Cigarette smoking and insulin resistance in patients with noninsulin-dependent diabetes mellitus.
To evaluate the effects of chronic cigarette smoking on insulin sensitivity in patients with noninsulin-dependent diabetes mellitus (NIDDM), we examined 28 smokers and 12 nonsmokers with NIDDM, of similar sex, age, body mass index, waist/hip ratio, alcohol consumption, physical activity level, glycometabolic control, diabetes duration, and treatment. Insulin and C-peptide responses to oral glucose load were significantly higher in smokers than nonsmokers, whereas glucose levels were not substantially different. During insulin clamp (20 mU/min.m2), carried out in combination with tritiated glucose infusion and indirect calorimetry, total glucose disposal was markedly reduced in smokers vs. nonsmokers [19 +/- 1.2 vs. 33 +/- 5 mumol/min.kg fat-free mass (FFM); P < 0.001], in a dose-dependent fashion (F = 6.8, P < 0.001 by ANOVA when subjects were categorized for number of cigarettes smoked per day). Oxidative (9 +/- 1 vs. 14 +/- 2 mumol/min.kg FFM; P < 0.01) and nonoxidative (10 +/- 1 vs. 19 +/- 4 mumol/min.kg FFM; P < 0.01) pathways of insulin-mediated intracellular glucose metabolism were similarly reduced in smokers vs. nonsmokers. Plasma free fatty acid levels (240 +/- 33 vs. 130 +/- 23 microEq/L; P < 0.05) and lipid oxidation rate (1.39 +/- 0.1 vs. 0.95 +/- 0.2 mumol/ min.kg FFM; P < 0.05) were less suppressed by hyperinsulinemia in smokers than nonsmokers. In conclusion, chronic cigarette smoking seems to markedly aggravate insulin resistance in patients with NIDDM.
Targher
G
G
Division of Endocrinology and Metabolic Diseases, University of Verona Medical School, Italy.
Alberiche
M
M
Zenere
M B
MB
Bonadonna
R C
RC
Muggeo
M
M
Bonora
E
E
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D015227:Lipid Peroxidation; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000009:adverse effects*
D001786:Blood Glucose; D002096:C-Peptide; D005230:Fatty Acids, Nonesterified; D007328:Insulin