Prognostic value of 24-hour ambulatory blood pressure patterns in diabetes: A 21-year longitudinal study

Aims To establish the long-term prognostic value of abnormal circadian blood pressure (BP) patterns in diabetes. Materials and Methods We retrospectively examined a cohort of 349 outpatients with diabetes who were screened for microvascular complications and followed up for 21 years. Dipping, nondipping and reverse-dipping status were defined based on 24-hour ambulatory BP monitoring (ABPM) as >= 10% reduction, <10% reduction, and any increase in average nighttime versus daytime systolic BP (SBP), respectively. Results After 6251 person-years of follow-up (median [range] follow-up 21.0 [1.1-22.0] years, 52% women, age 57.1 +/- 11.9 years, 81.4% type 2 diabetes and 18.6% type 1 diabetes), a total of 136 deaths (39%) occurred. Compared with dippers, the nondippers and reverse dippers showed progressively higher prevalence of chronic kidney disease (CKD), cardiac autonomic neuropathy (CAN) and postural hypotension. Reverse dippers showed a 13.4% (2.5-year) reduction in mean overall survival and a twofold increased risk of all-cause mortality after adjustment for traditional risk factors (hazard ratio 2.2 [95% confidence interval 1.3-3.8]). Each 1% decrease in nighttime versus daytime SBP ratio was independently associated with a 4% reduction in 20-year mortality risk. Conclusions In patients with diabetes, reverse dipping is associated with a higher prevalence of CKD and CAN and more than doubled the adjusted risk of all-cause mortality over a 21-year observation.