Lack of effect of simvastatin on insulin sensitivity in Type 2 diabetic patients with hypercholesterolaemia: results from a double-blind, randomized, placebo-controlled crossover study.
OBJECTIVE
To evaluate the effects of simvastatin on serum lipids and insulin sensitivity in Type 2 diabetic patients with hypercholesterolaemia.


METHODS
A double-blind, randomized, placebo-controlled and two-period crossover study. After a 2-month run-in, 19 eligible Type 2 diabetic patients with hypercholesterolaemia were randomized to receive either simvastatin or placebo for 3 months, exchanging their treatment thereafter for another 3 months. Blood samples were taken in month 0 and at monthly intervals to measure serum lipids and indices of glycaemic control. An euglycaemic insulin clamp was performed in months 0, 3 and 6 to assess change of insulin sensitivity. The amount of glucose infused during 90-120 min of the clamp (M), and the mean values of serum insulin during 90-120 min (I) were measured. The M and M/I ratio were used to represent the in vivo insulin sensitivity of the subject.


RESULTS
Simvastatin significantly reduced serum total cholesterol (TC) by 23+/-18% and low density lipoprotein-cholesterol (LDL-C) by 30+/-26%. It did not alter glycaemic control. The M-values and M/I ratios were similar in both groups in each period and no drug effect on insulin sensitivity could be identified.


CONCLUSIONS
Simvastatin significantly reduced the serum TC and LDL-C levels without alteration of insulin sensitivity in Type 2 diabetic patients with hypercholesterolaemia.
Hwu
C M
CM
Department of Medicine, Veterans General Hospital-Taipei, Taiwan.
Kwok
C F
CF
Chen
H S
HS
Shih
K C
KC
Lee
S H
SH
Hsiao
L C
LC
Lin
S H
SH
Ho
L T
LT
D000328:Adult; D000368:Aged; D000924:Anticholesteremic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D004311:Double-Blind Method; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D006937:Hypercholesterolemia / Q000188:drug therapy* / Q000209:etiology; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D019821:Simvastatin / Q000009:adverse effects / Q000627:therapeutic use*
D000924:Anticholesteremic Agents; D001786:Blood Glucose; D008078:Cholesterol, LDL; D007328:Insulin; D010919:Placebos; D002784:Cholesterol; D019821:Simvastatin