Prevalence of Metabolic Syndrome in Patients with Uric Acid and Calcium–based Kidney Stones

Abstract

The aim of the study was to investigate the prevalence of metabolic syndrome in patients with uric acid and calcium–based kidney stones and to investigate the relationship between metabolic syndrome and type of kidney stone using infrared spectroscopy to evaluate the chemical composition of kidney stones
Sixty patients with urolithiasis were examined. Metabolic syndrome was diagnosed according to clinical and laboratory criteria. Weight, height, body mass index, waist circumference, and blood pressure of patients were measured. Blood tests were performed. Concentrations of total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, glucose and uric acid in blood, were analyzed. The kidney stones of patients were removed and the composition of each kidney stone was analyzed using Fourier transform infrared spectroscopy.
Metabolic syndrome was diagnosed in 55% of the patients; 86.7% of patients with uric acid (UA) kidney stones and 44.4% of patients with calcium (Ca) based stones had metabolic syndrome. All patients diagnosed with metabolic syndrome were overweight or obese. Even though there were no statistically significant differences observed concerning the anthropometrical measures and arterial blood pressure (BP) between the UA stone formers and Ca–based stone formers, the results show a trend that failed to reach significance: higher waist size, BMI and arterial BP means in the group of patients with UA stones than in the patients with Ca–based stones. No statistically significant differences in lipid profile between the groups were found. Concentration of UA in blood serum was significantly higher in patients with UA kidney stones than it was in patients with Ca–based kidney stones. Significant positive correlation between triglycerides and serum UA concentrations, as well as body mass index and serum UA concentration, and negative correlation between concentrations of high-density lipoprotein cholesterol and UA was found.
Conclusion: Metabolic syndrome was more prevalent in patients with uric acid stones than in the patients with calcium–based kidney stones, even though this relationship was not statistically significant, most likely because of the limited number of patients investigated.