Population-based family case–control proband study on familial aggregation of metabolic syndrome: Finding from Taiwanese people involved in Keelung community-based integrated screening (KCIS no. 5)

A population-based case–control proband study was undertaken to elucidate familial aggregation, independent environmental factors, and the interaction between them. A total of 7308 metabolic syndrome (MET-S) cases were identified from the Keelung community-based integrated screening programme between 1999 and 2002. The study has a case–control/family sampling design. A total of 1417 case probands were randomly selected from 3225 metabolic syndrome cases and the corresponding 2458 controls selected from 16,519 subjects without metabolic syndrome by matching on sex, age (±3 years) and place of residence. The generalized estimation equation model was used to estimate odds ratios and corresponding 95% confidence intervals. The risk for having metabolic syndrome among family members for cases versus control probands was 1.56-fold (1.29–1.89) after controlling for significant environmental factors. Higher risk of metabolic syndrome was found in parents than spouse. Low education against high education had 2.06-fold (1.36–3.13) risk for metabolic syndrome. Betel quid chewing was positively associated with the risk of MET-S, with 1.99-fold (1.13–3.53) risk for 1–9 pieces and 1.76-fold (0.96–3.23) risk for ≥10 pieces compared with non-chewer. Moderate and high intensity of non-occupational exercise led to 21.0% (OR = 0.79 (0.63–0.98)) and 26.0% (OR = 0.74 (0.59–0.94)) reduction in the risk for metabolic syndrome, respectively. The frequent consumption of vegetable reduced 24.0% (OR = 0.76 (0.62–0.92)) risk for MET-S. The frequent consumption of coffee was associated the increased risk for metabolic syndrome (OR = 1.32 (1.07–1.64)). The present study confirmed the risk of metabolic syndrome not only has the tendency towards familial aggregation but is affected by independent effect of environmental or individual correlates.