rdin

g to

T le

vel

20/1

8211

/84

27.1

/21.

515

.6/2

8.7

T, FS

H, T

V, R

ateS

, Ti

meS

, SpC

, Ra

teP,

AR

Orc

hido

met

er

Scho

pohl

et a

l (19

91)

[12]

a , Sch

opoh

l (19

93)

[20]

a

PRP,

SCGe

rman

y4–

16 μ

g ev

ery

90 o

r 120

m

inut

es

HCG

2,50

0 IU

thre

e tim

es a

wee

k in

itial

ly a

nd

then

redu

ced

acco

rdin

g to

T a

nd e

stra

diol

le

vel

HMG

150

IU tw

ice

a w

eek

was

add

ed 2

–3

mon

ths l

ater

and

dos

age

incr

ease

d

acco

rdin

g to

test

icul

ar g

row

th a

nd sp

erm

co

unt (

i.m.)

18/1

88/

921

.1/2

3.6

9.3/

14.4

T, TV

, Rat

eS,

Tim

eS, S

pC,

Rate

P, AR

Orc

hido

met

er

GnRH

: gon

adot

ropi

n-re

leas

ing

horm

one,

GT:

gon

adot

ropi

n th

erap

y, C

HH: c

onge

nita

l hyp

ogon

adot

ropi

c hy

pogo

nadi

sm, K

alS:

Kal

lman

n sy

ndro

me,

FU:

follo

w-u

p, R

TP: r

etro

spec

tive,

SC:

sin

gle

cent

er, P

RP: p

rosp

ectiv

e, H

CG: h

uman

cho

rioni

c go

nado

trop

in, H

MG:

hum

an m

enop

ausa

l gon

adot

ropi

n, i.

m.:

intr

amus

cula

r inj

ectio

n, s.

c.: su

bcut

aneo

us in

ject

ion,

NS:

not

spec

ified

, TV:

test

icul

ar

volu

me,

Rat

eS: r

ate

of p

ositi

ve sp

erm

atog

enes

is, T

imeS

: tim

e ne

eded

to in

duce

sper

mat

ogen

esis,

Rat

eP: r

ate

of p

regn

ancy

, T: p

ost-

trea

tmen

t tes

tost

eron

e, F

SH: p

ost-

trea

tmen

t fol

licul

ar-s

timul

at-

ing

horm

one,

AR:

adv

erse

reac

tion,

SpC

: spe

rm co

unt,

US: u

ltras

onog

raph

y.a Th

ese

two

artic

les r

epor

ted

the

sam

e ou

tcom

es fr

om th

e sa

me

stud

y.


658 www.wjmh.org

the calculation of Egger’s linear regression test, which was conducted in STATA ver. 12.0 (Stata Corp., College Station, TX, USA).

RESULTS

1. Characteristics of the included studiesOverall, eight articles with 420 patients were includ-

ed in the meta-analysis after screening (Fig. 1) [10-16,20]. Among these patients, 204 patients and 216 patients were diagnosed with KalS and IHH respectively. Of these studies, two articles reported the outcomes of the same research, and the relevant outcomes were used

only once in our analysis [12,20]. Huang et al [13] and Mao et al [14] conducted two studies with overlapping data, as well as Büchter et al [15] and Kliesch et al [16]. When two studies were included in a single analysis, we used the data of Huang et al [13] and Kliesch et al [16] because of their higher quality.

The characteristics of the included studies are pre-sented in Table 1. Most of these studies were conducted in Germany and China, and one was conducted in the USA in 1988. Four of the seven included studies were retrospective, and others were prospective. The com-bination of HCG and HMG for GT was used in most studies except for the study conducted by Gong et al

Domains:

D1: bias due to confounding

D2: bias due to selection of participants

D3: bias in classification of interventions

D4: bias due to deviations from intended interventions

D5: bias due to missing data

D6: bias in measurement of outcomes

D7: bias in selection of the reported result

SeriousModerateLowNo information

Judgement

Stu

dy

D1

D2

D3

D4

D5

D6

D7

Ove

rall

Buchter et al (1998) [15]

Gong et al (2015) [10]

Huang et al (2015) [13]

Kliesch et al (1994) [16]

Liu et al (1988) [11]

Mao et al (2017) [14]

Schopohl et al (1991) [12]

Risk of bias domains

..

Fig. 2. The risk of bias graph of included studies based on the ROBINS-1 method.

Fig. 3. Forest plots of posttreatment physiological parameters of patients after gonadotropin-releasing hormone (GnRH) or gonadotropin therapy (GT). (A) Forest plot of posttreatment testosterone of patients after GnRH or GT. The posttreatment testosterone level of the GnRH group was significantly lower than that of the GT group. (B) Forest plot of posttreatment testicular volume of patients after GnRH or GT. GnRH therapy was related to larger posttreatment testicular volume. HCG: human chorionic gonadotropin, HMG: human menopausal gonadotropin, SD: standard deviation, CI: confidence interval, df: degree of freedom.

Study or subgroupHCG/HMG GnRH Mean difference

Huang et al (2015) [13]


Liu et al (1988) [11]


Total (95% CI)

Heterogeneity: Tau =9.76; chi =15.36, df=3 (p=0.002); I =80%

Test for overall effect: Z=4.39 (p<0.0001)

2 2 2

14.4

26.8

21.0

22.5

8.0

2.4

2.5

8.1

Mean SD Total

52

11

11

18

92

Weight

26.7%

24.5%

28.2%

20.6%

100.0%

IV, random, 95% CI

7.00 [4.29, 9.71]

5.40 [2.04, 8.76]

12.00 [9.77, 14.23]

5.70 [1.18, 10.22]

7.75 [4.29, 11.21]

IV, random, 95% CIMean difference

20 0 10 20

Favours[GnRH]

Favours[HCG/HMG]

7.4

21.4

9.0

16.8

5.2

3.8

1.9

5.5

Mean SD Total

40

6

5

18

69

10

Study or subgroupHCG/HMG GnRH Std. mean difference

Gong et al (2015) [10]

Huang et al (2015) [13]


Liu et al (1988) [11]


Total (95% CI)

Heterogeneity: Tau =1.33; chi =36.00, df=4 (p<0.00001); I =89%

Test for overall effect: Z=2.53 (p=0.01)

2 2 2

6.01

7.6

14.5

8.9

8.4

1.33

4.2

5.7

0.51

3.0

Mean SD Total

22

52

11

11

18

114

Weight

20.2%

23.3%

20.1%

14.5

22.0

100.0

%

%

%

IV, random, 95% CI

2.78 [ 3.78, 1.79]

0.12 [ 0.53, 0.29]

0.42 [ 1.43, 0.58]

3.77 [ 5.61, 1.93]

0.97 [ 1.67, 0.28]

1.43 [ 2.55, 0.32]

IV, random, 95% CIStd. mean difference

4 0 2 4

Favours[GnRH]

Favours[HCG/HMG]

13.09

8.1

17.3

11.4

11.1

3.82

4.0

7.3

0.85

2.4

Mean SD Total

12

40

6

5

18

81

2

A

B

Testosterone

Testicular volume


659www.wjmh.org

[10], in which the patients were adolescent boys treated with HCG alone. Notably, most included studies were conducted based on limited sample size (the number of the GnRH cases was less than 10 in three studies).

Most studies were of low and moderate bias (Fig. 2 and Supplement Table 2). The imbalanced sample sizes, follow-up durations, and baseline characteristics includ-ing initial testicular volume and age of the two arms might be the reasons for the relatively lower quality. In particularly, Büchter et al [15] and Gong et al [10] did not report their follow-up length, but the follow-up strategies were described, as every 3 to 6 months in Büchter et al’s study [15] and every 3 months in Gong

et al’s study [10] until the treatment finished.Two arms of the comparison were not significantly

different in age (p=0.19), the proportion of KalS (p=0.53), and the percentage of cryptorchidism (p=0.78). Pretreatment hormones, including FSH (p=0.26), LH (p=0.11), and testosterone (p=0.65), were also similar in the GnRH group and GT group. Notably, the pre-treatment testicular volume in the GnRH group was larger than that in the GT group (WMD=0.32 mL, 95% CI=0.08–0.57; p=0.01).

Fig. 4. Forest plots of spermatogenesis of patients after gonadotropin-releasing hormone (GnRH) compared to gonadotropin therapy (GT). (A) Forest plot of rate of spermatogenesis of patients after GnRH compared to GT. The spermatogenesis rates of the two groups were not significantly different. (B) Forest plot of time to first sperm detection of patients after GnRH compared to GT. GnRH therapy was related to earlier spermato-genesis. (C) Forest plot of sperm count of patients after GnRH compared to GT. No significant difference was detected. HCG: human chorionic gonadotropin, HMG: human menopausal gonadotropin, M–H: Mantel–Haenszel, CI: confidence interval, df: degree of freedom, SD: standard de-viation.

Study or subgroupGnRH HCG/HMG Mean difference

Huang et al (2015) [13]



Total (95% CI)



2 2 2

6.5

9.0

12.0

3.1

8.8

1.6

Mean SD Total

20

5

10

35

Weight

41.7%

13.9%

44.3%

100.0%

IV, random, 95% CI

4.30 [ 6.61, 1.99]

0.30 [ 7.97, 8.57]

8.00 [ 9.88, 6.12]

5.30 [ 8.93, 1.67]

IV, random, 95% CIMean difference

20 0 10 20

Favours[GnRH]

Favours[HCG/HMG]

10.8

8.7

20.0

3.7

4.8

2.3

Mean SD Total

15

10

8

33

10

B Time to spermatogenesis

Study or subgroupHCG/HMG GnRH Risk ratio

Huang et al (2015) [13]


Liu et al (1988) [11]


Total (95% CI)

Total events

Heterogeneity: chi =5.72, df=3 (p=0.13); I =48%


2 2

15

10

8

8

41

Events Total

52

12

10

17

91

Weight

52.7%

15.5%

6.2%

25.6%

100.0%

M H, fixed, 95% CI

0.58 [0.34, 0.98]

1.00 [0.65, 1.55]

2.00 [0.65, 6.11]

0.66 [0.36, 1.20]

0.75 [0.55, 1.03]

M H, fixed, 95% CIRisk ratio

0.2 1 2 5

Favours[GnRH]

Favours[HCG/HMG]

20

5

2

10

37

Events Total

40

6

5

14

65

0.5

A Rate of spermatogenesis

Study or subgroupHCG/HMG GnRH Mean difference


Mao et al (2017) [14]


Total (95% CI)



2 2

4.0

12.5

8.0

3.6

3.7

7.35

Mean SD Total

10

140

8

158

Weight

28.8%

37.4%

33.8%

100.0%

IV, fixed, 95% CI

1.60 [ 7.56, 4.36]

4.60 [ 9.82, 0.62]

2.16 [ 3.34, 7.66]

1.45 [ 4.65, 1.74]

IV, fixed, 95% CIMean difference

10 0 5 10

Favours[GnRH]

Favours[HCG/HMG]

5.6

17.1

5.84

6.3

9.9

3.34

Mean SD Total

5

14

10

29

5

C Sperm count


660 www.wjmh.org

2. Efficacy of gonadotropin-releasing hormone and gonadotropin therapy

Although the plasma testosterone in the GT group was significantly higher than plasma testosterone in the GnRH group (WMD=7.75 nmol/L, 95% CI=4.29–11.21; p<0.0001), the testicular volumes increased con-siderably more in the GnRH group (SMD=-1.43, 95% CI=-2.55–-0.32; p=0.01; Fig. 3). There was no significant difference in the rate of positive spermatogenesis (RR=0.75, 95% CI=0.55–1.03; p=0.08), but GnRH treat-ment was related to earlier spermatogenesis (WMD=-5.30 months, 95% CI=-8.93–-1.67; p=0.004; Fig. 4). The sperm count (WMD=-1.45×106/mL, 95% CI=-4.65–1.74; p=0.37) and rate of pregnancy (RR=0.60, 95% CI=0.31–1.13; p=0.11) were not significantly different between the two groups (Fig. 4, 5).

The subgroup analysis according to the presence of cryptorchidism showed that the rate of spermatogene-sis remained similar for these two therapies in patients with or without cryptorchidism (Supplement Fig. 1, 2). Additionally, the presence of cryptorchidism was a predictor of the spermatogenesis rate of CHH patients (Supplement Fig. 3).

Considering that in Gong et al’s study [10], only HCG was used for the GT group, a formal meta-analysis was also performed after excluding Gong at al’s study [10]. The final outcome was consistent with the previous outcome and suggested that GnRH therapy was re-lated to larger testicle volume.

3. Side effects of gonadotropin-releasing hormone and gonadotropin therapy

Adverse reactions reported during the therapy were allergy, breast development, and acne. The incidence of overall adverse reactions was comparable in the two groups (RR=1.55, 95% CI=0.56–4.35; p=0.40). However,

the allergy occurred mostly during GnRH therapy (RR=37.93, 95% CI=7.03–204.74; p<0.0001), and the GT was related to gynecomastia and acne (RR=0.27, 95% CI=0.09–0.83; p=0.02; Fig. 6).

4. Publication bias and sensitivity analysisAll the egger’s tests showed no significant publica-

tion bias. Sensitivity analyses were conducted by changing ef-

fect model and the effect model changing did not alter any outcomes of this analysis.

DISCUSSION

To the best of our knowledge, this review is the first meta-analysis to compare GnRH therapy to GT in male CHH patients. In this analysis, we evaluated posttreat-ment physiological conditions, fertility, and adverse reactions. In conclusion, GnRH is related to larger tes-ticular volume and earlier spermatogenesis, though the rates of spermatogenesis and pregnancy are similar in both groups.

1. Interpretation of outcomesLH and FSH play an important role in the develop-

ment of sperm and the levels of them could be nor-malized in the majority of CHH after pulsatile GnRH therapy [21]. Several hormone outcomes after pulsatile GnRH were reported in our included studies and all these results showed a greatly increased level of LH and FSH [10,13,14,16]. Compared to GT, GnRH therapy was more efficient in the normalization of LH and FSH levels [10,11]. However, due to the lack of relevant data, we were unable to conduct a quantitative analy-sis to compare the posttreatment level of LH and FSH after these two therapies.

Fig. 5. Forest plot of pregnancy rate after gonadotropin-releasing hormone (GnRH) compared to gonadotropin therapy. HCG: human chorionic gonadotropin, HMG: human menopausal gonadotropin, M–H: Mantel–Haenszel, CI: confidence interval, df: degree of freedom.

Study or subgroupHCG/HMG GnRH Risk ratio

Huang et al (2015) [13]


Liu et al (1988) [11]


Total (95% CI)

Total events



2 2

0

4

1

1

6

Events Total

15

6

11

1

33

Weight

13.0%

44.5%

27.5%

15.0%

100.0%

M H, fixed, 95% CI

0.44 [0.02, 10.05]

0.73 [0.38, 1.43]

0.23 [0.03, 1.96]

1.00 [0.32, 3.10]

0.60 [0.31, 1.13]


0.01 1 10 100

Favours[GnRH]

Favours[HCG/HMG]

1

3

2

1

7

Events Total

20

3

5

1

29

0.1


661www.wjmh.org

Patients in the GnRH group had a lower testosterone concentration than the GT group. In the beginning, GnRH therapy aimed to maintain testosterone within the normal range [11,16]. However, later studies sug-gested that plasma testosterone levels of 8–10 nmol/L may be sufficient to induce spermatogenesis in CHH patients [13,14]. Pulsatile GnRH therapy can maintain the pulsatile secretion of gonadotropin by the pituitary gland and therefore stabilize the testosterone level. In the GT group, the fluctuation of testosterone was significant [22]. In addition, the GnRH receptors were found in spermatogonia, spermatocytes, and mature sperm [23]. Therefore, GnRH might be directly involved

in spermatogenesis, sperm maturation, and fertilization [24]. These reasons might explain why GnRH therapy could efficiently induce spermatogenesis with a lower testosterone level. Notably, the normalization of tes-tosterone could only be achieved by supraphysiological levels of LH and FSH in a subset of patients [25], and in specific populations, the level of testosterone is not correlated with the sperm concentration [26,27]. These studies suggested that the normalization of testoster-one might be unbeneficial and unessential.

The ability to restore fertility in CHH patients is the critical efficacy of these two therapies, and whether GnRH therapy is related to a higher rate of sper-

Study or subgroupGnRH HCG/HMG Risk ratio

Gong et al (2015) [10]


Mao et al (2017) [14]


Total (95% CI)

Total events



2 2 2

3

3

8

0

14

Events Total

12

6

20

18

56

Weight

24.0%

27.1%

38.6%

10.3%

100.0%

M H, fixed, 95% CI

1.83 [0.44, 7.72]

1.83 [0.52, 6.42]

2.70 [1.42, 5.11]

0.09 [0.01, 1.45]

1.55 [0.56, 4.35]


0.005 1 10 200

Favours[GnRH]

Favours[HCG/HMG]

3

3

27

5

38

Events Total

22

11

182

17

232

0.1

A Total adverse reaction



Mao et al (2017) [14]

Total (95% CI)

Total events


Test for overall effect: Z=4.23 (p<0.0001)

2 2

3

7

10

Events Total

6

20

26

Weight

78.2%

21.8%

100.0%

M H, fixed, 95% CI

12.00 [0.72, 199.87]

130.71 [7.74, 2208.09]

37.93 [7.03, 204.74]


0.001 1 10 1,000

Favours[GnRH]

Favours[HCG/HMG]

0

0

0

Events Total

11

182

193

0.1

B Allergy


Gong et al (2015) [10]


Mao et al (2017) [14]


Total (95% CI)

Total events



2 2

1

0

1

0

2

Events Total

12

6

20

18

56

Weight

13.5%

16.4%

34.1%

36.0%

100.0%

M H, fixed, 95% CI

0.61 [0.07, 5.25]

0.24 [0.01, 4.08]

0.34 [0.05, 2.35]

0.09 [0.01, 1.45]

0.27 [0.09, 0.83]


0.002 1 10 500

Favours[GnRH]

Favours[HCG/HMG]

3

3

27

5

38

Events Total

2

11

182

17

232

0.1

C Gynecomastia and acne

Fig. 6. Forest plots of adverse reaction events after gonadotropin-releasing hormone (GnRH) or gonadotropin therapy (GT). (A) Forest plot of total adverse reaction events after GnRH or GT. The incidences of adverse reactions were similar in two groups. (B) Forest plot of allergy events after GnRH or GT. Allergies occurred only in the GnRH group, and the difference was significant. (C) Forest plot of incidence of gynecomastia and acne after GnRH or GT. GnRH therapy resulted in more estradiol-related adverse reactions, including gynecomastia and acne. HCG: human chorionic gonadotropin, HMG: human menopausal gonadotropin, M–H: Mantel–Haenszel, CI: confidence interval, df: degree of freedom.


662 www.wjmh.org

matogenesis has not been determined. In our analysis, the testes were enlarged in both treatment groups, but GnRH therapy was related to a larger volume. Although the testicular volume may be related to fertility [5,28,29], the rate of spermatogenesis was not significantly different between the two groups. An analysis of 48 studies of HCG/HMG therapy and 16 studies of pulsatile GnRH therapy showed that the rate of spermatogenesis was 68% (95% CI=58%–77%) in HCG/HMG treatment, which is lower than that of 77% (95% CI=63%–87%) in GnRH therapy for patients with prepuberty-onset hypogonadotropic hypogonadism [30]. This analysis was mostly based on single-arm studies. Combined with our analysis, we are optimistic about pulsatile GnRH therapy. Moreover, it was suggested that GnRH therapy is related to earlier spermatogen-esis, and GnRH therapy is associated with a shorter time to achieve sperm concentrations at various pre-determined thresholds [14]. With the aid of assisted re-production techniques such as intracytoplasmic sperm injection, shorter time to achieve pregnancy might also be practical for patients receiving GnRH therapy. Additionally, for these patients who failed to induce spermatogenesis after HCG/HMG therapy, GnRH still might be effective [31]. Therefore, patients who desire fertility may benefit more from GnRH therapy.

The sperm concentrations were compared in our analysis, and the sperm count in the GnRH group was slightly higher, though without statistical significance. In the included studies, the study conducted by Scho-pohl et al [12] was the only one that favored GT. In fact, in their research, one patient in the GT group had a sperm concentration of 26×106/mL, which was 2 to 12 fold higher than that of other patients. However, as the GnRH group was associated with a shorter time to achieve sperm concentrations at various predetermined thresholds [14], whether the final concentrations differ in the long-term treatment has not been determined. Several studies also compared sperm motility and mor-phology and obtained an insignificant difference [12,16].

There was no difference in the rate of pregnancy between the two groups (p=0.11). Büchter et al [15] and Kliesch et al [16] suggested that most pregnancies oc-curred with counts far below the normal range, and the sperm concentrations at pregnancy were similar. This might explain the similarity of pregnancy rate with different sperm concentrations because the low concentration of sperm is sufficient for pregnancy.

Büchter et al [15] showed that GnRH therapy tended to be related to a shorter duration before pregnancy, but the difference was not significant because of the limited study size. A study with a larger size is still warranted to ascertain the effect of different therapies on the duration until pregnancy.

Although the overall incidence of adverse reactions was comparable in the two therapies, the specific ad-verse responses were different. GT was related to gyne-comastia and acne, and the increased level of estradiol induced by HCG might be a reasonable explanation [32]. Allergy occurred mostly in GnRH therapy, and most of them were mild to moderate dermatological allergic re-actions. Before the decision of treatment, these related adverse reactions should be considered, and the ad-verse responses during GnRH therapy seem to be more acceptable for patients.

The cost of treatment is an essential factor in clini-cal practice. The pulsatile GnRH therapy is much more expensive than the HCG/HMG therapy and the burden of drug and device cost could limit the use of GnRH therapy. Besides, the constant carrying of the pump, the refilling of medication, and frequent chang-ing of injection sites also result in inconvenience for patients. However, with the decreasing of medication and device, more patients can afford the cost of treat-ment and the improved devices with smaller size and more volume could also reduce the inconvenience in the future. In addition, HCG/HMG therapy requires frequent hospital visits, twice to three times a week, which is also inconvenience for patients living in the place where the community doctors and family doctors are not available. Patients and doctors can choose the optimal treatment method by considering the efficacy and the patterns of these treatment.

2. Effect of cryptorchidism statusCryptorchidism was reported to be a predictor for

spermatogenesis in CHH patients [21,29]. Our analysis confirmed that cryptorchidism was related to a lower rate of spermatogenesis (Supplement Fig. 3). Mao et al [14] suggested that cryptorchidism was also related to a longer time to first sperm detection and a lower sperm concentration. Büchter et al [15] also reported a delayed duration until spermatogenesis, but the difference was not significant in their study. In particular, Büchter et al [15] noted that the two patients who failed sper-matogenesis had bilateral cryptorchidism until 22 and


663www.wjmh.org

17 years of age, respectively. This finding suggests that early intervention is essential for patients with crypt-orchidism.

According to the subgroup analysis (Supplement Fig. 1, 2), the rates of spermatogenesis did not differ between GnRH therapy and GT, regardless of the cryptorchidism status. The cryptorchidism status was unlikely to affect the clinical decision on therapy selec-tion.

3. Strengths and limitationsOur study is the first meta-analysis that compared

the effect and adverse reactions of GnRH therapy to GT based on comparative studies. We comprehensively evaluated the effect of these two therapies using vari-ous parameters. Subgroup analyses were also per-formed to assess the effect of cryptorchidism status.

There are several limitations to our study. First, some biases were inevitable because of their nonrandomized and retrospective nature. For example, in the retro-spective study, testicular volumes were not assessed in a standardized manner or by the same clinician, leading to variation in determining testicular volumes. Also, the orchidometer was used in the majority of the included studies and the reliability could be com-promised. Second, the follow-up time of some included studies was not long enough, and in some studies, the follow-up durations and sample sizes of two arms were not comparable. Third, the sample size of most included studies was small, and the two studies from the same group had the majority of included cases which could be a potential source of bias. Additionally, as an es-sential parameter, the time to pregnancy was not well-documented in most studies, and in future research, this parameter should be analyzed to compare the efficacy of different therapies. Fourth, the baseline features, such as age, of the patient population differed vastly among the included studies and the dosages of regimens were also different among the included re-searches. Finally, our conclusions were based on studies investigating HMG and should be cautiously applied to recombinant human FSH, which is widely used in CHH treatment.

CONCLUSIONS

Our study suggested that although the two therapies exhibited no significant difference in spermatogenesis

rate, sperm count, and pregnancy rate, GnRH therapy was related to larger testicular size, shorter time to sperm detection, and less estradiol-related adverse reac-tions. More prospective, randomized studies with larger sample sizes are warranted to ascertain the advantages of pulsatile GnRH therapy.

ACKNOWLEDGEMENTS

This research was supported by National Natural Science Foundation of China (Grant Number: 81702518, 81500636) and Innovation Foundation of Huazhong University of Science and Technology (Grant Number 2019kfyXKJC06).

Conflict of Interest

The authors have nothing to disclose.

Author Contribution

Conceptualization: XL, DM. Data curation: CW, YZ, TW. For-mal analysis: GL, YZ, SW. Funding acquisition: XL. Project ad-ministration: XL. Supervision: JL. Writing – original draft: CW, GL. Writing – review & editing: TW, SW.

Supplementary Materials

Supplementary materials can be found via https://doi.org/10.5534/wjmh.200043.

REFERENCES

1. Young J, Xu C, Papadakis GE, Acierno JS, Maione L, Hietamäki J, et al. Clinical management of congenital hypo-gonadotropic hypogonadism. Endocr Rev 2019;40:669-710.

2. Bianco SD, Kaiser UB. The genetic and molecular basis of idiopathic hypogonadotropic hypogonadism. Nat Rev Endo-crinol 2009;5:569-76.

3. Bhasin S, Cunningham GR, Hayes FJ, Matsumoto AM, Sny-der PJ, Swerdloff RS, et al. Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clini-cal practice guideline. J Clin Endocrinol Metab 2010;95:2536-59.

4. Finkel DM, Phillips JL, Snyder PJ. Stimulation of spermato-genesis by gonadotropins in men with hypogonadotropic hypogonadism. N Engl J Med 1985;313:651-5.

5. Liu PY, Baker HW, Jayadev V, Zacharin M, Conway AJ,


664 www.wjmh.org

Handelsman DJ. Induction of spermatogenesis and fertility during gonadotropin treatment of gonadotropin-deficient in-fertile men: predictors of fertility outcome. J Clin Endocrinol Metab 2009;94:801-8.

6. Miyagawa Y, Tsujimura A, Matsumiya K, Takao T, Tohda A, Koga M, et al. Outcome of gonadotropin therapy for male hypogonadotropic hypogonadism at university affiliated male infertility centers: a 30-year retrospective study. J Urol 2005;173:2072-5.

7. Belchetz PE, Plant TM, Nakai Y, Keogh EJ, Knobil E. Hy-pophysial responses to continuous and intermittent delivery of hypopthalamic gonadotropin-releasing hormone. Science 1978;202:631-3.

8. Hoffman AR, Crowley WF Jr. Induction of puberty in men by long-term pulsatile administration of low-dose gonadotropin-releasing hormone. N Engl J Med 1982;307:1237-41.

9. Boehm U, Bouloux PM, Dattani MT, de Roux N, Dodé C, Dunkel L, et al. Expert consensus document: European Consensus Statement on congenital hypogonadotropic hypo-gonadism--pathogenesis, diagnosis and treatment. Nat Rev Endocrinol 2015;11:547-64.

10. Gong C, Liu Y, Qin M, Wu D, Wang X. Pulsatile GnRH is superior to hCG in therapeutic efficacy in adolescent boys with hypogonadotropic hypogonadodism. J Clin Endocrinol Metab 2015;100:2793-9.

11. Liu L, Banks SM, Barnes KM, Sherins RJ. Two-year compari-son of testicular responses to pulsatile gonadotropin-releasing hormone and exogenous gonadotropins from the inception of therapy in men with isolated hypogonadotropic hypogonad-ism. J Clin Endocrinol Metab 1988;67:1140-5.

12. Schopohl J, Mehltretter G, von Zumbusch R, Eversmann T, von Werder K. Comparison of gonadotropin-releasing hormone and gonadotropin therapy in male patients with idiopathic hypothalamic hypogonadism. Fertil Steril 1991;56:1143-50.

13. Huang B, Mao J, Xu H, Wang X, Liu Z, Nie M, et al. [Sper-matogenesis of pulsatile gonadotropin-releasing hormone infusion versus gonadotropin therapy in male idiopathic hypogonadotropic hypogonadism]. Zhonghua Yi Xue Za Zhi 2015;95:1568-71. Chinese.

14. Mao JF, Liu ZX, Nie M, Wang X, Xu HL, Huang BK, et al. Pul-satile gonadotropin-releasing hormone therapy is associated with earlier spermatogenesis compared to combined gonado-tropin therapy in patients with congenital hypogonadotropic hypogonadism. Asian J Androl 2017;19:680-5.

15. Büchter D, Behre HM, Kliesch S, Nieschlag E. Pulsatile GnRH or human chorionic gonadotropin/human menopausal go-nadotropin as effective treatment for men with hypogonado-

tropic hypogonadism: a review of 42 cases. Eur J Endocrinol 1998;139:298-303.

16. Kliesch S, Behre HM, Nieschlag E. High efficacy of gonado-tropin or pulsatile gonadotropin-releasing hormone treat-ment in hypogonadotropic hypogonadal men. Eur J Endocri-nol 1994;131:347-54.

17. Sterne JA, Hernán MA, Reeves BC, Savović J, Berkman ND, Viswanathan M, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ 2016;355:i4919.

18. McGuinness LA, Higgins JPT. Risk-of-bias VISualization (robvis): an R package and Shiny web app for visualizing risk-of-bias assessments. Res Synth Methods 2020. doi: 10.1002/jrsm.1411 [Epub].

19. Hozo SP, Djulbegovic B, Hozo I. Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol 2005;5:13.

20. Goldstein M. Surgical management of male infertility and other scrotal disorders. Male and female sterilization. Na-tional evidence-based clinical guidelines 1998;2:6.

21. Schopohl J. Pulsatile gonadotrophin releasing hormone ver-sus gonadotrophin treatment of hypothalamic hypogonadism in males. Hum Reprod 1993;8 Suppl 2:175-9.

22. Pitteloud N, Hayes FJ, Dwyer A, Boepple PA, Lee H, Crowley WF Jr. Predictors of outcome of long-term GnRH therapy in men with idiopathic hypogonadotropic hypogonadism. J Clin Endocrinol Metab 2002;87:4128-36.

23. Ulloa-Aguirre A, Mendez JP, Diaz-Sánchez V, Altamirano A, Pérez-Palacios G. Self-priming effect of luteinizing hormone-human chorionic gonadotropin (hCG) upon the biphasic testicular response to exogenous hCG. I. Serum testosterone profile. J Clin Endocrinol Metab 1985;61:926-32.

24. van Biljon W, Wykes S, Scherer S, Krawetz SA, Hapgood J. Type II gonadotropin-releasing hormone receptor transcripts in human sperm. Biol Reprod 2002;67:1741-9.

25. Ramakrishnappa N, Rajamahendran R, Lin YM, Leung PC. GnRH in non-hypothalamic reproductive tissues. Anim Re-prod Sci 2005;88:95-113.

26. Sykiotis GP, Hoang XH, Avbelj M, Hayes FJ, Thambundit A, Dwyer A, et al. Congenital idiopathic hypogonadotropic hypogonadism: evidence of defects in the hypothalamus, pi-tuitary, and testes. J Clin Endocrinol Metab 2010;95:3019-27.

27. Qin DD, Yuan W, Zhou WJ, Cui YQ, Wu JQ, Gao ES. Do re-productive hormones explain the association between body mass index and semen quality? Asian J Androl 2007;9:827-34.

28. Jensen TK, Andersson AM, Jørgensen N, Andersen AG, Carlsen E, Petersen JH, et al. Body mass index in relation to semen quality and reproductive hormones among 1,558 Dan-


665www.wjmh.org

ish men. Fertil Steril 2004;82:863-70.29. Warne DW, Decosterd G, Okada H, Yano Y, Koide N, Howles

CM. A combined analysis of data to identify predictive factors for spermatogenesis in men with hypogonadotropic hypogo-nadism treated with recombinant human follicle-stimulating hormone and human chorionic gonadotropin. Fertil Steril 2009;92:594-604.

30. Rastrelli G, Corona G, Mannucci E, Maggi M. Factors af-fecting spermatogenesis upon gonadotropin-replacement

therapy: a meta-analytic study. Andrology 2014;2:794-808.31. Blumenfeld Z, Makler A, Frisch L, Brandes JM. Induction of

spermatogenesis and fertility in hypogonadotropic azoosper-mic men by intravenous pulsatile gonadotropin-releasing hormone (GnRH). Gynecol Endocrinol 1988;2:151-64.

32. Han TS, Bouloux PM. What is the optimal therapy for young males with hypogonadotropic hypogonadism? Clin Endocri-nol (Oxf) 2010;72:731-7.

spermatogenesis of male patients with congenital

Documents