Visit‐to‐visit variability in blood pressure strongly predicts all‐cause mortality in patients with type 2 diabetes: a 5·5‐year prospective analysis

BACKGROUND: Elevations in blood pressure and visit-to-visit variability have been found to significantly increase the risk of cardiovascular morbidity and mortality in nondiabetic individuals. This study has assessed the association between all-cause mortality and blood pressure parameters systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial pressure (MAP) and visit-to-visit variability in patients with type 2 diabetes. MATERIALS AND METHODS: A longitudinal cohort study of 2161 patients with type 2 diabetes and a mean follow-up period of 66·7 ± 7·5 months. Using Cox regression models, blood pressure parameters were related to the risk of all-cause mortality. RESULTS: Visit-to-visit variability in SBP HR: 1·048 (95% CI: 1·005-1·092; P = 0·03), DBP HR: 1·090 (95% CI: 1·021-1·163; P = 0·01) and MAP HR: 1·099 (95% CI: 1·033-1·170; P = 0·003) significantly predicted all-cause mortality in patients with type 2 diabetes after adjusting for baseline data, mean follow-up blood pressure profiles and HbA1c. Visit-to-visit variability in PP HR: 1·139 (95% CI: 1·030-1·258; P = 0·01) significantly predicted cardiovascular mortality. Neither baseline nor follow-up SBP, DBP, PP nor MAP was significantly associated with all-cause and cardiovascular mortality after adjusting for blood pressure variability. The risk of all-cause mortality with a mean follow-up SBP has a U-shaped distribution. Patients with a mean follow-up DBP > 90 mmHg were at higher risk of mortality than those with DBP < 90 mmHg. CONCLUSIONS: Visit-to-visit variability in blood pressure was significantly associated with all-cause mortality independent of mean BP in patients with type 2 diabetes. The data for blood pressure variability might be regarded as a potentially important therapeutic target in the management of type 2 diabetes.