Lovastatin lowers serum cholesterol levels in non-insulin-dependent diabetes mellitus patients without altering their insulin sensitivity.
BACKGROUND
Lovastatin, a potent 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has been widely used in the treatment of hypercholesterolemia. It is also applied to dyslipidemia in patients with diabetes mellitus. The influence of lovastatin on insulin sensitivity was evaluated in twelve Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients with hypercholesterolemia.


METHODS
This double-blind, randomized, placebo-controlled, and two-period cross-over experiment enrolled 12 patients. After a run-in period of two months, the patients were randomized into 2 groups to receive either lovastatin (20 mg once daily) or placebo treatment. Eight weeks later, two groups of patients exchanged their treatment for another 8 weeks. Blood samples were collected at the end of the run-in period and at 4-week intervals during the study to observe serum lipid profiles. A modified insulin suppression test was made to assess insulin sensitivity three times: at the end of run-in period, in week 8 and week 16, respectively. Wilcoxon signed rank test was used for analysis of statistical significance of the difference between lovastatin and placebo treatments.


RESULTS
As compared with the placebo, lovastatin reduced serum total cholesterol (TC) levels significantly. Serum total triglyceride (TG) concentrations decreased slightly by lovastatin. The ratio of TC to high density lipoprotein-cholesterol (HDL-C) also decreased significantly in lovastatin period. No difference was found in serum apolipoprotein A1 levels. A significant reduction of serum apolipoprotein B concentrations was also noted in lovastatin period. No difference in glycemic indices and insulin sensitivity was observed in the base-line, placebo or lovastatin periods.


CONCLUSIONS
The results demonstrated that lovastatin significantly lowered the serum TC levels without perturbation of insulin sensitivity in hypercholesterolemic NIDDM patients.
Hwu
C M
CM
Department of Internal Medicine, Veterans General Hospital-Taipei, Taiwan, R.O.C.
Shih
K C
KC
Kwok
C F
CF
Chang
C L
CL
Ho
L T
LT
D000368:Aged; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D002784:Cholesterol / Q000097:blood*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D007333:Insulin Resistance; D008148:Lovastatin / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged
D000924:Anticholesteremic Agents; D007328:Insulin; D002784:Cholesterol; D008148:Lovastatin