RESUMO
OBJECTIVE: We investigated, in a sample of Chinese families, the associations of body mass index (BMI), blood pressure (BP), serum lipids, fasting plasma glucose, serum creatinine and uric acid with the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene. METHODS: We genotyped 902 subjects from 186 nuclear families recruited in Shanghai, China, via a specialized hypertension clinic. We performed family-based association analyses for continuous and dichotomous phenotypic measurements using the quantitative and sib- transmission/disequilibrium tests (QTDT and Sib-TDT), respectively. RESULTS: The study sample included 121 parents and 781 offspring from 25 two-parent families, 71 one-parent families, and 90 families without parental information. The median number of offspring was four (range from 2 to 10). Of the 654 (85.4%) hypertensive offspring, 458 took antihypertensive drugs. The 354 male offspring were slightly younger than the 427 female siblings (48.1 versus 49.2 years, P = 0.03), but they had similar BMI (25.1 kg/m). In 482 informative offspring, QTDT analyses demonstrated a significant association between BMI and the transmission of the ACE D allele (regression coefficient 0.563, chi 2 = 4.02, P = 0.04). In 106 families with at least one hypertensive offspring and at least one normotensive sibling, Sib-TDT analyses showed that the ACE D allele was slightly over-transmitted from heterozygous parents to hypertensive offspring (P = 0.08). CONCLUSIONS: Our family-based study suggests that in Chinese, the ACE I/D polymorphism might play a role in the development of obesity and hypertension, which are closely linked cardiovascular risk factors.
