Urolithiasis in Primary Gout, Incidence of Clinically Presented and Asymptomatic Kidney Stones: Identification of Significant Risk Factors

Abstract

Background The aim of this study is to explore the prevalence of urolithiasis in patients with primary gout as well as its correlation with other associated risk factors. Methods The study was conducted on 102 patients with primary gout, they underwent ultrasonography examination and their general, clinical, and urinalysis data were recorded for further assessment and statistical analysis. Results There were 102 patients with primary gout included in our study, 69 (67.6%) males, mean age of patients was 64.3±9.7. The overall prevalence of urolithiasis in our patients with primary gout is 37.3% and 15.7% have “silent” urolithiasis. Patients with urolithiasis (Group 1) are significantly older, 68.9±7.4-years, had a long history of gout 10.3±4.5-years, presence of tophi in 9 (23.6%) patients and more than 3 gouty arthritis attacks per year in 17(44.7%) patients. Also, patients in Group 1 have a significantly lower urine pH of 5.2±0.4 compared to patients without urolithiasis (Group 2) who have a urine pH of 6.6±0.2. Results showed that obesity, diabetes, and hyperlipidemia are significantly more common in patients with urolithiasis (Group 1) while the presence of hypertension is not significantly different between groups. Correlation between urolithiasis and parameters related to disease (duration, tophi, and more than three attacks per year) and parameters related to urinalysis (pH and crystalluria) was tested and found statistically significant. Logistic regression analyses (univariate and multivariate) of tested parameters confirmed that obesity, diabetes mellitus, and hyperlipidemia are predictive factors for the presence of urolithiasis in patients with primary gout. Conclusion There is a high prevalence of urolithiasis in patients with primary gout including asymptomatic urolithiasis, associated with the age of patients, duration, and severity of gout, obesity, diabetes, and hyperlipidemia. Therefore, ultrasonographic screening as harmless and available should be recommended in order to prevent complications.