Dawid Madej

The effect of iron and zinc supplementation and discontinuation of this practice on iron and zinc level in tissues in rats fed deficient diets.

The effect of iron and iron/zinc supplementation on their levels in tissues of rats fed initially one of the three following regimen: C - control AIN-93 diet, D - iron deficient diet and R - diet with 50% reduction of all vitamins and minerals was investigated. The study was conducted on 6-week male Wistar rats, in 3 stages: (1) 4-week adaptation to the diets (C, D or R); (2) 4-week supplementation with the same regimen enriched with 10-times more iron (CSFe, DSFe, RSFe) or iron/zinc (CSFeZn, DSFeZn, RSFeZn); (3) 2-week post-supplementation period (the same diets as the stage I). Iron and zinc content in serum, the initial segment of intestine, liver and kidney were measured using FAAS method. After supplementation period (stage II) the content of iron in the intestine, liver and kidney in groups of rats fed DSFe and DSFeZn-diet were significantly higher (all p-values≤0.05) than in rats fed D-diet (intestine: DSFe=50.1±9.0 μg/g wet weight, DSFeZn=43.0±9.9 μg/g vs. D=16.5±2.1 μg/g; liver: DSFe=149±30 μg/g, DSFeZn=152±25 μg/g vs. D=56±13 μg/g; kidney: DSFe=74.0±8.1 μg/g, DSFeZn=72.7±6.6 μg/g vs. D=59.3±9.5 μg/g). The same significant associations (all p-values≤0.05) were observed in R rats in the intestine and liver (intestine: RSFe=60.8±6.6 μg/g, RSFeZn=54.8±6.6 μg/g vs. R=31.5±8.2 μg/g; liver: RSFe=161±10 μg/g, RSFeZn=166±21 μg/g vs. R=136±24μg/g). After post-supplementation period the statistically significant differences between supplemented and non-supplemented rats fed D- and R-diets were still observed. There was not found the effect of applied treatments on zinc status. In conclusion, iron or iron/zinc supplementation increased similarly iron level in tissues of rats fed D-diet or R-diet with prolonged effect after supplementation discontinuation.

Adverse effect after cessation of rats' unjustified iron or iron and zinc supplementation on hematological parameters but not ferritin concentration

BACKGROUND & AIMS Studies on the impact of supplementation cessation are lacking. We investigated the effect of iron and iron/zinc supplementation and cessation of this intervention on iron status parameters. METHODS The study was conducted on 6-week male Wistar rats, in 3 stages: 4-week adaptation to the diets: C--control (AIN-93M) and D--iron deficient (mineral mix without iron); 4-week supplementation: 10-times more iron (CSFe, DSFe) or iron/zinc (CSFeZn, DSFeZn) compared to C; 2-week post-supplementation period (the same diets as in the first stage). Red blood cell count, hemoglobin, hematocrit, transferrin saturation (TSAT) and ferritin concentration were determined. RESULTS After stage II D rats had statistically significantly (p-value ≤ 0.05) lower hemoglobin and TSAT in comparison to DSFe rats, but not DSFeZn, and significantly lower ferritin concentration in comparison to DSFe and DSFeZn rats. After stage III, CSFe and CSFeZn rats had a significantly lower level of all analyzed hematology parameters compared to C, in contrast rats fed DSFe and DSFeZn diets had higher hemoglobin concentration and hematocrit in comparison to D group. Moreover, in comparison to D rats those fed DSFe diet had higher TSAT and those fed DSFe and DSFeZn diets had significantly higher ferritin concentration. CONCLUSIONS After cessation of unjustified both iron and iron/zinc supplementation resulted in an adverse effect on hematological but not other iron status parameters. In the situation of iron deficiency in the diet, iron supplementation alone had a prolonged beneficial effect and was more effective than simultaneous iron/zinc supplementation in the improvement of the iron status.

Effect of iron and zinc supplementation and its discontinuation on lipid profile in rats

The aim of this research was to investigate whether combined iron/zinc supplementation is more beneficial than iron supplementation alone from the perspective of the lipid profile in rats. The study was conducted on 6-week male Wistar rats in 3 stages: (1) 4-week adaptation to the diets: C (AIN-93M) and D (mineral mix without iron); (2) 4-week supplementation: 10-times more iron or iron and zinc compared to C; (3) 2-week post-supplementation period (the same diets as in the first stage). The iron and zinc content in serum was measured using ASA. Total cholesterol (TC), HDL cholesterol (HDL-C), non-HDL cholesterol (non-HDL-C) and triglycerides (TG) were determined. After 4-week supplementation (stage II) and post-supplementation (stage III) periods combined iron/zinc supplementation decreased HDL-C and increased non-HDL-C concentrations in control rats, and in contrast to iron supplementation alone TG concentration decreased. After stage II combined iron/zinc supplementation did not result in increased non-HDL-C and TG concentrations in iron deficient rats in contrast to iron supplementation alone. After stage III both iron and simultaneous iron/zinc supplementation were the cause of TC increase which was the result of the increase of non-HDL-C but not HDL-C concentration in iron deficient rats. In conclusion, there were no beneficial effects of simultaneous iron and zinc supplementation on the lipid profile of rats fed control and iron deficient diets. Combined iron and zinc supplementation may contribute to lower HDL-C and higher non-HDL-C concentrations.

Short Telomere Length Is Related to Limitations in Physical Function in Elderly European Adults

The present study aims to explore the potential influence of leucocyte telomere length (LTL) on both a single indicator and a composite construct of physical functioning in a large European population of elderly men and women across diverse geographical locations. A total of 1,221 adults (65–79 years) were recruited from five European countries within the framework of NU-AGE study. The physical functioning construct was based on the 36-item Short Form Health Survey. Handgrip strength was used as a single indicator of muscle function and LTL was assessed using quantitative real-time PCR. Women had significantly longer (p < 0.05) LTL than men. Participants in Poland had significantly shorter LTL than in the other study centers, whereas participants in the Netherlands had significantly longer LTL than most of the other centers (p < 0.01). An analysis of LTL as a continuous outcome against physical functioning by using linear models revealed inconsistent findings. In contrast, based on an analysis of contrasting telomere lengths (first vs. fifth quintile of LTL), a significant odds ratio (OR) of 1.7 (95% CI: 1.1 – 2.6; p < 0.05) of having functional limitation was observed in those belonging to the first LTL quintile compared to the fifth. Interestingly, having the shortest LTL was still related to a higher likelihood of having physical limitation when compared to all remaining quintiles (OR: 1.5, 95% CI: 1.1 – 2.1; p < 0.05), even after adjustment by study center, age, sex, and overweight status. Collectively, our findings suggest that short LTL is an independent risk factor that accounts for functional decline in elderly European populations. The influence of LTL on functional limitation seems driven by the detrimental effect of having short telomeres rather than reflecting a linear dose-response relationship.

Iron absorption after introducing and discontinuation of iron and zinc supplementation in rats.

The aim of this study was to investigate the changes in iron apparent absorption (IAA%) during and after iron and zinc supplementation in rats. The study was conducted on 6-week old male Wistar rats in 3 stages: 4-week period of adaptation to the control (C) and iron deficient (D) diets (stage I); 4-week period of supplementation with 10-time more iron (CSFe, DSFe), zinc (CSZn, DSZn) or both iron and zinc (CSFeZn, DSFeZn) compared to C diet (stage II); 2-week of post-supplementation period (rats were fed the same diets as in the adaptation period, stage III). IAA% was measured in five consecutive days directly after introducing and discontinuation of iron and zinc supplementation as well as in the end of stage II (days: 22-24th) and stage III (days: 8-10th). Overall in the second day after introducing and in the fifth day after discontinuation of iron or iron and zinc supplementation, the IAA% had undergone to the level compatible with the values in the end of each stage. At the end of stage II, IAA% in CSFeZn (54.1 ± 2.7%) rats was not different from the IAA% in CSFe rats (53.9 ± 1.9%), but in DSFeZn group IAA% (49.4 ± 2.1%) was significantly lower than in DSFe (57.4 ± 2.3%) group. Moreover, IAA% after stage II and stage III in DSZn group was significantly lower (39.2 ± 2.8% and 38.6 ± 2.6%, respectively) than in group D (60.7 ± 1.9% and 54.3 ± 3.0%, respectively). In conclusion, zinc administered simultaneously with iron (Zn:Fe weight ratio=1:1) decreased IAA% in adult rats fed on iron deficient diet, but not in rats fed on control diet. IAA% reduction by zinc supplementation has been extended to 10 days after discontinuation of the treatment. Adaptation of the rats to high doses of iron or iron and zinc and also to the cessation of these treatments was relatively fast. However, IAA% was stabilized faster after introducing the supplementation than its discontinuation.