Zinc and copper concentration in plasma of pregnant women in Nigeria

Association between serum copper, zinc, and selenium concentrations and depressive symptoms in the US adult population, NHANES (2011-2016)

BACKGROUND

Evidence suggests that alterations in serum trace element concentrations are closely associated with mental illness. However, ​studies on the relationship between serum copper, zinc, and selenium concentrations and depressive symptoms are limited and with controversial results. We aimed to investigate the association between serum concentrations of these trace elements and depressive symptoms in US adults.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) (2011-2016) were used in this cross-sectional study. The Patient Health Questionnaire-9 Items (PHQ-9) was employed to assess depressive symptoms. Multiple logistic regression was performed to determine the relationship between the serum concentrations of copper, zinc, and selenium and depressive symptoms.

RESULTS

A total of 4552 adults were included. Subjects with depressive symptoms had higher serum copper concentrations (123.88 ± 1.87) than those without depressive symptoms (116.99 ± 0.86) (p < 0.001). In Model 2, weighted logistic regression analysis showed that the second (Q2) quartile of zinc concentrations (odds ratio [OR] = 1.534, 95% confident interval [CI]: 1.018 to 2.313) were significantly associated with an increased risk of depressive symptoms. Subgroup analysis revealed that the third (Q3) and fourth (Q4) quartiles of copper concentrations (Q3: OR = 2.699, 95% CI: 1.285 to 5.667; Q4: OR = 2.490, 95% CI: 1.026 to 6.046) were also positively associated with depressive symptoms in obese individuals after controlling for all confounders. However, no significant relationship between serum selenium concentrations and depressive symptoms was observed.

CONCLUSIONS

Obese US adults with high serum copper concentrations, as well as US adults in general with low serum zinc concentrations, were susceptible to depressive symptoms. Nevertheless, the causal mechanisms underlying these relationships need to be further explored.

Toxics (Pb, Cd) and trace elements (Zn, Cu, Mn) in women during pregnancy and at delivery, South Benin, 2014-2015

During pregnancy, fetal development can be hindered by maternal exposure to toxic elements and abnormal concentrations of trace elements. Few data are available in African countries. Our goal was to assess the body burden of lead (Pb), cadmium (Cd), manganese (Mn), zinc (Zn) and copper (Cu) in pregnant women in Benin. The study was carried out in Sô-Ava district, from November 2015 to April 2016. Sixty women were recruited from the RECIPAL pre-conceptional cohort study. In all women, blood samples were collected during the first trimester of pregnancy. Thirty-two women had additional maternal and cord blood samples collected at delivery. Blood samples were analyzed by inductively coupled plasma mass spectrometry. At delivery, Cd median (IQR) concentration in maternal blood was 0.34 µg/L (0.24-0.46) in this non-smoking population. Pb median (IQR) concentration in maternal blood at delivery was 37.4 µg/L (30.5-52.0), with 31.3% of blood Pb levels above the 50 μg/L threshold. These pregnant women lived in semi-rural lakeside villages. Potential sources of Pb exposure identified during pregnancy were having water supply by drill pump and activities such as smoking fish by the woman and fishing by the household head. At delivery, Zn, Cu, and Mn median (IQR) concentrations in maternal blood were, respectively, 5415 μg/L (4894-5822), 1609 μg/L (1295-1771) and 16.0 μg/L (12.5-20.8). Pb, Cd, Mn and Cu blood concentrations were significantly higher at delivery than during the first trimester of pregnancy. Pb, Cd, Zn and Cu concentrations were significantly lower in cord blood than in maternal blood, contrary to Mn concentration, which was significantly higher in cord blood than in maternal blood at delivery. This exploratory study is the first one performed in Benin, and warns us about exposition of women from Sô-Ava district to Pb and Cd during pregnancy.

Zinc: The Metal of Life

The importance of zinc was 1st reported for Aspergillus niger. It took over 75 y to realize that zinc is also an essential trace element for rats, and an additional 30 y went by before it was recognized that this was also true for humans. The adult body contains about 2 to 3 g of zinc. Zinc is found in organs, tissues, bones, fluids, and cells. It is essential for many physiological functions and plays a significant role in a number of enzyme actions in the living systems. Bioinformatics estimates report that 10% of the human proteome contains zinc-binding sites. Based on its role in such a plethora of cellular components, zinc has diverse biological functions from enzymatic catalysis to playing a crucial role in cellular neuronal systems. Thus, based on the various published studies and reports, it is pertinent to state that zinc is one of the most important essential trace metals in human nutrition and lifestyle. Its deficiency may severely affect the homeostasis of a biological system. This review compiles the role of zinc in prophylaxis/therapeutics and provides current information about its effect on living beings.

Study of serum zinc in neonates and their mothers in Shimla hills (Himachal Pradesh)

Serum zinc level in cord blood of 159 neonates was estimated by atomic absorption spectrophotometer. The cases were classified according to birth weight and gestation of babies as Term appropriate for date (TAFD), Term small for date (TSFD), Term large for date (TLFD), Preterm appropriate for date (PAFD), Preterm small for date (PSFD) and Preterm large for date (PLFD). The zinc level were also estimated in mothers of these groups at the time of delivery, and compared with cord blood levels of those in non-pregnant mothers. Mean serum zinc level in infant born full term AFD, full term SFD, full term LFD, preterm AFD, preterm SFD and preterm LFD were 79.6 +/- 17.8 micrograms/dl, 58.2 +/- 13.4 micrograms/dl, 84.1 +/- 21.1 micrograms/dl, 81 +/- 25.2 micrograms/dl, 51.2 +/- 51.7 micrograms/dl and 76 +/- 14.7 micrograms/dl respectively. The maternal zinc levels in respective groups were 67 +/- 9.6 micrograms/dl, 56.5 +/- 7.5 micrograms/dl, 63.6 +/- 14.4 micrograms/dl, 62.7 +/- 21.1 micrograms/dl, 54.5 +/- 5.4 micrograms/dl, and 58.2 +/- 2.7 micrograms/dl. The mean serum zinc values in mothers and babies in birth weight group ranging from 1500-2000 gm were 55.3 +/- 4.3 micrograms/dl and 60 +/- 23.1 micrograms/dl, 2001-2500 gm were 59.5 +/- 11.3 and 65.8 +/- 17 micrograms/dl, 2501-3000 gm were 69.2 +/- 9.5 and 84.7 +/- 14 micrograms/dl, 3001-3500 gm were 65.8 +/- 12.7 micrograms/dl, 82.2 +/- 20.8 micrograms/dl and 3501 and above were 70.5 +/- 8.2 micrograms/dl and 85 +/- 14.3 micrograms/dl respectively. Statistically significant low zinc levels were observed in SFD babies and their mothers.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of a glucose challenge on plasma copper levels during pregnancy

This study examined the effect of pregnancy and glucose loading on plasma copper (Cu) levels. In a completely random design with repeated measures, 18 nonpregnant women, 16 early pregnant women (13-17 weeks), and 16 late pregnant women (28-34 weeks) ingested 100 g glucose with blood collected at 0, 30, 60, 120, and 180 minutes to evaluate changes in Cu levels in blood. Plasma Cu and plasma ceruloplasmin (CP) activity increased significantly (p less than 0.05) as pregnancy progressed, even though there were no significant differences in dietary Cu intakes. Plasma Cu and CP activity responses to the glucose challenge were similar for the three groups. Combined data from the three groups showed a significant (p less than 0.05) increase in plasma Cu by 30 minutes, which dropped significantly (p less than 0.05) by 180 minutes, and a significant decrease (p less than 0.05) in plasma CP activity from baseline to 180 minutes. Although plasma Cu and CP activity were altered with pregnancy, their responses to a glucose challenge did not appear to be associated with the diabetogenic state of pregnancy.

Plasma zinc and copper in pregnant Nigerian women at term and their newborn babies

The concentration of copper and zinc was determined by atomic absorption spectrophotometry in 26 normal Nigerian women at term and their newborn babies. Cord zinc was significantly greater than maternal zinc. In contrast, cord copper was lower than maternal copper. There was only a weak correlation between cord copper and maternal copper but none between cord zinc and maternal zinc. There was no correlation between maternal and cord zinc and neonatal birthweight. However, an inverse correlation was found between maternal and cord copper and neonatal birthweight. These results indicate that: (1) zinc has no effect on fetal growth in Nigerian women but (2) copper may have a negative effect on fetal growth.