Effects of renal dysfunction on cardiovascular events in diabetic patients with hypertension: challenge-DM Study subgroup analysis.

BACKGROUND: This study investigated the relation between renal dysfunction and cardiovascular events in patients from the Challenge-DM Study (a large-scale investigation of Japanese diabetic patients with hypertension on candesartan therapy).
METHODS: The subjects were 4706 patients in whom renal function could be assessed at the time of registration among 16860 patients analyzed in the Challenge-DM Study. The definition of renal dysfunction (low GFR) was an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2) calculated by the formula for Japanese.
RESULTS: The low GFR group was older, and had a high proportion of females and a high prevalence of cerebrovascular or cardiovascular disease (CVD) compared to the normal GFR group (eGFR ≥ 60 ml/min/1.73 m(2)). Univariate Cox regression analysis of cardiovascular events showed a significant increase in the incidence of primary events and total events in the low GFR group. Among patients <65 years old, the same results were obtained, but no differences were found between the low GFR and normal GFR groups aged over 65 years. Multivariate Cox regression analysis was done with patient characteristics at registration and the presence/absence of achieving the target blood pressure and HbA(1c) before the event as explanatory variables. As a result, low GFR was not the main cause of cardiovascular events, but it had a significant influence on primary events and total events among patients <65 years old.
CONCLUSIONS: Low GFR may be an independent risk factor for cerebrovascular and CVD among young and middle-aged Japanese diabetic patients with hypertension on candesartan therapy.