Recurrence Risk Ratio of Siblings and Familial Aggregation of the Metabolic Syndrome among Tehranian Population

In this study, we aimed to determine the extent of possible genetic influence on cardio-metabolic risk factors, evaluate the familial aggregation of MetS and estimate the siblings’ recurrence risk ratios in a Tehrani population. In a cross-sectional observational study, we made anthropometric, blood pressure, and biochemical measurements in each member of 566 Tehrani nuclear families. Grandmothers had the highest incidence of atherosclerotic risk factors. Four factors were found which accounted for 77.7% of the overall variance. Recurrence risk ratio among siblings was 5.61 (95% confidence interval [CI]: 3.15–9.97). The adjusted odds ratio (OR) of proband’s MetS status was 1.33 (95% CI: 1.06–1.67). The adjusted OR for the four factors to predict MetS were all significant, with obesity having the highest risk (OR: 7.50, CI: 5.91–9.52), followed by dyslipidemia/hyperglycemia (OR: 4.86, CI: 4.03–5.87), and blood pressure (OR: 4.20, CI: 3.51–5.02). A high risk of MetS (five-fold) was found in siblings with MetS proband. Moreover, findings confirm the importance of obesity for the aggregation of MetS by nearly seven-fold in the study population.