REVERSED CIRCADIAN BLOOD-PRESSURE RHYTHM IS ASSOCIATED WITH OCCURRENCES OF BOTH FATAL AND NONFATAL VASCULAR EVENTS IN NIDDM SUBJECTS

To assess the significance of reversed circadian blood pressure (BP) r hythms as a predictive factor of vascular events in NIDDM, vital statu s after an average 4-year follow-up was determined in 325 NIDDM subjec ts in whom the circadian BP profile had been monitored between 1988 an d 1996. Circadian BP rhythm was analyzed by the COSI-NOR (a compound w ord for cosine and vector) method, as previously described. After excl usion of 37 dropped-out subjects, 288 were recruited to the further an alysis, of which 201 had a normal circadian BP rhythm (group N) and th e remaining 87 had a reversed one (group R). There was no difference i n sex, HbA(1c), the prevalence of smokers, serum Lipids, or serum elec trolytes between groups N and R at baseline, whereas age, the prevalen ce of hypertension, serum creatinine, and diabetic complications were more pronounced in group R than in group N. During the followup period (which averaged 52 months in group N and 36 months in group R), fatal and nonfatal vascular (cerebrovascular, cardiovascular, peripheral va scular arteries, and retinal artery) events occurred in 20 subjects in group N and 56 in group R. Unadjusted survival times and event-free t imes were estimated by the Kaplan-Meier product-limit method, and ther e was a significant difference in both unadjusted survival and event-f ree survival rates between groups N and R (P < 0.001 each; log-rank te st). The Cox proportional-hazards model adjusted for age, sex, circadi an BP pattern, duration of diabetes, therapy for diabetes, various dia betic complications, and hypertension demonstrated that circadian BP p attern and age exhibited significant, high adjusted relative risks for fatal events, and that diabetic nephropathy, postural hypotension, an d hypertension as well as circadian BP pattern exhibited significant, high adjusted relative risks with respect to the occurrence of various nonfatal vascular events. These results suggest that reversed circadi an BP rhythm is associated with occurrences of both fatal and nonfatal vascular events in NIDDM subjects.