Physical activity and the risk of gestational diabetes mellitus: a systematic review and dose–response meta-analysis of epidemiological studies

Abstract

Physical activity has been inconsistently associated with risk of gestational diabetes mellitus in epidemiological studies, and questions remain about the strength and shape of the dose–response relationship between the two. We therefore conducted a systematic review and meta-analysis of cohort studies and randomized trials on physical activity and gestational diabetes mellitus. PubMed, Embase and Ovid databases were searched for cohort studies, and randomized controlled trials of physical activity and risk of gestational diabetes mellitus, up to August 5th 2015. Summary relative risks (RRs) were estimated using a random effects model. Twenty-five studies (26 publications) were included. For total physical activity the summary RR for high versus low activity was 0.62 (95 % CI 0.41–0.94, I2 = 0 %, n = 4) before pregnancy, and 0.66 (95 % CI 0.36–1.21, I2 = 0 %, n = 3) during pregnancy. For leisure-time physical activity the respective summary RRs for high versus low activity was 0.78 (95 % CI 0.61–1.00, I2 = 47 %, n = 8) before pregnancy, and it was 0.80 (95 % CI 0.64–1.00, I2 = 17 %, n = 17) during pregnancy. The summary RR for pre-pregnancy activity was 0.70 (95 % CI 0.49–1.01, I2 = 72.6 %, n = 3) per increment of 5 h/week and for activity during pregnancy was 0.98 (95 % CI 0.87–1.09, I2 = 0 %, n = 3) per 5 h/week. There was evidence of a nonlinear association between physical activity before pregnancy and the risk of gestational diabetes mellitus, pnonlinearity = 0.005, with a slightly steeper association at lower levels of activity although further reductions in risk were observed up to 10 h/week. There was also evidence of nonlinearity for physical activity in early pregnancy, pnonlinearity = 0.008, with no further reduction in risk above 8 h/week. There was some indication of inverse associations between walking (before and during pregnancy) and vigorous activity (before pregnancy) and the risk of gestational diabetes mellitus. This meta-analysis suggests that there is a significant inverse association between physical activity before pregnancy and in early pregnancy and the risk of gestational diabetes mellitus. Further studies are needed to clarify the association between specific types and intensities of activity and gestational diabetes mellitus.Electronic supplementary materialThe online version of this article (doi:10.1007/s10654-016-0176-0) contains supplementary material, which is available to authorized users.

Associations between maternal physical activity in early and late pregnancy and offspring birth size: remote federated individual level meta‐analysis from eight cohort studies

“…To explore which covariate contributed most to heterogeneity, we conducted further analyses by including each potential confounding variable one at a time. Physical activity is likely to exert its effect on birth size by altering maternal metabolic pathways such as glucose metabolism, and there is evidence of its association with GDM . Therefore, GDM was added in a subsequent model to explore its possible mediating effect.…”

Accelerometer assessed moderate-to-vigorous physical activity and successful ageing: results from the Whitehall II study

“…Similar findings, albeit with questionnaire-assessed physical activity and a range of health outcomes, have been reported404142. A recent meta-analysis concluded that although more total physical activity was associated with lower risk for breast and colon cancer, diabetes, ischemic heart disease, and ischemic stroke, major gains were observed at lower levels of activity, with diminishing returns at higher levels of activity42.…”

Physical activity and the risk of preterm birth: a systematic review and meta‐analysis of epidemiological studies

“…Another limitation was that few of the studies reported results in such a way that they could be included in dose–response analyses (for example in three‐four or more categories by hours or MET‐hours per month or week), and therefore the dose–response analyses may not have been representative for all the studies. This problem has also been observed in our previous meta‐analyses of physical activity and preeclampsia, gestational diabetes and type 2 diabetes, and point to a need for more standardized reporting of physical activity data in epidemiological studies. Based on the nonlinear dose–response analysis, the data suggest that 2–4 hours per week of physical activity will be needed to reduce the risk of preterm birth by 15–16%, although for other pregnancy complications further benefits are observed for higher levels of activity …”

“…We conducted dose–response analyses and found evidence of a dose–response relationship up to 2–4 hours per week, but no further reductions in risk with higher levels of activity; however, because of few data points at higher levels of physical activity further studies are needed to clarify the dose–response relationship at higher levels of activity. In contrast, we have previously reported further benefits of higher levels of physical activity (up to 5–7 hours per week) in relation to preeclampsia, gestational diabetes and type 2 diabetes, and any recommendations regarding physical activity need to take into consideration overall health, not just the risk of preterm birth.…”