This study conducted a secondary analysis to examine the hypertension risk among different generations of Chinese using China Health and Nutrition Survey data. This is an accelerated longitudinal panel study in that same individuals were followed up from 1997 to 2006, including 7,710 participants who were classified into 5 birth cohorts according to birth date by decade from 30's to 70's. They came from 8 provinces in a line from south to north China. Primary outcome of the study was systolic and diastolic blood pressure. The secondary outcome was binary one defined as hypertension yes or not using conventional criteria.

Three linear mixed model-based approaches were used to disentangle the age, period and cohort effects. Growth curve random intercept model provided most precise adjustment of curvature age effect thus was preferable. The age trajectories of systolic blood pressure for cohort 70's and diastolic blood pressure for cohort 70's and 60's stood out from other cohorts, predicating higher risk of hypertension among younger generation. Specifically, LSmean of systolic blood pressure for 70's was 121.9 ± 0.6 mmHg, which was significantly higher than that of 50's and 60's. Lsmeans of diastolic blood pressure for 70's was 80 ± 0.4 mmHg, which was significantly higher than all other generations.

GEE model on binary outcome didn't find significant cohort effect. However, consistent with finding from continuous outcome, female was less likely to be hypertensive than male, and those from rural region were less likely to be hypertensive than those from urban. Interestingly, there was a spacial trend of the risk of hypertension. The odds of being hypertension increased gradually from south to north China.

The finding of this study would be useful to plan hypertension prevention in China.