Ambulatory blood pressure in diabetic subjects

Ambulatory blood pressure (ABP) was measured every 15 min for 24 h in 82 diabetic subjects aged 35 to 79 years and in 66 healthy controls having the same age and office blood pressure. The autonomic control in diabetic subjects was evaluated by the total score of five cardiovascular function tests (a high score means an autonomic neuropathy). The diurnal cycle of BP was assessed by the difference of BP between daytime and nighttime (delta BP = BP in the day - BP in the night). The variability of BP was evaluated by the standard deviations of the readings. Compared with control subjects, diabetic subjects had the same 24-h mean level of BP, a smaller delta BP, and an increased variability during the daytime; however, the differences were in the limit of statistical significance. Clearcut results were obtained in diabetic subjects with autonomic neuropathy. In the latter, the score of autonomic neuropathy was (1) negatively correlated to delta SBP (systolic) and delta DBP (diastolic) (r = 0.44, P = .0004 and r = 0.46, P = .0004, respectively) and (2) positively correlated to the variability of SBP and DBP during the daytime (r = 0.46, P .0004 and r = 0.29, P = .03, respectively). In diabetic subjects, mean level and variability of ABP were positively correlated to urinary microalbumin. The relationships were the most significant when one relates microalbuminuria to the level of SBP in the night (r = 0.42, P < .0003) and to the variability of SBP in the day (r = 0.32, P = .008).(ABSTRACT TRUNCATED AT 250 WORDS)