Effects of metoprolol and carvedilol on pre-existing and new onset diabetes in patients with chronic heart failure: data from the Carvedilol Or Metoprolol European Trial (COMET).
BACKGROUND
Beta blocker treatment may worsen glucose metabolism.


OBJECTIVE
To study the development of new onset diabetes in a large cohort of patients with heart failure treated with either metoprolol or carvedilol.


METHODS
Prospective and retrospective analysis of a controlled clinical trial.


METHODS
Multinational multicentre study.


METHODS
3029 patients with chronic heart failure.


METHODS
Randomly assigned treatment with carvedilol (n = 1511, target dose 50 mg daily) or metoprolol tartrate (n = 1518, target dose 100 mg daily).


RESULTS
Diabetic events (diabetic coma, peripheral gangrene, diabetic foot, decreased glucose tolerance or hyperglycaemia) and new onset diabetes (clinical diagnosis, repeated high random glucose level or glucose lowering drugs) were assessed in 2298 patients without diabetes at baseline. Diabetic events occurred in 122/1151 (10.6%) patients in the carvedilol group and 149/1147 (13.0%) patients in the metoprolol group (hazard ratio (HR) = 0.78; 95% confidence interval (CI) 0.61 to 0.99; p = 0.039). New onset diabetes was diagnosed in 119/1151 (10.3%) v 145/1147 (12.6%) cases in the carvedilol and metoprolol treatment groups (HR = 0.78, CI 0.61 to 0.997; p = 0.048), respectively. Patients with diabetes at baseline had an increased mortality compared with non-diabetic subjects (45.3% v 33.9%; HR = 1.45, CI 1.28 to 1.65). Both diabetic and non-diabetic subjects at baseline had a similar reduction in mortality with carvedilol compared with metoprolol (RR = 0.85; CI 0.69 to 1.06 and RR = 0.82; CI 0.71 to 0.94, respectively).


CONCLUSIONS
A high prevalence and incidence of diabetes is found in patients with heart failure over a course of 5 years. New onset diabetes is more likely to occur during treatment with metoprolol than during treatment with carvedilol.
Torp-Pedersen
Christian
C
Department of Cardiology, Bispebjerg University Hospital, Copenhagen NV, Denmark. ctp@heart.dk
Metra
Marco
M
Charlesworth
Andrew
A
Spark
Phillip
P
Lukas
Mary Ann
MA
Poole-Wilson
Philip A
PA
Swedberg
Karl
K
Cleland
John G F
JG
Di Lenarda
Andrea
A
Remme
Willem J
WJ
Scherhag
Armin
A
D000319:Adrenergic beta-Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002227:Carbazoles / Q000009:adverse effects* / Q000627:therapeutic use; D000077261:Carvedilol; D016009:Chi-Square Distribution; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000401:mortality; D004311:Double-Blind Method; D005060:Europe; D005260:Female; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D015994:Incidence; D008297:Male; D008790:Metoprolol / Q000009:adverse effects* / Q000627:therapeutic use; D008875:Middle Aged; D015995:Prevalence; D011412:Propanolamines / Q000009:adverse effects* / Q000627:therapeutic use; D011446:Prospective Studies; D012189:Retrospective Studies
D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D008790:Metoprolol