Clinical and metabolic evaluation of patients with history of renal calculi in Qazvin, Iran

Nephrolithiasis is a common clinical disorder with significant health and economic burden. We conducted this study to evaluate clinical and metabolic parameters in adult patients with history of renal calculi.

A total of 213 patients with history of nephrolithiasis participated in this study. Evaluation included the measurement of serum calcium, uric acid, parathormone, renal function tests, urinalysis, and urinary tests for cystinuria. Also, parameters such as volume, creatinine, calcium, uric acid, citrate, and oxalate levels were measured on 24-h urine. All patients underwent urinary tract system sonography.

Of total patients, 52 % were males and 48 % females. The mean age was 45.16 ± 13.16 years. Also, 51.2 % of subjects had positive family history of nephrolithiasis. The mean body mass index was (26.8 ± 4.2) kg/m². The mean 24-h urine biochemical profiles were volume (1,748 ± 860 ml), Ca (183 ± 115), uric acid (544 ± 220), citrate (490 ± 351), and oxalate (17.1 ± 15.3) mg/day; urine calcium to creatinine ratio (0.15 ± 0.10) mg/mg, and urine calcium to weight ratio (2.4 ± 1.7) mg/kg. While there were weak positive correlations between the body mass index and urinary calcium (r = 0.101, P < 0.001) and uric acid (r = 0.200, P < 0.001), a weak negative correlation with urine pH (r = −0.104, P < 0.001) was found.

Urine calcium, uric acid, and oxalate excretion were low in our patients while urine citrate was relatively high. Higher BMI maybe a risk factor for nephrolithiasis.