Gazdikova K

Effects of Long-Term Cholecalciferol Supplementation on Mineral Metabolism and Calciotropic Hormones in Chronic Kidney Disease

Background: Data on the efficacy and safety of long-term vitamin D supplementation in chronic kidney disease (CKD) are scarce. We assessed the effects of the 12-month vitamin D3 treatment on mineral metabolism and calciotropic hormones in patients with CKD stages 2–4. Methods: Eighty-seven patients (mean age 66 years, men/women 33/54) were randomized to cholecalciferol treatment with either 5,000 or 20,000 IU/week. Serum calcium, phosphate, 25(OH)D3, 1,25(OH)2D3, PTH and urinary mineral concentrations were obtained at baseline and after 4, 8 and 12 months. Results: The median serum mineral concentrations were normal and not changed throughout the study. The number of hypercalciuric patients slightly increased with higher dose, but no sustained rise in calciuria was present. Vitamin D insufficiency/deficiency was revealed in 72 (83%) patients at baseline and 37 (43%) at month 12. The 25(OH)D3 levels increased more with higher dose; a rise in 1,25(OH)2D3 was less impressive. The parathyroid hormone (PTH) concentrations were reduced, but the number of subjects with PTH below the lower limit for CKD stage 3 increased equally with both doses. Conclusions: Vitamin D insufficiency/deficiency in CKD significantly improved after the 12-month cholecalciferol treatment, with higher dose being more effective and equally safe. Further studies of vitamin D3 effects on bone metabolism are warranted.

Decreased levels of coenzyme Q10 in patients with bronchial asthma

Background: The contribution of free oxygen radicals in the pathogenesis of bronchial asthma is generally accepted. The modulation of antioxidative defence by supplementation with antioxidants represents additive therapy in complex management of disease. The aim of the study was to assess the levels of coenzyme Q10, α‐tocopherol, and β‐carotene both in plasma and whole blood, and malondialdehyde (MDA) and eosinophil cationic protein (ECP) in plasma of asthmatics (As).

Oxidative Stress and Plasma Concentrations of Coenzyme Q10, α-Tocopherol, and β-Carotene in Patients with a Mild to Moderate Decrease of Kidney Function

Accessible online at: www.karger.com/journals/nef Dear Sir, Oxidative stress (OS) and decreased function of the antioxidant system are apparent in dialysis patients [1] and even in ‘uremic patients’ during the predialysis phase [2, 3]. However, data on OS in predialysis patients with a just mild to moderate kidney function decrease are lacking. We have determined OS plasma concentrations of malondialdehyde (MDA), the parameter of lipid peroxidation, coenzyme Q10 (CoQ10), ·-tocopherol (·-TOC), and ß-carotene (ß-CAR) and performed standard kidney function tests in a group of 55 predialysis patients with mild (creatinine clearance 160 ml/min; n = 21), moderate (n = 25), and severe (creatinine clearance !25 ml/min; n = 9) glomerulonephritis or interstitial nephritis. The reference values were obtained from original procedures and previous studies of our group. The MDA plasma levels were increased even in a group with a mild decrease of the creatinine clearance (table 1), and no further significant MDA increase was apparent with further decreases of the creatinine clearance (r = –0.242, p = 0.078). On the other hand, the CoQ10 concentrations were decreased in patients with mildly decreased creatinine clearance, and no further decreases were apparent with further decreasing kidney function (r = 0.186, p = 0.179). A correlation was found between these two variables (r = 0.327, p = 0.018). The concentrations of ßCAR were in the normal range in patients with a mildly decreased creatinine clearance, but decreased with deteriorating kidney function (r = 0.320, p = 0.030). The ·-TOC plasma concentrations were slightly increased in patients with mildly decreased creatinine clearance, but increased further with the decreasing creatinine clearance (r = –0.364, p = 0.007). Thus, OS develops during the early phase of kidney disease (marker of OS: increased MDA levels). The changes of ·-TOC and ßCAR are opposite: while ·-TOC concentrations increase, ß-CAR concentrations decrease. This basic relationship could be modified by various factors: for instance, the highest values of MDA (p = 0.010) were found in 5 patients treated with prednisone combined with ciclosporin. It could be concluded that OS develops early in patients with kidney disease, probably with pathogenetic significance and the possibility of preventing the progression of kidney impairment. The significance of CoQ10 seems to be of outstanding interest.