위암환자에 있어서 위절제 후의 칼슘대사

Abstract

Objectives: Metabolic bone disease may occur as a late complication of gastrectomy. The main causes are decreased absorption of dietary calcium and vitamin D in the gastrointestinal tract and disturbaces in calcium uptake of bone related to lower level of gastrin which are supposed to stimulate postprandial secretion of calcitonin. We tried a short-term prospective study to identify the early metabolic effects of gastrectomy including calcium absorption and changes of hormones related to calcium metabolism. Methods: We studied fractional calcium absorption, urinary calcium excretion and serum levels of 25-OH-D3 and 1,25-(OH)2-D3 as well as changes in postprandial patterns of ionized calcium, gastrin, calcitonin and parathyroid hormone between the pre and 30 days post-operative periods after subtotal gastrectomy in 7 male patients with stomach carcinoma. Results: 1) The mean age of subjects was 62.1±4.8 years, the mean height was 168±5cm, the preoperative mean weight was 57±5 kg, and the mean loss of weight was 5 kg. 2) Daily calcium intake in the postoperative period was decreased by 24% compared to the preoperative period (652±203 mg/d) and intakes of calorie, carbohydrate, protein and fat were also decreased by 40-50%. 3) Serum biochemical tests related to calcium metabolism and the ratios of calcium and phosphorus to creatinine in 24-hour urine were not different between two periods. 4) Fractional calcium absorption test using 45Ca showed delayed peak serum level at 2 hour in the postoperative period while at 1 hour in the preoperative period. However, areas under the curve for 3 hours were similar between two periods (4.73% vs. 4.43%). At the same time, urinary excretions of 45Ca for 3 hours were also not different. 5) Serum levels of 25-OH-D3 (16.57±6.39 us. 12.92±2.6ng/ml) and 1,25-(OH)2-D3 (131.7±66.38 vs. 131.57±24.51pg/ml) were similar. 6) The preprandial level of gastrin (49.00±42.71 vs. 17.52±11.58pg/ml) was decreased but those of ionized calcium (4.1±0.5 vs. 4.4±0.7 mg/dl), calcitonin (45.35±7.49 vs. 47.13±l5.97pg/ml) and parathyroid hormone (21.64±5.18 vs. 23.94±5.05pg/ml) were not changed after gastrectomy. The postprandial changing patterns of ionized calcium, calcitonin and parathyroid hormone were also not different except for absent reponse of gastrin. Conclusion: Fractional calcium absorption and serum levels of 25-OH-D3 and 1,25-(OH)2-D3 were similar and postprandial patterns of ionized calcium, calcitonin and parathyroid hormone were not changed although gastrin was deficient. Calcium intake was decreased in spite of encouraged high calcium diet and so it may be concluded that calcium balance is not maintained due to inadequate oral calcium intake rather than poor calcium absortion in 30 days after subtotal gastrectomy. We need long-term follow-up study and also comparative study between total and subtotal gastrectomy to clarify the effects of gastrectomy on calcium metabolism.