Aim:
Western populations demonstrate a strong role of obesity in clustering of cardiovascular (CV) risk factors. We hypothesized that obesity would not have a dominant role in the clustering of CV risk factors in South Asians, who develop CV disease at young ages despite relatively low BMI.
Methods:
We selected 6224 South Indians without diabetes from a population-based cross-sectional survey (mean age 42 years; 58% women) for analysis. We used gender-specific principal components analysis (PCA), a multivariate correlation technique, with orthogonal rotation (to produce interpretable factors) to test the hypothesis. The PCA was done using measures of fasting (FPG) and 2 h plasma glucose (2h PG), haemoglobin A1c (A1c), fasting insulin (FIns), triglycerides (TG) and high-density lipoprotein (HDL), diastolic (DBP) and systolic blood pressure (SBP), body mass index (BMI) and waist circumference (WC). We did separate subgroup analyses stratified by various potential modifiers.
Results:
The obesity indices correlated positively with CV risk variables (except HDL), regardless of gender. PCA failed to demonstrate a single dominant underlying pathological role (one component was rejected at P < 0.0001), but suggested three non-overlapping factors (physiological domains) underlying the clustering of the risk variables, accounting for 60% of the total variance in the data [Fig]. Obesity indices had significant positive loading (95% confidence interval >0.8) only in Factor 1, which included FIns, TG, and HDL. The FPG, 2hPG and A1C were associated with Factor 2. The SBP and DBP were associated with Factor 3. The factor patterns were virtually identical among all the subgroups with coefficients of congruence close to 1.0.
Conclusions:
These findings are consistent with the presence of three distinct physiological domains underlying CV risk variable clustering. Obesity did not have a dominant role in the clustering of CV risk factors in the South Asian population.
Association of APOE polymorphisms with diabetes and cardiometabolic risk factors and the role of APOE genotypes in response to anti-diabetic therapy: results from the AIDHS/SDS on a South Asian population