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1.
Olusi S Al-Awadhi A Abiaka C Abraham M George S 《Biological trace element research》2003,91(2):137-144
Leptin, the obesity gene protein product, is a hormone with multiple physiological functions in the human. However, there
are few reports in the literature on its role in trace element metabolism in the normal population. Therefore, we investigated
the association among serum leptin, zinc, copper, and zinc/copper ratio in 570 healthy men and women aged 15 yr and older.
Serum leptin assay was done with a commercial enzymelinked immunosorbent assay kit; serum zinc and copper levels were measured
by an atomic absorption spectrophotometer. Serum leptin was found to be positively associated with age (r=0.254, p<0.001), sex (r=0.406, p<0.001), body mass index (BMI) (r=0.553, p<0.001), and serum copper (r=0.419, p<0.001), but negatively associated with the zinc/copper ratio (r=−0.423, p<0.001). There was no significant association between serum leptin and zinc (r=−0.131, p>0.05). When the confounding effects of age, sex, and BMI were removed, serum leptin was still positively associated with
serum copper (r=0.197, p=0.02) and the serum zinc/copper ratio (r=−0.182, p=0.03). These results suggest that copper and not zinc has an effect on serum leptin levels. 相似文献
2.
Gonzalez-Reimers E Santolaria-Fernandez F Galindo-Martín L Duran-Castellon MC Aleman-Valls MR Garcia-Valdecasas-Campelo E Ros-Vilamajo R Barroso-Guerrero F 《Biological trace element research》2000,78(1-3):121-129
This study was performed in order to analyze the relative and combined effects of ethanol and protein deficiency on hair copper,
zinc, manganese, and iron content in four groups of seven animals each which were pair-fed during 8 wk with (1) a nutritionally
adequate diet, (2) a 36% (as energy) ethanol-containing isocaloric diet, (3) a 2% protein, isocaloric diet, and (4) a 36%
ethanol, 2% protein isocaloric diet, respectively, following the Lieber-DeCarli model, and to analyze the relationship between
hair copper, zinc, manganese, and iron content, and the liver and muscle content of these elements. Although there was a trend
to higher levels of all the elements analyzed in the the hair of the low-protein fed animals, differences were statistically
significant regarding copper and manganese, effects being solely attributable to the low protein diet, not to ethanol. Moreover,
hair copper was significantly, inversely related with final weight and weight loss. There were significant relationship between
liver zinc and muscle zinc (r=0.57, p=0.002), but not between liver or muscle zinc and hair zinc; no correlations were observed between muscle copper and hair
copper, nor between liver manganese and hair manganese. An inverse, statistically significant correlation was observed between
liver copper and hair copper (r=−0.39, p<0.05). 相似文献
3.
Women with preeclampsia have been shown to have elevated blood levels of the metabolite homocysteine, and alterations in blood
levels of zinc and copper have also been reported. This study measured plasma levels of zinc, copper, and homocysteine in
women with preeclampsia and in women with healthy, normotensive pregnancies.
For the patients with preeclampsia compared with controls, significantly higher mean plasma levels were found of homocysteine
(16.39 vs 9.45 nmol/mL; p≤0.001), zinc (15.53 vs 11.93 μg/g protein; p < 0.05), and copper (47.90 vs 31.60 μg/g protein; p=0.001). The ratio of plasma Cu/Zn levels tended to be higher in preeclamptic women and could be taken as an index of inflammatory
reaction, but the difference was not significant. Homocysteine concentrations correlated positively with plasma zinc concentrations
in women with preeclampsia (r=0.588, p=0.003) but not in women with healthy pregnancies. No correlations were observed between plasma levels of homocysteine and
copper.
Thus, the present study found evidence that preeclampsia might be associated with hyperhomocysteinemia and elevated blood
levels of zinc and copper. Furthermore, elevated blood levels of zinc were significantly associated with hyperhomocysteinemia
in preeclampsia. More studies are warranted to investigate further any relationship between altered homocysteine metabolism
and levels of zinc and copper in preeclampsia. 相似文献
4.
Reza Amani Somaye Saeidi Zahra Nazari Sorour Nematpour 《Biological trace element research》2010,137(2):150-158
It has been suggested that mood disorders and depressive status may be accompanied by lowered zinc status in the body, and
adequate consumption of zinc increases a general perceived well-being. The main objective of this study was to assess the
correlation between serum zinc concentrations and dietary zinc intakes with depression scores in university female students.
In the first phase, Beck's depression questionnaire was applied in a random sampling of 308 selected 20–25-year-old female
students (one third of total students in Ahvaz Jondi-Shapour University of Medical Sciences Golestan dormitories) to assess
the major depressive disorder (MDD) scales. Then, in the second phase, 23 students who identified as having moderate and severe
depression were selected as the case group, and 23 healthy age matched were chosen as the controls. Each of them completed
a 12-item semiquantitative food frequency questionnaire containing the main food sources of zinc in the usual dietary patterns
and also a 24-h food recall questionnaire to assure the daily zinc intakes. Daily zinc intakes were obtained by multiplying
each portion size by its zinc content using food tables. A 5-ml blood sample was taken for further serum zinc status using
flame atomic absorption spectrophotometry technique. Pearson's r was used to show the correlation between quantitative variables. Both daily zinc intake and serum zinc concentrations of
MDD group were about two thirds of healthy index (p < 0.01). Depressed individuals used to eat lower servings of red meats and chicken as the main food sources of zinc in students'
usual diets (p < 0.001). Consumption of other foods as the sources of zinc was not significantly different in two groups. A linear significant
correlation between dietary zinc intakes and its serum levels was seen in samples (r = 0.62; p < 0.001) and MDD students (r = 0.55; p < 0.001). There was a linear inverse correlation between Beck questionnaire scores and serum zinc concentrations in all of
the investigated students(r = -0.65; p < 0.001) and MDD girls (r = −0.71; p < 0.001). Beck questionnaire scores and diatary zinc intakes were also inversly correlated (r = −0.58; p < 0.001). However, no statistical correlation was seen between these two variables in MDD cases. In depressed female students,
dietary zinc intake is correlated to its serum concentrations; however, the serum zinc levels are inversely correlated to
depression scales. Consumption of the main dietary sources of zinc such as red meats and chicken should be encouraged in young
depressed girls. 相似文献
5.
The relationship between established coronary risk factors and serum copper and zinc concentrations in a large Persian Cohort 总被引:1,自引:0,他引:1
M. Ghayour-Mobarhan A. Shapouri-Moghaddam M. Azimi-Nezhad H. Esmaeili S.M.R. Parizadeh M. Safarian S.M.R. Kazemi-Bajestani G.H. Khodaei S.J. Hosseini S.M.J. Parizadeh G.A. Ferns 《Journal of trace elements in medicine and biology》2009,23(3):167-175
IntroductionThe relationship between demographic and biochemical characteristics, including several established coronary risk factors, and serum copper and zinc was assessed in a large Iranian population sample.Materials and methodsA group of 2233 individuals, 15–65 years of age [1106 (49.5%) males and 1127 (50.5%) females] was recruited from residents of the Greater Khorasan province in northeast of Iran. Demographic data were collected using questionnaires. Coronary risk factors were determined using standard protocols, and trace elements were measured in serum using atomic absorption spectroscopy.ResultsDegree of glucose tolerance and smoking habit were not associated with serum zinc and copper levels. Serum copper levels were significantly higher in obese and hypertensive than in normal subjects (p<0.001). In the whole group and for the female subgroup, serum zinc (p<0.01) and copper (p<0.001) were both significantly lower in individuals with normal versus high levels of low-density lipoprotein cholesterol.A strong positive correlation was found between serum copper and body mass index (BMI) (r=0.85, p<0.001). Weaker positive associations were found between serum copper and calculated 10 years’ coronary risk (r=0.11, p<0.001). Serum zinc/copper ratio was strongly inversely associated with calculated 10 years’ coronary risk (r=?0.10, p<0.001). The partial Eta squared (PES) values for factors determining serum zinc were hypertension (0.007, p=0.01) and BMI (0.004, p=0.01); and for serum copper, they were gender (0.02, p=0.001), hypertension (0.004, p=0.009), and 10 years’ coronary risk for men (0.003, p=0.03) and women (0.002, p=0.07).ConclusionSignificant associations between serum trace element concentrations and several coronary risk factors, including calculated 10 years’ coronary risk scores, were found. 相似文献
6.
Gianfranco Vivoli Margherita Bergomi Sergio Rovesti Mirco Pinotti Eva Caselgrandi 《Biological trace element research》1995,49(2-3):97-106
Imbalance of zinc and copper status has been hypothesized in human hypertension. A case-control study was carried out to elucidate the possible relationship between zinc and copper status and essential hypertension. Thirty-one subjects affected by mild stable hypertension, pharmacologically untreated, were investigated together with 31 normotensive controls individually matched for sex, age, and smoking habits. Zinc and copper in serum and urine were measured, and serum activities of alkaline phosphatase (AP), lactic dehydrogenase (LDH), copper-zinc superoxide dismutase (Cu?Zn SOD), lysyl oxidase (LOX), and monoamine oxidase (MAO) were evaluated. No significant difference in serum and urine zinc and copper content as far as in serum activity of zinc (AP and LDH) or copper (Cu?Zn SOD, LOX, and MAO)-dependent enzymes was found between hypertensives and normotensives. Positive relationships were found in normotensives between serum and urine levels of zinc (r=0.577;p=0.001) and copper (r=0.394;p=0.028), and between serum copper and Cu?Zn SOD (r=0.534;p=0.002). In normotensives, diastolic blood pressure and serum zinc were positively related (r=0.370;p=0.041). In hypertensives, inverse correlations were observed between diastolic blood pressure and AP (r=?0.498;p=0.004) and Cu?Zn SOD (r=?0.452;p=0.011), and between systolic blood pressure and LOX (r=?0.385;p=0.033). Diastolic blood pressure was related to LDH inversely in hypertensives (r=?0.357;p=0.049) and positively in normotensives (r=0.457;p=0.010). In normotensives, diastolic blood pressure was inversely related with MAO (r=?0.360;p=0.046). These findings support the hypothesis that an imbalance of zinc and copper status might be involved in human hypertension. 相似文献
7.
Superoxide dismutase activity and zinc and copper concentrations in growth retardation 总被引:1,自引:0,他引:1
The aim of this study was to determine the effects of oral zinc treatment on red cell copper/zinc-superoxide dismutase (Cu/Zn-SOD)
activity and zinc and copper concentrations in growth retardation.
Thirty-five patients, average age of 11 yr, were selected. The control group consisted of 10 healthy children whose average
age was 10 yr. Superoxide dismutase activity was determined by spectrophotometer. Copper and zinc concentrations were measured
by an atomic absorption spectrophotometer. The activity of Cu/Zn-SOD before zinc treatment was higher than the controls (p<0.001). There was a decrease in Cu/Zn-SOD activity after zinc treatment (p<0.001) and the values after treatment were still higher than the controls (p<0.001). Plasma zinc concentrations before zinc treatment were lower than controls (p<0.01). After treatment, there was an increase in plasma zinc concentrations compared to controls and the patients' values
before zinc treatment, respectively (p<0.001, p<0.001). After zinc treatment, plasma copper concentrations were decreased significantly (p<0.01). An increase in red cell zinc concentration (p<0.01) and a decrease in copper concentration (p<0.001), which were statistically significant, were seen after zinc treatment.
The results suggested that there were significant alterations in Cu/Zn-SOD activity and zinc and copper concentrations during
growth retardation. With zinc treatment, these parameters appeared to approach normal values. 相似文献
8.
Koury JC de Oliveira Kde J Lopes GC de Oliveira AV Portella ES de Moura EG Donangelo CM 《Biological trace element research》2007,115(1):23-30
This study evaluated levels of plasma zinc, copper, and leptin, body composition, and their relationship in nine elite female
judo athletes under two different training conditions. Body composition and biochemical measurements (hematological indexes,
plasma zinc, plasma copper, and plasma leptin) were analyzed 24 h after intense training and following a 5-d period without
training (no-training). Plasma leptin and plasma zinc increased with no-training. Plasma zinc correlated negatively with percent
fat mass (r=−0.62; r=0.05) and positively with plasma leptin (r=0.83; p=0.002) in the no-training condition Plasma copper did not change during the study and correlated positively with plasma leptin
(r=0.66; p=0.05) and with percent fat mass (r=0.80; p=0.007) after training. Percent fat mass was associated negatively with plasma zinc (r=−0.62; p=0.05) in the no-training condition. Moreover percent fat mass was negatively associated with the Zn/Cu plasma ratio under
both training conditions (r<−0.78, p<0.001). These results are consistent with the possible function of zinc as a lipid-mobilizing factor and of copper
as a limiting factor in energy metabolism. 相似文献
9.
The relationship of copper and zinc status with blood pressure in young adults was studied (N=59). Copper and zinc status was assessed through analysis of serum, urine, hair, and diet records. Males (N=27) had greater systolic and pulse pressures than females (N=32). Multiple regression analysis suggested that males and higher caloric and dietary copper intakes were the predominant factors associated with higher systolic and diastolic pressures, whereas higher dietary zinc intakes were associated with lower pressures. Higher urine zinc excretion rates and serum zinc concentrations were associated with higher diastolic pressures. The sex variable was the strongest factor affecting pulse pressures, with males having higher pulse pressures. Serum zinc concentrations had an inverse relationship to pulse pressures. The data suggest that the weight/height index and age had a low association with blood pressure in this normotensive sample. 相似文献
10.
Mariana Vlad E. Bordas Rodica Tomus Doina Sava Ecaterina Farkas G. Uza 《Biological trace element research》1993,38(1):47-54
Serum copper concentration increases significantly (p<0.01) in rats with experimental atherosclerosis compared to a control group. The serum zinc, the zinc, and copper concentration
in abdominal aorta and in liver decreases significantly (p<0.05) compared to the control group. Administration of copper sulfate for 100 d in these animals induces a significant increase
of serum copper (p<0.01), decrease of serum cholesterol (p<0.05) and increase of liver copper concentration as compared with the group fed only a high cholesterol diet. In the aorta
of these animals the copper concentration increases and edema and lipid infiltration are considerably less than in the group
of animals fed only a high lipid diet. 相似文献
11.
Karla de Jesus Fernandes de Oliveira Carmen Marino Donangelo Astrogildo Vianna de Oliveira Jr. Carmen Lucia Porto da Silveira Josely Correa Koury 《Cell biochemistry and function》2009,27(3):162-166
Puberty associated with intense physical activity results in oxidation stress. Zinc supplementation may benefit antioxidant capacity although it may also affect iron and copper status. This study evaluated the effect of zinc supplementation on antioxidant, zinc and copper status of physically active male football players (13 years ± 0.4 years), divided in two groups and studied during 12 weeks: Zn‐supplemented (Zn‐SUP, 22 mg Zn d?1 as zinc gluconate, n = 21) and placebo (PLA, n = 26). At baseline, there was no significant difference in biochemical indices between the two groups. After treatment, plasma zinc and erythrocyte iron increased in both groups (p < 0.001); urinary zinc increased (p < 0.001) only in Zn‐SUP, and erythrocyte zinc decreased (p = 0.002) only in PLA. Plasma iron and copper decreased (p = 0.01 and p = 0.015, respectively) only in Zn‐SUP. Plasma ferric‐reducing ability and plasma conjugated dienes increased, and erythrocyte osmotic fragility decrease in both groups, although the latter two were significantly lower in Zn‐SUP compared to PLA (p < 0.01). In conclusion, our study indicates that the use of 22 mg d?1 of supplemental zinc during 12 week in adolescent athletes did not affect growth, improved markers of antioxidant status but reduced plasma iron and copper. Therefore, it appears that the use of zinc supplementation by healthy adolescent athletes benefits their antioxidant capacity but impairs copper and iron nutritional status. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
12.
This study compares the seminal plasma trace metal levels of hospital workers with groups of industrial workers in a petroleum
refinery, smelter, and chemical plant. The metals measured were the essential metals (copper, zinc, nickel, cobalt, and manganese)
and the toxic metals (lead, cadmium, and aluminum). The group mean±SE metal level for each group (50 subjects per group) was
calculated, and the statistical significance of the group mean differences of the industrial groups with the hospital group
(control) was determined by the Student’s t-test.
The differences observed in the smelter group were increased copper and zinc (p≤0.001) and decreased nickel, cobalt, and manganese (p≤0.001,≤0.01). The refinery group differences were increased copper, zinc, and nickel (p≤0.001) but decreased cobalt and manganese (p≤0.001). The chemical group differences were increased zinc (p≤0.001) and decreased cobalt (p≤0.001). The seminal plasma levels of the toxic metals lead and aluminum were increased in each of the industrial groups (p≤0.001). Concurrent differences were (1) decreased accumulation of nickel, cobalt, and manganese in the smelter group, (2)
decreased cobalt and managanese in the refinery group, and (3) only decreased cobalt in the chemical group. 相似文献
13.
Casimiro-Lopes G de Oliveira-Junior AV Portella ES Lisboa PC Donangelo CM de Moura EG Koury JC 《Biological trace element research》2009,127(2):109-115
The purpose of this study was to compare plasma leptin, plasma zinc, and plasma copper levels and their relationship in trained
female and male judo athletes (n = 10 women; n = 8 men). Blood samples were obtained 24 h after training to measure plasma zinc, copper, and leptin levels. Subjects presented
similar values to age (22 ± 2 years old), body mass index (24 ± 1 kg/m2), plasma zinc (17.2 ± 2 μmol/L), copper (12.5 ± 2 μmol/L), and leptin (5.6 ± 1.3 μg/L). However, height, total body mass,
lean mass, fat mass, and sum of ten-skinfold thickness were higher in male than female. Plasma leptin was associated with
sum of ten skinfolds in male (r = 0.91; p < 0.001) and female athletes (r = 0.84; p < 0.003). Plasma zinc was associated with leptin in males (r = 0.82; p < 0.05) while copper was associated with plasma leptin in females (r = 0.66; p < 0.05). Our results suggest that young judo athletes lost sex-related differences in leptin levels. Plasma zinc, plasma
copper, and energy homeostasis may be involved in regulation of plasma leptin. 相似文献
14.
The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper
(Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood
asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations,
malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC
ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status.
Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to
be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r=0.485, p<0.021), and a negative correlation between TAC and MDA values (r= −0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content
in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood
asthma may be responsible for the oxidant/antioxidant imbalance. 相似文献
15.
The plasma and erythrocyte levels of zinc, copper, and magnesium and the activities of red-cell copper-zinc superoxide dismutase
(Cu/Zn-SOD) and catalase (CAT) were determined in patients with benign and malignant tumors of the larynx. Blood samples from
patients and healthy controls were drawn using heparinized tubes. The erythrocyte Cu/Zn-SOD and CAT activities were determined
spectrophotometrically and the zinc, copper, and magnesium concentrations were determined in erythrocyte and plasma by atomic
absorption spectrometry. Variance analysis was employed in the statistical evaluation of the findings.
There was a significant increase in red-cell Cu/Zn-SOD activity in the subjects with malignant and benign tumors compared
to controls (p<0.001). The CAT activity increased only in the benign tumor group (p<0.01). The plasma zinc concentrations were significantly lower in the malignant tumor group (p<0.05) and significantly higher in the benign tumor group (p<0.01). The erythrocyte copper concentrations were significantly lower in both benign and malignant tumor groups (p<0.001). The plasma copper and magnesium and the erythrocyte magnesium concentrations did not show significant differences
relative to controls (p>0.05).
The increases in the activities of SOD and CAT activities and the changes in trace elements concentrations can indicate the
presence of increased reactive oxygen species that might play a part in the pathogenesis larynx tumors.
Presented at the IX Asian-Pacific Congress of Clinical Biochemistry, March 9–14, 2002, New Delhi, India. 相似文献
16.
The study describes the concentrations of zinc, magnesium, copper, iron, and biochemical markers of seminal vesicle and prostate
in seminal plasma of different categories of infertile men. The zinc level in oligasthenospermic subjects was significantly
higher than in azoospermic, asthenospermic, and oligospermic subjects. The γ-glutamyl transpeptidase activity in both oligoasthenospermic
and azoospermic subjects were significantly lower than in asthenospermic and oligospermic individuals. There was no significant
difference in iron, copper, and magnesium levels and acid phosphatase activity among the different infertile categories. A
positive correlation between zinc and acid phosphatase (r=0.84, r=0.73; p<0.05), and between copper and fructose (r=0.81, r=0.72; p<0.05) was observed in oligoasthenospermic and azoospermic men, respectively. On the basis of our results, it may be postulated
that there is a direct effect of the trace elements zinc and copper on acid phosphatase and fructose, respectively, in oligoasthenospermic
and azoospermic subjects. 相似文献
17.
Aydin Ece Bekir Sami Uyamik Akin IŞcan Pelin Ertan M. Ramazan Yiğitolu 《Biological trace element research》1997,59(1-3):31-39
In order to evaluate serum copper and zinc status in children with iron deficiency anemia (IDA), 60 children with IDA aged
1–14 yr and 64 healthy children as controls aged 1–14 yr were included the study. Serum copper levels were higher in children
with IDA (189 ± 49 (Μg/dL) than those of controls (163 ± 37 Μg/dL) (p = 0.001). Serum zinc levels were lower in the patient group (109 ± 59 Μg/dL) than those of control subjects (135 ± 56 Μg/dL)
(p = 0.017). In addition, there were statistically significant negative correlations between hematological parameters and serum
copper levels in the patient group, but not in controls. No correlation between hematological parameters and serum zinc levels
were found in both patient and control groups, except positive correlation between mean corpuscular volume (MCV) and serum
zinc level in patients.
It was concluded that at the time of managing children with IDA, zinc deficiency must be borne in mind and if necessary treatment
should be initiated with zinc. 相似文献
18.
Yasmin H. Neggers Robert L. Goldemberg Suzzane P. Cliver Rachel L. Copper 《Biological trace element research》1998,64(1-3):221-228
A prospective study was conducted to evaluate and compare the determinants of dietary zinc intake in black and white low-income
pregnant women. The study population consisted of 1298 low-income women (70% Black, 30% White) who received prenatal care
at University Hospital at the University of Alabama in Birmingham from 1985 to 1989. Various maternal characteristics were
evaluated at the first prenatal visit. Two 24 h recalls were obtained at 18 and 30 wk of gestation to calculate the intakes
of dietary zinc and other nutrients. Student’st test, ξ2, Pearson correlation coefficients, and multiple regression analyses were used to compare and evaluate the determinants of
zinc and other nutrient intakes in Black and White subjects. The mean prepregnancy body mass index and the mean intake of
zinc, energy, and all the other nutrients except calcium were significantly higher in Black than in White subjects. There
was a significant correlation between zinc and energy intake (r- 0.69,p = 0.001). Age, marital status, parity, socioeconomic status, smoking, and alcohol intake were not significant predictors of
zinc or other nutrient intakes. After adjusting for energy intake, race was the only significant predictor of dietary zinc
intake. Race and energy intake explained 24% of the variation in zinc intake. Results of this study indicate that after adjusting
for other covariates, race and energy intakes are the only predictors of zinc intake in low-income pregnant women. 相似文献
19.
Lucianna Fernandes J. C. Marques Carmen Marino Donangelo Juliana Gastao Franco Luciane Pires Aderval Severino Luna Gustavo Casimiro-Lopes Patricia Cristina Lisboa Josely Correa Koury 《Biological trace element research》2011,142(3):415-423
Intense physical activity is associated with biological adaptations involving hormones and trace elements. Zinc supplementation
may affect plasma copper concentration, thyroid-stimulating hormone (TSH), thyroid hormones, insulin, and glucose homeostasis,
but data in athletes are scarce. The aim of this study was to evaluate in competitive athletes (cyclists, n = 7, 32 ± 8 years) the effect of zinc supplementation (22 mg/day as zinc gluconate) during 30 days, and discontinuation using
placebo (maltodextrin) during the following 30 days, on plasma zinc and copper concentrations, serum thyroid hormones, insulin
and glucose levels, and HOMA2-IR. Compared to baseline, plasma zinc and Zn:Cu plasma ratio increased, but plasma copper decreased
after zinc supplementation (day 30) and discontinuation (day 60) (p < 0.05). Zn supplementation and discontinuation had no effect on TSH, T3, and T4. Fasting serum insulin and HOMA2-IR increased
(27% and 47%, respectively) on day 60 compared to baseline (p = 0.03), suggesting a delayed effect of zinc supplementation. Moreover, plasma zinc was positively associated with serum
insulin (r = 0.87, p = 0.009) and HOMA2-IR (r = 0.81, p = 0.03) after zinc supplementation (day 30), indicating that supplemental zinc may impair glucose utilization in cyclists. 相似文献
20.
Carmiña L. Vargas Zapata Tania M. R. Simões Carmen M. Donangelo 《Biological trace element research》1997,57(2):115-124
Erythrocyte metallothionein (E-MT) is considered a promising index of zinc status in humans, since it may be more sensitive
than other biochemical indices to changes in dietary zinc. However, conditions of high zinc demand with substantial redistribution
of tissue zinc and specific changes in hormone profile, such as pregnancy, may have an influence on E-MT levels in addition
to dietary zinc. In this study, we compared E-MT concentrations in relation to other biochemical zinc indices in healthy pregnant
women at delivery (n=40) and nonpregnant women (n=22) with similar habitual dietary zinc intakes (average 13.3 mg/d). Pregnant women had lower serum zinc and albumin-bound
serum zinc, but higher levels of {ie115-1}-macroglobulin-bound serum zinc than the nonpregnant women. Erythrocyte zinc (E-Zn)
was similar in both groups, but E-MT (mean±SE) was slightly but significantly (p<0.05) higher in the pregnant women (2.9±0.09 nmol/g protein) compared to nonpregnant women (2.6±0.06 nmol/g protein). A significant
correlation was observed between E-MT and E-Zn in the nonpregnant women (r=0.70;p<0.001), consistent with the role of intracellular zinc in the regulation of metallothionein synthesis. However, such correlation
was not observed in the pregnant women, suggesting that E-MT levels in pregnancy may be influenced by factors related to the
pregnant state. 相似文献