Type 2 Diabetes and Metabolic Syndrome in Filipina-American Women: A high-risk nonobese population

MARIA ROSARIO G. ARANETA 0 PHD DEBORAH L. WINGARD 0 PHD ELIZABETH BARRETT-CONNOR 0 0 From the Department of Family and Preventive Medicine, School of Medicine, University of California San Diego, La Jolla, California. Preventive Medicine, University of California , San Diego, 9500 Gilman Dr., Box 0607, La Jolla, CA 92093- 0607 E p i d e m i o l o g y / H e a l t h S e r v i c e s / P s y c h o s o c i a l R e s e a r c h OBJECTIVE - To compare the prevalence of type 2 diabetes and features of the metabolic syndrome among Filipina and Caucasian women in San Diego County, California. RESEARCH DESIGN AND METHODS - Data on several chronic diseases were collected between 1992 and 1999 from community-dwelling Filipina (n 294) and Caucasian (n 379) women aged 50 - 69 years. RESULTS - Filipina and Caucasian women did not differ in mean age (59.7 vs. 60 years, respectively), BMI (25.6 vs. 25.4 kg/m2), percentage of body fat (33.5 vs. 34.2%), or waist-to-hip ratio (0.84 vs. 0.83), although Filipinas had larger waist circumferences and higher percentages of truncal fat. Compared with Caucasians, Filipinas were less likely to be obese (BMI 30 kg/m2, 8.8 vs. 14%, P 0.04) and less likely to smoke, consume alcohol, or take postmenopausal estrogen; Filipinas also had lower levels of HDL cholesterol. Compared with Caucasians, Filipinas had higher prevalence of type 2 diabetes by oral glucose tolerance test criteria (36 vs. 9%) and the metabolic syndrome (34 vs. 13%). These differences persisted after adjusting for age, body size, fat distribution, percentage of body fat, smoking, alcohol consumption, exercise, and estrogen therapy. CONCLUSIONS - A total of 10% of Filipinas with diabetes were obese, compared with one third of Caucasians with diabetes. The finding of a high prevalence of diabetes in an unstudied nonobese ethnic group reinforces the importance of expanding the study of diabetes to diverse populations. The high prevalence of diabetes in populations who are not of Northern European ancestry may be missed when they are not obese by Western standards. - C of type 2 diabetes in the U.S. is alompared with Caucasians, the risk most twice as high for AfricanAmericans, Latinos, Native Americans, and Native Hawaiians (13). Components of the metabolic syndrome, often defined as the concomitant occurrence of hypertension, dyslipidemia, and altered glucose tolerance, are associated with diabetes and cardiovascular disease (4) and may differ in ethnic minorities (5). The increasing incidence of diabetes and the metabolic syndrome and the relationship with increasing adiposity among ethnic minorities have not been fully elucidated (6). Filipinos comprise the largest and fastest growing Asian population in California (7). However, the prevalence of diabetes and the metabolic syndrome in Filipinos is unknown. Evidence of excess risk comes from studies showing elevated rates of gestational diabetes among Filipina parturients in the U.S. (8). A 1958 1959 study reported higher prevalence of diabetes in Filipinos compared with Caucasians in Hawaii (22 vs. 7%) (9), and 1994 U.S. mortality data indicated that diabetes was the seventh leading cause of death overall but the fourth leading cause of death in women of four ethnic groups: African-American, Native American, Hawaiian, and Filipina (10). Other studies indicate that hypertension, a frequent component of the metabolic syndrome, is more common among Filipina women than other Asians or African-Americans (11,12). The population of San Diego County (California) includes 120,000 Filipinos (13). We compared data from community-dwelling Filipina and Caucasian women from San Diego County. The objectives of this study were: 1) to compare the prevalence of diabetes and the metabolic syndrome between Filipinas and Caucasians; 2) to compare the distribution of anthropometric measures associated with diabetes and the metabolic syndrome by ethnicity; and 3) to determine whether ethnic differences in the prevalence of diabetes or the metabolic syndrome were explained by differences in behaviors, body size, or fat distribution. RESEARCH DESIGN AND METHODS Study population Filipina women were recruited between October 1995 and February 1999 for a cross-sectional study designed to estimate the prevalence of several chronic diseases. This study population included community-dwelling women aged 50 69 years who were self-identified as Filipina. Most of the Filipina women lived in north San Diego County, primarily Mira Mesa, a middle-class community with a high proportion of Filipino residents. This population was chosen because it is located 10 miles from our research clinic in Rancho Bernardo, residence of the Caucasian comparison cohort, and because Filipinos are not identified separately in the San Diego census, so random sampling of the entire county was not feasible. Filipinas were recruited with the help of Filipino community leaders and organizations, local Filipino media, and brochures posted in stores, medical clinics, and social service centers that serve Filipino populations. Research staff included bilingual Filipinas who recruited study participants at churches and during Filipino social functions and festivals. Recruitment materials emphasized general health and included tests for osteoporosis and other diseases, in addition to diabetes, to reduce self-selection bias for participants with known diabetes. All recruitment materials and informed consent documents were translated into Tagalog, the primary language of the Philippines. The comparison group of nonHispanic Caucasian women (primarily of Northern European descent) were participants in the Rancho Bernardo Heart and Chronic Disease Study (14), a community-based longitudinal study. From May 1992 to January 1995, 75% of surviving local, noninstitutionalized members of this middle-class cohort participated in the same study of several chronic diseases, including diabetes. Data collection Clinical evaluations for Filipina and Caucasian women took place at the University of California, San Diego Rancho Bernardo Research Clinic using the same protocol, clinic facility, and clinic staff. All participants gave written informed consent. Standardized questionnaires were used. The data instrument was not translated into Tagalog but was administered by a P h i l i p p i n e - b o r n , n a t i v e T a g a l o g speaking female nurse and translated when necessary. All participants spoke functional English. Demographic characteristics, including age, education, occupation, birthplace, marital and employment status, years of U.S. residence, and ethnic identity, were elicited for each group. Cigarette smoking, alcohol use, physical activity, parity, menopausal status, selfreported health and stress, physiciandiagnosed diseases, medication history, and family history of diabetes, hypertension, and other selected chronic diseases were determine (...truncated)