Changes in bone metabolism after gastric cancer surgery in male patients: a prospective observational study

BackgroundSeveral retrospective studies have shown that bone disorders occur after gastric cancer surgery. This study was designed to prospectively evaluate the changes in bone metabolism after gastrectomy for gastric cancer.MethodsWe prospectively enrolled 39 men with early gastric cancer who underwent gastrectomy. We excluded women to avoid the effects of menopause. We employed dual energy X-ray absorptiometry (DEXA) to measure bone mineral density (BMD) of the lumbar spine. DEXA was performed before and 1 and 2years after surgery. The serum levels of alkaline phosphatase (ALP), 1,25-dihydroxy vitamin D [1,25(OH)(2)VD], 25-hydroxy vitamin D [25(OH)VD], and estradiol were measured before surgery and every 3months until 2years after surgery.ResultsDEXA revealed that BMD significantly decreased by 0.0360.033g/cm(2) 12months after gastrectomy (P<0.001) and by 0.046 +/- 0.040g/cm(2) 24months after gastrectomy (P<0.001). The serum ALP level significantly increased by 38.31 +/- 103.8IU/L 24months after surgery (P=0.013). The serum 25(OH)VD level significantly decreased by 4.88 +/- 6.42ng/ml 24months after surgery (P<0.001), whereas the serum 1,25(OH)(2)VD levels were consistently in the normal range. The serum estradiol level significantly increased by 2.94 +/- 7.49pg/ml 12months after gastrectomy (P=0.035). A lower preoperative body mass index (BMI) significantly correlated with the reduction in BMD 12months after surgery; the correlation coefficient was 0.37 (P=0.025).ConclusionsThis study showed that a significant decrease in BMD was observed for up to 24months after gastrectomy, not only 12months.