10 Background: Several reports have showed that bone disorders occur after gastric cancer surgery, however there are few studies that compared pre- and postoperative bone mineral density of the same patient. The purpose of this study was to assess changes in bone metabolism after gastric cancer surgery prospectively. Methods: We prospectively enrolled 39 men undergoing gastrectomy for early gastric cancer. We excluded women to avoid the effect of menopause. Patients with severe kidney disease requiring dialysis treatment, patients with severe liver disease and patients with treatment with bisphosphonates or any other bone-active drugs were also excluded. Dual energy X-ray absorptiometry (DEXA) was performed before and 1 and 2 years after surgery to evaluate bone mineral density (BMD). The serum levels of 1,25-dihydroxy vitamin D (1,25(OH)2VD), 25-hydroxy vitamin D (25(OH)VD), estradiol, and alkaline phosphatase (ALP) were measured before surgery and every three months until two years after surgery. Results: DEXA revealed that BMD was significantly decreased by 0.036±0.033 g/cm2 at 12 months after gastrectomy (P < 0.001). The serum ALP was significantly increased by 38.88±6.42 IU/l at 24 months after surgery (P = 0.013), and there was a marginally significant correlation between the changes in BMD and the changes in the serum ALP at 24 months after surgery; the correlation coefficient was -0.30 (P = 0.090). The serum 25(OH)VD was significantly decreased by 4.88±6.42 ng/ml at 24 months after surgery (P < 0.001), however there was no significant correlation between the changes in BMD and the changes in the serum 25(OH)VD. The serum 1,25(OH)2VD and estradiol were not significantly changed before and after surgery. The factor significantly correlated to the reductions of BMD at 12 months after surgery included preoperative lower body mass index (BMI); the correlation coefficients was 0.37 (P = 0.025). Conclusions: This study showed a significant reduction in the BMD of gastric cancer patients at 12 months after gastrectomy and suggested that low preoperative BMI could be a high risk factor for the bone disorder after gastric cancer surgery.
The change of bone mineral density and bone metabolism after gastrectomy for gastric cancer: A meta-analysis