Insulin treatment increases skeletal muscle fibre area in patients with diabetes mellitus type 2.
The effects of insulin treatment on skeletal muscle characteristics were studied in 18 patients (62 +/- 11 years) with poorly controlled diabetes mellitus type 2 (mean duration 7.5 +/- 6 years). Skeletal muscle biopsy samples were taken from the lateral portion of the quadriceps muscle before and after a period of insulin treatment of 40 +/- 14 days. Enzyme activities (phosphofructokinase, 3-hydroxyacyl-CoA dehydrogenase, citrate synthase, lactate dehydrogenase and creatine kinase) and myoglobin content were assessed. In a subgroup of 11 patients (60 +/- 11 years), skeletal muscle fibre type composition (type I, IIA, IIB and IIC) and fibre type cross-sectional area were also analysed. Following insulin treatment there were 32 and 38% increases, respectively, in the cross-sectional areas of type IIA and IIB fast-twitch fibres (P<0. 02). The fibre type distribution did not change. The myoglobin content in muscle decreased by 20% (P<0.01). Of the enzymes tested, the 3-hydroxyacyl-CoA dehydrogenase activity decreased by 10% (P<0. 04). Serum glucose, HbA1C and serum triglyceride levels decreased (P<0.001) and body weight and arm muscle circumference increased (P<0.02). In conclusion, insulin treatment of patients with poorly controlled non-insulin-dependent diabetes mellitus increased the fast-twitch fibre area, reduced myoglobin levels and decreased muscle enzyme activity related to fatty acid oxidation.
Cederholm
T
T
Department of Geriatric Medicine, Huddinge University Hospital, Huddinge, Sweden.
Sylvén
C
C
Esbjörnsson-Liljedahl
M
M
Jansson
E
E
D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight; D002784:Cholesterol / Q000097:blood; D003402:Creatine Kinase / Q000378:metabolism; D003710:Demography; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000627:therapeutic use*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018656:Muscle Fibers, Fast-Twitch / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009211:Myoglobin / Q000378:metabolism; D010732:Phosphofructokinase-1 / Q000378:metabolism; D012044:Regression Analysis; D014280:Triglycerides / Q000097:blood
D015094:3-Hydroxyacyl CoA Dehydrogenases; D001786:Blood Glucose; D002784:Cholesterol; D003402:Creatine Kinase; D006442:Glycated Hemoglobin; D007328:Insulin; D007770:L-Lactate Dehydrogenase; D009211:Myoglobin; D010732:Phosphofructokinase-1; D014280:Triglycerides