Predictive power of home blood pressure and clinic blood pressure in hypertensive patients with impaired glucose metabolism and diabetes.

Objectives: We evaluated the predictive power of home blood pressure and clinic blood pressure based on the long-term cardiovascular outcome in hypertensive patients with and without impaired glucose metabolism (IGM).
Method: The multicentre Hypertension Objective Treatment Based on Measurement by Electrical Devices Blood Pressure trial (HOMED-BP) involved 3080 patients (50.5% women; mean age 59.7 years) with a baseline, untreated home/clinic blood pressure as well as follow-up, on-treatment blood pressure. Of those, 979 had IGM and 475 of these patients had diabetes. We applied Cox regression pooling all participants in a cohort analysis in which IGM and normal glucose metabolism (NGM) were separated.
Results: During median 5.45 years follow-up, cardiovascular events occurred in 48 patients with IGM and 53 patients with NGM. Baseline home SBP significantly predicted cardiovascular outcome among IGM group [hazard ratio 1.68, 95% CI 1.26-2.26, P = 0.0005]. On-treatment home blood pressure was a significant predictor for cardiovascular risk even after the further adjustment of baseline blood pressure level (P ≤ 0.027), whereas on-treatment clinic blood pressure was not in NGM group (P ≥ 0.37). The event rate in IGM was approximately two times higher than that in NGM (9.95 vs. 4.88 per 1000 patient-years), resulted to the low 5-year number needed to treat in IGM patients [83 vs. 121 for 1-SD (13.1 mmHg) home SBP reduction, and 62 vs. 104 for 1-SD (9.5 mmHg) home DBP reduction).
Conclusion: The present findings suggest that long-term cardiovascular risk in IGM patients should be assessed based on home blood pressure, not on clinic blood pressure.