Obesity and Calcium Oxalate Renal Stones

Nicola Th¹, Dobreanu Minodora², Buda Brîndușa³, Oșan V⁴, Gliga Florina³, Satan Edit¹

1 Department of Laboratory Medicine, County Emergency Clinical Hospital, Tîrgu Mureș, Romania
2 Department of Laboratory Medicine, University of Medicine and Pharmacy, Tîrgu Mureș, Romania
3 Department of Pathophysiology, University of Medicine and Pharmacy, Tîrgu Mureș, Romania
4 Department of Urology, University of Medicine and Pharmacy, Tîrgu Mureș, Romania

Introduction: Kidney stones are a major cause of morbidity. The lifetime prevalence of symptomatic renal stones is approximately 10% in men and 5% in women. The rate of backsliding for calcium oxalate stones is 10% in one year, 30% in 5 years and 50% in 10 years. Urine pH is one of the important factors for urinary stone formation.
Material and methods: We studied 283 renal stone formers (131 men, 152 female), divided according to their BMI (body mass index) in normal body weight (BMI <25 kg/m2), overweight (BMI 25–30 kg/m2) and obese (BMI >30 kg/m2).
Results: Urine pH is inversely related to BMI among patients with urolithiasis (higher BMI will have lower urine pH). The mean urine pH of the normal body weight, overweight, and obese groups was 6.1, 5.5 and respectively 5.7 (p <0.0001).
Conclusions: Obesity is associated with both hypercalciuria and with proteinuria, demonstrated factors in the etiology of urolithiasis, and urinary pH is inversely related to BMI in patients with urinary stones.