Table 3.
Characteristics of studies on pharmacological and lifestyle interventions included in review
| Trial | Population | Interventions | Definitions of impaired glucose tolerance and type 2 diabetes |
|---|---|---|---|
| Diabetes prevention programme (DPP), USA (2002)w1 w23 | n=3234 with impaired glucose tolerance, aged ≥25. Minimum BMI 24 (22 in Asians), 32.3% men, 54.7% white | Four interventions: standard lifestyle recommendations plus placebo, standard lifestyle recommendations plus metformin (850 mg twice daily), standard lifestyle recommendations plus troglitazone (400 mg daily) and an intensive programme of lifestyle modification. Troglitazone arm discontinued early because of safety reasons | ADA 1997 criteria. |
| Fang, China (2004)w19 | n=178 with impaired glucose tolerance, 55% men | Four interventions: standard prevention education, education and monitoring of diet and exercise, acarbose 25-50 mg 3 times/day, or flumamine 125-250 mg 3 times/day | WHO 1985 criteria |
| Indian diabetes prevention programme (IDDP), India (2006)w39 | n=531 native Asian Indians with impaired glucose tolerance, aged 35-55, 21% women | Four interventions: standard lifestyle advice, lifestyle modification, metformin (500 mg twice daily, dropping to 250 mg twice daily after median of 40 days), combination of lifestyle modification and metformin | WHO 1999 criteria |
| Jarrett, UK (1979)w2 | n=204 men with impaired glucose tolerance | Factorial trial: 50 mg phenformin daily or placebo and recommendation to limit carbohydrate intake to 120 g/day or just to limit sucrose (table sugar) | Survey blood glucose 6.1-11.0 mmol/l and OGTT peak blood glucose ≥10 mmol/l and 2 hr blood glucose 6.7-11.0 mmol/l; or 2 values >10 mmol/l; or peak blood glucose ≥10.0 and mean 2 hr glucose ≥6.7. Two successive 2 hour post glucose blood glucose concentrations >11.1; 3 non-successive 2 hr tests >11.1; development of symptoms and raised glucose |
| Keen, UK (1982)w36 | n=241 with impaired glucose tolerance | Factorial trial: tolbutamide (0.5 g twice daily) or placebo and either dietary teaching to restrict carbohydrate intake to 120 g/day or advice to restrict table sugar | Blood glucose 6.7-11.1 mmol/l 2 hours after oral glucose load of 50 g. Two hour post load glucose >11.1 mmol/l |
BMI=body mass index; OGTT=oral glucose tolerance test.