Glucose Metabolism in Renal Stone Patients

Abstract

The calciuric response and the changes of plasma glucose and insulin produced by a 75-gram oral glucose tolerance test were determined in 27 male patients with idiopathic calcium renal stones (6 with dietary hypercalciuria, 5 with nondietary hypercalciuria and 16 with normocalciuria) and 22 healthy male subjects. The subjects were classified as obese (≧ 120% ideal weight) and nonobese. The incidence of an abnormal response to glucose loading was similar in the stone patients and the healthy subjects. In addition, the plasma glucose and insulin levels after oral glucose load did not differ between the stone patients and control subjects and were affected by the individual degree of obesity. Urinary calcium excretion increased significantly after glucose ingestion in both the stone patients and the control subjects. Urinary calcium excretion was greater in the stone patients than in the control subjects due to the presence of patients with nondietary hypercalciuria, and the increment in urinary calcium excretion in the dietary hypercalciuric and normocalciuric stone patients was indistinguishable from that in the control subjects. The degree of obesity did not affect the increment in urinary calcium excretion. These results suggest that overconsumption of refined carbohydrates such as sugar-sweetened soft drinks, soda and cakes may be a risk factor for stone formation, especially in the patients with nondietary hypercalciuria.

Urolithiasis and obesity: metabolic and technical considerations

“…Iguchi et al [12] demonstrated that an oral load of glucose increases the urine calcium excretion in patients irrespective of body weight or stone history. This suggests that regular consumption of refined carbohydrates might predispose to stone formation.…”

Epidemiology and Natural History of Nephrolithiasis

“…Refined carbohydrate increased urine calcium excretion in normal volunteers [112,113] and in stone formers [113] to a similar degree. However, comparison of food diaries in 91 subjects showed no difference in refined carbohydrate consumption in stone formers and controls [114].…”

Current Practice Patterns of Urologists Providing Nutrition Recommendations to Patients with Kidney Stones

“…4 Hypercalciuria does, however, have several nutritional influences, including high sodium intake, 10,11 high dietary acid load, 12,13 suboptimal fiber intake, 14 and/or excessive carbohydrate intake. 15,16 Responses varied widely on the use of calcium supplements (Fig. 2).…”