OBJECTIVES: To examine the association between blood pressure and diabetes mellitus in middle-aged and elderly Chinese.

METHODS: A total of 6653 middle-aged and elderly Chinese adults (≥45 years old; 45.7% men) from the China Health and Retirement Longitudinal Study were included for analyses. Blood pressure was the average of three consecutive measurements by the Omron HEM-7200 Blood Pressure Monitor at baseline in 2011. All participants were divided into normal blood pressure (NBP) group (systolic BP <120 mmHg and diastolic BP <80 mmHg), prehypertension group (systolic BP≥120 mmHg and ≤139 mmHg; diastolic BP≥80 mmHg and ≤89 mmHg) and hypertension group (systolic BP >139 mmHg or diastolic BP >89 mmHg). Incident diabetes mellitus was determined by self-report in two follow-up surveys in 2013 and 2015. Multivariable logistic regression models were applied to estimate odds ratios (ORs) and 95% confidence interval (95% CI) associated with prehypertension and hypertension.

RESULTS: During the 4-year follow-up, 330 participants (5.0%) developed diabetes mellitus, with 3.9% in men and 5.8% in women. The incidence of diabetes mellitus was 2.8%, 5.4%, and 7.0%, respectively, in the NBP, prehypertension, and hypertension groups. After adjusted for age, sex, education, waist, fasting glucose, total cholesterol, high-density lipoprotein cholesterol, body mass index, alcohol consumption, and smoking status, prehypertension (OR, 1.51; 95% CI, 1.10-2.05) and hypertension (1.62; 1.18-2.24) were associated with increased risk of diabetes mellitus, compared with those with NBP. When the analyses were restricted to participants with normal glucose tolerance, the associations still existed with prehypertension (2.28, 1.44-3.63) and hypertension (2.41, 1.48-3.91) . However, in the participants with prediabetes, the associations did not show statistical difference (1.00; 0.65-1.53 for prehypertension and 1.10; 0.71-1.70 for hypertension).

CONCLUSIONS: High BP is a risk factor for diabetes mellitus in middle-aged and elderly Chinese. Normal blood pressure may be a target for the prevention of diabetes mellitus.