childhood obesity, childhood exposures, and adult morbidities frank biro division of adolescent...
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Childhood obesity, childhood exposures, and adult
morbiditiesFrank Biro
Division of Adolescent Medicine
Cincinnati Children’s Hospital
Source: CDC Behavioral Risk Factor Surveillance System.
1998
Obesity Trends* Among U.S. AdultsBRFSS, 1990, 1998, 2007
(*BMI 30, or about 30 lbs. overweight for 5’4” person)
2007
1990
No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%
Trends in overweight for girls (BMI > 95%tile), by age and study
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1012141618
per
cen
tag
e o
verw
eig
ht
6-11 yo girls 12-19 yo girls
NHANES I
NHANES II
NHANES III
NHANES99
NHANES06
NHANES I ’71-74; NHANES II ’76-80; NHANES III ’88-94; NHANES ’99-00; NHANES ’03-6
Prevalence of “obesity” (BMI > 30) in girls 12-19 yo, by race and
ethnicity
0
5
10
15
20
25
30p
erce
nta
ge
ob
ese
non-Hispanic
white
non-Hispanic
black
Mexican-American
NHANES III
NHANES99
NHANES03
NHANES III: 1988-94; NHANES 1999-2000; NHANES 2003-2006
What is the impact of childhood obesity? What are the contributing
factors?• Most agree that onset of breast
development in girls has declined over the past 30 years in US– Greater decline in African American, contrasted
to white females, suggesting race (genetics) and environment interaction
– Does puberty serve as a sensitive and early indicator of genetic/ environmental interaction? (Parent 2004)
Pubertal onset in girls
Authors Year Age breast stage II
Reynolds & Wines 1948 10.8
Marshall & Tanner 1969 11.2
Harlan (NHES) 1980 12.8
Herman-Giddens (PROS)
1997 8.9/10.0
Sun (NHANES III) 2002 9.5/10.4
Biro (NGHS) 2006 9.8/10.4
Factors that contribute to age of pubertal onset
• 4-5 year variability in onset of puberty• Genetic• Behavioral/ environmental factors
– Health, public health issues – Nutrition/ overnutrition– (Lack of) physical activity– Environmental exposures
Factors impacting onset of puberty
• Genetic factors account for 30-70% of variability– Selective advantage in lower age of maturation
• Age of menarche as fitness trait• Advantage conferred in past, disadvantage contemporary• Cultural changes faster than genetic accommodations• “Stone Age genes in Space Age times” (Eaton)
– Thrifty phenotype (feast/famine, activity/rest; insulin resistance)
– Early menarche with later risk of hormone-dependent cancers
Factors impacting onset of puberty
• Single most important environmental factor is nutritional– Up to 25% of variance– Caloric density; carb sources; omega 6:3
• Studies suggest interaction between genetics and environment; studies have shown an interaction between BMI and race on age of onset of puberty
Physical (in)activity patterns
• YRBS has noted decreased physical activity among adolescents; odds of being inactive 1.3-1.6 more likely in 2003 contrasted to 1993– Inactivity rose by year; by grade; females >
males; more likely with lower SES
• Increased time in sedentary behaviors (TV, video games, computers); boys > girls for all
Environmental factors impacting pubertal onset
• Stress; nonbiologic adult male in household• Endocrine disruptors
– Androgen skin cream; shampoo w/ placenta extract– DDT-like pesticides and feminization of male gators;
immigrants to Europe/ precocious puberty/ DDE levels
– Food contamination in MI, flame retardant PBB– Earlier thelarche in PR; association with phthalates– Lead levels and delay in maturation– Phytoestrogens: agonists or antagonists?– BPA and LHRH pulse generator
Sources of phthalates
• DEP: shampoo, scents, soap, cosmetics, medications;
• DEHP: soft plastics, food containers, packaging film/clear food wrap
Sources of phenols
• Phenols: parabens in personal care products – Triclosan: microbicide, including hand
sanitizers and toothpaste
• BPA: polycarbonate (Nalgene; liners for metal cans), dental sealant
Costs of childhood obesity
• Earlier maturation in girls– Data less clear in boys
• Body composition and BMI in adulthood• Association with insulin resistance,
metabolic syndrome• Puberty as a window of susceptibility to
environmental exposures• Adult morbidity and mortality
Costs of earlier maturation to contemporary teens
• Lower self esteem during adolescence and lower levels of body satisfaction
• Greater likelihood of depression• Greater likelihood of eating disorders• Greater perceived stress• Greater vulnerability to peer pressures• Younger ages sexual initiation, smoking,
drug use
Costs of earlier maturation to contemporary women
• Poorer adjustment in relationships• Lower lifelong academic achievement• Greater weight and BMI• Increased likelihood insulin resistance and
cardiovascular disease• Breast cancer with younger age of menarche• Relationship of childhood diet and physical
activity on subsequent adult morbidity
FFMI and FMI, by BMI group at age 9, and by age, NGHS girls
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9 10 11 12 13 14 15 16 17 18
age
BM
I co
mp
on
en
t
FFMI hi
FFMI mid
FFMI lo
FMI hi
FMI mid
FMI lo
Biro, in press
We are changing human biology: Correlation of onset of puberty to age of
menarche, by study and year of birth
00.10.20.30.40.50.60.70.80.9
1
1933 1940 1947 1954 1961 1968 1975
year of birth
co
rrela
tio
n
12
3
4
5
67
1 Reynolds; 2 Bielicki; 3 Largo; 4 Taranger; 5 Marshall; 6 deRidder; 7 NGHS
Childhood diet and physical activity on subsequent adult
morbidity• Metabolic syndrome and childhood BMI• Cancer incidence and BMI
– Men: esophageal, thyroid, colon, renal– Women: endometrial, esophageal, gallbladder,
renal; breast (postmenopausal)
• Dietary intake and cancer (fiber, fish, fruit, bad fat)
• Physical activity and risk of cancer– Physical activity at ages 14-20 may be most
beneficial (Kruk 2007)
Potential mechanisms for childhood diet, activity, and morphology on
adult morbidity• Lifestyle patterns (diet, activity,
tobacco)• Tracking of obesity • Fat patterning • Role of insulin resistance• Adipocytokines
What can you recommend?• Dietary practices
– Limiting consumption of sugar-sweetened beverages; eating breakfast daily; limiting meals at fast food restaurants; encouraging family meals, eating together
• Physical activity patterns– Limit screen time to 2 hours daily; removing TV and
computers from bedrooms; participating in vigorous physical activity daily (AAP, NFL: 60 minutes daily)
• Recs similar to prevention of childhood obesity
What can you recommend?
• Eighty companies produce phthalate-free cosmetics– Lists available on line
• “Not too pretty”• “Skin Deep”
• Use products in moderation and with appropriate intention; avoid clear plastic wrap in microwaves; sun screen important, limit sun exposure
• Use of “organic” products
It’s Greek to me, but the Goddesses of Yesteryear lived well, though not long, and Today live longer
but…
Greece 2000 BC
USA 2000 AD
Age of menarche 17 12
Interval menarche-first birth
3 years 12 years
Number of children 6 1.8
Duration of breast feeding
3 years 0-6 months
Daily energy expenditure
20 kcal/kg/day
<5 kcal/kg/day
Age at death 40 years 75 years
Risk of breast cancer Unknown (low)
1:8
Stone Age genes in Space Age times (Eaton)
From J Pediatr Adolesc Gynecol. 2009; 22:3-6