Familial aggregation of blood pressure in a rural Chinese community.

This study investigated blood pressure in 1,183 Chinese nuclear families (mother, father, and first two children) via a cross-sectional 1994-1997 survey. The mother's, the father's, and the first sibling's blood pressures were each significantly and independently related to the second sibling's blood pressure after adjustment for sex, age, height, weight, education, smoking, and alcohol consumption. The association was consistent across the four age strata (6-10, 11-14, 15-19, and > or = 20 years). The rate of high systolic blood pressure in the second sibling was lowest (2.3%) when both parents and the first sibling were in the low blood pressure tertile (low-low group) and highest (26.0%) when these family members were in the high blood pressure tertile (high-high group). The rate was intermediate if only the parents (10.7%, high-low group) or the first sibling (8.4%, low-high group) was in the high blood pressure tertile. As compared with the low-low group, the odds ratios for the high-high, high-low, and low-high groups were 14.3 (95% confidence interval 4.3-48.2), 4.3 (95% confidence interval 1.2-15.6), and 3.9 (95% confidence interval 1.1-14.4), respectively. A similar pattern was found for diastolic blood pressure. The data indicate a strong familial aggregation of blood pressure in this population and show that such a familial influence on blood pressure can be detected from early childhood onward.