The aim of the study was to assess bone mineral density, bone metabolism markers, and vitamin D level in children with idiopathic nephrotic syndrome in the course of 1-year observation. Twenty five children with nephrotic syndrome aged 5-17 years were enrolled into the study. The median number of relapses was 6 (range 1-22). All patients were treated with prednisone and vitamin D (800 IU/day). Bone mineral density of total body (TB-BMD) and lumbar spine (L-BMD), evaluated by dual energy X-ray absorptiometry (DXA) expressed as Z-score, and serum calcium, phosphorus, parathormone (iPTH), alkaline phosphatase (ALP), bone alkaline phosphatase (BAP), osteocalcin (OC), albumin, creatinine, 25(OH)D3, 1,25(OH)2D3 and urine calcium/creatinine ratio (uCa/Cr) were evaluated at the enrollment visit and after 1 year of therapy. After 1 year significant decreases of TB-BMD Z-score (from -0.24±1.34 to -0.74±1.31, p<0.05) and 25(OH)D3 serum level (from 31.7±16.3 to 23.7±9.3; p<0.05) were observed. No other appreciable differences were found. At the study onset, negative correlations were found between L-BMD Z-score and serum ALP, BAP, and phosphorus and between TB-BMD Z-score and urine uCa/Cr. After 1 year, L-BMD Z-score correlated negatively with serum BAP and OC, and positively with serum 25(OH)D3. Multivariate analysis showed that BAP was the strongest predictor of L-BMD Z-score (beta=-0.49; p<0.05). We conclude that children with nephrotic syndrome treated with corticosteroids are at risk of bone mass loss. Serum BAP concentration seems to be a good indicator of spongy bone metabolism in these children, who should be supplemented with vitamin D in an adjustable dose, possibly higher than 800 IU/24 h to prevent osteopenia.

IntroductionAcute kidney injury biomarkers are opening a new era in diagnosing kidney failure. The requirement for a specific and sensitive marker of kidney function is highly desirable in neonates because the diagnostic possibilities in this age group are not sufficient. Recent research show that neutrophil gelatinase-associated lipocalin (NGAL) can have a great potential but there is a wide range of medical conditions, that may influence their expression.The aim of the studywas to evaluate the impact of perinatal risk factors on NGAL level in neonates.Material and methodsNGAL was measured in umbilical cord blood and peripheral blood in full term neonates with perinatal risk factors during the first days of life.ResultsWe found significantly higher umbilical cord blood NGAL levels in neonates with perinatal risk factors (117.69 ng/ml) compared to the control group (64.37 ng/ml). No significant difference in peripheral blood NGAL level was shown between the two groups. Umbilical cord blood NGAL level correlated positively with peripheral blood NGAL level (r = 0.36, p < 0.01). Umbilical cord blood NGAL level was significantly higher in neonates with fetal distress and infection compared to neonates with other perinatal risk factors. Peripheral blood NGAL level was significantly higher in neonates with infection compared to neonates with other perinatal risk factors. Significantly higher umbilical cord blood NGAL levels were seen in neonates born by operative delivery compared to born by natural delivery.