Beneficial effects of metformin in normoglycemic morbidly obese adolescents.
Hyperinsulinemia and insulin resistance are common features of obesity in humans and experimental animals. It has been demonstrated that metformin, an antihyperglycemic agent, decreases hyperinsulinemia and insulin resistance leading to decreased adiposity in obese and non-insulin-dependent diabetes mellitus (NIDDM) adults. To evaluate the antiobesity effect of metformin, we conducted a randomized double-blind placebo controlled trial in 24 hyperinsulinemic nondiabetic obese adolescents (body mass index [BMI] >30 kg/m(2)). All subjects were placed on a low-calorie (1,500 kcal for women and 1,800 kcal for men) meal plan. After an initial 1-week lead-in period, 12 subjects (mean +/- SE for age and BMI, 15.6 +/- 0.4 and 41.2 +/- 1.8, respectively) received metformin (850 mg twice daily) for 8 weeks, and 12 subjects (mean +/- SE for age and BMI, 15.7 +/- 0.5 and 40.8 +/- 1.4, respectively) received placebo. Compared to the placebo group, the metformin group had greater weight loss (6.5% +/- 0.8% v 3.8 +/- 0.4%, P <.01), greater decrease in body fat (P <.001), greater increase in fat-free mass to body fat ratio (P <.005), and greater attenuation of area under the curve (AUC) insulin response to an oral glucose tolerance test (P <.001). This was associated with enhanced insulin sensitivity, as determined by the fasting plasma glucose:insulin, 2-hour glucose:insulin, and AUC glucose:AUC insulin ratios, in the metformin group compared to controls (P <.01). This corresponded to a significant reduction in plasma leptin (P <.005), cholesterol, triglycerides, and free fatty acid (FFA) levels (P <.05) only in the metformin-treated subjects. Combined metformin treatment and low-calorie diet had a significant antiobesity effect in hyperinsulinemic obese adolescents compared to a low-calorie diet alone.
Kay JP
,Alemzadeh R
,Langley G
,D'Angelo L
,Smith P
,Holshouser S
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《METABOLISM-CLINICAL AND EXPERIMENTAL》
Metformin reduces weight, centripetal obesity, insulin, leptin, and low-density lipoprotein cholesterol in nondiabetic, morbidly obese subjects with body mass index greater than 30.
We studied 31 nondiabetic, habitually (> or =5 years) morbidly obese subjects (mean +/- SD body mass index [BMI] 43 +/- 8.7, median 43). Our specific aim was to determine whether metformin (2.55 g/d for 28 weeks) would ameliorate morbid obesity and reduce centripetal obesity; lipid and lipoprotein cholesterol, insulin, and leptin levels; and plasminogen activator inhibitor activity (PAI-Fx), risk factors for coronary heart disease (CHD). The patients were instructed to continue their prestudy dietary and exercise regimens without change. After 2 baseline visits 1 week apart, the 27 women and 4 men began receiving metformin, 2.55 g/d, which was continued for 28 weeks with follow-up visits at study weeks 5, 13, 21, and 29. Daily food intake was recorded by patients for 7 days before visits then reviewed with a dietitian. Kilocalories per day and per week were calculated. At each visit, fasting blood was obtained for measurement of lipid profile, insulin, leptin, and PAI-Fx. The mean +/- SD kilocalories consumed per day, 1,951 +/- 661 at entry, fell by week 29 to 1,719 +/- 493 (P =.014) but did not differ at weeks 5, 13, and 21 from that at week 29 (P >.2). Weight fell from 258 +/- 62 pounds at entry to 245 +/- 54 pounds at week 29 (P =.0001). Girth was reduced from 51.8 +/- 6.2 to 49.2 +/- 4.5 inches (P =.0001). Waist circumference fell from 44.0 +/- 6.4 inches to 41.3 +/- 5.9 (P =.0001). The waist/hip ratio fell from 0.85 +/- 0.09 to 0.84 +/- 0.09 (P =.04). Fasting serum insulin, 28 +/- 15 microU/mL at entry, fell to 21 +/- 11 microU/mL at week 29 (P =.0001), and leptin fell from 79 +/- 33 ng/mL to 55 +/- 27 ng/mL (P =.0001). On metformin, there were linear trends in decrements in weight, girth, waist circumference, waist/hip ratio, insulin, and leptin throughout the study period (P <.007). Low-density lipoprotein (LDL) cholesterol, 126 +/- 34 mg/dL at study entry, fell to 112 +/- 43 mg/dL at week 29 (P =.001), with a linear trend toward decreasing levels throughout (P =.036). By stepwise linear regression, the higher the entry weight, the larger the reduction in weight on metformin therapy (partial R(2) = 31%, P =.001). The greater the reduction in kilocalories consumed per day, the greater the decrease in weight on metformin therapy (partial R(2) = 15%, P =.011). The higher the waist/hip ratio at entry, the greater its reduction on metformin therapy (partial R(2) = 11%, P =.004). The higher the entry serum leptin, the greater its reduction on metformin therapy (partial R(2) = 29%, P =.002). The greater the reduction in insulin on metformin, the greater the reduction in leptin (partial R(2) = 8%, P =.03). The higher the entry PAI-Fx, the greater the reduction in PAI-Fx on metformin (partial R(2) = 43%, P =.0001). Metformin safely and effectively reduces CHD risk factors (weight, fasting insulin, leptin, LDL cholesterol, centripetal obesity) in morbidly obese, nondiabetic subjects with BMI > 30, probably by virtue of its insulin-sensitizing action.
Glueck CJ
,Fontaine RN
,Wang P
,Subbiah MT
,Weber K
,Illig E
,Streicher P
,Sieve-Smith L
,Tracy TM
,Lang JE
,McCullough P
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《METABOLISM-CLINICAL AND EXPERIMENTAL》