Selenium status in a Northern Irish pregnant cohort with iodine deficiency

Selenium and iodine are trace elements that are maximally concentrated in the thyroid. Iodine is a substrate for thyroid hormone synthesis, while the selenoproteins protect the thyroid from the oxidative stress incurred. We measured plasma selenium concentration in 241 pregnant women in 1st trimester, previously reported to have iodine deficiency. Mean age was 30.3 years (SD 5.4), BMI 26.2 kg/m² (SD 4.9) and 53% reported taking supplements. Median urinary iodine concentration was 73 μg/L (IQR 37-122) (WHO recommendation, ≥150 μg/L). Mean plasma selenium concentration was 75 µg/L (SD 7.7) which is below the 80-125 µg/L reported to be optimal. Four-day food diaries revealed a selenium intake of 43 µg/day (SD 15.9), also below the 55-70 µg/day reported to be optimal. This is the first report of selenium status in pregnancy on the island of Ireland. The possible combined effects of iodine and selenium deficiencies in pregnancy merit further investigation.

Speciation and Bioavailability of Selenium in Yeast-Based Intervention Agents Used in Cancer Chemoprevention Studies

This study investigated the speciation and bioavailability of selenium in yeast-based intervention agents from multiple manufacturers from several time points. Sources of selenized yeast included Nutrition 21 (San Diego, CA), which supplied the Nutritional Prevention of Cancer (NPC) Trial from 1981–1996; Cypress Systems (Fresno, CA; 1997–1999); and Pharma Nord (Vejle, Denmark; 1999–2000), which supplied the Prevention of Cancer by Intervention by Selenium (PRECISE) Trial pilot studies. The low-molecular-selenium species were liberated from the samples by proteolytic hydrolysis followed by separation by ion exchange liquid chromatography and detection by inductively coupled plasma-mass spectrometry. The results for the NPC tablets showed that selenomethionine, together with 3 unidentified selenium compounds, were predominant in the sample hydrolysates. The relative amounts of the 4 selenium species varied (p < 0.05) among several of the 7 tablet batches used during the course of the NPC Trial. In comparison, 5 batches of more recently produced selenized yeasts, which were used as a source of selenium in the PRECISE and other trials, contained less of the unknown compounds and more selenomethionine at 54–60% of the total selenium in the yeasts. One batch of yeast, however (from 1985), which originated from the same producer as the yeast used in the NPC tablets, contained only 27% of selenium in the sample as selenomethionine. Human subjects receiving 200 μg selenium/day in the UK PRECISE Pilot Trial showed a higher concentration (p < 0.01) and higher increase from baseline in plasma selenium than did the same dosage used in the NPC Trial. Differences in intake, speciation, or bioavailability of selenium from the yeast-based supplements in the population groups studied may explain this. Furthermore, the selenium concentration in whole blood from the Danish PRECISE Pilot Trial was higher (p < 0.001) than that obtained with synthetic L-selenomethionine in a comparable group of Danes, both groups having been treated with 300 μg selenium/day.

Iodine status of teenage girls on the island of Ireland

PURPOSE

The trace element iodine is a vital constituent of thyroid hormones. Iodine requirements increase during pregnancy, when even mild deficiency may affect the neurocognitive development of the offspring. Urinary iodine concentration (UIC) is the means of assessing iodine status in population surveys; a median UIC of 100-199 µg/L is deemed sufficient in a non-pregnant population. Milk is the main dietary source of iodine in the UK and Ireland.

METHODS

We surveyed the iodine status of 903 girls aged 14-15 years in seven sites across the island of Ireland. Urine iodine concentration was measured in spot-urine samples collected between March 2014 and October 2015. Food group intake was estimated from iodine-specific food-frequency questionnaire. Milk-iodine concentration was measured at each site in summer and winter.

RESULTS

The median UIC overall was 111 µg/L. Galway was the only site in the deficient range (median UIC 98 µg/L). All five of the Republic of Ireland sites had UIC ≤ 105 µg/L. In the two sites surveyed twice, UIC was lower in summer vs winter months [117 µg/L (IQR 76-165) vs 130 µg/L (IQR 91-194) (p < 0.01)]. Milk samples collected from Galway and Roscommon had a lower mean iodine concentration than those from Derry/Londonderry (p < 0.05). Milk intake was positively associated with UIC (p < 0.001).

CONCLUSIONS

This is the largest survey of its kind on the island of Ireland, which currently has no iodine-fortification programme. Overall, the results suggest that this young female population sits at the low end of sufficiency, which has implications if, in future, they enter pregnancy with borderline status.

Strategies for optimising musculoskeletal health in the 21st century

We live in a world with an ever-increasing ageing population. Studying healthy ageing and reducing the socioeconomic impact of age-related diseases is a key research priority for the industrialised and developing countries, along with a better mechanistic understanding of the physiology and pathophysiology of ageing that occurs in a number of age-related musculoskeletal disorders. Arthritis and musculoskeletal disorders constitute a major cause of disability and morbidity globally and result in enormous costs for our health and social-care systems.By gaining a better understanding of healthy musculoskeletal ageing and the risk factors associated with premature ageing and senescence, we can provide better care and develop new and better-targeted therapies for common musculoskeletal disorders. This review is the outcome of a two-day multidisciplinary, international workshop sponsored by the Institute of Advanced Studies entitled "Musculoskeletal Health in the 21st Century" and held at the University of Surrey from 30th June-1st July 2015.The aim of this narrative review is to summarise current knowledge of musculoskeletal health, ageing and disease and highlight strategies for prevention and reducing the impact of common musculoskeletal diseases.

How Do We Improve the Impact of Iodine Deficiency Disorders Prevention in Europe and Beyond?

BACKGROUND

Iodine deficiency disorders (IDD) represent a global health threat to individuals and societies. IDD prevention programmes have been introduced in many parts of the world. However, challenges remain, particularly in Europe due to fragmentation and diversity of approaches that are not harmonized.

OBJECTIVES

This review is dedicated to the public-health impact of IDD prevention programmes. It sums up experiences collected by the EUthyroid consortium so far and provides information on stakeholders that should be involved in actions directed to improve the impact of IDD prevention.

METHODS

A joint European database for combining registry-based outcome and monitoring data as well as tools for harmonizing study methods were established. Methods for analyzing thyroglobulin from a dried blood spot are available for assessing the iodine status in the general population and at-risk groups. Mother-child cohorts are used for in-depth analysis of the potential impact of mild-to-moderate iodine deficiency on the neurocognitive development of the offspring. A decision-analytic model has been developed to evaluate the long-term effectiveness and cost effectiveness of IDD prevention programmes.

RESULTS

EUthyroid has produced tools and infrastructure to improve the quality of IDD monitoring and follows a dissemination strategy targeting policymakers and the general public. There are tight connections to major stakeholders in the field of IDD monitoring and prevention.

CONCLUSIONS

EUthyroid has taken steps towards achieving a euthyroid Europe. Our challenge is to inspire a greater sense of urgency in both policymakers and the wider public to address this remediable deficit caused by IDD.

Higher selenium status is associated with adverse blood lipid profile in British adults

Recent findings have raised concern about possible associations of high selenium exposure with diabetes and hyperlipidemia in the US, a population with high selenium status. In the UK, a population with lower selenium status, there is little data on the association of selenium status with cardio-metabolic risk factors in the general population. We examined the association of plasma selenium concentration with blood lipids in a nationally representative sample of British adults. A cross-sectional study was conducted among 1042 white participants (aged 19-64 y) in the 2000-2001 UK National Diet and Nutrition Survey. Plasma selenium was measured by inductively coupled-plasma mass spectrometry. Total and HDL cholesterol were measured in nonfasting plasma samples. Mean plasma selenium concentration was 1.10 +/- 0.19 micromol/L. The multivariate adjusted differences between the highest (> or =1.20 micromol/L) and lowest (<0.98 micromol/L) quartiles of plasma selenium were 0.39 (95% CI 0.18, 0.60) mmol/L for total cholesterol, 0.38 (0.17, 0.59) for non-HDL cholesterol, and 0.01 (-0.05, 0.07) for HDL cholesterol. Higher plasma selenium (i.e., > or =1.20 micromol/L) was associated with increased total and non-HDL cholesterol levels but not with HDL in the UK adult population. These findings raise additional concern about potential adverse cardio-metabolic effects of high selenium status. Randomized and mechanistic evidence is necessary to assess causality and to evaluate the impact of this association on cardiovascular risk.

Impact of selenium on mood and quality of life: a randomized, controlled trial

BACKGROUND

Selenium is known to be important to the brain. Three small, published studies have suggested an effect of selenium supplementation or deprivation on mood in healthy volunteers. We investigated these findings on a much larger scale.

METHODS

In this double-blind, placebo-controlled intervention, 501 UK participants aged 60-74 were randomly allocated to receive 100, 200 or 300 microg selenium/d as high-selenium yeast or placebo yeast. Mood (Profile of Moods States - Bipolar Form [POMS-BI] questionnaire), "quality of life" (Short Form 36 [SF-36] questionnaire) and plasma selenium were measured at baseline and six months.

RESULTS

Supplementation significantly increased plasma selenium above baseline values: from an overall mean (SD) of 90(19) ng/g to 91(26), 144(27), 191(41) and 227(53) ng/g in the placebo, 100, 200, 300 microg selenium groups respectively (p < .001). Four hundred forty-eight participants completed the POMS-BI questionnaires at both time points, with no significant differences in total mood or mood-subscale scores seen between doses. After six months of supplementation, mean (SD) total mood scores for the four doses were 163(36), 161(37), 162(33), 162(34), F(3,443) = .25, p = .86. Quality of life was similarly unaffected.

CONCLUSIONS

There was no evidence that selenium supplementation benefited mood or quality of life in these elderly volunteers. Though this is at odds with some previous results, our robust study design, much larger sample size and longer supplementation period, together with the evidence that the brain is a privileged site for selenium retention, suggest that this is a reliable finding.

Speciation and bioavailability of selenium in yeast-based intervention agents used in cancer chemoprevention studies

This study investigated the speciation and bioavailability of selenium in yeast-based intervention agents from multiple manufacturers from several time points. Sources of selenized yeast included Nutrition 21 (San Diego, CA), which supplied the Nutritional Prevention of Cancer (NPC) Trial from 1981-1996; Cypress Systems (Fresno, CA; 1997-1999); and Pharma Nord (Vejle, Denmark; 1999-2000), which supplied the Prevention of Cancer by Intervention by Selenium (PRECISE) Trial pilot studies. The low-molecular-selenium species were liberated from the samples by proteolytic hydrolysis followed by separation by ion exchange liquid chromatography and detection by inductively coupled plasma-mass spectrometry. The results for the NPC tablets showed that selenomethionine, together with 3 unidentified selenium compounds, were predominant in the sample hydrolysates. The relative amounts of the 4 selenium species varied (p < 0.05) among several of the 7 tablet batches used during the course of the NPC Trial. In comparison, 5 batches of more recently produced selenized yeasts, which were used as a source of selenium in the PRECISE and other trials, contained less of the unknown compounds and more selenomethionine at 54-60% of the total selenium in the yeasts. One batch of yeast, however (from 1985), which originated from the same producer as the yeast used in the NPC tablets, contained only 27% of selenium in the sample as selenomethionine. Human subjects receiving 200 microg selenium/day in the UK PRECISE Pilot Trial showed a higher concentration (p < 0.01) and higher increase from baseline in plasma selenium than did the same dosage used in the NPC Trial. Differences in intake, speciation, or bioavailability of selenium from the yeast-based supplements in the population groups studied may explain this. Furthermore, the selenium concentration in whole blood from the Danish PRECISE Pilot Trial was higher (p < 0.001) than that obtained with synthetic L-selenomethionine in a comparable group of Danes, both groups having been treated with 300 microg selenium/day.