To evaluate the effect of lifestyle modifications on metabolic syndrome (MetS) as assessed by its resolution and improved values for its components.

OBJECTIVE—To evaluate the efficacy of lifestyle education for preventing type 2 diabetes in individuals at high risk by meta-analysis of randomized controlled trials, as assessed by incidence and a reduced level of plasma glucose 2 h after a 75-g oral glucose load (2-h plasma glucose). RESEARCH DESIGN AND METHODS—Through an electronic search, 123 studies were identified. A literature search identified eight studies that met strict inclusion criterion of meta-analysis for 2-h plasma glucose and five studies for the incidence of diabetes. All were randomized controlled trials of ≥6 months with lifestyle education that included a dietary intervention. Subjects were adults diagnosed as being at high risk for type 2 diabetes. The difference in mean reduction of 2-h plasma glucose from baseline to the 1-year follow-up and relative risk (RR) of the incidence of diabetes in the lifestyle education group versus the control group were assessed. Overall estimates were calculated using a random-effects model. Those estimates were confirmed by several models, and the possibility of selection bias was examined using a funnel plot. RESULTS—Lifestyle education intervention reduced 2-h plasma glucose by 0.84 mmol/l (95% CI 0.39–1.29) compared with the control group. The 1-year incidence of diabetes was reduced by ∼50% (RR 0.55, 95% CI 0.44–0.69) compared with the control group. Results were stable and little changed if data were analyzed by subgroups or other statistical models. Funnel plots revealed no selection bias. CONCLUSIONS—Lifestyle education was effective for reducing both 2-h plasma glucose and RR in high-risk individuals and may be a useful tool in preventing diabetes.

OBJECTIVE—The aim of this study was to assess the effectiveness of a new dietary education (NDE) program in reducing plasma glucose (PG) levels in Japanese male workers at high risk for type 2 diabetes through a randomized controlled trial. RESEARCH DESIGN AND METHODS—We randomly assigned 173 high-risk men (mean age, 55 years) to either the NDE or the control (conventional dietary education) group. Each subject in the NDE group received two individualized interventions especially aimed at reducing total energy intake at dinner by modifying dietary intake. The control group received conventional group counseling. An “overintake/underintake fraction” for total energy intake was used to measure the status of dietary intake. Our hypothesis was that the NDE group would have a 10% decrease in 2-h PG 1 year after the start of the education. Outcome measures were compared with ANCOVA by adjusting for baseline values. RESULTS—The NDE group had a significantly lower total energy intake at dinner and daily than the control group. The adjusted differences in changes from baseline in the absolute value of the “overintake/underintake fraction” were −15.3% (95% CI −24.6 to −6.0%, P = 0.002) for the NDE group and −6.0% (−9.8 to −2.2%, P = 0.002) for the control group. The NDE group had a decreased 2-h PG after 1 year, whereas that value was increased in the control group. The adjusted difference in the percent change of 2-h PG was significant (−15.2%, −22.0 to −8.4%, P < 0.001). CONCLUSIONS—The NDE was shown to reduce glucose levels in high-risk subjects for type 2 diabetes.

Background: The prevalence of type 2 diabetes is rising worldwide, as has been the global mean fasting plasma glucose level. This study aimed to evaluate the effectiveness of a structured individual-based lifestyle education (SILE) program to reduce the hemoglobin A1c (HbA_1c) level in type 2 diabetes patients delivered by registered dietitians in primary care clinical settings. Methods: This was a 6-month prospective cluster randomized controlled trial in a primary care setting with randomization at the practice level. Twenty general practitioners in 20 clinics in Kanagawa prefecture, Japan, were involved. 193 adults (51% men, mean age 61.3 years) with type 2 diabetes and HbA_1c ≥6.5% who received treatment in medical clinics were the participants. A SILE program was implemented through 4 sessions with trained registered dietitians during the 6-month study period. Results were compared with those of a control group who received usual care. The primary endpoint was the change in HbA_1c levels at 6 months from baseline. Secondary endpoints were the changes at 6 months from baseline in fasting plasma glucose, lipid profile, blood pressure, BMI, energy, and nutrient intakes (whole day and each meal). Intention-to-treat analysis was conducted. Mixed-effects linear models were used to examine the effects of the treatment. Results: The mean change at 6 months from baseline in HbA_1c was a 0.7% decrease in the intervention group (n = 100) and a 0.2% decrease in the control group (n = 93) (difference −0.5%, 95%CI: -0.2% to −0.8%, p = 0.004). After adjusting for baseline values and other factors, the difference was still significant (p = 0.003 ~ 0.011). The intervention group had a significantly greater decrease in mean energy intake at dinner compared with the control group and a greater increase in mean vegetable intake for the whole day, breakfast, and lunch as shown in crude and adjusted models. A tendency toward improvement was observed in the other secondary endpoints but the improvement was not statistically significant. These results were confirmed by several sensitivity analyses. Conclusions: The SILE program that was provided in primary care settings for patients with type 2 diabetes resulted in greater improvement in HbA_1c levels than usual diabetes care and education. Trial registration: http://UMIN000004049