[Incidence of lactase deficiency in patients with involution osteoporosis and in normal subjects. Its effect on the nutritional intake of calcium and phosphorus].

The incidence of lactase deficiency, evaluated by means of a lactose absorption test with blood glucose measurements, was compared in a group of 58 women suffering from postmenopausal osteoporosis and a control group of 51 normal women of the same age and ethnic origin. In the patients suffering from osteoporosis, the examination was completed by a glucose-galactose absorption test and in the control group by a hydrogen breath test. The prevalence of lactase deficiency is of approximately the same magnitude in the two groups (25.8% and 33.3% respectively). Dietary investigations showed a calcium intake superior to 1 g per day in only 40% of the osteoporotic patients, this deficiency being more important in cases where lactase deficiency was observed than in those showing normal lactose absorption. The influence of lactose malabsorption on the calcium balance, and the role of the latter in the pathogenesis of osteoporosis, are discussed.