Increased urinary zinc excretion in cancer patients is linked to immune activation and renal tubular cell dysfunction

Electrolytes and Nutritional Element Assessment among Iraqi Cancer Patients Receiving Chemotherapy

INTRODUCTION: Cancer may lead to abnormalities in electrolyte levels and acid-base disturbances in affected patients that could be induced by the tumor itself or by chemotherapy treatment. Thus, early detection is vital to improve short-term outcome and quality of life. AIM: This study aims to assess the electrolyte and protein changes in cancer patients on chemotherapy. MATERIALS AND METHODS: A cohort study was carried out on 100 newly diagnosed patients with cancer in Al-Amal National Radiation Oncology Hospital in Baghdad, Iraq, during the period from January 2019 to July 2019. An assessment of the studied samples was conducted as a baseline measure before receiving chemotherapy and after the third cycle of that treatment. Quantitative parameters included measurements of serum magnesium, calcium, sodium, chloride, potassium, zinc, Hb1Ac, total protein, and ferritin. Data analysis was carried out using Student’s t-test for variable levels. Level of significance of ≤0.05 was considered as significant. RESULTS: The studied sample comprised 77 females (77%) and 23 males (23%). There were significant decreases in the levels of magnesium and zinc while no significant changes were noted in the levels of other electrolytes. On the other hand, there was a significant decrease in the level of proteins and a significant rise in HBA1c and ferritin. CONCLUSION: Cancer patients on chemotherapy regimens suffer from major changes in the levels of vitamins, elements, and neurotransmitter that affect their lifestyle, survival, and prognosis. Frequent regular monitoring of such changes is required to harvest a positive impact on the lifestyle of cancer patients lifestyle and their outcome.

Association of Zinc Deficiency with Development of CVD Events in Patients with CKD

Deficiency of the micronutrient zinc is common in patients with chronic kidney disease (CKD). The aim of this review is to summarize evidence presented in literature for consolidation of current knowledge regarding zinc status in CKD patients, including those undergoing hemodialysis. Zinc deficiency is known to be associated with various risk factors for cardiovascular disease (CVD), such as increased blood pressure, dyslipidemia, type 2 diabetes mellitus, inflammation, and oxidative stress. Zinc may protect against phosphate-induced arterial calcification by suppressing activation of nuclear factor kappa light chain enhancer of activated B. Serum zinc levels have been shown to be positively correlated with T₅₀ (shorter T₅₀ indicates higher calcification propensity) in patients with type 2 diabetes mellitus as well as those with CKD. Additionally, higher intake of dietary zinc was associated with a lower risk of severe abdominal aortic calcification. In hemodialysis patients, the beneficial effects of zinc supplementation in relation to serum zinc and oxidative stress levels was demonstrated in a meta-analysis of 15 randomized controlled trials. Thus, evidence presented supports important roles of zinc regarding antioxidative stress and suppression of calcification and indicates that zinc intake/supplementation may help to ameliorate CVD risk factors in CKD patients.

Renal handling of zinc in chronic kidney disease patients and the role of circulating zinc levels in renal function decline

BACKGROUND

Zinc deficiency is commonly encountered in chronic kidney disease (CKD). The aims of this study were to assess whether zinc deficiency was related to increased renal excretion of zinc and to the progression of CKD.

METHODS

Plasma and 24-h urinary zinc levels, urinary electrolytes and uromodulin were measured in 108 CKD patients and 81 individuals without CKD. Serum creatinine values were collected for 3 years to calculate the yearly change in estimated glomerular filtration rate (eGFR). Multivariable regression analysis was performed to assess the association between baseline zinc levels and yearly change in eGFR.

RESULTS

CKD patients had lower circulating zinc levels and higher 24-h urinary zinc excretion than non-CKD participants (612.4 ± 425.9 versus 479.2 ± 293.0 µg/day; P = 0.02). Fractional excretion (FE) of zinc was higher and it significantly increased at more advanced CKD stages. Zinc FE was correlated negatively with 24-h urinary uromodulin excretion (r=-0.29; P < 0.01). Lower baseline plasma zinc levels were associated with a faster yearly decline of renal function in age, gender, diabetes and hypertension adjusted models, but this relationship was no longer significant when baseline eGFR or proteinuria were included.

CONCLUSIONS

Zinc levels are lower in CKD, and not compensated by reduced renal zinc excretion. The inverse association between urinary zinc excretion and uromodulin possibly points to an impaired tubular activity, which could partly account for zinc imbalance in CKD. These data suggest that zinc status is associated with renal function decline, but further studies elucidating the underlying mechanisms and the potential role of zinc supplements in CKD are needed.

Zinc transporter genes and urological cancers: integrated analysis suggests a role for ZIP11 in bladder cancer

Although zinc transporters were shown to play roles in the development of prostate, bladder, and renal cancer, no study has evaluated the genetic variants in zinc transporter genes with risk of urological cancers. A candidate gene association study using genome-wide association study (GWAS) datasets was conducted for variants in 24 zinc transporter genes. Genotypes were analyzed using logistic regression models adjusted for covariates. The function of identified variants was assessed by using the Encyclopedia of DNA Elements (ENCODE). We further evaluated tumors for somatic change of the implicated gene(s) and the associations between identified variants and patient survival from data in The Cancer Genome Atlas (TCGA). A ZIP11 variant, rs8081059, was significantly associated with increased risk of renal cell carcinoma (odds ratios (OR) = 1.28, 95 % confidence intervals (CI) (1.13-1.45), p = 0.049). No zinc transporter variants were associated with prostate cancer risk. Four variants within ZIP11 were significantly associated with bladder cancer risk: rs11871756 (OR = 1.43, 95 % CI (1.24-1.63), p = 0.0002), rs11077654 (OR = 0.76, 95 % CI (0.68-0.85), p = 0.001), rs9913017 (OR = 0.76, 95 % CI (0.68-0.85), p = 0.002), and rs4969054 (OR = 0.78, 95 % CI (0.69-0.88), p = 0.02); the three protective variants were co-located and highly correlated. These variants were located within predicted transcribed or enhancer regions. Among the 253 bladder cancer patients in TCGA, two had tumors that contained deleterious missense mutations in ZIP11. Moreover, rs11077654 was significantly associated with survival of bladder cancer patients (p = 0.046). In conclusion, zinc transporter gene, ZIP11, may play an important role in bladder cancer. Further studies of the gene are warranted.

Zinc status of patients with benign prostatic hyperplasia and prostate carcinoma

OBJECTIVES

The exact cause of benign prostatic hyperplasia (BPH) and prostatic carcinoma is unknown. Changes in the level of the trace element zinc (Zn) are known to be associated with the functioning of different organs (breast, colon, stomach, liver, kidney, prostate, and muscle). This study is aimed at estimating and comparing the zinc levels in the prostate tissue, plasma, and urine obtained from patients diagnosed with BPH or prostatic carcinoma.

MATERIALS AND METHODS

The prostate tissue zinc, plasma zinc, and urine zinc/creatinine ratio in BPH, prostate cancer, and normal subjects were measured by atomic absorption spectrophotometry.

RESULTS

In prostate carcinoma, the mean tissue zinc was decreased by 83% as compared to normal tissue and in BPH, there was a 61% decrease in mean tissue zinc as compared to normal tissues. Both these values were statistically significant. The plasma zinc in prostate cancer patients showed a 27% decrease (P < 0.01) as compared to controls and 18% decrease (P < 0.01) as compared to BPH. The urine zinc/creatinine (ratio) was significantly increased to 53% in prostate cancer patients, and a 20% significant increase was observed in BPH as compared to normal subjects.

CONCLUSIONS

It is evident from this study that BPH or prostate carcinoma may be associated with a reduction in the levels of tissue zinc, plasma zinc, and an increase in urine zinc/creatinine.

Neopterin as an indicator of immune activation and prognosis in patients with gynecological malignancies

Malignant tumors may contribute to host response that involves both the adaptive and innate immune systems. Among other biochemical indicators of systemic immune and inflammatory activity, activation of macrophages by interferon-gamma induces a marked increase in the production of neopterin. Neopterin production by activated macrophages is also associated with tryptophan degradation. In addition to tumors of other primary locations, increased urinary and serum neopterin concentrations have been reported in patients with gynecological cancers, including epithelial ovarian carcinoma, cervical carcinoma, endometrial carcinoma, uterine sarcomas, and vulvar carcinoma, but not in women with benign neoplasms or precancerous disorders. Increased neopterin concentrations have been associated with poor prognosis. Elevated levels of neopterin have also been observed in the tumor microenvironment. Systemic (urinary or serum) or local (ascitic fluid) neopterin concentrations increased after therapeutic administration of cytokines. Elevated neopterin concentrations have been associated with anemia of chronic disease and increased urinary zinc loss in patients with gynecological malignancy. Elevated neopterin has also been connected with depressed function of peripheral blood lymphocytes and a decrease in CD4+ T-cell numbers.

In-vitro studies of aluminium-induced toxicity on kidney proximal tubular cells

The toxicity of aluminium (Al) to various cells is well described. However, little is known about its effect on kidney cells, which can be exposed to relatively high concentrations. In this study, the effect of aluminium as the citrate complex in concentrations up to 100 microM/l was investigated using a monolayer cell culture of kidney proximal tubular cells (PTC). Aluminium was found to be slightly toxic; at 100 microM/l the PTCs lost viability by 15, 20 and 24% after incubation for 24, 48 and 72 h, respectively. Viability was significantly reduced (P<0.001) after 48 h incubation with aluminium concentrations of 25, 50, 75 and 100 microM/l compared with controls. Lactate dehydrogenase (LDH) release was significantly increased (P<0.001) with 100 microM/l Al to 44.67+/-1.76 and 50.33+/-0.88 compared with controls 24+/-1.00 and 28.33 2.34 U/l after 24 and 48 h incubation, respectively, indicating damage to the plasma membrane. However, N-acetyl-beta-D-glucosaminidase (NAG) release in the medium of cells exposed to aluminium showed no difference from control values (P>0.1). Glucose consumption in aluminium-exposed cells at 100 microM/l was slightly, but not significantly (P=0.14), increased during 48 h incubation. Electron micrographs of cells exposed to aluminium at 100 microM/l showed a slight reduction in microvilli density and the cell tight junctions were not as clear compared with the control cells. Pretreatment with protective agents glutathione and tiopronin partly restored the viability of kidney proximal tubular cells to control values, whereas vitamin C and/or cysteine showed no effect. This study indicates that aluminium may show toxicity to kidney cells in culture. Several sites on the cell, i.e. microvilli, membrane and the cell junction, seem to be affected, however the mechanism(s) of damage remain unclear.

Biochemical profile and survival in nonagenarians

OBJECTIVES

Old age is associated with an increase in frequency of disorders involving virtually all organ systems, resulting in a rise of mortality. The aim of the project was to study the relationship between biochemical markers and all-cause mortality in a defined age group.

DESIGN AND METHODS

Thirty-eight nonagenarians, aged 92 +/- 2 (range 90-100) years entered the study. At the start of the study, a sample of peripheral blood and urine were obtained for analysis of 50 basic biochemical, hematologic and biologic parameters. The assessment was then repeated in 6 to 12 months intervals. The significance of difference between surviving subjects and those who died was examined by Mann-Whitney U test and the correlation between the variables was studied by Spearman rank correlation coefficient.

RESULTS

During the observation period, 21 of the studied subjects died leaving 17 persons still alive at the end of the study. The mean time from the first measurement to the death was 12 +/- 10 (range 0-33) months. The mean follow-up time in surviving subjects was 31 +/- 12 (range 4-45) months. Serum vitamin E and calcium were significantly higher, and serum alanine aminotransferase (ALT) and urinary neopterin were significantly lower in survivors compared to the subjects who died. No other parameters were significantly different in survivors and in persons who died. Urinary neopterin exhibited a significant negative correlation with serum sodium concentration (RS = -0.50, p < 0.01), but the other parameters did not correlate significantly.

CONCLUSION

In conclusion, among the parameters studied, differences between survivors and nonsurvivors were observed only for serum vitamin E, calcium, ALT and urinary neopterin. These findings may form a basis for prospective interventional trials in this group of patients.

Correction of hypozincemia following liver transplantation in children is associated with reduced urinary zinc loss

Zinc deficiency is a relatively common problem in children with chronic liver disease. We have previously shown inappropriate urinary zinc excretion in children with chronic liver disease and hypozincemia. This study was designed to determine if zinc deficiency and inappropriate urinary zinc losses are corrected in children with liver disease by liver transplantation. Thirty-three patients (age 1-19 years) underwent 35 liver transplants for acute and chronic liver disease. At the time of transplant, 17 patients had low plasma zinc (hypozincemic) (plasma zinc, 45.4 +/- 1.8 microg/dL), whereas 18 had normal plasma zinc (75.7 +/- 3.8). Before transplant, patients with zinc deficiency had higher urinary zinc to creatinine ratio compared with those with normal zinc status (6.6 +/- 1.9 vs. 2.2 +/- 0.6; P =.03) and lower serum albumin concentrations (low: 2.8 +/- 0.1 vs. normal: 3.3 +/- 0.2; P =.02). After transplant, there was a significant reduction in urinary zinc losses in the hypozincemic group followed by normalization of plasma zinc levels by 7 days posttransplant. These data suggest that the abnormal renal zinc homeostasis that is present in approximately 50% of pediatric patients undergoing liver transplant is rapidly improved and biochemical zinc deficiency is reversed after liver transplantation.

Zinc metabolism in patients with exocrine pancreatic insufficiency

OBJECTIVE

Metabolism of zinc was studied by administering radioactive zinc (Zn65), and by performing metabolic balance studies in eight patients with exocrine pancreatic insufficiency and eighteen control subjects.

METHODS

Retention of radioactive zinc was measured by total body counter, and its urinary and fecal excretion by gamma scintillation counter. Metabolic balance studies were carried out by measuring dietary zinc intake as well as fecal and urinary excretion of zinc by atomic absorption spectrophotometry in this group of patients.

RESULTS

These studies revealed a 50% reduction in intestinal absorption of Zn65 in patients with exocrine pancreatic insufficiency as compared to alcoholic and non-alcoholic control subjects. In addition, there was a 2 to 4 fold increase (p<0.05) in urinary excretion of zinc in subjects with pancreatic disease. In pancreatic insufficiency, reduced zinc absorption and increased urinary zinc excretion were balanced by lower (p<0.05) endogenous excretion of zinc as evidenced by reduced excretion of Zn65 in feces during the second 4-day period. The mean biological half-life of Zn65 tended to be lower in patients with pancreatic insufficiency as compared to alcoholic control subjects, however the difference did not reach statistical significance.

CONCLUSION

These observations indicate marked alterations in zinc metabolism in patients with advanced chronic pancreatic disease and provide greater insight into development of zinc deficiency in this group of patients.