RELATIONSHIP BETWEEN LUNG-FUNCTION AND BLOOD-PRESSURE IN CHINESE MEN AND WOMEN OF BEIJING AND GUANGZHOU

Background Previous studies of western populations have shown an inver se association between lung function and blood pressure. Methods As pa rt of a People's Republic of China-United States cardiopulmonary epide miology study, we investigated the cross-sectional relationship betwee n lung function and blood pressure in 6757 Chinese men and women, aged 35-54, from Beijing and Guangzhou, China. We also evaluated the longi tudinal association between lung function and incident hypertension am ong 4818 initially normotensive subjects followed up between 2 and 4 y ears later. Results In our cross-sectional analyses of baseline data, lung function varied inversely with baseline systolic (SEP) and diasto lic blood pressure (DBP) in all women and in Beijing men. This associa tion held for absolute and height-standardized forced vital capacity ( FVC) and one-second forced expiratory volume (FEV1) (correlations: 0.1 0, -0.18, P < 0.0001), but was weaker after adjustment for age (correl ations: -0.02, -0.11). The longitudinal follow-up showed that lower in itial lung function levels were associated with a higher incidence of hypertension (SEP greater than or equal to 140 mmHg or DBP greater tha n or equal to 90 mmHg or currently using antihypertensive medications) , but only among women in Guangzhou. Relative risks for hypertension i ncidence for those in the two lowest quintiles for FEV1 and FVC, compa red to those in the two highest quintiles, ranged from 1.9 to 2.3 for Guangzhou women and from 0.9 to 1.4 for all other gender-city subgroup s. Logistic regression analyses adjusting for age, baseline SEP, body mass index, smoking, education, and urban versus rural setting general ly confirmed these patterns. Conclusions These results suggest a stati stically significant, though weak, inverse relationship between lung f unction and blood pressure in Chinese men and women. This association is largely attributable to age and is present prospectively only in wo men.