OBJECTIVEThe association between habitual physical activity (PA) and lowered risk of all-cause mortality (ACM) and cardiovascular disease (CVD) has been suggested in patients with diabetes. This meta-analysis summarizes the risk reduction in relation to PA, focusing on clarifying dose-response associations.RESEARCH DESIGN AND METHODSElectronic literature searches were conducted for cohort studies that examined relative risk (RR) of ACM or CVD in relation to PA in patients with diabetes. For the qualitative assessment, RR for the highest versus the lowest PA category in each study was pooled with a random-effects model. We added linear and spline regression analyses to assess the quantitative relationship between increases in PA and ACM and CVD risk.RESULTSThere were 17 eligible studies. Qualitatively, the highest PA category had a lower RR [95% CI] for ACM (0.61 [0.52–0.70]) and CVD (0.71 [0.60–0.84]) than the lowest PA category. The linear regression model indicated a high goodness of fit for the risk of ACM (adjusted R2 = 0.44, P = 0.001) and CVD (adjusted R2 = 0.51, P = 0.001), with the result that a 1 MET-h/day incrementally higher PA was associated with 9.5% (5.0–13.8%) and 7.9% (4.3–11.4%) reductions in ACM and CVD risk, respectively. The spline regression model was not significantly different from the linear model in goodness of fit (P = 0.14 for ACM risk; P = 0.60 for CVD risk).CONCLUSIONSMore PA was associated with a larger reduction in future ACM and CVD risk in patients with diabetes. Nevertheless, any amount of habitual PA was better than inactivity.

In terms of glycemic control, RT could be recommended in the early stage of T2DM, especially for patients with relatively poor glycemic control. More benefit would be elicited in less obese patients within a limited range of the BMI. A substantial amount of exercise might be required to stimulate post-exercise glucose uptake, although the dose-dependency was not specifically clarified.

This meta-analysis quantified the risk of type 2 diabetes mellitus (T2DM) preceded by body weight (BW) gain in the general population. Systematic literature searches retrieved 15 eligible studies. The BW gain was divided into early weight-gain, which was defined as BW gain from early adulthood (18-24 years of age) to cohort entry (≥25 years of age), and late weight-gain, which was defined as BW gain from cohort entry. The pooled relative risk (RR; 95% confidence interval [CI]) of T2DM for an increment of BW gain standardized into a 5-kg m(-2) increment in the body mass index (BMI) was 3.07 (2.49-2.79) for early weight-gain and 2.12 (1.74-2.58) for late weight-gain. When limiting analysis to studies that concurrently examined T2DM risk for current BMI (defined in both groups as BMI at cohort entry), a larger magnitude of T2DM risk was revealed for early weight-gain compared with current BMI (RR [95% CI], 3.38 [2.20-5.18] vs. 2.39 [1.58-3.62]), while there was little difference between late weight-gain (RR [95% CI], 2.21 [1.91-2.56]) and current BMI (RR [95% CI], 2.47 [1.97-3.30]). The meta-analysis suggested that BW gain was a quantifiable predictor of T2DM, as well as current obesity in adults. Particularly, BW gain in early rather than middle-to-late adulthood played an important role in developing T2DM.