[Bone disorder after gastrectomy--clinical & experimental studies]

To study the pathophysiology of bone disorder after gastrectomy, 320 patients and 40 Wistar male rats were used. Clinically, patients who had received gastrectomy 1-15 years previously, were examined for skeletal symptoms, serum biochemistry, microdensitometry of second metacarpal bone, and 20 of them were then studied in a calcium infusion test. Using microdensitometry, abnormality of bone metabolism was observed in 38% of the patients. In severe cases, a significant decrease of serum Ca. and increase of alkaline phosphatase were observed (p less than 0.05), 65% complained of joint pain. In the calcium infusion test, severe cases showed a low urinary excretion of Ca, like osteomalacia, and unlike osteoporosis. Experimentally, body weight & amount of food intake decreased and fatty diarrhea was observed in rats after total gastrectomy. Skeletal changes including thinning of the cortex, loss of medullary trabeculation & decrease of bone ash and biochemical changes such as low serum Ca. 25(OH)D3, 24, 25(OH)2D3 and high iPTH levels were observed. Also the bone formation rate was lower than control as detected by tetracycline double labelling method. As low food intake & fatty diarrhea after gastrectomy which result in Ca. & vit. D insufficiency may be the major etiology of bone disorder.