Effect of vitamin D deficiency on spatial contrast sensitivity function.

CLINICAL RELEVANCE: Vitamin D has regulatory effects on non-skeletal tissues including neurons. The contrast sensitivity function occurs as a result of interaction between retinal neurons. BACKGROUND: The association between plasma vitamin D deficiency and contrast sensitivity function was investigated. METHODS: Forty-one eyes of 41 subjects with vitamin D deficiency with plasma vitamin D level <20 ng/mL (Group 1), and 30 eyes of 30 subjects without vitamin D deficiency with plasma vitamin D level ≥20 ng/mL (Group 2), were included in this prospective study. OPTEC 6500 was used to measure the contrast sensitivity function at all spatial frequencies involving 1.5 cpd, 3 cpd, 6 cpd, 12cpd, and 18 cpd. The average and sectorial retinal nerve fibre layer thickness, the average and minimum ganglion cell-inner plexiform thickness and tear meniscus height were measured by using optical coherence tomography. RESULTS: A significant difference was present between Group 1 and Group 2 regarding the plasma vitamin D level (12.4 ± 4.7 ng/mL in Group 1 versus 27.1 ± 6.7 ng/mL in Group 2 p < 0.001). All spatial frequencies of contrast sensitivity function were significantly greater in Group 2 than those in Group 1, as follows: 45 ± 22.6 in Group 1 versus 57.5 ± 20.9 in Group 2, p = 0.08 in 1.5cpd; 71.3 ± 31.3 in Group 1 versus 91.8 ± 27.8 in Group 2, p = 0.001 in 3cpd; 77.9 ± 39.9 in Group 1 versus 100.4 ± 38.4 in Group 2, p = 0.013 in 6cpd; 32 ± 17.5 in Group 1 versus 48.8 ± 25.2 in Group 2, p = 0.002 in 12cpd; and 12.1 ± 5 in Group 1 versus 17.5 ± 9.5 in Group 2, p = 0.001 in 18cpd. However, there were no significant difference between two groups in terms of retinal fibre layer thicknesses, ganglion cell-inner plexiform layer thicknesses, and tear meniscus height. CONCLUSION: Vitamin D deficiency can lead to a decrease in contrast sensitivity function that is an indicator of visual quality. This may be an underlying reason for certain visual complaints.

Serum chitotriosidase and YKL-40 in acute pancreatitis: Reliability as prognostic marker for disease severity and correlation with inflammatory markers

Background/aim: Chitotriosidase and YKL-40, also called chitinase 3-like protein 1, are homologs of family 18 glycosyl hydrolases, secreted by human macrophages and granulocytes under inflammatory conditions. Although increased levels of chitotriosidase and YKL-40 are linked with several inflammatory diseases, the physiological utility of these two enzymes is still not fully characterized. This study aims to analyse the serum YKL-40 and chitotriosidase levels of acute pancreatitis patients to assess whether their activity correlates with acute pancreatitis and its severity. Materials and methods: Chitotriosidase and YKL-40 levels, along with routine laboratory parameters, were determined from the serum samples of 41 acute pancreatitis patients, at both onset and remission (male/female: 22/19), and 39 healthy subjects (male/female: 19/20). The Modified Glasgow Prognostic Score was used to predict the severity of the disease, and a correlation analysis was performed between study variables. Results: A statistically significant increase in both chitotriosidase and YKL-40 levels was observed in acute pancreatitis patients compared to healthy controls (P < 0.001). Higher levels of YKL-40, chitotriosidase and C-reactive protein were found in patients with acute pancreatitis at onset than in remission. The correlation analysis showed a statistically significant association between YKL-40 and chitotriosidase (p = 0.039, r = 0.323). The cut-off point for YKL-40, for detecting acute pancreatitis, was 60.3 with a sensitivity and specificity of 84.9% and 84.6% (AUC: 0.890). The optimum cut-off points for chitotriosidase, for detecting acute pancreatitis, was 33.5 with a sensitivity and specificity of 79.5% and 78.4% (AUC: 0.899). Conclusion: Elevated YKL-40 and chitotriosidase levels in acute pancreatitis patients demonstrate the importance of possible macrophage involvement in the pancreatic microenvironment during acute pancreatitis progression.

The Association Between Delayed Graft Function and Renal Resistive Index in Kidney Transplant Recipients.

Background and objectives Delayed graft function (DGF) may increase the risk for kidney graft dysfunction. Renal resistive index (RRI) in Doppler ultrasonography is useful in measuring blood flow changes in kidneys which is indicative of tubulointerstitial damage. Most of the diseases in DGF etiology are related to tubulointerstitium and arteries of the kidneys. In this study, we investigated whether there is a relationship between delayed graft function and renal resistive index in kidney transplant recipients (KTR). Materials and methods Patients who underwent kidney transplantation were included in this retrospective study. KTR were divided into two groups as DGF (+) and DGF (-). Comparison of RRI values of DGF (+) and DGF (-) groups according to the measurements at different times. Results The findings showed that both RRI measurements (post-transplant in the first week and the end of the first year) of the DGF (+) group were higher than DGF (-) group (p=0.001 and p=0.003, respectively). The interaction of measurements and DGF did not have an effect on RRI (p>0.05). Conclusion The value of RRI in the DGF (-) group was lower than DGF (+) group in the first week after kidney transplantation.

Neutrophil gelatinase-associated lipocalin is a better biomarker than cystatin C for the prediction of imminent acute kidney injury in critically ill patients.

Aims The prevention of acute kidney injury can be lifesaving for the intensive care unit patients. However, conventional methods are not sufficient for the prediction of the risk of future acute kidney injury. In this study, the promising biomarker, neutrophil gelatinase-associated lipocalin, was compared with cystatin C as an indicator for the risk of future acute kidney injury. Methods One hundred and eighty-three adult patients without chronic kidney disease or renal replacement therapy were included in this study. The plasma and urine concentrations of neutrophil gelatinase-associated lipocalin and cystatin C were assessed on the second day after intensive care unit admission and were followed for seven days to monitor the development of acute kidney injury. Acute kidney injury diagnosis was based on the risk, injury, failure, loss, end-stage renal failure criteria. Results Thirty-four per cent of the patients had acute kidney injury; 17 patients who did not fulfil criteria at the beginning, developed acute kidney injury from days 3 to 7 after admission. The mean serum creatinine on admission did not significantly differ between this and control groups (0.72 ± 0.20 and 0.83 ± 0.21; P = 0.060); however, the serum and urinary neutrophil gelatinase-associated lipocalin concentrations on the second day were significantly different (median: 75.69 [54.18-91.18] and 123.68 [90.89-166.31], P = 0.001; and median: 17.60 [8.56-34.04] and 61.37 [24.59-96.63], P = 0.001). Notably, the 48-h serum cystatin C concentration did not differ. Conclusion Neutrophil gelatinase-associated lipocalin concentrations in the urine and serum on the second day of intensive care unit admission could be used to predict the development of acute kidney injury in the following three to seven days in the intensive care unit; however, the cystatin C concentration did not have predictive value.

Neutrophil gelatinase-associated lipocalin levels during the first 48 hours of intensive care may indicate upcoming acute kidney injury.

PURPOSE: The recognition of acute kidney injury (AKI) as early as possible is important in the intensive care unit. This study proposes that serum and urine levels of neutrophil gelatinase-associated lipocalin (NGAL) may be used for this purpose. METHODS: One hundred and seven critically ill adult patients with no previous renal failure were included. NGAL levels were measured during the first 48 hours after admission; NGAL levels were followed for 7 days and classified based on Risk, Injury, Failure, Loss, and End-Stage Renal Failure criteria. RESULTS: The AKI incidence was 35.5%, and serum NGAL (sNGAL) and urinary NGAL (uNGAL) levels were higher in the AKI group. The area under the receiver operating characteristic curve was 0.76 (P<.001) for sNGAL and 0.75 (P<.001) for uNGAL. Seventy-one percent of AKI cases were observed within 48 hours, with 11 additional cases in the ensuing 7 days. The mean serum creatinine levels in the 11 patients were not different from non-AKI levels (P=.197), but the NGAL values were different, and the area under the receiver operating characteristic curve for sNGAL uNGAL was 1.00 (P=.014) and 0.93 (P=.02), respectively. CONCLUSIONS: Most AKI cases were diagnosed within the first 48 hours after admission, and NGAL was useful for predicting upcoming AKI.