Circadian rhythms of diuresis, proteinuria and natriuresis in children with chronic glomerular disease

The aim of our study was to examine diurnal variation in urine volume (UV) output, proteinuria (UPRT), urine creatinine (UCr) and urine sodium ion excretion (UNa) in children with chronic glomerulopathy. In 56 patients (20 boys/36 girls, aged 11.7 ± 0.6 years) samples for UPRT, UCr and UNa were collected during the day and night, with continuous ambulatory blood pressure (BP) monitoring. On the basis of creatinine clearance (CrCl) the patients were divided into group I ( n = 44, with CrCl 131 ± 3.6 ml/min per 1.73 m 2 body surface area), or group II ( n = 12, with CrCl 44.6 ± 7.7 ml/min per 1.73 m 2 body surface area). Nocturnal polyuria was defined as night time UV ≥ 35% of the 24 h UV. Age, gender, body mass index of the patients, 24 h UV, UCr and UNa were similar in both groups. However, arterial hypertension and nocturnal polyuria were widespread ( P