The Farther From Town the Lower the Blood Pressure: Report From Rural Yunnan Province

BACKGROUND: Hypertension (HTN) is a major cause of death in Chinese farmers. Remoteness from population centers may independently affect HTN prevalence and severity. METHODS: We used random cluster sampling to select 27 villages in Yunnan province, China. Within each village, we randomly selected 50-80 men and women between the ages of 50 and 70 years. A total of 1,177 participants underwent interviews and blood pressure (BP) measurement. We evaluated the relationship between BP and distance of the participants' village from the town and county centers with and without adjustment for covariates. RESULTS: There was a significant (P < 0.001) inverse relationship between BP and distance from populations centers. For every 10 km from the town center, the mean systolic BP (SBP) in the village decreased by 1.2 mm Hg and the mean diastolic by 0.5 mm Hg. After adjustment for age, gender, ethnicity, body mass index, smoking, and drinking, we found that SBP decreased by 1.8 mm Hg (P = 0.03) and diastolic BP by 1.0 mm Hg (P = 0.02) for every 10 km distance from the town center. CONCLUSIONS: HTN prevalence and severity are significantly linked to distance from population centers in rural Chinese farmers. The farther a farmer's village is from larger population centers, the greater is the probability that his/her BP will be normal. This relationship is independent of age, gender, ethnicity, body mass index, smoking, and alcohol use. Strategies in addressing HTN in rural regions should take account of this geographic dependence on distance from population centers.