Prevalence of diabetes, metabolic syndrome, and cardiovascular risk factors in US Asian Indians: results from a national study
BACKGROUND: Although studies of immigrant Asian Indians in other countries show high rates of diabetes (DM), metabolic syndrome (MetS), and cardiovascular disease (CVD), no randomized, population-based studies of this rapidly growing ethnic group exist in the US. METHODS: The sample comprised 1038 randomly selected Asian Indian immigrants, aged 18 years and older at seven US sites. Prevalence of diabetes and MetS (age-adjusted and sex-adjusted means) was estimated and ANOVA was used to calculate gender and group differences (normoglycemia/impaired fasting glucose/diabetes) for CVD risk factors. RESULTS: The mean age was 48.2 years. The majority of respondents were male, married, educated, and with some form of health insurance. Prevalence of diabetes was 17.4%, and 33% of the respondents had prediabetes. Cardiovascular risk factors, especially high levels of triglycerides, total cholesterol, LDL cholesterol, homocysteine, and C-reactive protein, and low levels of HDL cholesterol, were also prevalent; elevated lipoprotein(a) was not observed. The age-adjusted prevalence of MetS was 26.9% by the original NCEP/ATP III criteria, 32.7% by the modified NCEP/ATP III criteria, and 38.2% by the IDF criteria. The MetS rates for women, but not for men, increased with age using all three criteria. There was a progressive worsening of all metabolic parameters as individuals progressed from normal to IFG to diabetes. CONCLUSION: The prevalence rates of diabetes and MetS among US Asian Indians are higher than reported in earlier, nonrandomized, smaller surveys. These data provide a firm basis for future mechanistic and interventional studies.