Analysis of Bone Density in Patients with Urolithiasis; Role of Hypercalciuria in Bone Loss: Do These Patients Need a Low-Calcium Diet?

Kidney stone is a common urologic complaint. In this study, bone density in stone formers was compared with that of a control group; bone density of stone formers was also analyzed based on age, sex and stone configuration.

In a group of 85 patients with upper urinary calcium stones and 85 healthy people, variables such as age, height, weight, BMI, T-score and Z-score results of bone densitometry of lumbar vertebrae (L2-L4) and femoral neck were recorded. The serum levels of uric acid, calcium, potassium, sodium, phosphor, alkaline phosphates and parathyroid hormone were also analyzed and recorded. Furthermore, all patients, 24-hour urine was studied for levels of cr, oxalate, citrate, uric acid calcium, urea and the total volume.

Lumbar and femoral bone mineral density (BMD) was significantly lower in patients suffering from renal stone. This difference was also significant when the study and control groups were classified into hypercalciuric and normocalciuric ones. Based on the densimetric results of lumbar vertebrae and femoral neck, BMD reduction among menopause women was significantly greater.

Noting the lack of relationship between hypercalciuria and bone loss, and noting that a low-calcium diet not only has no proved role in renal stone prevention, but also it leads to calcium imbalance and finally bone loss, low-calcium diets are not suggested for renal stone formers.