Familial aggregation and determinants of post challenge blood glucose in four ethnic populations.

We determine the familial aggregation and determinants of post challenge blood glucose (BG) in four ethnic populations. A national health survey was conducted in Malaysia in 1996. 18,372 subjects aged 30 years or older had post challenge BG measurements and another 846 subjects were pre-diagnosed to have diabetes on drug treatment. We imputed the BG of diagnosed diabetics by randomly selecting a value from the BG distribution of undiagnosed diabetics. Covariates of interest include ethnicity, gender, age, urban-rural residence, body mass index (BMI), physical activity, education, and household income. Ethnic and gender differences in mean BG persisted after adjustment for other covariates. Age and BMI were the only two factors with strong, positive and consistent effects on mean BG in all ethnic-sex groups. Family resemblance for BG as measured by intraclass correlation was small and homogenous across all ethnic groups and did not differ from resemblance in BG between spouses. In conclusion, BMI was the only consistent modifiable predictor of BG in all ethnic-sex groups. Environmental factors are probably more important than genetic factors as determinant of BG in the four ethnic populations studied.