The Effect of Dietary Counselling in Reducing Sodium Consumption Among Hypercalciuric Stone Formers and its Impact on Metabolic Risk Factors

Abstract

Introduction Excessive dietary sodium (Na) consumption is a major health care issue in the developed world and linked to many poor health outcomes. Elevated urinary Na may lead to hypercalciuria and an increase in urinary stone risk. Our study aimed to assess the impact of targeted dietary counseling, and its effect on normalizing urinary Na levels in hypercalciuric stone patients. Methods A retrospective analysis of a prospectively collected metabolic stone clinic database was performed. Patients with hypercalciuria and elevated urine Na on 24-hour urine collection (24-HUC) were counselled by the attending nephrologist, urologist or a registered dietician to limit their intake of dietary Na to < 2g/day in addition to receiving general dietary advice. Repeat metabolic testing was performed at least 6 months later. Logistic regression was used to determine correlations between elevated urinary Ca and Na to other urinary abnormalities and to evaluate the effect of normalizing urinary Na on other urinary parameters. Results Metabolic evaluations from 1184 patients were analyzed. The ninety-eight patients with concomitant hypercalciuria and hypernatriuria were predominantly male (67.3%) and had a higher median BMI than the entire cohort. The presence of elevated urinary Na was also associated with hyperuricosuria (p < 0.001) and hyperphosphaturia (p < 0.001). In follow-up, 59.4% corrected their urinary Na, and 43.8% also had their urinary Ca corrected. Patients who corrected their urinary Na were also more likely to have normal urinary values for volume (p = 0.045), oxalate (p = 0.004), and urate (p = 0.008). Conclusions Targeted dietary counseling can be effective in normalizing both elevated urinary Na and Ca levels in stone patients and may obviate the need for pharmacotherapy for the treatment of hypercalciuria in some patients.