Prognostic Importance of Vitamins A, E and Retinol-binding Protein 4 in Renal Cell Carcinoma Patients.

AIM: To assess the prognostic importance of serum levels of retinol, retinol-binding protein 4 (RBP4) and vitamin E at the time of diagnosis in patients with renal cell carcinoma (RCC). PATIENTS AND METHODS: In this prospective study, in a cohort of 102 renal cell carcinoma patients, relationships between serum levels of the aforementioned markers and recurrence-free survival (RFS), overall survival (OS), as well as cancer-specific survival (CSS), were evaluated. The vitamin A and vitamin E levels were determined by high-performance liquid chromatography (HPLC), while the RBP4 level by enzyme-linked immunosorbent assay (ELISA). RESULTS: The median follow-up period was 39 months. Renal cell carcinoma recurred in 9 patients; 23 patients died with 12 of them from RCC. The preoperative vitamin E level was associated to RFS (p=0.02). We found a significant relationship between OS and the level of RBP4 (p=0.002), retinol (p=0.037) and vitamin E (p=0.007). The CSS period was significantly associated with the level of RBP4 (p=0.0001) and retinol (p=0.0003). Patients with an RBP4 level less than 21.0 mg/l at the time of diagnosis had a 13.5-times higher risk of death due to RCC progression; this risk was up to 7.7-times higher with vitamin A levels under 0.52 mg/l. CONCLUSION: Low levels of vitamin A, E and RBP4 at the time of RCC diagnosis are associated with a poorer prognosis after surgery.

Vitamin D Binding Protein Is Not Involved in Vitamin D Deficiency in Patients with Chronic Kidney Disease.

OBJECTIVE: This study was designed to evaluate vitamin D status with separate determination of 25-OH D2 and 25-OH D3 and its relationship to vitamin D binding protein (VDBP) in patients with chronic kidney disease (CKD) and long-term haemodialysis patients (HD). METHODS: 45 CKD patients, 103 HD patients, and 25 controls (C) were included. Plasma vitamin D concentrations were determined using chromatography and VDBP in serum and urine in CKD using enzyme immunoassay. RESULTS: Plasma vitamin D levels were lower in CKD (30.16 ± 16.74 ng/mL) and HD (18.85 ± 15.85 ng/mL) versus C (48.72 ± 18.35 ng/mL), P < 0.0001. 25-OH D3 was the dominant form of vitamin D. Serum VDBP was higher in CKD (273.2 ± 93.8 ug/mL) versus C (222 ± 87.6 ug/mL) and HD (213.8 ± 70.9 ug/mL), P = 0.0003. Vitamin D/VDBP ratio was the highest in C and the lowest in HD; however, there was no correlation between vitamin D and VDBP. Urinary concentration of VDBP in CKD (0.25 ± 0.13 ug/mL) correlated with proteinuria (r = 0.43, P = 0.003). CONCLUSIONS: Plasma levels of vitamin D are decreased in CKD patients and especially in HD patients. 25-OH D3 was the major form of vitamin D. Despite urinary losses of VDBP, CKD patients had higher serum VDBP concentrations, indicating compensatory enhanced production. Vitamin D binding protein is not involved in vitamin D deficiency.

Lower retinol levels as an independent predictor of mortality in long-term hemodialysis patients: a prospective observational cohort study.

BACKGROUND: Malnutrition, inflammation, and oxidative stress are inter-related mechanisms linked to the progression of cardiovascular disease and prognosis of long-term hemodialysis (HD) patients. In this study, we focus on antioxidant vitamins and trace elements and the relationship of their serum levels to the prognosis of long-term HD patients. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: 261 long-term HD patients prospectively followed up for 5 years (2003-2008). The control group consisted of 66 healthy participants. PREDICTORS: Retinol, alpha-tocopherol, retinol-binding protein 4 (RBP-4), and the trace elements zinc and selenium. OUTCOMES: Mortality and cardiovascular mortality. During follow-up, 146 patients (56%) died, and for 71 of these, death was due to cardiovascular causes. MEASUREMENTS: Retinol, alpha-tocopherol, RBP-4, zinc, selenium, and basic nutritional and inflammatory parameters measured at the beginning of the study. RESULTS: Retinol and RBP-4 levels were significantly increased, whereas retinol:RBP-4 ratio and alpha-tocopherol, selenium, and zinc levels were decreased in HD patients compared with controls (retinol, 168.1 +/ 64.4 microg/dL in HD patients vs 99.1 +/-23.3 [corrected] microg/dL in controls; P<0.001). Lower retinol level was found to be a significant independent predictor of overall and cardiovascular mortality in multivariate Cox analysis (HR, 0.733 [95% CI, 0.599-0.896], P=0.002, and 0.694 [95% CI, 0.511-0.942], P=0.02, per 1 SD, respectively). The worst prognoses for patients with lower retinol levels were observed when these were combined with low albumin levels. LIMITATIONS: Sample size, investigation of prevalent, not incident, dialysis patients. CONCLUSIONS: This is the first study showing a lower retinol level as an independent predictor of overall and cardiovascular mortality in HD patients. It has to be elucidated whether the beneficial effects of higher serum retinol levels should be attributed to only better nutritional support or also to retinol's role in immune response and differentiation.

Changes in hemostatic variables induced by estrogen replacement therapy: comparison of transdermal and oral administration in a crossover-designed study.

AIM: The purpose of this study was to determine the changes of biochemical risk factors for thromboembolisms using different administration routes of early estrogen replacement therapy. METHODS: In a 12-week prospective, randomized crossover trial, estradiol was administered orally (2 mg daily) or transdermally (0.05 mg daily). Forty-five healthy early postmenopausal women were included into the study within 12 weeks after hysterectomy and oophorectomy. Forty-one women (age 49 +/- 6 years) completed the study, and their data were analyzed. The hemocoagulation parameters were determined prior to beginning of the study and at the end of each treatment period, separated by a 1-week washout period. RESULTS: After oral therapy, the average tissue factor pathway inhibitor levels decreased statistically significantly (p < 0.0001) from 87.5 +/- 39.1 to 68 +/- 37.49 ng/ml. The plaminogen activator inhibitor-1 levels also decreased statistically significantly (p = 0.001) after the oral estrogen therapy from 11.39 +/- 12.02 to 5.0 +/- 5.27 IU/l. These changes were also significant when compared with the nonsignificant changes after the transdermal therapy. No significant changes occurred in the levels of D-dimers. After both treatment methods, the antithrombin III and fibrinogen levels decreased, but within their physiological ranges. CONCLUSIONS: Oral administration of estrogen statistically significantly reduced the tissue factor pathway inhibitor and plasminogen activator inhibitor-1 levels when compared with the transdermal route. These changes cannot be unambiguously considered risky, and the zero change of D-dimers suggests that there was no activation of the coagulation cascade. We consider the neutral effect of the transdermal therapy more beneficial.