Metabolic syndrome and associated urolithiasis in adults enrolled in a community-based health program

Urolithiasis is a common and recurrent disease, whose prevalence rate has recently increased in parallel to obesity pandemic.

To estimate the prevalence of history of urolithiasis in a non-randomized sample of adults assisted by a community-based health program and to analyze its association with metabolic syndrome.

Cross-sectional study set in Niteroi, Rio de Janeiro, Brazil, including adults (non-diabetic hypertensives, diabetics or controls). Participants were assessed through a standardized questionnaire and underwent clinical and laboratory evaluation, including blood and urine samples. The diagnosis of metabolic syndrome was based on harmonized criteria.

A total of 740 adults were enrolled (M: F = 0.85; 43±12 years; 30% white, and 70% non-white). Almost half of subjects (42.5%) had metabolic syndrome. The prevalence of urolithiasis in the sample was 10.1%. White skin colour, family history, and metabolic syndrome were independently associated with urolithiasis (P < 0.05). Subjects with the syndrome (excluding cases on diuretics) had more acidic urine (P = 0.014), increased natriuresis (P = 0.01) and higher uricosuria (P = 0.001) compared with non-affected ones. The prevalence of urolithiasis increased in proportion to the number of criteria for metabolic syndrome (P for trend <0.005).

Metabolic syndrome is a modifiable factor associated with urolithiasis in a way that the frequency of positive history increases proportionally to the number of its diagnostic criteria. These findings reinforce the recent suggested link between urolithiasis and cardiovascular risk factors.