Cross-over study of influence of oral vitamin C supplementation on inflammatory status in maintenance hemodialysis patients.

BACKGROUND: Both vitamin C deficiency and inflammation are prevalent in maintenance hemodialysis (MHD) patients. In this study, we aimed to elucidate the effect of oral vitamin C supplementation on inflammatory status in MHD patients with low vitamin C level and high hypersensitive C-reactive protein (hs-CRP) level. METHODS: A total of 128 patients were recruited in our present study. Patients were divided into two groups. In group 1 (n = 67), patients were orally administered with 200 mg/day vitamin C in the first 3 months, and then the vitamin C supplementation was withdrawn in the next 3 months. In group 2 (n = 61), patients were not given vitamin C in the first 3 months, and then they were orally administered with 200 mg/day in the next 3 months. Levels of hs-CRP, prealbumin, albumin and hemoglobin as well as the EPO resistance index (ERI) were determined at the baseline and every 3 months throughout the study. Plasma vitamin C level was determined by high-performance liquid chromatography with UV detection. RESULTS: Among the 128 patients, 28 of them dropped out of the study before completion. Consequently, a total of 100 patients (group 1: n = 48; group 2: n = 52) were included in the final analysis. At the baseline, the plasma vitamin C level of all patients was less than 4 µg/mL. However, this proportion was decreased to 20% after the vitamin C supplementation for 3 months. Compared with patients without the vitamin C supplementation, a decreased level of hs-CRP and an increased level of prealbumin were induced by the vitamin C supplementation for 3 months in both groups. However, levels of these biomarkers returned to their original state after the supplementation was withdrawn. Same beneficial effects on plasma albumin, hemoglobin and ERI response to vitamin C supplementation were observed in the two groups without statistical significance. CONCLUSIONS: The inflammatory status in MHD patients with plasma vitamin C deficiency and high levels of inflammatory markers could be partially improved by long-term oral administration of small doses of vitamin C. TRIAL REGISTRATION: The clinical trial number: NCT01356433.

Association between vitamin C deficiency and dialysis modalities.

AIM: We designed a cross-sectional study to investigate plasma vitamin C level in patients who underwent maintenance haemodialysis (MHD) and continuous ambulatory peritoneal dialysis (CAPD) to explore whether there is a difference in vitamin C deficiency between MHD patients and CAPD patients. METHODS: This investigation included 382 dialysis patients without vitamin C supplement before the study. Demographic characteristics, laboratory tests, ascorbic acid and total plasma vitamin C level were measured. A linear regression model was built to explore the association between vitamin C deficiency and dialysis modalities after adjusting for age, dialysis vintage, gender, Charlson index, modality of dialysis and hsCRP. RESULTS: The range of plasma vitamin C level was from 0.48 µg/mL to 31.16 µg/mL. 35.9% (n = 137) patients had severe vitamin C deficiency (<2 µg/mL). Plasma vitamin C level was inversely associated with age and dialysis vintage. After age and dialysis vintage were adjusted, vitamin C deficiency was associated with MHD. R square for model fitting was relatively low, which implied that there were other vitamin C influencing factors not included in the model. CONCLUSIONS: Vitamin C deficiency is common in dialysis patients, especially in patients treated with MHD.

Development and validation of a new dry weight estimation method using single frequency bioimpedance in hemodialysis patients.

BACKGROUND: We proposed a new method to estimate dry weight (DW) using single frequency bioimpedance. METHODS: We hypothesized that the change in whole body resistance at 50 kHz (R(50)) was proportional to the ultrafiltration volume (UFV) during a hemodialysis (HD) session. When the targeted resistance estimated in healthy subjects was reached, the patient achieved his/her DW. UFV and R(50) were monitored in 40 HD patients. Another 43 HD patients were stratified into 2 groups to validate this method. RESULTS: The change in whole body resistance was proportional to UFV in each of the 40 HD patients. In the DW(decrease) group, pre-dialysis systolic blood pressure (n = 29, 154.5 ± 22.8 vs. 146.9 ± 22.3, p < 0.05) and antihypertensive medicine (4.7 ± 3.6 vs. 3.3 ± 2.2, p < 0.05) decreased without adverse symptoms change. In the DW(increase) group, the number of adverse symptoms in 1 week (n = 14, 26 vs. 6, p < 0.05) decreased without a change in systolic blood pressure. CONCLUSION: This method may become a convenient and cheaper way to estimate DW in HD patients.

MRI anatomy of the anal region.

PURPOSE: The aim of this study was to identify the normal anatomy of the anal region on magnetic resonance images. METHODS: T1-weighted turbo spin-echo images of anal sagittal sections, anal coronal sections, and oblique anal transverse planes were obtained with a body coil in 60 normal volunteers (30 women and 30 men, aged 19-25 years) at rest in the supine position. RESULTS: T1-weighted images showed fat spaces and muscles simultaneously, allowing visualization of 7 image layers, including the mucosa, submucosa, anal smooth muscle, inner (intersphincteric) space, vertical levator, outer (intersphincteric) space, and external anal sphincter. The anal smooth muscle was derived from the rectal smooth muscle, and the inner space originated from the perirectal space. The outer space lay between the vertical levator and the external sphincters. The puborectalis did not have a longitudinal portion. The deep, superficial, and SC sphincters were 3 separate muscle bundles. The perianal spaces had a complex interconnection. CONCLUSIONS: Multiplanar body-coil MRI studies can show anorectal fat spaces and musculature simultaneously, allowing fat spaces and musculature to serve as mutual referents. The results of imaging of the anal region with this method are different from previous imaging descriptions and may provide a more accurate and systemic description of the anal region structures than was previously available.