Table 1 Study Characteristics
Study | Methods | Participants | Country | Numbers | Intervention | |
|---|---|---|---|---|---|---|
1. | Armen 2008 | Parallel group RCT Duration 12 weeks | Age < 20 years On risperidone 2–6 mg | Saudi Arabia | Metformin N = 16 Placebo N = 16 | Metformin 500 mg twice daily or placebo |
2. | Baptista 2006 | Parallel group RCT Duration 14 weeks | Age ≥18 years Olanzapine monotherapy > 4 months | Venezuela | Metformin N = 19 Placebo N = 18 | Metformin 850–1750 mg Balanced diet of 2500-300Kcal |
3. | Baptista 2007 | Parallel group RCT Duration 12 weeks | Age ≥18 years Olanzapine monotherapy > 4 months | Venezuela | Metformin N = 36 Placebo N = 36 | Metformin 850–2550 mg or placebo Diet and exercise counseling at start of study |
4. | Carrizo 2009 | Parallel group RCT Duration 14 weeks | clozapine treatment > 3 months | Venezuela | Metformin N = 31 Placebo N = 30 | Extended release metformin 500–1000 mg/day or placebo |
5. | Chen | Parallel group RCT Duration 24 weeks | clozapine treatment > 3 months BMI ≥24 or one metabolic syndrome criteria | Taiwan | Metformin N = 28 Placebo N = 27 | Metformin 1500 mg/day |
6. | De Silva 2015 | Parallel group RCT Duration 24 weeks | Age ≥18 years Weight gain > 10 % of body weight Females 78.8 % | Sri Lanka | Metformin N = 34 Placebo N = 32 | Metformin or placebo 500 mg twice daily Diet and exercise counseling given at start of study |
7. | Jarskog 2013 | Parallel group RCT Duration 16 weeks | Age 18–65 years BMI ≥27 Duration of illness ≥ 1 year Females 30.8 % | United States | Metformin N = 75 Placebo N = 71 | Metformin 500 mg twice daily increased upto maximum of 2000 mg/day or placebo Weekly diet and exercise counseling |
8. | Klein | Parallel group RCT Duration 16 weeks | Age 10–17 years Gained > 10 % body weight | United States | Metformin N = 34 Placebo N = 32 | Metformin 850 mg twice daily or placebo nutritional counseling |
9. | Wang 2012 | Parallel group RCT Duration 12 weeks | Age 18–60 years Gained > 7 % of body weight | China | Metformin N = 32 Placebo N = 34 | Metformin 500 mg twice daily or placebo |
10. | Wu 2012 | Parallel group RCT Duration 24 weeks | Age 18–40 years First episode Female patients only | China | Metformin N = 42 Placebo N = 42 | Metformin 1000 mg/day or placebo |
11. | Wu 2008a JAMA | Parallel group RCT Duration 12 weeks | Age 18–45 years First episode patient who gained > 10 % of bodyweight | China | Metformin N = 32 Placebo N = 32 | Metformin 750 mg or placebo (also metformin + lifestyle and lifestyle + placebo groups) |
12. | Wu 2008b AM J | Parallel group RCT Duration 12 weeks | Age 18–50 years First episode patients on olanzapine | China | Metformin N = 18 Placebo N = 19 | Metformin 250 mg thrice daily or placebo No special diet or exercise program |