The association between plasma selenium and chronic kidney disease related to lead, cadmium and arsenic exposure in a Taiwanese population.

This study aimed to determine the interaction of red blood cell cadmium and lead, total urinary arsenic, and plasma selenium in chronic kidney disease (CKD). We recruited 220 CKD patients as well as 438 gender- and age-matched controls, and we defined CKD as <60 mL/min/1.73 m2 estimated glomerular filtration rate (eGFR) for three or more consecutive months. Plasma selenium and red blood cell cadmium and lead concentrations were measured by ICP-MS. Urinary arsenic species were determined via HPLC-HG-AAS and were summed to determine the total urinary arsenic concentration. Plasma selenium was positively correlated to eGFR, and subjects with high plasma selenium levels (>243.90 µg/L) had a significantly lower odds ratio (OR) and 95% confidence interval (CI) (0.23, 0.13-0.42) for CKD compared to those with low plasma selenium levels (≤ 196.70 µg/L). High plasma selenium and low red blood cell cadmium or lead concentrations interacted to decrease the OR and 95% CI for CKD (0.12, 0.06-0.26; 0.09, 0.04-0.19). High plasma selenium and low red blood cell lead levels also interacted to increase the eGFR (20.70, 15.56-26.01 mL/min/1.73 m2). This study is the first to suggest that selenium modifies the eGFR and OR in CKD induced by environmental toxicants.

Plasma selenium influences arsenic methylation capacity and developmental delays in preschool children in Taiwan.

Inefficient arsenic methylation capacity has been associated with developmental delay in preschool children. Selenium has antioxidant and anti-inflammatory properties that protect experimental animals from chemically induced neurotoxicity. The present study was designed to explore whether plasma selenium levels affects arsenic methylation capacity related to developmental delay in preschool children. A case-control study was conducted from August 2010 to March 2014. All participants were recruited from the Shin Kong Wu Ho-Su Memorial Teaching Hospital. In total, 178 children with a developmental delay and 88 children without a delay were recruited. High-performance liquid chromatography-linked hydride generator and atomic absorption spectrometry were used to determine urinary arsenic species, including arsenite (AsIII), arsenate (AsV), monomethylarsonic acid (MMAV), and dimethylarsinic acid (DMAV). Plasma selenium levels were measured by inductively coupled plasma mass spectrometry. As results, plasma selenium concentration was significantly inversely associated with the odds ratio (OR) of developmental delay. Plasma selenium concentration was positively associated with arsenic methylation capacity [percentage of inorganic arsenic and percentage of MMAV (MMAV%) decreased, and percentage of DMAV (DMAV%) increased]. High plasma selenium concentration and high DMA% significantly and additively interacted to decrease the OR of developmental delay; the OR and 95% confidence interval were 0.40 (0.18-0.90). This is the first study to show a combined dose-response effect of plasma selenium concentration and that efficient arsenic methylation capacity decreased the OR of developmental delay in preschool children.

Effects of calorie restriction plus fish oil supplementation on abnormal metabolic characteristics and the iron status of middle-aged obese women.

The increasing prevalence of obesity and sedentary lifestyles has led to a higher incidence of metabolic syndrome (MetS) worldwide as well as in Taiwan. Middle-aged women are at a greater risk of MetS, type 2 diabetes, and cardiovascular disease than men because they have more subcutaneous fat and larger waist circumferences compared with men with equal visceral fat levels. In this study, we investigated the effects of calorie restriction (CR) and fish oil supplementation (CRF) on middle-aged Taiwanese women with MetS. An open-label, parallel-arm, controlled trial was conducted for 12 weeks. A total of 75 eligible participants were randomly assigned to the CR or CRF group. Both the dietary intervention groups were further divided into two age groups: ≤45 and >45 years. Changes in MetS severity, inflammatory status, iron status, and red blood cell fatty acid profile were evaluated. A total of 71 participants completed the trial. Both dietary interventions significantly ameliorated MetS and improved the participants' inflammatory status. CR significantly increased the total iron-binding capacity (TIBC) whereas CRF increased hepcidin levels in women aged >45 years. Furthermore, CRF significantly increased the n-6/n-3 and arachidonic acid/docosahexaenoic acid ratios. Both interventions improved the anthropometric and MetS characteristics, including body weight, blood glucose and triglyceride levels, and the score of the homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index. In conclusion, the 12-week dietary interventions improved the abnormal metabolic status of middle-aged obese women. CRF was demonstrated to be more effective in ameliorating postprandial glucose level and TIBC in women aged >45 years than in those aged ≤45 years.

Ferric Citrate Supplementation Reduces Red-Blood-Cell Aggregation and Improves CD163+ Macrophage-Mediated Hemoglobin Metabolism in a Rat Model of High-Fat-Diet-Induced Obesity.

SCOPE: In adults, >90% of the daily iron requirement is derived from macrophage-mediated heme iron, recycling from senescent red blood cells (RBCs) or free hemoglobin (Hb). Currently, the effects of pharmacological doses of iron supplementation on RBCs and heme iron recycling in obesity are unclear. METHODS AND RESULTS: Sprague Dawley rats are fed a standard diet or a 50% high-fat diet (HFD) with (0.25, 1, and 2 g of ferric iron per kg diet) or without ferric citrate supplementation for 12 weeks. Ferric iron increases hepatic iron accumulation in macrophages and hepatocyte-like cells. Compared with rats that received the standard diet, HFD-fed rats exhibit higher RBC aggregation and serum-free Hb levels but lower LVV-hemorphin-7 levels. These effects are reversed by ferric citrate supplementation. Immunofluorescent staining reveals that ferric iron increases the expression of hepatic CD163+ macrophages and heme oxygenase (HO)-1. A further analysis reveals the dose-related effects of ferric iron on hepatic globin degradation proteins (cathepsin D and glyoxalase 1), cytochrome p450 reductase expression, and HO-1 enzyme activity. CONCLUSIONS: Ferric citrate supplementation reduces RBC aggregation and improves CD163+ macrophage-mediated Hb metabolism in HFD-induced obese rats. These findings suggest that ferric citrate may be explored as an alternative treatment method for RBC dysfunction.

Levels of plasma selenium and urinary total arsenic interact to affect the risk for prostate cancer.

This study investigated whether plasma selenium levels modified the risk for prostate cancer (PC) related to arsenic exposure. We conducted a case-control study that included 318 PC patients and 318 age-matched, healthy control subjects. Urinary arsenic profiles were examined using HPLC-HG-AAS and plasma selenium levels were measured by ICP-MS. We found that plasma selenium levels displayed a significant dose-dependent inverse association with PC. The odds ratio (OR) and 95% confidence interval (CI) for PC was 0.07 (0.04-0.13) among participants with a plasma selenium level >28.06 µg/dL vs. ≤19.13 µg/dL. A multivariate analysis showed that participants with a urinary total arsenic concentration >29.28 µg/L had a significantly higher OR (1.75, 1.06-2.89) for PC than participants with ≤29.89 µg/L. The combined presence of a low plasma selenium level and a high urinary total arsenic concentration exponentially increased the OR for PC, and additively interacted with PSA at levels ≥20 ng/mL. This is the first epidemiological study to examine the combined effects of plasma selenium and urinary total arsenic levels on the OR for PC. Our data suggest a low plasma selenium level coupled with a high urinary total arsenic concentration creates a significant risk for aggressive PC.

Effect of Feedback Signal on Blood Pressure Self-regulation Capability in Individuals With Prehypertension or Stage I Hypertension: A Randomized Controlled Study.

OBJECTIVES: We aimed to determine the efficacy of an 8-week direct blood pressure (BP) biofeedback training program for prehypertensive or stage I hypertensive patients with a particular focus on the impact of the authenticity of feedback signals on the efficacy of BP regulation. DESIGNS: This study has a randomized, double-blind, parallel-group design. PARTICIPANTS AND METHODS: Fifty-nine individuals with ages from 18 to 64 years and who met the criteria for the diagnosis of prehypertenion or stage 1 hypertension participated in this study. The participants were referrals from physicians or community-dwelling volunteers. No participants had taken antihypertensive medication within the previous 2 months prior to enrollment. The participants were randomly assigned to the biofeedback group (n = 31) trained with real-time BP feedback signals or the control group (n = 28) trained with pseudofeedback signals. The primary outcome measures were systolic BP (SBP) and diastolic BP (DBP). Systolic BP and DBP were assessed at baseline, 1 week after training (week 9), and 8 weeks after training (week 16) in both groups. Only 54 participants had week 16 data. RESULTS: The changes in SBP and DBP from baseline to week 9, from baseline to week 16, and from week 9 to week 16 were not significantly different between the groups (All P > 0.05). Both groups were able to significantly decrease BP after completing the training. A percentage of 45.2% of the participants in the biofeedback group and 63.0% of the participants in the control group lowered their SBP by 5 mm Hg or more at week 9. The SBP-lowering effects were also maintained for at least 8 weeks after the completion of training. CONCLUSIONS: The equivalent magnitude of BP reduction between the 2 study groups suggests that repeated practice in BP self-regulation was more likely responsible for the efficacy of direct BP biofeedback training than was the type of feedback signals.