Incidence and risk factors of osteoporotic status in outpatients who underwent gastrectomy for gastric cancer.

Background And Aim: Disorders in bone metabolism have long been recognized as typical sequelae of gastrectomy; however, the pathogenesis has not been fully elucidated, resulting in a variation of reported incidence. This study aimed to evaluate current bone health by measuring bone mineral density (BMD) in patients treated by gastrectomy for gastric cancer, with a focus on incidence and risk factors of osteoporosis.

Methods: The study enrolled 81 patients who underwent gastrectomy for gastric cancer at Kochi Medical School. BMD of the lumbar spine was measured by dual-energy X-ray mineral absorptiometry, with the results expressed as a percentage of the young adult mean (YAM). Clinical data were also obtained to investigate associations with BMD.

Results: Of the 81 study patients, 12 (14.8%) were deemed to have osteoporosis, defined by a percentage of YAM <70, with a dominance of females over males (66.7% 17.4%;  < 0.001). The median body weight, hemoglobin concentration, and serum alkaline phosphatase (ALP) level of the patients with osteoporosis was significantly lower than in those with a percentage of YAM ≥70 group (39.6 kg 53.1 kg,  < 0.001; 10.9 mg/dL 12.5 mg/dL, = 0.010; 210 U/L 251 U/L, = 0.002). Further analyses revealed a significant positive correlation between body weight and percentage of YAM (r = 0.441,  < 0.001). Despite the administration of bisphosphonates in these patients during this study, one acquired a bone fracture.

Conclusion: Osteoporosis was found in 14.8% of postoperative gastric cancer patients, with female gender, low body weight, and low ALP proposed as risk factors for osteoporosis and thus future bone fracture.