Network meta- analysis revealed that in adolescents , intervention with 2000 mg/day metformin ranked better than other interventions ; however , 1000 mg/day metformin for 3 months may be most suitable for adolescents .
For adults , metformin at doses of 3000 and 1000 mg/day ranked the highest , other than minimeal and lifestyle interventions ; moreover , intervention with 3000 mg/day for 6 months and 1000 mg/day for 0.5 months may be suitable for adults .
Conclusion When considering the efficacy of interventions for losing weight , metformin offers clear advantages for overweight and obese population
Purpose Our aim was to assess the efficacy of metformin for weight loss in overweight and obese people through a systematic review and network meta- analysis and to identify the most suitable dosage and intervention period for using metformin  in adolescents and adults .
The Effects of Metformin on Body Mass Index and Glucose Tolerance in Obese Adolescents With Fasting Hyperinsulinemia and a Family History of Type 2 Diabetes
Objectives . The prevalence of type 2 diabetes in American adolescents has increased markedly during the past generation . Although the factors that contribute to the development of type 2 diabetes are complex and not wholly eluci date d , the triad of severe obesity , hyperinsulinemia , and a family history of type 2 diabetes places a child at an increased risk for development of the disease . Current approaches to the prevention of type 2 diabetes , including dietary counseling and exercise , have had limited success . We reasoned that drugs that increase glucose tolerance in diabetic patients might prove useful in preventing the progression to glucose intolerance in high-risk patients . To that end , we conducted a double-blind , placebo-controlled study of the effects of metformin  on body mass index ( BMI ) , serum leptin , glucose tolerance , and serum lipids in obese adolescents with fasting hyperinsulinemia and a family history of type 2 diabetes . Methods . The study population consisted of 29 white and black adolescents aged 12 to 19 years . All had BMI s exceeding 30 kg/m2 . Criteria for enrollment included : 1 ) a fasting insulin concentration exceeding 15 μU/mL ; and 2 ) at least 1 first- or second-degree relative with type 2 diabetes . All patients had fasting plasma glucose concentrations < 110 mg% and hemoglobin A1c concentrations ≤6.0 % . All had normal linear growth and sexual development for age , with no marked hirsutism , severe acne , or menstrual irregularities characteristic of polycystic ovary syndrome . Eight participants had acanthosis nigricans . After baseline laboratory studies including a rapidly sample d intravenous glucose tolerance test , patients were r and omized to receive metformin ( 500 mg twice daily ) or a placebo for a total of 6 months . The effects of metformin  on BMI st and ard deviation score , serum leptin , glucose tolerance , and serum lipids were analyzed . The study was double-blinded and included no specific dietary restrictions . Results . Metformin caused a decline of 0.12 st and ard deviation in BMI in study participants ( −1.3 % from baseline ) , and a 5.5 % reduction in serum leptin in girls . In contrast , BMI and serum leptin rose 0.23 st and ard deviation ( 2.3 % ) and 16.2 % , respectively , in the placebo group during the treatment period . Metformin caused a progressive decline in fasting blood glucose ( from a mean of 84.9 to 75.1 mg% ) and a reduction in fasting insulin levels ( from 31.3 to 19.3 μU/mL ) . In contrast , fasting glucose levels in the placebo group rose slightly from 77.2 to 82.3 mg% , and fasting insulin levels did not change . Insulin sensitivity , as assessed by the ratio of fasting insulin to glucose concentrations and the quantitative insulin sensitivity check index ( 1/[log fasting insulin + log fasting glucose ] ) and homeostasis model assessment insulin resistance index ( fasting insulin × fasting glucose/22.5 ) indices , increased slightly in the metformin-treated participants . However , the insulin sensitivity measured using Bergman 's minimal model did not change . There were also no significant changes in glucose effectiveness , hemoglobin A1c , serum lipids , or serum lactate in the metformin or placebo groups . Metformin was tolerated well by the majority of patients . Transient abdominal discomfort or diarrhea occurred in 40 % of treated participants ; there were no episodes of vomiting or lactic acidosis . Conclusions . The treatment of obesity and insulin resistance in adults often proves ineffective because the vicious cycle leading to type 2 diabetes may have become entrenched and , to some extent , may be irreversible . Early detection and therapy of the obese adolescent with a family history of type 2 diabetes may interrupt the cycle of weight gain and insulin resistance that leads to glucose intolerance in adulthood . Through its ability to reduce fasting blood glucose and insulin concentrations and to moderate weight gain , metformin might complement the effects of dietary and exercise counseling and reduce the risk of type 2 diabetes in selected patients
Network meta- analysis revealed that in adolescents , intervention with 2000 mg/day metformin ranked better than other interventions ; however , 1000 mg/day metformin for 3 months may be most suitable for adolescents .
For adults , metformin at doses of 3000 and 1000 mg/day ranked the highest , other than minimeal and lifestyle interventions ; moreover , intervention with 3000 mg/day for 6 months and 1000 mg/day for 0.5 months may be suitable for adults .
Conclusion When considering the efficacy of interventions for losing weight , metformin offers clear advantages for overweight and obese population
Purpose Our aim was to assess the efficacy of metformin for weight loss in overweight and obese people through a systematic review and network meta- analysis and to identify the most suitable dosage and intervention period for using metformin  in adolescents and adults .