Usefulness of morning home blood pressure measurements in patients with type 2 diabetes mellitus: results of a 10-year, prospective, longitudinal study

Previous cross-sectional studies and 6-year longitudinal study have demonstrated that home blood pressure (HBP) measurements upon awakening have a stronger predictive power for death, micro- and macrovascular complications than clinic blood pressure (CBP) measurements in patients with type 2 diabetes (T2DM). This study investigated which of these measurements offers stronger predictive power for outcomes over 10 years. At baseline, 400 Japanese patients with T2DM were classified as having hypertension (HT) or normotension (NT) based on HBP and CBP. The mean survey duration was 95 months. Primary and secondary end-points were death and new or worsened micro- and macrovascular complications, respectively. Differences in outcomes for each end-point between HT and NT patients were analyzed using Kaplan-Meier survival curves and log-rank testing. Associated risk factors were assessed using Cox proportional hazards analysis. Based on HBP, death and micro- and macrovascular complications were significantly higher in patients with HT than with NT at baseline and end-point. Based on CBP, there were no significant differences in incidence of death, micro- or macrovascular complications between patients with HT and NT at baseline and end-point, although a significant difference in incidence of death was observed between the HT and NT groups at end-point. However, the significance was significantly lower in CBP than in HBP. One risk factor associated with micro- and macrovascular complications in patients with HBP was therapy for HT. This 10-year longitudinal study of patients with T2DM demonstrated that elevated HBP upon awakening is predictive of death, and micro- and macrovascular complications.