Use of calcium channel blockers and beta blockers as antihypertensives in relation to mortality in type 2 diabetes patients: A population-based observational study

Objectives - In previous trials, patients with type 2 diabetes using calciu m channel blockers (CCB) have suffered a less favourable outcome when compa red with patients on other treatments. The present study was designed to co mpare mortality in type 2 diabetes patients using either CCB or beta blocke rs (BB) as antihypertensive agents. Design - Retrospective observational study. Patients were followed from the first day they were on either of the study drugs until 31 December 1996, o r until death. Settings - Two Swedish municipalities. Subjects - All patients with type 2 diabetes who were using a CCB or a BE a s an antihypertensive agent during 1984-1994. Main outcome measures - Adjusted odds ratio for overall and cause-specific mortality in CCB users versus BE users. Results - Ninety-six users of CCB and 270 users of BE were included. The od ds ratio for overall mortality, adjusted for age, sex, inclusion year and m unicipality was 1.78 (95% CI 1.17-2.71) in CCB users versus BE users. Corre sponding odds ratios for mortality from IHD, stroke, cancer and other cause s were 1.11, 2.41, 1.63 and 2.61, respectively. However, among those, only mortality due to other causes was significantly elevated. Conclusions - This study adds support to the possibility of an adverse outc ome in patients with diabetes using a CCB. An agent interfering with variou s cell functions such as calcium ion channels may also interfere with many pathways, increasing mortality. Therefore, a relation between blockade of c alcium ion channels and miscellaneous causes of death should not be discard ed. Our findings warrant careful examinations in other population-based stu dies. Copyright (C) 2000 John Wiley & Sons, Ltd.