Serum vitamin A and beta -carotene concentrations and renal scarring in urinary tract infections

Abstract

Objective-To evaluate the role of vitamin A on renal scarring in recurrent urinary tract infections (UTIs). Design-Twenty three children with UTIs and renal scarring (mean (SD) age 7.3 (3.9) years) and 91 children without renal scarring (6.4 (3.4) years) were studied. All the children had serum vitamin A and -carotene measurements and nutritional evaluation. Renal scarring was assessed by technetium-99m dimercaptosuccinic acid ( The role of vitamin A in recurrent urinary tract infections (UTIs) and urolithiasis has been assessed previously.1 Vitamin A was proposed as eVective in the regeneration of epithelial tissue in the urinary tract 2 ; -carotene has been reported to have antioxidant properties.3 Technetium 99-m dimercaptosuccinic acid ( 99m Tc DMSA) scintigraphy is the gold standard for demonstration of scarring in renal cortical tissue. 4 We hypothesised that the regenerative eVect of vitamin A on epithelial tissue could also be considered to play a part on renal parenchymal epithelium, as in the case of epithelium lining the lower urinary tract. The aim of this study was to evaluate the relation between vitamin A metabolism and scarred and unscarred renal parenchymal tissues and also to evaluate whether vitamin A and -carotene had an eVect on prevention of renal scarring. Subjects and methodsChildren with renal scarring due to recurrent UTIs were enrolled in this study. A control group was composed of children with recurrent UTIs but without renal scarring.Each patient was evaluated twice by 99m Tc DMSA scans performed at least six months apart. Persisting hypodense areas on two consecutive DMSA scans were considered as renal scarring. 4 Patients with normal or nonpersisting DMSA findings were considered as free of scarring. Uptake of each kidney was determined as per cent of total uptake of both kidneys which was considered to be 100%. When the diVerence between uptakes of kidneys exceeds 10% on scanning, renal function was considered to be diminished on the lower uptake side. 4 All the scans were read blindly by two specialists.Nutritional status of patients was evaluated by body mass index and the results were compared with published standards.Vitamin A and -carotene concentrations were measured by the Neeld and Pearson method in venous blood samples obtained during acute UTI episodes. 5 The intrabatch coeYcients of variation for vitamin A and -carotene were 6.5% and 7.8 % respectively in preliminary standardisation.Patients were grouped according to whether they had renal scarring (study group) or not (control group). The groups were compared for serum vitamin A and serum -carotene concentrations and nutritional status. In addition, the extent of kidney scarring was compared with serum concentrations of vitamin A and -carotene, when the diVerence between 99m Tc DMSA uptakes of kidneys was greater than 10%.Results were analysed by unpaired t test and correlation analysis. ResultsThere were 23 children with renal scars (mean (SD) age 7.3 (3.9) years and 91 unscarred children (mean age 6.4 (4.4) ...

Serum Carotenoid and Retinol Levels during Childhood Infections

“…Serum lutein and zeaxanthin were somewhat lower than those observed in American children by Neuhouser et al [28]. Serum pro-vitamin-A carotenoid concentrations in our healthy children were in a similar range to those of healthy, 12-to 17-year-old American children [28] but higher than those of Filippino [29] or Turkish children [30]. Lycopene serum levels in the healthy Hungarians were as low as those observed in young babies in Honduras [31] in spite of the sufficient lycopene intakes.…”

The effect of vitamin A on renal damage following acute pyelonephritis in children

“…The majority of these studies used laboratory animal models [3,9,14,18,20], and to our knowledge, only two studies of this kind were performed on children [13,21]. There are other studies in which the effects of pentoxifylline, melatonin, and ebselen on prevention of renal scar were examined, but again all were carried out on animal models [10,11,26].…”

“…In a study performed on children with recurrent UTI, the severity of renal scarring was revealed to have an inverse correlation with the serum vitamin A concentration [13,15]. There are several factors affecting the degree of renal tissue damage such as bacterial colonization, endotoxin production, interleukin, and oxidative effect [3,13,21]. Vitamin A is needed by all epithelial cells of body tissues.…”

“…According to several studies, vitamin A deficiency causes an increase in urinary infections incidence while the administration of vitamin A leads to reduction in UTI incidence [2,4,6,15]. In a study performed on children with recurrent UTI, the severity of renal scarring was revealed to have an inverse correlation with the serum vitamin A concentration [13,15]. There are several factors affecting the degree of renal tissue damage such as bacterial colonization, endotoxin production, interleukin, and oxidative effect [3,13,21].…”

“…Based on data findings of these studies, the WHO suggests that children must have a recommended dose of vitamin A capsule every 6 months [8]. There are a limited number of studies regarding the effect of vitamin A in urinary tract infections [13,15]. On the contrary, in another study, the administration of vitamin A not only failed to considerably affect the clinical and pathophysiological course of renal ablation nephropathy in rats but also when given at higher doses it could cause damage to kidney tissue [22].…”