Trace mineral status in post menopausal women: impact of hormonal replacement therapy

Hair and Serum Trace Element and Mineral Levels Profiles in Women with Premenopausal and Postmenopausal Osteoporosis

The objective of the present study was to evaluate serum and hair trace element and mineral levels in women with osteoporosis, as well as to estimate the impact of menopausal status on the profile of trace element and mineral status in women with osteoporosis. 207 women with diagnosed osteoporosis 22-85 years-of-age, and 197 healthy women of the respective age participated in the present study. Analysis of the levels of mineral and trace element in hair and serum samples was performed by inductively-coupled plasma mass-spectrometry (ICP-MS). Women with osteoporosis were characterized by significantly lower hair Ca, Mg, Co, I, Li, and Mn levels, as well as serum Ca, Mg, Co, Fe, V, and Zn concentrations compared to women in the control group. After additional grouping according to menopausal status, the lowest hair Ca and Mg content was observed in postmenopausal osteoporotic women, whereas serum Ca and Mg concentrations were the lowest in premenopausal osteoporotic women. Hair Co, Mn, and Zn levels in postmenopausal osteoporotic women were lower than in healthy postmenopausal women. The lowest circulating Zn levels were observed in osteoporotic postmenopausal women. Taken together, decreased hair and serum levels in osteoporotic women are indicative of increased risk of Ca, Mg, Co, and Zn deficiency in women with osteoporosis. In turn, alterations in hair trace element and mineral levels in osteoporosis are more profound in postmenopausal women. Hypothetically, improvement in trace element and mineral metabolism especially in postmenopausal women may be considered as a potential strategy for mitigating osteoporosis.

Consequences of Disturbing Manganese Homeostasis

Manganese (Mn) is an essential trace element with unique functions in the body; it acts as a cofactor for many enzymes involved in energy metabolism, the endogenous antioxidant enzyme systems, neurotransmitter production, and the regulation of reproductive hormones. However, overexposure to Mn is toxic, particularly to the central nervous system (CNS) due to it causing the progressive destruction of nerve cells. Exposure to manganese is widespread and occurs by inhalation, ingestion, or dermal contact. Associations have been observed between Mn accumulation and neurodegenerative diseases such as manganism, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. People with genetic diseases associated with a mutation in the gene associated with impaired Mn excretion, kidney disease, iron deficiency, or a vegetarian diet are at particular risk of excessive exposure to Mn. This review has collected data on the current knowledge of the source of Mn exposure, the experimental data supporting the dispersive accumulation of Mn in the brain, the controversies surrounding the reference values of biomarkers related to Mn status in different matrices, and the competitiveness of Mn with other metals, such as iron (Fe), magnesium (Mg), zinc (Zn), copper (Cu), lead (Pb), calcium (Ca). The disturbed homeostasis of Mn in the body has been connected with susceptibility to neurodegenerative diseases, fertility, and infectious diseases. The current evidence on the involvement of Mn in metabolic diseases, such as type 2 diabetes mellitus/insulin resistance, osteoporosis, obesity, atherosclerosis, and non-alcoholic fatty liver disease, was collected and discussed.

The Role of Trace Elements and Minerals in Osteoporosis: A Review of Epidemiological and Laboratory Findings

The objective of the present study was to review recent epidemiological and clinical data on the association between selected minerals and trace elements and osteoporosis, as well as to discuss the molecular mechanisms underlying these associations. We have performed a search in the PubMed-Medline and Google Scholar databases using the MeSH terms "osteoporosis", "osteogenesis", "osteoblast", "osteoclast", and "osteocyte" in association with the names of particular trace elements and minerals through 21 March 2023. The data demonstrate that physiological and nutritional levels of trace elements and minerals promote osteogenic differentiation through the up-regulation of BMP-2 and Wnt/β-catenin signaling, as well as other pathways. miRNA and epigenetic effects were also involved in the regulation of the osteogenic effects of trace minerals. The antiresorptive effect of trace elements and minerals was associated with the inhibition of osteoclastogenesis. At the same time, the effect of trace elements and minerals on bone health appeared to be dose-dependent with low doses promoting an osteogenic effect, whereas high doses exerted opposite effects which promoted bone resorption and impaired bone formation. Concomitant with the results of the laboratory studies, several clinical trials and epidemiological studies demonstrated that supplementation with Zn, Mg, F, and Sr may improve bone quality, thus inducing antiosteoporotic effects.

Blood Copper Levels and the Occurrence of Colorectal Cancer in Poland

There is a need for sensitive and specific biomarkers for the early detection of colorectal cancer. In this retrospective study, we assessed whether a high blood copper level was associated with the presence of colorectal cancer. The blood copper level was measured among 187 colorectal cancer patients and 187 matched controls. Cases and controls were matched for sex, smoking status (yes/no) and year of birth. Among the cases, the mean blood copper level was 1031 µg/L (range 657 µg/L to 2043 µg/L) and among the controls, the mean blood copper level was 864 µg/L (range 589 µg/L to 1433 µg/L). The odds ratio for colorectal cancer for those in the highest quartile of copper level (versus the lowest) was 12.7 (95% CI: 4.98–32.3; p < 0.001). Of the patients with stage I–II colon cancer, 62% had a copper level in the highest quartile. A blood copper level in excess of 930 µg/L is associated with an increase in the prevalence of colorectal cancer in the Polish population and its potential use in early detection programs should be considered.

Evaluation of biomarkers related to zinc nutritional status, antioxidant activity and oxidative stress in rheumatoid arthritis patients

BACKGROUND

Oxidative stress (OS) is an important process related to the pathophysiology of rheumatoid arthritis and can be increased by the low intake of antioxidants. Zinc (Zn) is an important antioxidant trace-element for human health and the assessment of the nutritional status of this micronutrient in these patients is of relevance.

AIM

This study aimed to evaluate Zn nutritional status in rheumatoid arthritis patients and its relation to OS.

METHODS

A case-control study was carried out with 51 patients diagnosed with rheumatoid arthritis (RA group) recruited in Hospital São Paulo (São Paulo, Brazil) and 55 healthy women (CO group) from the campus of the University of São Paulo. Blood and 24-hour urine collection were used for biochemical parameters related to Zn status and OS. The assessment of dietary Zn was performed by three 24-hour dietary recalls.

RESULTS

The RA group presented significative low Zn intake (p < 0.001) and plasma concentration (p = 0.040) of this mineral compared to the CO group. However, both groups were Zn deficient and the disease activity (DAS28 score) for RA patients did not influence Zn biomarkers. In addition, the antioxidant enzymes (superoxide dismutase and glutathione peroxidase) activity and the urinary 8-isoprostanes were reduced in RA patients.

CONCLUSION

The evaluation of dietary intake and biochemical biomarkers indicates that rheumatoid arthritis patients are zinc deficient and have increased OS.

Multi-element Analysis of Brain Regions from South African Cadavers

Trace elements are vital for a variety of functions in the brain. However, an imbalance can result in oxidative stress. It is important to ascertain the normal levels in different brain regions, as such information is still lacking. Therefore, this study aimed to provide baseline trace element concentrations from a South African population, as well as determine trace element differences between sex and brain regions. Samples from the caudate nucleus, putamen, globus pallidus and hippocampus were analysed using inductively coupled plasma mass spectrometry. Aluminium, antimony, arsenic, barium, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, phosphorus, potassium, selenium, silicon, sodium, strontium, vanadium and zinc were assessed. A multiple median regression model was used to determine differences between sex and regions. Twenty-nine male and 13 female cadavers from a Western Cape, South African population were included (mean age 35 years, range 19 to 45). Trace element levels were comparable to those of other populations, although magnesium was considerably lower. While there were no sex differences, significant anatomical regional differences existed; the caudate nucleus and hippocampus were the most similar, and the globus pallidus and hippocampus the most different. In conclusion, this is the first article to report the trace element concentrations of brain regions from a South African population. Low magnesium levels in the brain may be linked to a dietary deficiency, and migraines, depression and epilepsy have been linked to low magnesium levels. Future research should be directed to increase the dietary intake of magnesium.

Comparison of Serum Iron, Zinc, and Selenium Levels in Premenopausal and Postmenopausal Women in Ekpoma, Nigeria: A Descriptive Study

Background: Estrogen deficiency following menopause creates an imbalance in plasma micronutrient resulting in several degenerative pathological conditions, including hypertension, cardiovascular disease, osteoporosis, etc. Objectives: The present study was designed to compare zinc (Zn), iron (Fe), and selenium (Se) concentrations between premenopausal and postmenopausal women. Methods: In this descriptive study a total of 200 participants were classified into two groups of postmenopausal (age range: 46-75 years, served as experimental) and premenopausal (age range: 30-45 years, served as control). Each group consisted of 100 subjects. After obtaining informed consent from all participants, blood samples were collected from the antecubital fossa vein of each participant by venipuncture. The concentrations of Fe, Zn, and Se in each blood sample were determined using Atomic Absorption Spectrophotometer. Results: No significant difference (P>0.05) was observed in serum Fe (114.24 ± 26.79 µg/dL), Zn (83.11 ± 20.45 µg/dL), and Se (41.99 ± 9.78 µg/dL) levels between the control and experimental groups. However, serum Fe and Zn showed progressive significant (P=0.04, 0.03, respectively) increase with increasing postmenopausal age. Conversely, serum Se concentration decreased significantly (P=0.03) with increasing menopausal age. Conclusion: Although no significant difference was observed in serum levels of Fe, Zn, and Se between pre- and post-menopausal women, the progressive significant increase in the serum Fe and Zn levels as well as significant decrease in serum Se level with advancing post-menopausal age portend a great risk.

Serum copper, zinc, and iron levels, and markers of carbohydrate metabolism in postmenopausal women with prediabetes and type 2 diabetes mellitus

The objective of the present study was to evaluate serum level of copper, zinc, iron and metabolic parameters in postmenopausal women with diabetes. A total of 413 postmenopausal women were enrolled in the current study. Women were divided into 4 groups with equal age and body mass index according to glycated hemoglobin (HbA_1c) levels (≤5.5; 5.5-6.0; 6.0-6.5; >6.5%). Serum Fe, Cu, and Zn levels were assessed using inductively-coupled plasma mass-spectrometry. Blood HbA_1c, serum glucose, insulin, C-reactive protein (CRP), ferritin, and ceruloplasmin (Cp) were assessed using commercial kits. Homeostatic model assessment insulin resistance (HOMA-IR) and transferrin (Tf) saturation were calculated. The obtained data demonstrate that every 0.5% increase in HbA_1c levels from 5.5% is associated with a significant elevation of glucose, insulin, CRP, and HOMA-IR values. Diabetic patients were characterized by significantly higher Fe (11%), Cu (8%), and Zn (6%) levels as compared to the controls. At the same time, the overall trend to increased metal levels in association with HbA_1c was detected only for Fe (p<0.05) and Cu (p<0.05). Serum ferritin levels in diabetic women was 3-fold higher than in the controls, whereas Tf saturation was decreased by 35%. Serum Cp levels were significantly increased by 19% in prediabetes, whereas in diabetic postmenopausal women no such increase was observed. A significant elevation of total metal concentration in diabetic subjects without a concomitant elevation of transport proteins may be indicative of increased levels of "free" Fe and Cu, known to be toxic.

Associations of Serum Manganese Levels with Prediabetes and Diabetes among ≥60-Year-Old Chinese Adults: A Population-Based Cross-Sectional Analysis

Older adults can experience glucose metabolism dysfunction, and although manganese may help regulate glucose metabolism, there is little information regarding this association among older people. This cross-sectional study included 2402 Chinese adults who were ≥60 years old in 2013 (Tianjin, China), and evaluated the associations of serum manganese with prediabetes and diabetes. Serum manganese levels were measured using inductively coupled plasma mass spectrometry. Multivariable logistic regression models were used to evaluate the sex-specific associations of manganese levels with diabetes and prediabetes after adjusting for confounding factors (age, sex, life style factors, and health status). Based on the WHO criteria, prediabetes was observed in 15.1% of men and 13.4% of women, while diabetes was observed in 30.0% of men and 34.4% of women. In the final model, the odds ratios (95% confidence interval) for prediabetes according to manganese quartile were 1.000, 0.463 (0.269–0.798), 0.639 (0.383–1.065), and 0.614 (0.365–1.031) among men and 1.000, 0.773 (0.498–1.200), 0.602 (0.382–0.947), and 0.603 (0.381–0.953) among women (p for trend = 0.134 and 0.015, respectively). The lowest prevalence of diabetes among men occurred at a moderate range of serum manganese (p < 0.05). Therefore, appropriate serum manganese levels may help prevent and control prediabetes and diabetes.

Zinc and copper status in childbearing age Tunisian women: Relation to age, residential area, socioeconomic situation and physiologic characteristics

Plasma zinc and copper status of 1689 non pregnant Tunisian women, aged 20-49 years old, was determined by flame atomic absorption spectrometry. A multiple regression was run to predict plasma trace element concentrations from age, BMI, marital status, menopause, education level, professional activity, economic level and area of living. The mean zinc and copper values were similar to those measured among comparable populations in earlier studies. However, a high prevalence of low plasma zinc and copper concentrations was observed assuming that women at childbearing age are at high risk of zinc and copper deficiencies and specific intervention may be considered. In univariate analysis, the mean values of plasma zinc and copper were associated with sitting areas and professional activity. For only plasma copper levels, there was an increase with BMI and parity, and a decrease with increasing schooling level and economic score. After adjustment for all variables, profession and parity showed a significant relationship between plasma levels copper.

Serum zinc concentrations correlate with mental and physical status of nursing home residents

INTRODUCTION

Zinc (Zn) is one of the most important trace elements in the body. Zn deficiency seems to play a role in the development of age-related diseases and impairment of quality of life. Zn status has been especially studied in free-living or hospitalised people, but data from older residents of nursing homes are scarce. This study aimed to determine the Zn status among the older individuals in correlation to their mental and physical performance.

METHODS

A total of 100 participants aged between 60-102 years were recruited between October 2010 and May 2012 at the nursing home in Bialystok (Poland). Zn status was evaluated by determining the concentration in serum by flame atomic absorption spectrometry. Anthropometric variables and fitness score (FS) were measured. Abbreviated Mental Test Score (AMTS), Geriatric Depression Scale (GDS), Self-Rated Health (SRH), independence in Activities of Daily Living (ADL) were recorded.

RESULTS AND DISCUSSION

The mean serum Zn concentration was 0.83 ± 0.20 mg/L, 28% of residents had Zn deficiency. Cognitive functions were impaired (AMTS ≤ 8) in 45% of the studied persons and 48% showed depressive symptoms (GDS ≥ 1). The ability to independently perform activities of daily living (ADL = 6) was found in 61% of participants, but most of them (90%) had weak body type (FS < 70), correlating with GDS, SRH and body mass index (BMI). Serum Zn concentration correlated with mental efficiency and was statistically significantly higher in older people with normal cognitive function and without depression than in patients with memory impairment and showing depressive symptoms.

CONCLUSIONS

Nursing home residents seem at risk of marginal Zn status, which correlates with their mental status as measured by the AMTS and GDS. Their low FS is associated with mental health deterioration and obesity.

Impact of aging on urinary excretion of iron and zinc

PROJECT

Data about the influence of aging on urinary excretion of iron and zinc are scarce. The objective of the present study was to compare the concentration of zinc and iron in the urine of healthy elderly subjects and younger adults.

PROCEDURE

Seven healthy elderly subjects and seven younger adults were selected and submitted to biochemical, clinical, and nutritional tests. After a fasting period, 12-hour urine was collected for the determination of iron and zinc concentrations by graphite furnace atomic absorption spectrophotometry.

RESULTS

Urinary zinc and iron concentrations of the elderly subjects were not significantly different from that of younger adults. However, the total zinc and iron urinary clearance in 24 hours for the elderly was significantly higher compared with that of younger adults.

CONCLUSION

There is an increase in urinary iron and zinc clearance with aging. The values reported in this manuscript may be used as references in future studies.

The effect of zinc deficiency and zinc supplementation on element levels in the bone tissue of ovariectomized rats: histopathologic changes

OBJECTIVE

Study aimed to determine the effects of zinc supplementation/deficiency on the histological structure and elements levels in bone tissue in ovariectomized rats.

METHODS

The study included 40 Sprague-Dawley type adult female rats, divided as follows: Control, ovariectomized, ovariectomized + zinc supplemented, ovariectomized + zinc deficient groups. At the end of the study bone tissues (femur) were collected to determine the levels of calcium, phosphorus, magnesium, zinc, iron, aluminium, chrome, lithium, lead, nickel, and manganese. The bone tissue was examined for histopathology.

RESULTS

Ovariectomy leaded to significant decrease in magnesium. Zinc supplementation to ovariectomized rats restored the reduced calcium, phosphorus, zinc. However, zinc deficiency in ovariectomized rats further reduced calcium, phosphorus, zinc, and manganese levels. Zinc deficiency in ovariectomized significantly increased Al, Cr, Li, Pb, and Ni levels. Tissue integrity was impaired due to ovariectomy and zinc deficiency.

CONCLUSION

Ovariectomy and zinc deficiency leads significant decreases elements of the bone.

Association of Zinc, Copper and Magnesium with bone mineral density in Iranian postmenopausal women - a case control study

BACKGROUND

The risk of inadequate nutrition such as trace elements and vitamin deficiencies is considerable in postmenopausal women. The aim of this study was to compare trace elements (Zinc, Copper and Magnesium) concentration in nail, urine and serum among osteoporotic postmenopausal women with control group in Iran.

METHODS

Forty eight postmenopausal women aged 36-60 years, were recruited, consisting 30 osteoporotic patients and 18 healthy controls. Blood, nail and urine concentration of Zinc (Zn), copper (Cu) and magnesium (Mg) were determined using Inductively Coupled Plasma -Atomic Emission Spectrometry (ICP-AES) method. Their Bone Mineral Density was measured by Dual X-ray Absorption (DEXA) method.

RESULTS

The urine level of trace elements had significant difference between osteoporotic groups and controls (p < 0.001). Moreover Mg level significantly differed in serum between two groups (p < 0.04). There was no statistically significant difference in trace minerals in nail beyond groups.

CONCLUSION

Our findings indicate that Urine Zn level could be considerable an appropriate marker for bone absorption, usage of Zn supplements in postmenopausal women may result a beneficial reduction in osteoporotic risk.

Serum levels of trace elements and heavy metals in patients with acute hemorrhagic stroke

Trace elements are essential components of biological structures, but alternatively, they can be toxic at concentrations beyond those necessary for their biological functions. Changes in the concentration of essential trace elements and heavy metals may affect acute hemorrhagic stroke. The aim of this study was to measure serum levels of essential trace elements [iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), and magnesium (Mg)] and heavy metals [cobalt (Co), cadmium (Cd), and lead (Pb)] in patients with acute hemorrhagic stroke. Twenty-six patients with acute hemorrhagic stroke and 29 healthy controls were enrolled. Atomic absorption spectrophotometry (UNICAM-929) was used to measure serum Fe, Cu, Pb, Cd, Zn, Co, Mn and Mg concentrations. Serum Cd, Pb and Fe levels were significantly higher in patients with acute hemorrhagic stroke than controls (p < 0.001), while serum Cu, Zn, Mg and Mn levels were significantly lower (all p < 0.001). However, there was no significant difference between the groups with respect to serum Co levels (p > 0.05). We first demonstrate increased Cd, Pb, and Fe levels; and decreased Cu, Zn, Mg, and Mn levels in patients with acute hemorrhagic stroke. These findings may have diagnostic and prognostic value for acute hemorrhagic stroke. Further studies are required to elucidate the roles of trace elements and heavy metals in patients with acute hemorrhagic stroke.

The effects of PPARδ agonist and zinc on ovariectomized rats' vagina

OBJECTIVES

This study aimed to measure the effects of peroxisome proliferator-activated receptor-δ (PPARδ) agonist GW501516 (GW) and zinc sulfate (ZS) on ovariectomized rats' vaginal histomorphology and collagen expression.

METHODS

Two weeks after ovariectomy, rats received daily treatment with vaginal suppositories containing placebo, ZS, GW, ZS with GW, or estradiol for 2 weeks. Macroscopic measurements were taken and the midsection of the vagina was used for histology. Immunofluorescence was performed with antibodies against collagen I, III, and anti-actin or collagen I and V and anti-actin. Gene expression analysis of 3 collagen genes was performed by qRT-PCR.

RESULTS

Macroscopic measurements revealed that the genital hiatus was narrower in the ZS and ZS with GW groups, and the vagina was significantly longer in the animals treated with GW, ZS with GW, and estradiol compared to the placebo group. Microscopic measurements of the vaginal layers showed that the lamina propria and the vaginal muscularis were significantly thicker in the ZS and ZS with GW group compared to the placebo.The ratio of vaginal Col1a1/Col3a1 mRNA expression was significantly up-regulated by ZS with GW compared to placebo, whereas the ratio of vaginal Col1a1/Col5a1 expression was significantly up-regulated by ZS, GW, and ZS with GW. The ratio of vaginal collagen I/III protein expression was significantly up-regulated by ZS and ZS with GW, whereas the ratio of vaginal collagen I/V expression was significantly up-regulated by estradiol, ZS, and ZS with GW compared to control.

CONCLUSIONS

Vaginal suppositories containing zinc and PPARδ agonist significantly altered the vagina of ovariectomized rats.

Relative and combined effects of ethanol and protein deficiency on bone manganese and copper

Both manganese and copper may affect bone synthesis. Bone content of both metals can be altered in alcoholics, although controversy exists regarding this matter. To analyse the relative and combined effects of ethanol and a low protein diet on bone copper and manganese, and their relationships with bone structure and metabolism, including trabecular bone mass (TBM), osteoid area (OA), osteocalcin (OCN), insulin-like growth factor-1 (IGF-1), parathyroid hormone (PTH), urinary hydroxyproline (uHP) and vitamin D. Adult male Sprague-Dawley rats were divided into four groups. The control rats received a 18% protein-containing diet; a second group, an isocaloric, 2% protein-containing diet; a third one, an isocaloric, 36% ethanol-containing diet and a fourth, an isocaloric diet containing 2% protein and 36% ethanol. After sacrifice, TBM and OA were histomorphometrically assessed; bone and serum manganese and copper were determined by atomic absorption spectrophotometry, and serum OCN, IGF-1, PTH, uHP and vitamin D by radioimmunoassay. Ethanol-fed rats showed decreased TBM and bone manganese. Significant relationships existed between bone manganese and TBM, serum IGF-1 and OCN. Ethanol leads to a decrease in bone manganese, related to decreased bone mass and bone synthesis. No alterations were found in bone copper.

Effects of shock waves on oxidative stress and some trace element levels of rat liver and diaphragm muscles

This study was designed to investigate whether the short-term extracorporeal shockwave lithotripsy (ESWL) exposure to kidney produces an oxidative stress and a change in some trace element levels in liver and diaphragm muscles of rats. Twelve male Wistar albino rats were divided randomly into two groups, each consisting of six rats. The animals in the first group did not receive any treatment and served as control group. The right-side kidneys of animals in group 2 were treated with two-thousand 18 kV shock waves while anesthetized with 50 mg kg(-1) ketamine. The localization of the right kidney was achieved after contrast medium injection through a tail vein under fluoroscopy control. The animals were killed 72 h after the ESWL treatment, and liver and diaphragm muscles were harvested for the determination of tissue oxidative stress and trace element levels. Although the malondialdehyde level increased, superoxide dismutase and glutathione peroxidase enzyme activities decreased in the livers and diaphragm muscles of ESWL-treated rats. Although glutathione level increased in liver, it decreased in diaphragm muscles of ESWL-treated animals. Fe, Mg and Mn levels decreased, and Cu and Pb levels increased in the livers of ESWL-treated animals. Fe and Cu levels increased, and Mg, Pb, Mn and Zn levels decreased in the diaphragm muscles of ESWL-treated animals. It also causes a decrease or increase in many mineral levels in liver and diaphragm muscles, which is an undesirable condition for the normal physiological function of tissues.

The protective effect of calcium on bone mass in postmenopausal women with high selenium intake

OBJECTIVE

Nutritional factors, especially the two essential nutrients calcium and vitamin D, have been shown to play an important role in bone health. We wanted to determine the possible protective effect of calcium intake in adequate amounts on bone mass as assessed by quantitative ultrasound in postmenopausal women who also have a high intake of selenium.

SETTING

Health district of Cáceres, Spain. PARTICIPANTS AND STUDY DESIGN: 335 postmenopausal women aged 60.9 (SD = 8.1) years. Women were stratified based on the vitamin D, vitamin E, calcium intake and the calcium/protein and calcium/phosphorous index.

MEASUREMENTS

Bone status (Ad-SoS measured at the phalanges) was assessed with an ultrasound device model DBM Sonic 1200R. Food intake was quantified using dietetic scales, measuring cups, and spoons based on 7 days of diet records. Urine samples were collected the morning of testing after an overnight fast. Venous blood samples for the hematological and biochemical studies were also obtained in the fasting state.

RESULTS

In the group of women with Ca intake < 800 mg / d we found a significant and negative relationship between Ad-SoS with age (β= -4.020, F = 23.327) and selenium intake (β = -0.419, F = 10.067), as well as a positive relationship with Ca intake (β= 0.104 and F = 7.084) (p <0.0001 in all). In the group of women with Ca intake > 800 mg / d, age has a significant and negative relationship (β = -4.829 and F = 106.745), whereas folic acid intake has a significant and positive relationship (β = 0.047 and F = 5.858) (p <0.0001 in both).

CONCLUSION

Elevated selenium intake negatively affects bone mass measurements in postmenopausal women over the age of 51 but only if calcium intake is also less than 800 mg / day. When calcium intake is greater than 800 mg/day, selenium did not appear to affect bone mass.

Estrogen status alters tissue distribution and metabolism of selenium in female rats

A reported association between estrogen and selenium status may be important in the regulation of selenium metabolism. In this study, the effect of estrogen status on the metabolism of orally administered (75)Se-selenite and tissue selenium status was investigated. Female Sprague-Dawley rats were bilaterally ovariectomized at 7 weeks of age and implanted with either a placebo pellet (OVX) or pellet containing estradiol (OVX+E2), or were sham operated (Sham). At 12 weeks of age, 60 µCi of (75)Se as selenite was orally administered to OVX and OVX+E2 rats. Blood and organs were collected 1, 3, 6 and 24 h after dosing. Estrogen status was associated with time-dependent differences in distribution of (75)Se in plasma, red blood cell (RBC), liver, heart, kidney, spleen, brain and thymus and incorporation of (75)Se into plasma selenoprotein P (Sepp1) and glutathione peroxidase (GPx). Estrogen treatment also significantly increased selenium concentration and GPx activity in plasma, liver and brain, selenium concentration in RBC and hepatic Sepp1 and GPx1 messenger RNA. These results suggest that estrogen status affects tissue distribution of selenium by modulating Sepp1, as this protein plays a central role in selenium transport.

Effects of 17β-estradiol and vitamin E treatments on blood trace element and antioxidant enzyme levels in ovariectomized rats

We investigated the effect of 17β-estradiol (E(2)) alone and separately vitamin E treatment on trace element status of rats following an ovariectomic operation. Forty rats were equally divided into four groups: Group 1, control, non-ovariectomized rats; Group 2, (OVX) rats, ovariectomized under general anesthesia; Group 3, (OVX+E(2)) rats, the group received a 40 µg kg(-1) subcutan dose of E(2) per day after ovariectomy; and Group 4, (OVX + E(2) + vitamin E) rats, received the same E(2) treatment, but with an additional 100 mg kg(-1) intraperitoneal dose of vitamin E per day after ovariectomy. At the end of the 30-day experiment, the rats were sacrificed and their blood was collected for the measurement of zinc, copper, iron, phosphorus, selenium, magnesium, calcium, manganese, and chromium; copper-zinc superoxide dismutase (SOD); manganese-superoxide dismutase (Mn-SOD); glutathione peroxidase (Se-GSH-Px); and catalase (CAT). The levels of zinc, copper, iron, phosphorus, selenium, calcium, chromium, and manganese and activities of SOD, Mn-SOD, Se-GSH-Px, and CAT were lower in the OVX than in the control group, but magnesium level was unaffected. However, zinc, copper, iron, phosphorus, selenium, calcium, chromium, and manganese levels and SOD, Mn-SOD, Se-GSH-Px, and CAT activities were higher under separate E(2) and E(2) + vitamin E treatments. The level of magnesium in the treated-OVX groups was not different than in the OVX group. In conclusion, E(2) treatment has an ameliorating effect on the trace element status in OVX, and this effect may be enhanced with the addition of vitamin E.

Determinants of serum zinc concentrations in a population of French middle-age subjects (SU.VI.MAX cohort)

BACKGROUND/OBJECTIVES

Few studies have been conducted on determinants of serum zinc concentration, especially in France. The aim of this study was to investigate the relationships between serum zinc concentrations, and age, education, living area and life style in a large sample cohort of French adults.

SUBJECTS/METHODS

Blood samples were collected after 12-h fasting in French adults (7448 women, 35-65 years old and 4926 men, 45-65 years old) participating to the SUpplementation in AntioXidant VItamins and Minerals cohort at enrolment. Serum zinc was determined by flame atomic absorption.

RESULTS

Serum zinc concentration was lower in women (mean: 12.9 μmol/l, 95% confidence interval: 9.2-16.6 μmol/l) compared with men (mean: 13.4 μmol/l, 95% confidence interval: 9.7-17.1 μmol/l, P<0.0001). In total, 10% of the women showed serum zinc values <10.7 μmol/l and 10% of the men showed serum zinc values <11.3 μmol/l. Age was negatively associated with serum zinc only in men (P=0.001). In women, a positive association between smoking and serum zinc concentration (P=0.0003), and a negative relationship between highest education level and serum zinc concentration (P=0.01) were observed. With regard to geographical areas, the highest serum zinc concentrations were found in the Center, and the lowest in the Southwest of France for both men and women. The association between serum zinc concentrations and food categories or macronutrient intake disappeared after stratifying by gender.

CONCLUSIONS

Age, gender and geographic area seem the main determinants of serum zinc concentrations in this study.

Plasma levels of copper, manganese and selenium in an adult population in southern Spain: influence of age, obesity and lifestyle factors

Copper, manganese and selenium are elements involved in protecting the body against oxidative stress. Determining their plasma level may contribute to assessing the health and nutritional status of populations. The aim of this study was to assess factors influencing copper, manganese and selenium plasma levels in an adult Mediterranean population and to identify groups at risk of deficiency. A cross-sectional survey was carried out in Andalusia, a region in southern Spain. Blood samples were obtained in a random subsample of 340 subjects. Food consumption was assessed by 48-h recall. Height, weight, skinfolds, waist and hip circumferences were measured. Copper, manganese and selenium were measured in plasma. Information about physical exercise, educational level, alcohol and smoking habits was obtained with a structured questionnaire. Plasma copper was found to be higher in women than among men. Hypocupraemia was found in 4.4% of the population, while 9.7% presented hypomanganesemia. Moreover, 86.5% presented plasma selenium values below 125microg/L (cutoff for optimal glutathione peroxidase activity). No association was found between plasma elements, anthropometric indices and lifestyle factors; there were tendencies, no more. Copper tended to decrease in obese and increase in sedentary, while selenium tended to decrease among smokers. Plasma Cu was positively correlated with the consumption of monounsaturated and polyunsaturated fats. Plasma Mn was directly correlated with the consumption of dairy products. Levels of Se were positively correlated with age, the consumption of fruit, vegetables, energy obtained from carbohydrates, and the consumption of fibre, and inversely correlated with the consumption of meat and sweets. Our results provide an estimate of the copper, manganese and selenium status in the adult population of southern Spain. The correlations found for Se suggest that there is a tendency for Se levels to be better maintained among the population that shows a stronger preference for the traditional diet.

Magnesium, Zinc, Copper, Manganese, and Selenium Levels in Postmenopausal Women with Osteoporosis. Can Magnesium Play a Key Role in Osteoporosis?

Introduction: There has been a resurgence of interest in studies concerning the role of elements in the development and maintenance of the skeleton. The aim of the study was to assess the plasma and red blood concentrations of some elements in postmenopausal women with osteoporosis. Materials and Methods: Seventy-seven postmenopausal women with osteoporosis aged 61 years (median interquartile range, 7.5; range, 46 to 74) and 61 age- and BMI-matched healthy postmenopausal women aged 60 years (median interquartile range, 8.0; range, 44 to 76) were included in the study. Element concentrations in plasma and red blood cells including magnesium (Mg), zinc, copper, manganese, and selenium were measured by atomic absorption spectrophotometry in both postmenopausal women with osteoporosis and healthy postmenopausal women. Results: Only statistically significant difference between the osteoporotic (51.51 [15.40] μg/mL) and healthy subjects (54.54 [15.42] μg/mL) was observed in red blood cell (RBC) magnesium concentration (Z = -2.07, P = 0.039). However, no significant difference was found between patient and control groups, both in plasma and in red blood concentrations, for zinc, copper, manganese, and selenium. Conclusion: Mg levels in red blood cells are significantly lower in postmenopausal women with osteoporosis. It is concluded that Mg transport mechanism(s) into the cell could be affected in patients with osteoporosis. Key words: Copper, Magnesium, Manganese, Osteoporosis, Selenium, Zinc

Selenium status, sex hormones, and thyroid function in young women

The aim of the study was to identify those parameters characterising selenium status and sex hormones secretion, which are responsible for the changes in indicators of thyroid function, and to reveal the correlation structure of parameters expressing selenium status, sex hormones secretion and thyroid function, if any exist. The general approach in this work was essentially the same as in our previous report (cf. [Zagrodzki P, Ratajczak R, Wietecha-Posłuszny R. The interaction between selenium status, sex hormones, and thyroid metabolism in adolescent girls during the luteal phase of their menstrual cycle. Biol Trace Elem Res 2007; 120: 51-60]), but the study group and parameters' spectrum were different. Thirty-six women aged 23.5+/-0.6 years were investigated. The parameters of interest were: plasma selenium concentration (Se) and plasma glutathione peroxidase activity (GPX3) (indicators of selenium status); serum estradiol (E2), progesterone (P4), follicle-stimulating hormone (FSH), luteotropic hormone (LH), and age of menarche (indicators of sex hormones secretion); thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), anti-thyroid peroxidase antibodies in serum (anti-TPO), and thyroid volume (indicators of thyroid function). Our findings show that Se, GPX3, P4, LH, FSH, TSH and fT4 were interrelated. The pairs of parameters: GPX3 and P4; LH and FSH exhibited the strongest associations. The thyroid function parameters were mainly influenced by GPX3 and P4. Partial least-squares method corroborated our hypothesis about the existence of complex interactions among selenium status, sex hormones secretion, and thyroid function in healthy young women in the luteal phase.

Food chromium content, dietary chromium intake and related biological variables in French free-living elderly

Trivalent chromium (Cr3+) is an essential trace element involved in insulin function. Cr deficiencies result in decreased insulin sensitivity, glucose intolerance and an increased risk of diabetes. Cr status decreases with age suggesting that the elderly may be at high risk of Cr deficiency. This study aimed to provide information about the Cr content of foods in France and the Cr intake in French free-living elderly. We measured the food Cr content and daily Cr intake of freely chosen diets for 3 d in twelve French free-living elderly people and their Cr excretion and plasma hormonal related variables, leptin, insulin and cortisol. Considering the relationship between insulin resistance and oxidative stress, we also determined plasma thiobarbituric acid reactive substance, thiol groups and total and reduced glutathione. Although these subjects had well-balanced diets, their daily Cr intakes did not reach the French recommendations. The low Cr intakes were due to the low Cr density of the foods. We found a negative correlation between Cr intakes and insulin, BMI and leptin.

Retention of ovaries and oxidative stress of surgery

OBJECTIVE

Surgical menopause results in severe menopausal symptoms due to the sudden withdrawal of estrogen. This study evaluated the impact of surgical menopause on oxidant and antioxidant status.

METHODS

Thirty eight women who underwent total hysterectomy with or without bilateral salpingo-oophorectomy were included. Oxidant status was assessed by measuring plasma levels of malondialdehyde (MDA) and antioxidant status by assessing glutathione (GSH) and estrogen levels.

RESULTS

The levels of MDA were increased in all women, and GSH levels were significantly decreased in women who underwent hysterectomy alone but significantly increased in those who also had oophorectomy. Estrogen levels were increased if the ovaries were retained even in postmenopausal women, while they were decreased in the women who underwent oophorectomy.

CONCLUSION

Oxidative stress of surgery, as assessed by increased MDA levels, occurred in all women. After oophorectomy, estrogen levels decreased and GSH levels increased in both premenopausal and postmenopausal women. The ovaries may therefore respond to oxidative stress of surgery by increasing estrogen production, estrogen being a better antioxidant than GSH.

Plasma selenium levels in healthy blood bank donors in the central-eastern part of Belgium

Graphite furnace atomic absorption spectrometry, with Zeeman background correction and after improved matrix modification, was used to measure the plasma selenium content of healthy blood bank donors in the central part of Belgium. The mean plasma selenium concentration of 80 men and 80 women was 79.7+/-4.4ng/mL with a range of 55.0-117.4ng/mL. There was no gender difference observed. Plasma selenium level was significantly highest for the adult group, aged 45-64 years, compared to the others, except the young adults (18-24 years). The mean plasma selenium concentration measured corresponded well with literature data for Belgium. The obtained values were found to be in the medium range, compared with recent literature values for the European countries.

Relationships between selenium, lipids, iron status and hormonal therapy in women of the SU.VI.M.AX cohort

Significant differences in serum selenium concentration according to contraceptive treatment and age have been evidenced in women of the SU.VI.M.AX cohort. This study aimed at verifying the physiopathological hypothesis that the observed increase in serum selenium concentration could be related to serum lipid increase and/or bleeding decrease. Women were divided into six groups: menopausal with or without hormonal replacement therapy; non-menopausal using contraceptive pills; intrauterine device; other contraceptive treatment or no contraceptive treatment. Adjusted linear regression indicated positive associations between selenium and apolipoprotein A1 (r(2) from 0.038 to 0.074, p<0.07 depending on groups) or ferritin in serum (r(2) from 0.032 to 0.075, p<0.07 depending on groups). These relationships could explain the differences observed according to hormonal treatment and age in the SU.VI.MAX study.

Serum selenium determinants in French adults: the SU.VI.M.AX study

The objective of the present work was to assess the relationship between serum Se concentrations and environmental determinants (i.e. lifestyle, social activity, geographic region, urban status, education, familial status, physical activity, BMI, tobacco, and food and alcohol consumption). Baseline results from 13 017 subjects (7876 women aged 35-60 and 5141 men aged 45-60) who participated in the SU.VI.M.AX (Supplémentation en Vitamines et Minéraux Antioxydants) study were analysed. Fewer than 2 % of the volunteers had a serum Se status under 0.75 micromol/l, which has been quoted as the cut-off of biological Se sub-deficiency. Women had significantly lower serum Se concentrations than men (1.09 (sd 0.19) micromol/l (n 7423) and 1.14 (sd 0.20) micromol/l (n 4915), P<0.0001, respectively). Significant differences in serum Se concentrations were observed between geographic areas. In both sexes, the serum Se concentration increased with alcohol, meat and fish consumption, and decreased with smoking. In premenopausal women, the serum Se concentration was higher in contraceptive-pill users than in non-users. In women only, age was associated with increased serum Se concentrations, and obesity (BMI> or =30 kg/m2) was associated with decreased serum Se levels. In men, we observed a decrease in serum Se concentrations with increased consumption of vegetables and fruits. In conclusion, though few of the volunteers participating in the SU.VI.M.AX study had Se status in the sub-deficiency range, 83 % of women and 75 % of men had serum concentrations below the value considered optimal for glutathione peroxidase activity. The largest Se associations in both sexes were found with regions, smoking, alcohol, meat and fish consumption. Further studies are needed to understand the difference in Se status between genders.

Influence of hormone replacement therapy on blood antioxidant enzymes in menopausal women

BACKGROUND

Natural loss of estrogen occurring in menopausal process may contribute to various health problems many of them possibly related to oxidative stress. Hormone replacement therapy (HRT) is the most common treatment to attenuate menopausal disturbances. This study was aimed at evaluating the influence of HRT on the activity of antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GPx) and lipid peroxidation (thiobarbituric acid reactive substances, TBARS) in menopausal women.

METHODS

Blood antioxidant enzyme activities were determined in premenopausal (n=18) and in postmenopausal healthy women without (n=21) or with (n=19) HRT (mean ages: 47, 59, and 57 years, respectively).

RESULTS

TBARS, CAT, and GPx activity were not significantly different among the groups of study. However, SOD activity was significantly lower in postmenopausal women without HRT (0.68+/-0.04 U/mg Hb) when compared both to premenopausal women (0.91+/-0.04 U/mg Hb) and to postmenopausal women with HRT (0.89+/-0.07 U/mg Hb). SOD activity was positively correlated to the duration of HRT in the postmenopausal groups (r=0.33, p<0.05).

CONCLUSIONS

HRT antagonizes the decrease of SOD activity that occurs after menopause, suggesting that HRT may play a beneficial role in the protection against oxidative stress.

Zinc intake and status in middle-aged and older European subjects: the ZENITH study

OBJECTIVE

Inadequate intakes of micronutrients in elderly negatively affect the nutritional status. Zinc is an essential micronutrient in the elderly, especially in relation to its impact on immune function, bone mass, cognitive function and oxidative stress. However, data are lacking on zinc intake and status during normal ageing. In this study, we evaluate the intake and status of zinc in late middle-aged and older free-living subjects.

DESIGN

Dietary zinc intake and zinc status in 188 middle-aged subjects from Clermont-Ferrand (Fr) and Coleraine (UK), and in 199 older subjects from Grenoble (Fr) and Roma (It) were assessed at the entry in the ZENITH study.

RESULTS

In relation to the zinc RDA for people older than 55 y, zinc intakes in most of the middle-aged and older subjects (more than 96%) in the present study were adequate. Older people had significantly lower (P < 0.01) energy intakes as compared to middle-aged. Zinc intake expressed per MJ was also significantly (P < 0.01) higher in older people compared to middle-aged. Erythrocyte and urinary zinc concentrations were significantly (P < 0.001) higher in middle-aged subjects compared to older ones. The prevalence of biological Zn deficiency in free-living ageing European people was low (<5%).

CONCLUSION

The results of the present study showed a relatively low prevalence of zinc deficiencies in healthy free-living late middle-age and older subjects. These results should be useful for health professionals to have reference data on zinc intake and status for a healthy ageing.

Age-related oxidative stress and antioxidant parameters in middle-aged and older European subjects: the ZENITH study

OBJECTIVE

Oxidative stress has been reported to increase with ageing. However, the data in healthy humans remain controversial and studies in free-living elderly people are scarce. The objective of the present study was to compare age-related oxidative stress in late middle-aged and older free-living subjects.

DESIGN

The effect of ageing on oxidative stress and antioxidant parameters was investigated in 188 middle-aged subjects from Clermont-Ferrand (France) and Coleraine (UK), and in 199 older subjects from Grenoble (France) and Roma (Italy). Plasma thiol (SH) groups, define definition (TBAR's) and total glutathione (GSH), define definition (FRAP), and superoxide dismutase (SOD) activity were measured at baseline of the ZENITH study.

RESULTS

Plasma SH groups and FRAP and, surprisingly, TBAR's were significantly lower in free-living older subjects compared to younger subjects (P < 0.001, P < 0.001, P < 0.01, respectively), but there was no significant differences in GSH levels.

CONCLUSION

European free-living healthy older do not appear to be exposed to an acute oxidative stress. However, the highly significant positive correlation between plasma SH group oxidation or decreased FRAP and ageing is predictive of an increased risk of oxidative stress in older subjects. Moreover, the comparison between middle-aged and older subjects regarding oxidative stress parameters suggests also a progressive and slow decline of antioxidant status in healthy free-living older elderly and underline the impact on life-style factors on successful ageing.

Dietary iron positively influences bone mineral density in postmenopausal women on hormone replacement therapy

The associations of dietary intakes of iron and calcium on change in bone mineral density (BMD) were examined over 1 y in healthy nonsmoking postmenopausal women (mean age 55.6 +/- 4.6 y) stratified by hormone replacement therapy (HRT) use (HRT, n = 116; no HRT, n = 112). BMD was measured at lumbar spine L(2)-L(4), trochanter, femur neck, Ward's triangle, and total body using dual-energy X-ray absorptiometry at baseline and 1 y. Mean nutrient intakes were assessed using 8-d diet records. All women received 800 mg/d of supplemental elemental calcium. Regression analyses examined the effects of iron and calcium intakes on BMD change adjusting for years past menopause, baseline BMD, weight change, exercise, and energy intake. The interaction of iron with calcium on BMD change was assessed using tertiles of iron and calcium intake and estimated marginal mean change in BMD. Iron was associated (P < or = 0.05) with greater positive BMD change at the trochanter and Ward's triangle in women using HRT. Calcium was associated (P < or = 0.05) with BMD change at the trochanter and femur neck for women not using HRT. In women using HRT in the lowest tertile of calcium intake, change in femur neck BMD increased linearly as iron intake increased. In women not using HRT, BMD increased in the women in the highest tertile of calcium intake. We conclude that HRT use appears to influence the associations of iron and calcium on change in BMD.

Comparison of the serum selenium content of healthy adults living in the Antwerp region (Belgium) with recent literature data

Graphite furnace atomic absorption spectrometry, after improved matrix modification and using Zeeman background correction, was used to measure the serum selenium content of healthy adults living in the Antwerp region (Belgium). The mean serum concentration of 13 men and 13 women, sampled once a month during 1 year, was 84.3 +/- 9.4ng/ml with a broad range of 51.4-121.7 ng/ml. The intra-individual variation was remarkably high. Recent literature on selenium concentrations is reviewed and values are tabulated, with limitation to healthy adults and European countries. The mean serum selenium concentration measured corresponded well to older literature data for Belgium. The obtained values were found to be in the medium range compared with the literature data for other European countries.