Causal effect of body mass index and physical activity on the risk of joint sports injuries: Mendelian randomization analysis in the European population

Wen Bi; Mengyue Yang; Changqing Jiang

doi:10.1186/s13018-023-04172-y

Causal effect of body mass index and physical activity on the risk of joint sports injuries: Mendelian randomization analysis in the European population

J Orthop Surg Res. 2023 Sep 12;18(1):676. doi: 10.1186/s13018-023-04172-y.

Authors

Wen Bi¹, Mengyue Yang², Changqing Jiang³

Affiliations

¹ Department of Sports Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, Guangdong, China.
² Department of Cardiology, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, Guangdong, China.
³ Department of Sports Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, Guangdong, China. changqingjiang2023@163.com.

Abstract

Background: Observational studies can suggest potential associations between variables but cannot establish a causal effect on their own. This study explored the causal associations between body mass index (BMI), physical activity (PA), and joint sports injuries.

Methods: We conducted two-sample Mendelian randomization (MR) using publicly accessed genome-wide association studies (GWAS) datasets to investigate the causal effects of BMI and PA on joint sports injury risk. The inverse-variance weighted method was believed to be the primary MR analysis. Subsequently, sensitivity, pleiotropy, and heterogeneity analyses were employed to estimate the reliability of the results of the current research.

Results: Genetically predicted increased BMI was causally related to the higher sports injury risk of the ankle-foot (OR 1.23, 95% CI 1.09-1.37, p = 4.20E-04), knee (OR 1.32, 95% CI 1.21-1.43, p = 1.57E-11), and shoulder (OR 1.23, 95% CI 1.08-1.40, p = 1.28E-03). Further, the mentioned effects were validated using another set of GWAS data on BMI. Similar causal linkages were exhibited between increased BMI and the growing risk of sports injuries of the ankle-foot (OR 1.34, 95% CI 1.13-1.60, p = 9.51E-04), knee (OR 1.26, 95% CI 1.09-1.45, p = 1.63E-03), and shoulder (OR 1.35, 95% CI 1.09-1.67, p = 5.66E-03). Additionally, accelerometer-based PA measurement (overall average acceleration) (AccAve) was negatively related to sports injuries of the ankle-foot (OR 0.93, 95% CI 0.87-0.99, p = 0.046) and lumbar spine (OR 0.68, 95% CI 0.51-0.92, p = 0.012). Furthermore, we verified that the effect of AccAve on the risk of injury at the ankle-foot still had statistical significance after adjusting BMI. Results were verified as reliable under all sensitive analyses.

Conclusions: This research determined that a higher BMI could raise the sports injury risk of the ankle-foot, knee, and shoulder, while an overall average acceleration PA could reduce the injury risk of the ankle-foot and lumbar spine. These conclusions contribute to a greater knowledge of the roles of BMI and PA in the mechanism of joint sports injuries and offer several suggestions for patients and clinicians.

Keywords: Body mass index; Causal relationship; FinnGen; Joint sports injuries; Mendelian randomization; Physical activity; Single-nucleotide polymorphisms.

MeSH terms

Athletic Injuries* / epidemiology
Athletic Injuries* / genetics
Body Mass Index
Exercise
Genome-Wide Association Study
Humans
Mendelian Randomization Analysis
Reproducibility of Results