Familial correlation and aggregation of body mass index and blood pressure in Chinese Han population

BACKGROUND: It remains unclear whether the body mass index (BMI) and blood pressure (BP) profile are clustered within families in Chinese Han population. The aim of this study is to explore familial aggregation and parent-offspring correlations of BMI and blood pressure in Chinese Han population. METHODS: 6,369 Han nucleus families, consisting of parents and at least one biological adult child who were living together, were enrolled from the nation-wide cross-sectional study (China National Nutrition and Health Survey) which was conducted in 2002, with a total number of 19,107 participants aged 18–64 years (6,369 sets of parents, 4,132 sons and 2,237 daughters). Family aggregation (Intra-class correlations, ICCs) and parent-offspring correlations in BMI, systolic BP (SBP) and diastolic BP (DBP) were estimated using linear mixed effect regression models. RESULTS: BMI and BP levels in two generations and ICCs of BMI, SBP and DBP varied across the country. Familial aggregation of overweight/obesity was observed in rural area (ICC = 5.4%, p<0.05), and high BP (defined as SBP ≥ 120 mmHg or DBP ≥ 80 mmHg) was more common in low income families (ICC = 4.4%, p<0.05) compared to middle income (ICC = 1.9%) and high income families (ICC = 2.6%). Additionally, offspring with more parents being overweight/obese tend to have higher BMI. The similar trend was found for high BP. However, we did not observe that same-sex parent-offspring correlations of BMI and BP were stronger than the correlations for mother-son or father-daughter. CONCLUSIONS: Our study suggested that familial environments, alongside the impact of genetic factors, could be important non-communicable chronic diseases (NCD) risk factors. Family-based intervention taking both mother and father into account might have great potential in NCD prevention for younger generation.