Muscle Strength Changes After Bariatric Surgery: Associations with Sex and Hemoglobin

This study aimed to evaluate changes in muscle strength after bariatric surgery and identify factors associated with these changes. This retrospective cohort study included patients who underwent bariatric surgery between January 2013 and December 2019 and had complete baseline and 12-month clinical, biochemical, and handgrip strength assessments. Muscle strength was measured by handgrip dynamometry. Correlation and multivariable linear regression analyses were performed. A total of 147 patients were included. Significant reductions were observed in body weight, body mass index, blood pressure, glycemic parameters, liver enzymes, and triglyceride levels at 12 months (all p<0.05). Overall muscle strength decreased modestly but significantly. Sex-stratified analysis showed a significant decrease in females but an increase in males. In multivariable analysis, hemoglobin change remained independently associated with muscle strength change, whereas surgical technique and weight loss were not. Bariatric surgery improves metabolic health but is accompanied by sex-specific changes in muscle strength, and the independent association with hemoglobin change supports postoperative functional and hematological assessment.