Associations of physical activity and egg intake with hypertension among Chinese middle-aged and older population

To explore the independent and interaction associations of physical activity (PA) and egg intake with hypertension. A cross-sectional study of 2189 individuals (aged >= 50 years) selected using multi-stage stratified random sampling was conducted in Mentougou of Beijing, China. Data of PA and egg intake were obtained from questionnaire survey, and blood pressure from physical examination. Individuals were divided into four groups by the level of PA: low, medium, high level 1 and high level 2; and were also divided into three groups by daily amount of egg intake: <1 egg/day, 1 egg/day and >1 egg/day. Self-reported hypertension was defined if individual had a self-reported diagnosis of hypertension or use of antihypertensive medication; examined abnormal blood pressure was defined if individual didn't belong to self-reported hypertension and mean blood pressure was above 130/80 mmHg measured during this examination. After adjusting demographic characteristics, health behavior, BMI, and family history of CVD, compared with medium level PA group, high level 2 group was associated with higher self-reported rate (OR: 1.5, 95% CI: 1.18-2.01) and examined abnormal rate (OR: 1.8, 95% CI: 1.21-2.20). The self-reported rate and examined abnormal rate in <1 egg/day group were both higher than 1 egg/day group (OR: 1.4, 95% CI: 1.06-1.91; OR: 1.4, 95% CI: 1.08-1.92). Compared with medium level PA and 1 egg/day group, high level 2 and >1 egg/day group with higher examined abnormal rate (OR: 2.3, 95% CI: 1.28-4.01), high level 2 and <1 egg/day group with higher self-reported rate and examined abnormal rate (OR: 2.5, 95% CI: 1.10-3.82; OR: 2.9, 95% CI: 1.54-4.96). In conclusion, excessive high level PA and inadequate egg intake were associated with hypertension, respectively, and the association further increased when both existed at the same time. Besides, moderate PA combined with reasonable egg intake was associated with the low examination rate of hypertension.