Prognostic value of 24-hour ambulatory blood pressure patter
A retrospectively examined a cohort of 349 outpatients with diabetes who were screened for microvascular complications and followed up for 21 years. Dipping, non-dipping and reverse dipping status were defined based on 24-hour ambulatory BP monitoring (ABPM) as 10% reduction, <10% reduction, and any increase in average night-time vs day-time systolic BP (SBP), respectively.

After 6,251 person-years of follow-up (median follow-up 21.0 years [range 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 (39%) deaths occurred. Compared with dippers, non-dippers 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 years) reduction in mean overall survival and a two-fold increased risk of all-cause mortality after adjustment for traditional risk factors (HR 2.2 [1.3-3.8]). Each 1% decrease in night-time vs day-time SBP ratio was independently associated with a 4% reduction in 20-year mortality risk.

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.