Relationship between physical activity and bone mineral density loss after gastrectomy in gastric cancer patients

The prevention of osteoporosis is a particularly relevant issue for gastric cancer survivors. We investigated the relationship between postoperative physical activity and the change of bone mineral density (BMD) in patients with gastric cancer.Patients who underwent radical gastrectomy for gastric cancer were enrolled in this single-center prospective cohort study. Physical activity was evaluated using the International Physical Activity Questionnaire Short Form at postoperative month (POM) 6 and patients were classified into high, middle, and low physical activity groups accordingly. The primary outcome was the change in BMD from baseline at POM 12, which was expressed as a percentage of the young adult mean (YAM). The YAM of the lumbar spine and femoral neck was measured by dual-energy X-ray absorptiometry.One hundred ten patients were enrolled in this study. The physical activity level at POM 6 was classified as high (n = 50; 45%), middle (n = 25; 23%), and low (n = 35; 32%). The mean decrease of YAM% was 5.1% in the lumbar spine and 4.2% in the femoral neck at POM 12. A multivariable-adjusted logistic regression model revealed that low physical activity at POM 6 was a significant risk factor for BMD loss at POM 12 (odds ratio, 3.76; 95% confidence interval, 1.48-9.55; p = 0.005).Low physical activity after gastrectomy is an independent risk factor for decreased BMD at POM 12. The introduction of exercise may prevent osteoporosis after the surgical treatment of gastric cancer.