The study of the relationship between physical activity and gestational diabetes mellitus in the second trimester of pregnancy: a dose-response analysis with the restricted cubic spline model

Previous studies have shown that higher levels of physical activity (PA) are generally associated with a lower risk of developing gestational diabetes mellitus (GDM). however, evidence regarding the dose-response relationship remains limited. This study aims to investigate the dose-response relationship between PA and GDM during the second trimester of pregnancy. A hospital-based cross-sectional study was conducted at Beijing Changping Hospital of Integrated Chinese and Western Medicine from August 2018 to October 2019. A total of 476 pregnant women, between 14 and 22 weeks of gestation, were enrolled in the study. Participants were categorized into a GDM group (n = 84) and a non-GDM group (n = 392) based on the results of a 75-g oral glucose tolerance test (OGTT) performed at 24–28 weeks of pregnancy. General information, PA, and dietary data were collected through validated questionnaires. PA levels and daily dietary energy intake (DDEI) were calculated using standard methods. Statistical analyses were performed using SAS 9.4 and R 4.2.1 software. The dose-response analysis was conducted, and optimal cut-off values of PA for the prevention of GDM were determined using the restricted cubic spline (RCS) model. Additionally, univariate and multivariate logistic regression analyses were employed to validate the identified cut-off values. (1) Compared to the non-GDM group, levels of total PA, moderate-to-vigorous intensity physical activity (MVPA), and walking PA were significantly lower (p < 0.05). (2) Non-linear dose-response relationships were identified between total PA, MVPA, and walking PA and the risk of GDM (p < 0.001), with optimal cut-off values established at 1714 MET-min/w, 638 MET-min/w, and 1098 MET-min/w, respectively. (3) Logistic regression analysis indicated that the risk of GDM significantly decreased as PA levels surpassed the established cut-off values (p < 0.001). A non-linear dose-response relationship exists between PA and GDM during the second trimester of pregnancy. The risk of GDM diminishes as PA levels increase, suggesting that effective prevention of GDM may require achieving adequate levels of PA.