Serum Copper and Zinc in a Representative Sample of Bulgarian Population

Copper (Cu) and zinc (Zn) are essential for life. Body Cu and Zn content depends on variety of factors - age, gender, and diet, type of drinking water, geographical location and genetic predisposition. Copper status becomes even more relevant not only in rare genetic disorders such as Wilson disease but in diseases such as cardiovascular ones, impaired glucose tolerance and neuro-degenerative and tumor diseases. The study aimed to examine the distribution of serum Cu and Zn in a representative group of the Bulgarian population and to describe factors which influence metal content. It also aimed to describe the link between serum Cu levels and the frequency of Alzheimer’s disease (AD) in Bulgarians. Cu and Zn in serum were measured in 379 individuals (172 males and 207 females) from 5 different regions in Bulgaria by flame atomic absorption using AAnalyst 400, Perkin Elmer. Statistical analyses were performed by SPSS, 19. Median and inert-quartile range (IQR) for blood Cu were 15.89 (13.87-7.89) μmol/L and for Zn - 13.00 (11.7-14.68) μmol/L in the examined group. Higher Cu levels in females than in males were found (p < 0.001). Decrease of Zn with aging was established (p > 0.05). Significant difference (p < 0.05) was found in serum Cu between young people (< 30 year old) and adults over 61 year old. Statistically significant difference in Cu and Zn was observed (p < 0.05) in respect of residences. Difference without significance was measured between serum lipids and serum Cu (p = 0.541) and Zn (p = 0.741).

Preanalysis in Serum Hepcidin Measurement

BACKGROUND

Hepcidin is a 25-amino peptide hormone that regulates iron homeostasis. Its serum quantification helps to provide the right therapeutic choice in iron-deficiency anemia and anemia in chronic diseases. Diurnal levels of serum iron might affect hepcidin secretion during the day. Blood collection time is an important part of the preanalytical phase of its quantification.

METHODS

During the period 2013 - 2014, we collected blood samples for serum hepcidin quantification in 100 healthy controls. The samples were collected in vacuettes with serum separator gel at three different times during the day: 07:30 - 08:30, 12:00 - 13:00, and 16:00 - 17:00 hours. Hepcidin levels were measured with an ELISA method.

RESULTS

We found a significant difference in serum hepcidin levels during the chosen three blood taking times. The normal range for Bulgarian population is 3.05 μg/L - 37.75 μg/L. The measured levels were: at 07:30 - 08:30 hours 12.2 μg/L (5.5 μg/L - 23.6 μg/L), 12:00 - 13:00 hours 14.1 μg/L (7.1 μg/L - 27.2 μg/L), and 16:00 - 17:00 hours 16.5 μtg/L (9.9 μg/L - 29.6 μpg/L) 10.7 < r < 1.0; p < 0.5 between 07:30 - 08:30 and 12:00 - 13:00 hours and p < 0.05 between 07:30 - 08:30 hours and 16:00 - 17:00 hours and 12:00 - 13:00 hours and 16:00 - 17:00 hours]. No significant differences were found for transferrin saturation between measured groups [0.1 < r < 0.3; p > 0.5].

CONCLUSIONS

In order to obtain the most correct results for serum hepcidin quantification (especially in border to referent range levels) in the preanalytical phase, it is important to consider the time of blood sampling.

Zinc status in patients with chronic renal failure on conservative and peritoneal dialysis treatment

BACKGROUND AND AIM

The physiological mechanisms regulating zinc homeostasis in humans have been elucidated and described, but the knowledge of zinc status and zinc distribution in the tissues and in the different biological compartments of patients with conservatively treated chronic renal failure (CRF) and on peritoneal dialysis is still insufficient. This investigation examines and compares zinc content in urine, erythrocytes, plasma, and outflow dialysis solution in a group of continuous ambulatory peritoneal dialysis (CAPD) patients, a group of patients with CRF on conservative treatment and in healthy controls.

MATERIAL AND METHODS

Data from the last 6 months of 22 adult hemodialysis patients with a mean age of 61 ± 14 years were analyzed retrospectively. Dialysis vintage, normalized protein catabolic rate (nPCR), serum biochemical parameters, mid arm muscle circumference (MAMC) were determined as mean and standard deviation. Correlations between the variables were computed by coefficient p of Pearson.

RESULTS AND CONCLUSION

In patients on CAPD treatment (group 3) compared to healthy controls (group 1) plasma zinc level was diminished (р<0.05), while erythrocyte zinc elevated (р<0.01). The investigation found out difference between plasma, erythrocyte and urine levels of zinc between the patients with chronic renal failure (group 2) on conservative treatment and those treated by CAPD (group 3), which proves, that continuous ambulatory peritoneal dialysis influences redistribution of zinc in human organism "per se".