Obesity in Asian & Pacific Islander Obesity in Asian & Pacific Islander Americans:Americans:

Research Priorities and DirectionsResearch Priorities and Directions

May C. Wang, DrPHMay C. Wang, DrPHUCLA School of Public HealthUCLA School of Public Health

APIOPA Quarterly Meeting, Los Angeles,APIOPA Quarterly Meeting, Los Angeles,May 20, 2010May 20, 2010

Overweight/Obesity is a risk factor for Overweight/Obesity is a risk factor for diabetes, cardiovascular disease, cancer diabetes, cardiovascular disease, cancer and other chronic health conditions.and other chronic health conditions.

Among children, obesity is associated with Among children, obesity is associated with poorer school performance, bullying, and poorer school performance, bullying, and lower self-esteem.lower self-esteem.

Question frequently asked,Question frequently asked,

““What is the prevalence of obesity in the API What is the prevalence of obesity in the API population?”population?”

Rephrase to,Rephrase to,

““What What are the prevalencesare the prevalences of obesity in the of obesity in the API population?”API population?”

Best data on obesity rates for the nation comes Best data on obesity rates for the nation comes from the NHANES (N ~ 5,000 per year)from the NHANES (N ~ 5,000 per year)

NHANES does not yet have a representative NHANES does not yet have a representative sample of APIssample of APIs

In 2007-2010, only 100 APIs were sampled.In 2007-2010, only 100 APIs were sampled. For the 2011-2014 Cycle, the sample size for For the 2011-2014 Cycle, the sample size for

APIs will increase to 750 per year, giving a APIs will increase to 750 per year, giving a sample of 1500 for the 2011-2012 data cycle.sample of 1500 for the 2011-2012 data cycle.

Source: http://www.cdc.gov/nchs/nhanes/about_nhanes.htmSource: http://www.cdc.gov/nchs/nhanes/about_nhanes.htm

In California, we have CHIS…In California, we have CHIS…

Report can be found at the UCLA Center for Health Policy Research website:

http://www.healthpolicy.ucla.edu/pubs/Publication.aspx?pubID=329

Overweight and obesity rates are highest among Overweight and obesity rates are highest among NHPI & FilipinosNHPI & Filipinos

From: Ponce, Tseng, Ong, et al. (2010). The State of Asian American, Native Hawaiian and Pacific Islander Health in California Report.

Similar pattern among children with Samoan Similar pattern among children with Samoan children having very high rates of body children having very high rates of body

composition not in the healthy fitness zonecomposition not in the healthy fitness zone

From: Ponce, Tseng, Ong, et al. (2010). The State of Asian American, Native Hawaiian and Pacific Islander Health in California Report.

But note! Data may have But note! Data may have limitations..limitations..

Adult data from CHIS and BMI is based on Adult data from CHIS and BMI is based on self reports of height and weight.self reports of height and weight.

Child data from the CDE’s Fitnessgram Child data from the CDE’s Fitnessgram program – reliability and validity of data program – reliability and validity of data have not been reported.have not been reported.

Still, subgroup patterns are probably Still, subgroup patterns are probably accurate.accurate.

What about rates of chronic diseases What about rates of chronic diseases among APIs?among APIs?

Leading causes of deathLeading causes of death

In California in 2004…In California in 2004…

Cancer is the leading cause of death Cancer is the leading cause of death among Chinese, Korean, and Vietnamese among Chinese, Korean, and Vietnamese Americans.Americans.

Heart disease is the leading cause of Heart disease is the leading cause of death among Filipino, Japanese, Indian death among Filipino, Japanese, Indian and NHPI Americansand NHPI Americans

Diabetes is of particular concern among Diabetes is of particular concern among Filipino, NHPI, Japanese, Chinese and Filipino, NHPI, Japanese, Chinese and Indian Americans. Indian Americans.

Increasing and high rates of diabetes Increasing and high rates of diabetes in Asians & Pacific Islandersin Asians & Pacific Islanders

0

5

10

15

20

25

NH Whites Asians NHPI

Age-adjusted diabetes death rates per 100,000

Source: Offuce of Minority Health, USDHHS at http://minorityhealth.hhs.gov/templates/content.aspx?ID=3057

Obesity is a major risk factor for chronic Obesity is a major risk factor for chronic diseases.diseases.

It is due to energy imbalance and can be It is due to energy imbalance and can be attributable directly to diet and physical attributable directly to diet and physical activity (chronic stress?)activity (chronic stress?)

Obesity rates are increasing.Obesity rates are increasing. Important to address obesity using a Important to address obesity using a

public health/preventive approach.public health/preventive approach.

How to screen for obesity?How to screen for obesity?

Body Mass Index (BMI) or Quetelet IndexBody Mass Index (BMI) or Quetelet Index

Weight in kg/(Height in m)Weight in kg/(Height in m)22

Current overweight/obesity cut-points Current overweight/obesity cut-points recommended by CDC & WHO recommended by CDC & WHO

Weight categoryWeight category BMI (kg/mBMI (kg/m22))

UnderweightUnderweight < 18.5 < 18.5

Healthy weightHealthy weight 18.5-24.918.5-24.9

OverweightOverweight 25.0-29.925.0-29.9

ObeseObese >> 30 30

CDC: http://www.cdc.gov/obesity/defining.html

WHO: http://www.who.int/mediacentre/factsheets/fs311/en/index.html

Are these cut-points appropriate for Are these cut-points appropriate for Asian populations?Asian populations?

Asians have higher % body fat but lower BMI Asians have higher % body fat but lower BMI than Whites (Wang, J, et al., 1994)than Whites (Wang, J, et al., 1994)

Lowest all-cause mortality associated with BMI Lowest all-cause mortality associated with BMI 23.0-24.9 kg/m23.0-24.9 kg/m2 2 (Gu, 2006; Jee, 2006; Tsugane, (Gu, 2006; Jee, 2006; Tsugane, 2002)2002)

Asians have higher risk for CVD at any given Asians have higher risk for CVD at any given BMI level (Razak, 2005; Razak, 2007; BMI level (Razak, 2005; Razak, 2007; Odegaard, 2009)Odegaard, 2009)

Are these cut-points appropriate for Are these cut-points appropriate for Pacific Islander populations?Pacific Islander populations?

Pacific Islanders have lower % body fat but Pacific Islanders have lower % body fat but higher BMI than Europeans (Rush, 2009)higher BMI than Europeans (Rush, 2009)

In a study of over 933 New Zealanders, Asian In a study of over 933 New Zealanders, Asian Indian men and women (BMI of 24 and 26 Indian men and women (BMI of 24 and 26 kg/m2, respectively) had the same percentage of kg/m2, respectively) had the same percentage of Body Fat as Europeans with a BMI of 30 kg/m2 Body Fat as Europeans with a BMI of 30 kg/m2 or Pacific Islander men and women with BMI of or Pacific Islander men and women with BMI of 34 and 35 kg/m2, respectively, suggesting that 34 and 35 kg/m2, respectively, suggesting that PI are more muscular.PI are more muscular.

Distribution of body fat Distribution of body fat varies with race/ ethnicityvaries with race/ ethnicity

South Asians have more South Asians have more centralized body data at a centralized body data at a given BMI level (McKeigue, given BMI level (McKeigue, 1991)1991)

East Asians have longer East Asians have longer relative sitting heightrelative sitting height

PIs have longer leg lengthPIs have longer leg length

Increasing obesity rates in the Increasing obesity rates in the Asian-Pacific RegionAsian-Pacific Region

Urban-rural differencesUrban-rural differences Ethnic differencesEthnic differences PIs have especially high rates of PIs have especially high rates of

obesityobesity Socioeconomic differencesSocioeconomic differences obesity rates associated with obesity rates associated with

rapidly increasing diabetes ratesrapidly increasing diabetes rates

Source: Report by the Regional Office of WHO Source: Report by the Regional Office of WHO Western Pacific Region, IASO, and IOTF, 2000Western Pacific Region, IASO, and IOTF, 2000

Reasons to have sensitive cut-points for Reasons to have sensitive cut-points for defining overweight/obesity in Asians & PIsdefining overweight/obesity in Asians & PIs

Lower (Asians) and higher (PIs) Lower (Asians) and higher (PIs) cut-points recommendedcut-points recommended

Weight Weight categorycategory

BMI (kg/mBMI (kg/m22))

WHO WHO (Global)(Global)

RecommendedRecommended

AsiansAsians PIsPIs

UnderweightUnderweight < 18.5< 18.5 <18.5<18.5 <18.5<18.5

Healthy Healthy weightweight

18.5-24.918.5-24.9 15.5-22.915.5-22.9 18.5-25.918.5-25.9

OverweightOverweight 25.0-29.925.0-29.9 23.0-24.923.0-24.9 26-31.926-31.9

ObeseObese >> 30 30 >> 25 25 > > 3232

Are different cut-points for defining Are different cut-points for defining overweight and obesity recommended overweight and obesity recommended

for Asian and Pacific Islanders for Asian and Pacific Islanders AmericansAmericans??

What are the consequences of using What are the consequences of using global cut-points?global cut-points?

For Asian Americans, it means that a higher For Asian Americans, it means that a higher percentage of overweight and obese individuals percentage of overweight and obese individuals will not be screened positive (overweight/obese), will not be screened positive (overweight/obese), and therefore not referred for treatment.and therefore not referred for treatment.

For Pacific Islander Americans, it means that a For Pacific Islander Americans, it means that a higher percentage of ‘healthy’ weight individuals higher percentage of ‘healthy’ weight individuals will be screened positive (overweight/obese) and will be screened positive (overweight/obese) and therefore unnecessarily referred for treatment.therefore unnecessarily referred for treatment.

Are the WHO recommended cut-points Are the WHO recommended cut-points appropriate for Asian and PI appropriate for Asian and PI AmericansAmericans??

Questions:Questions:

Are API Americans at a different risk for Are API Americans at a different risk for obesity-related conditions at a given obesity-related conditions at a given BMI?BMI?

Are there differences in these Are there differences in these relationships between APIs raised in API relationships between APIs raised in API societies and APIs raised in western societies and APIs raised in western societies? societies?

Few studiesFew studies Most of Asian Americans, not of Pacific Most of Asian Americans, not of Pacific

Islander Americans.Islander Americans.

Are Asian Americans at a higher risk for Are Asian Americans at a higher risk for obesity-related conditions at a given BMI?obesity-related conditions at a given BMI?

Several studies of Asian immigrants Several studies of Asian immigrants suggest higher levels of CVD risk factors suggest higher levels of CVD risk factors at a given BMI. at a given BMI.

For example, in a random sample of 1078 For example, in a random sample of 1078 Canadians including Chinese and South Canadians including Chinese and South Asians, higher levels of glucose and lipid-Asians, higher levels of glucose and lipid-related factors. (Razak, 2007)related factors. (Razak, 2007)

Wang, Jack, et al. Am J Clin Nutrition, 1994Wang, Jack, et al. Am J Clin Nutrition, 1994

N = 242 Asian (97% born in Asia) and 445 N = 242 Asian (97% born in Asia) and 445 White adults (18-94 yr)White adults (18-94 yr)

Results:Results: Asians have more % body fat than Whites at Asians have more % body fat than Whites at

the same level of BMIthe same level of BMI Asians had more subcutaneous fat in the arm Asians had more subcutaneous fat in the arm

and trunkand trunk

Do Do young adultyoung adult Asian Asian Americans born in AmericaAmericans born in America have an excess of adipose tissue at a given BMI?have an excess of adipose tissue at a given BMI?

Used anthropometric and body composition data fromUsed anthropometric and body composition data from

Berkeley Bone Health Study Berkeley Bone Health Study (1998-2000)(1998-2000)

N=690 Non-Hispanic Black and White N=690 Non-Hispanic Black and White women aged 20-24 yearswomen aged 20-24 years

Latina & Asian Bone Health Study Latina & Asian Bone Health Study (1998-2000)(1998-2000)

N=291 Latinas and Asian N=291 Latinas and Asian women aged 20-25 yearswomen aged 20-25 years

Do young adult Asians have an ‘excess’ Do young adult Asians have an ‘excess’ of adipose tissue at a given BMI?of adipose tissue at a given BMI?

Height and weight were measuredHeight and weight were measured Body composition (fat mass and lean mass) Body composition (fat mass and lean mass)

measured using DXA (Lunar IPX-IQ)measured using DXA (Lunar IPX-IQ) Compared mean % body fat among US-born Compared mean % body fat among US-born

Asians, foreign-born Asians and non-Asians, foreign-born Asians and non-Hispanic Caucasians at varying levels of BMIHispanic Caucasians at varying levels of BMI

Examined association between BMI and % Examined association between BMI and % body fat using linear regression body fat using linear regression

Description of SampleDescription of Sample

Asians (N=132) Age = 22.0 1.0 47% US born, 53% foreign-born 50% Chinese, 14% Korean, 7% Filipino,

5% Japanese, 5% Other

Caucasians (N=279) Age = 21.9 0.9

At varying BMI levels, At varying BMI levels, US-bornUS-born Asian young Asian young women have lower % BF than women have lower % BF than foreign-bornforeign-born

Asian and Caucasian American womenAsian and Caucasian American women

20

25

30

35

40

18.5+ 25-29.9 23-24.9 20-24.9 18.5-22.9

BMI (kg/ m2)

Foreign-born Asians US-born Asians Caucasians

42 41 139

7 8 79

10 11 48

42 39 121

61 59 279

Preliminary findingPreliminary finding

Some preliminary evidence in young Some preliminary evidence in young adults suggesting that US-born Asian adults suggesting that US-born Asian Americans have lower adiposity than Americans have lower adiposity than foreign-born Asian Americans at the same foreign-born Asian Americans at the same BMI level.BMI level.

Implications for practiceImplications for practice

BMI is simply a tool for screening for individuals BMI is simply a tool for screening for individuals who may be at risk for obesity-related chronic who may be at risk for obesity-related chronic diseasesdiseases

No evidence to indicate a need for lowering cut-No evidence to indicate a need for lowering cut-points for points for young Asian American women raised young Asian American women raised in North Americain North America

APIs are a heterogeneous groupAPIs are a heterogeneous group Helpful for clinicians to understand that each Helpful for clinicians to understand that each

sub-group may different risk factors for chronic sub-group may different risk factors for chronic diseases – whether raised in the United States, diseases – whether raised in the United States, South Asian vs. East Asian, PIs vs. Asians, etc.South Asian vs. East Asian, PIs vs. Asians, etc.

Research priorities & directionsResearch priorities & directions Adiposity increases over the life courseAdiposity increases over the life course Do US-born APIs increase % body fat at a Do US-born APIs increase % body fat at a

different rate than foreign-born APIs?different rate than foreign-born APIs? Is the distribution of body fat for APIs raised in Is the distribution of body fat for APIs raised in

API societies different than that for APIs API societies different than that for APIs raised in North America?raised in North America?

What are effective intervention strategies for What are effective intervention strategies for addressing obesity?addressing obesity?

What other factors influence Asian & Pacific What other factors influence Asian & Pacific Islander Americans’ risk for diabetes and Islander Americans’ risk for diabetes and other chronic diseases?other chronic diseases?

Contact Information:Contact Information:

May Wang, DrPHMay Wang, DrPH

UCLA School of Public HealthUCLA School of Public Health

Email: maywang@ucla.eduEmail: maywang@ucla.edu

Thank you! Gracias! Arigato! Xie Xie! Tu Ji Shay! Salamat!