Degree of Blood Pressure Control and Incident Diabetes Mellitus in Chinese Adults With Hypertension

BACKGROUND: The association between blood pressure (BP) control and incident diabetes mellitus remains unknown. We aim to investigate the association between degree of time‐averaged on‐treatment systolic blood pressure (SBP) control and incident diabetes mellitus in hypertensive adults. METHODS AND RESULTS: A total of 14 978 adults with hypertension without diabetes mellitus at baseline were included from the CSPPT (China Stroke Primary Prevention Trial). Participants were randomized double‐masked to daily enalapril 10 mg and folic acid 0.8 mg or enalapril 10 mg alone. BP measurements were taken every 3 months after randomization. The primary outcome was incident diabetes mellitus, defined as physician‐diagnosed diabetes mellitus, or use of glucose‐lowering drugs during follow‐up, or fasting glucose ≥126 mg/dL at the exit visit. Over a median of 4.5 years, a significantly higher risk of incident diabetes mellitus was found in participants with time‐averaged on‐treatment SBP 130 to <140 mm Hg (10.3% versus 7.4%; odds ratio [OR], 1.37; 95% CI, 1.15‒1.64), compared with those with SBP 120 to <130 mm Hg. Moreover, the risk of incident diabetes mellitus increased by 24% (OR, 1.24; 95% CI, 1.00‒1.53) and the incidence of regression to normal fasting glucose (<100 mg/dL) decreased by 29% (OR, 0.71; 95% CI, 0.57‒0.89) in participants with intermediate BP control (SBP/diastolic blood pressure, 130 to <140 and/or 80 to <90 mm Hg), compared with those with a tight BP control of <130/<80 mm Hg. Similar results were found when the time‐averaged BP were calculated using the BP measurements during the first 6‐ or 24‐month treatment period, or in the analysis using propensity scores. CONCLUSIONS: In this non‐diabetic, hypertensive population, SBP control in the range of 120 to <130 mm Hg, compared with the 130 to <140 mm Hg, was associated with a lower risk of incident diabetes mellitus.