Comparison of effects of quinapril and metoprolol on glycaemic control, serum lipids, blood pressure, albuminuria and quality of life in non-insulin-dependent diabetes mellitus patients with hypertension. Swedish Quinapril Group.
OBJECTIVE
To compare the long-term effects of the angiotensin-converting enzyme (ACE)-inhibitor quinapril and the cardioselective beta-adrenergic blocking agent metoprolol on glycaemic control, with glycosylated haemoglobin (HbA1c) as the principal variable, in non-insulin-dependent diabetes mellitus (NIDDM) patients with hypertension.


METHODS
A randomized, double-blind, double-dummy, multicentre study during 6 months preceded by a 4 week wash-out and a 3 week run-in placebo period. Quinapril (20 mg) and metoprolol (100 mg, conventional tablets) were given once daily. No change was made in the treatment of diabetes (diet and hypoglycaemic agents).


METHODS
Seventy-two patients fulfilling the criteria were randomized and entered the double-blind period. Twelve patients did not complete the study. Sixty patients, 26 on quinapril and 34 on metoprolol, were available for the final analysis.


METHODS
The effect was assessed by changes in HbA1c, the fasting serum glucose and the post-load serum glucose, C-peptide and insulin levels during the oral glucose tolerance test.


RESULTS
In the quinapril group, the fasting serum glucose, oral glucose tolerance and the C-peptide and insulin responses, determined as the incremental area under the curves (AUC), showed no change, but the mean HbA1c level increased from 6.2 +/- 1.1% to 6.5 +/- 1.3% (P < 0.05). In the metoprolol group, the rise in the mean level of HbA1c, from 6.3 +/- 1.0% to 6.8 +/- 1.3% (P < 0.01), tended to be more marked than after quinapril, although there was no significant difference between the increments. The mean fasting serum glucose showed an increase from 9.1 +/- 1.9 mM to 10.1 +/- 2.8 mM (P < 0.01) which correlated significantly with the duration of diabetes (P < 0.01) and the increase in fasting serum triglycerides (P < 0.001). Moreover, in the metoprolol group we found significant decreases in the oral glucose tolerance as well as C-peptide and insulin responses to the glucose load.


CONCLUSIONS
Treatment with quinapril for 6 months appears to have advantages over metoprolol in NIDDM patients with hypertension. Although treatment with quinapril or metoprolol over 6 months was concomitant with a rise in the HbA1c, increased fasting blood glucose, decreased oral glucose tolerance and decreased C-peptide and insulin responses to a glucose challenge were observed only in patients treated with metoprolol.
Ostman
J
J
Centre of Metabolism and Endocrinology, Huddinge University Hospital, Karolinska Institute, Stockholm, Sweden.
Asplund
K
K
Bystedt
T
T
Dahlöf
B
B
Jern
S
S
Kjellström
T
T
Lithell
H
H
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000368:Aged; D000419:Albuminuria / Q000209:etiology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001786:Blood Glucose / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications*; D004311:Double-Blind Method; D005260:Female; D005951:Glucose Tolerance Test; D006441:Hemoglobin A / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D007328:Insulin / Q000097:blood; D007546:Isoquinolines / Q000494:pharmacology*; D008055:Lipids / Q000097:blood*; D008297:Male; D008790:Metoprolol / Q000494:pharmacology*; D008875:Middle Aged; D011788:Quality of Life; D000077583:Quinapril; D013548:Sweden; D044005:Tetrahydroisoquinolines
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D007546:Isoquinolines; D008055:Lipids; D044005:Tetrahydroisoquinolines; D006441:Hemoglobin A; D008790:Metoprolol; D000077583:Quinapril