Effectiveness of a lifestyle intervention on metabolic syndrome. A randomized controlled trial. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. Lifestyle intervention in overweight individuals with a family history of diabetes. Prevention of type 2 diabetes by lifestyle intervention: a Japanese trial in IGT males. Effects of diet and exercise in preventing NIDDM in people with impaired glucose tolerance. The Da Qing IGT and Diabetes Study. Randomised controlled trial evaluating lifestyle interventions in people with impaired glucose tolerance. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. The Indian Diabetes Prevention Programme shows that lifestyle modification and metformin prevent type 2 diabetes in Asian Indian subjects with impaired glucose tolerance (IDPP-1).
Intensive lifestyle intervention significantly reduces the progression to diabetes in high-risk individuals.
                It is not known whether a program of moderate intervention might effectively reduce metabolic abnormalities in the general population.
                Two-arm randomized controlled 1-year trial.
                Three hundred and thirty-five patients participated from a dysmetabolic population-based cohort of 375 adults aged 45-64 years in northwestern Italy.
                We compared the effectiveness of a general recommendation-based program of lifestyle intervention carried out by trained professionals versus standard unstructured information given by family physicians at reducing the prevalence of multiple metabolic and inflammatory abnormalities.
                At baseline, clinical/anthropometric/laboratory and lifestyle characteristics of the intervention (n = 169) and control (n = 166) groups were not significantly different. The former significantly reduced total/saturated fat intake and increased polyunsaturated fat/fiber intake and exercise level compared to the controls. Weight, waist circumference, high-sensitivity C-reactive protein, and most of the metabolic syndrome components decreased in the intervention group and increased in the controls after 12 months. Lifestyle intervention significantly reduced metabolic syndrome (odds ratio [OR] = 0.28; 95% CI 0.18-0.44), with a 31% (21-41) absolute risk reduction, corresponding to 3.2 (2-5) patients needing to be treated to prevent 1 case after 12 months. The intervention significantly reduced the prevalence of central obesity (OR = 0.33; 0.20-0.56), and hypertriglyceridemia (OR = 0.48; 0.31-0.75) and the incidence of diabetes (OR = 0.23; 0.06-0.85).
                A lifestyle intervention based on general recommendations was effective in reducing multiple metabolic/inflammatory abnormalities. The usual care by family physicians was ineffective at modifying progressive metabolic deterioration in high-risk individuals. Type 2 diabetes affects approximately 8 percent of adults in the United States. Some risk factors--elevated plasma glucose concentrations in the fasting state and after an oral glucose load, overweight, and a sedentary lifestyle--are potentially reversible. We hypothesized that modifying these factors with a lifestyle-intervention program or the administration of metformin would prevent or delay the development of diabetes.
                We randomly assigned 3234 nondiabetic persons with elevated fasting and post-load plasma glucose concentrations to placebo, metformin (850 mg twice daily), or a lifestyle-modification program with the goals of at least a 7 percent weight loss and at least 150 minutes of physical activity per week. The mean age of the participants was 51 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 34.0; 68 percent were women, and 45 percent were members of minority groups.
                The average follow-up was 2.8 years. The incidence of diabetes was 11.0, 7.8, and 4.8 cases per 100 person-years in the placebo, metformin, and lifestyle groups, respectively. The lifestyle intervention reduced the incidence by 58 percent (95 percent confidence interval, 48 to 66 percent) and metformin by 31 percent (95 percent confidence interval, 17 to 43 percent), as compared with placebo; the lifestyle intervention was significantly more effective than metformin. To prevent one case of diabetes during a period of three years, 6.9 persons would have to participate in the lifestyle-intervention program, and 13.9 would have to receive metformin.
                Lifestyle changes and treatment with metformin both reduced the incidence of diabetes in persons at high risk. The lifestyle intervention was more effective than metformin. To assess the effect of lifestyle intervention over 2 years on changes in weight, coronary heart disease (CHD) risk factors, and incidence of diabetes in overweight individuals with a parental history of diabetes.
                Participants (n = 154), who were 30-100% over ideal body weight, had one or both parents with diabetes, and were currently nondiabetic, were randomly assigned to 2-year treatments focused on diet (decreasing calories and fat intake), exercise (goal of 1,500 kcal/week of moderate activity), or the combination of diet plus exercise or to a no-treatment control group. Subjects were reassessed at 6 months, 1 year, and 2 years.
                At 6 months, the groups differed significantly on measures of eating, exercise, and fitness; weight losses in the diet and diet-plus-exercise groups were significantly greater than in the exercise and control conditions. Weight losses were associated with positive changes in CHD risk factors. After 6 months, there was gradual deterioration of behavioral and physiological changes, so that at 2 years, almost no between-group differences were maintained. Differences between groups in risk of developing diabetes were of borderline significance (P = 0.08). Strongest predictors were impaired glucose tolerance at baseline, which was positively related to risk of developing diabetes, and weight loss from baseline to 2 years, which was negatively related; in all treatment groups, a modest weight loss of 4.5 kg reduced the risk of type 2 diabetes by approximately 30% compared with no weight loss.
                Although initially successful, the interventions studied here were not effective in producing long-term changes in behavior, weight, or physiological parameters. However, weight loss from 0 to 2 years reduced the risk of developing type 2 diabetes. Since modest weight loss significantly reduced risk of type 2 diabetes, further research is needed to determine how best to increase the percentage of subjects achieving at least a modest weight loss. Prevention of type 2 diabetes by intensive lifestyle intervention designed to achieve and maintain ideal body weight was assessed in subjects with impaired glucose tolerance (IGT). Male subjects with IGT recruited from health-screening examinees were randomly assigned in a 4:1 ratio to a standard intervention group (control group) and intensive intervention group (intervention group). The final numbers of subjects were 356 and 102, respectively. The subjects in the control group and in the intervention group were advised to maintain body mass index (BMI) of <24.0 kg/m2 and of <22.0 kg/m2, respectively, by diet and exercise. In the intervention group, detailed instructions on lifestyle were repeated every 3-4 months during hospital visits. Diabetes was judged to have developed when two or more consecutive fasting plasma glucose (FPG) values exceeded 140 mg/dl. A 100g oral glucose tolerance test was performed every 6 months to detect improvement of glucose tolerance. The subjects were seen in an ordinary outpatient clinic. The cumulative 4-year incidence of diabetes was 9.3% in the control group, versus 3.0% in the intervention group, and the reduction in risk of diabetes was 67.4% (P < 0.001). Body weight decreased by 0.39 kg in the control group and by 2.18 kg in the intervention group (P < 0.001). The control group was subclassified according to increase and decrease in body weight. The incidence of diabetes was positively correlated with the changes in body weight, and the improvement in glucose tolerance was negatively correlated. Subjects with higher FPG at baseline developed diabetes at a higher rate than those with lower FPG. Higher 2h plasma glucose values and higher BMI values at baseline were also associated with a higher incidence of diabetes, but the differences were not significant. Subjects with a low insulinogenic index (DeltaIRI/DeltaPG 30 min after an oral glucose load) developed diabetes at a significantly higher rate than those with a normal insulinogenic index. Comparison of the BMI data and incidence of diabetes in five diabetes prevention studies by lifestyle intervention revealed a linear correlation between the incidence of diabetes and the BMI values, with the exception of the DaQing Study. However, the slope of the reduction in incidence of diabetes in the intensive intervention groups was steeper than expected simply on the basis of the reduction of BMI, suggesting that the effect of lifestyle intervention cannot be solely ascribed to the body weight reduction. We conclude that lifestyle intervention aimed at achieving ideal body weight in men with IGT is effective and can be conducted in an outpatient clinic setting. Individuals with impaired glucose tolerance (IGT) have a high risk of developing NIDDM. The purpose of this study was to determine whether diet and exercise interventions in those with IGT may delay the development of NIDDM, i.e., reduce the incidence of NIDDM, and thereby reduce the overall incidence of diabetic complications, such as cardiovascular, renal, and retinal disease, and the excess mortality attributable to these complications.
                In 1986, 110,660 men and women from 33 health care clinics in the city of Da Qing, China, were screened for IGT and NIDDM. Of these individuals, 577 were classified (using World Health Organization criteria) as having IGT. Subjects were randomized by clinic into a clinical trial, either to a control group or to one of three active treatment groups: diet only, exercise only, or diet plus exercise. Follow-up evaluation examinations were conducted at 2-year intervals over a 6-year period to identify subjects who developed NIDDM. Cox's proportional hazard analysis was used to determine if the incidence of NIDDM varied by treatment assignment.
                The cumulative incidence of diabetes at 6 years was 67.7% (95% CI, 59.8-75.2) in the control group compared with 43.8% (95% CI, 35.5-52.3) in the diet group, 41.1% (95% CI, 33.4-49.4) in the exercise group, and 46.0% (95% CI, 37.3-54.7) in the diet-plus-exercise group (P < 0.05). When analyzed by clinic, each of the active intervention groups differed significantly from the control clinics (P < 0.05). The relative decrease in rate of development of diabetes in the active treatment groups was similar when subjects were stratified as lean or overweight (BMI < or > or = 25 kg/m2). In a proportional hazards analysis adjusted for differences in baseline BMI and fasting glucose, the diet, exercise, and diet-plus-exercise interventions were associated with 31% (P < 0.03), 46% (P < 0.0005), and 42% (P < 0.005) reductions in risk of developing diabetes, respectively.
                Diet and/or exercise interventions led to a significant decrease in the incidence of diabetes over a 6-year period among those with IGT. To evaluate the effectiveness of lifestyle interventions in people with impaired glucose tolerance (IGT).
                Participants with IGT (n=78), diagnosed on two consecutive oral glucose tolerance tests (OGTTs), were randomly assigned to a 2-year lifestyle intervention or to a control group. Main outcome measures were changes from baseline in: nutrient intake; physical activity; anthropometry, glucose tolerance and insulin sensitivity. Measurements were repeated at 6, 12 and 24 months follow-up.
                After 24 months follow-up, there was a significant fall in total fat consumption (difference in change between groups (Delta intervention-Delta control)= -17.9, 95% confidence interval (CI) -33.6 to -2.1g/day) as a result of the intervention. Body mass was significantly lower in the intervention group compared with controls after 6 months (-1.6, 95% CI -2.9 to -0.4 kg) and 24 months (-3.3, 95% CI -5.7 to -0.89 kg). Whole body insulin sensitivity, assessed by the short insulin tolerance test (ITT), improved after 12 months in the intervention group (0.52, 95% CI 0.15-0.89%/min).
                These findings complement the findings of the Finnish Diabetes Prevention Study and the American Diabetes Prevention Study, both of which tested intensive interventions, by showing that pragmatic lifestyle interventions result in improvements in obesity and whole body insulin sensitivity in individuals with IGT, without change in other cardiovascular risk factors. Type 2 diabetes mellitus is increasingly common, primarily because of increases in the prevalence of a sedentary lifestyle and obesity. Whether type 2 diabetes can be prevented by interventions that affect the lifestyles of subjects at high risk for the disease is not known.
                We randomly assigned 522 middle-aged, overweight subjects (172 men and 350 women; mean age, 55 years; mean body-mass index [weight in kilograms divided by the square of the height in meters], 31) with impaired glucose tolerance to either the intervention group or the control group. Each subject in the intervention group received individualized counseling aimed at reducing weight, total intake of fat, and intake of saturated fat and increasing intake of fiber and physical activity. An oral glucose-tolerance test was performed annually; the diagnosis of diabetes was confirmed by a second test. The mean duration of follow-up was 3.2 years.
                The mean (+/-SD) amount of weight lost between base line and the end of year 1 was 4.2+/-5.1 kg in the intervention group and 0.8+/-3.7 kg in the control group; the net loss by the end of year 2 was 3.5+/-5.5 kg in the intervention group and 0.8+/-4.4 kg in the control group (P<0.001 for both comparisons between the groups). The cumulative incidence of diabetes after four years was 11 percent (95 percent confidence interval, 6 to 15 percent) in the intervention group and 23 percent (95 percent confidence interval, 17 to 29 percent) in the control group. During the trial, the risk of diabetes was reduced by 58 percent (P<0.001) in the intervention group. The reduction in the incidence of diabetes was directly associated with changes in lifestyle.
                Type 2 diabetes can be prevented by changes in the lifestyles of high-risk subjects. Lifestyle modification helps in the primary prevention of diabetes in multiethnic American, Finnish and Chinese populations. In a prospective community-based study, we tested whether the progression to diabetes could be influenced by interventions in native Asian Indians with IGT who were younger, leaner and more insulin resistant than the above populations.
                We randomised 531 (421 men 110 women) subjects with IGT (mean age 45.9+/-5.7 years, BMI 25.8+/-3.5 kg/m(2)) into four groups. Group 1 was the control, Group 2 was given advice on lifestyle modification (LSM), Group 3 was treated with metformin (MET) and Group 4 was given LSM plus MET. The primary outcome measure was type 2 diabetes as diagnosed using World Health Organization criteria.
                The median follow-up period was 30 months, and the 3-year cumulative incidences of diabetes were 55.0%, 39.3%, 40.5% and 39.5% in Groups 1-4, respectively. The relative risk reduction was 28.5% with LSM (95% CI 20.5-37.3, p=0.018), 26.4% with MET (95% CI 19.1-35.1, p=0.029) and 28.2% with LSM + MET (95% CI 20.3-37.0, p=0.022), as compared with the control group. The number needed to treat to prevent one incident case of diabetes was 6.4 for LSM, 6.9 for MET and 6.5 for LSM + MET.
                Progression of IGT to diabetes is high in native Asian Indians. Both LSM and MET significantly reduced the incidence of diabetes in Asian Indians with IGT; there was no added benefit from combining them.