Serum Zinc Values Research Articles

Abnormal immune responses during hypozincaemia in acrodermatitis enteropathica.

Immune responses were characterized in six patients with acrodermatitis enteropathica during a break in zinc supplementation and during resupplementation. During hypozincaemia the number of T-cells increased but the amount of B-cells and the responses of T- and B-lymphocytes to phytohaemagglutinin, concanavalin A-, pokeweed mitogen- and Staphylococcus aureus stimulations in vitro were subnormal. Cell counts and stimulation results both normalized when serum zinc values improved. One patient was anergic to tuberculin while showing signs of acrodermatitis enteropathica; she converted during supplementation whereas the others were continuously positive. Three females had antibodies against nuclear antigens and slightly elevated serum IgE concentrations; these values were not affected by the break in supplementation. Four females were continuously rheumatoid factor positive. Our findings suggest that zinc deficiency is closely associated with impaired immune responses in patients with acrodermatitis enteropathica, and laboratory markers of autoimmunity occur in a considerable number of the acrodermatitis enteropathica patients, irrespective of their zinc status.

The Rate of Rhodopsin Regeneration in the Bleached Eyes of Zinc-Deficient Rats in the Dark

Rats fed a zinc-deficient, phytate-containing diet (ZD rats) for 4 wk showed typical signs of zinc deficiency: reduced food intake, slow weight gain, a poor food efficiency ratio and subnormal zinc concentrations in the serum, femur and eye. Pair-fed, weight-matched rats fed a zinc-sufficient diet (PF rats) showed normal serum zinc values, intermediate femur zinc levels and eye zinc concentrations similar to those in ZD rats. The vitamin A status of all three groups, expressed as the concentration of vitamin A in the liver, was comparable. After extensive bleaching, the initial rate of rhodopsin regeneration in ad libitum-fed, zinc-sufficient rats (AL rats), ZD rats and PF rats was the same, whereas the extent of rhodopsin regeneration in AL rats kept in the dark for 120 min was almost twice that found in ZD and PF rats. These results are not consistent with the hypothesis that zinc deficiency primarily affects dark adaptation by reducing the activity of alcohol dehydrogenase in the eye. Rather, zinc deficiency and the generalized malnutrition that results from markedly reduced food intake seem to depress the synthesis of opsin, and probably other proteins as well, in the rod cells of the eye.

Copper and zinc levels in "healthy" and "sick" elderly.

Healthy elderly as a group have a wider range for serum copper, ceruloplasmin, and serum zinc than the adjusted ranges for the laboratory. In disease serum copper and/or ceruloplasmin act as acute-phase reactants in vascular disease, inflammation, and malignancy. Serum zinc values likewise are affected by the presence of inflammation and malignancy. The reported low level of copper in patients with osteoporosis was not confirmed by the present study. Neither was there any evidence found for zinc deficiency in patients with dementia.

Copper, zinc and copper/zinc ratio in chronic pancreatitis and pancreatic cancer

Serum copper and zinc levels and their ratio were evaluated in 48 control subjects, 29 patients with pancreatic cancer, 46 with chronic pancreatitis and 32 with extra-pancreatic diseases, with the purpose of ascertaining modifications in chronic pancreatic disease. Hepatic involvement and age were also investigated as possible factors influencing results. Cu/Zn ratio was found to be significantly increased in pancreatic cancer (2.66 +/- 0.16, mean +/- SE) as compared to controls (1.39 +/- 0.06, p less than 0.001), chronic pancreatitis (1.82 +/- 0.09. p less than 0.001) and extra-pancreatic diseases (1.81 +/- 0.18, p less than 0.001), but without practical clinical value. Serum zinc levels appear to decrease with age, while copper and Cu/Zn ratio increase. However, covariance analysis demonstrated that age does not play an important role in influencing copper and Cu/Zn ratio. A decreased liver synthetic function, at least in part age-related, seems to be an additional factor in decreasing serum zinc values.

Zinc supplementation during pregnancy in low-income teenagers of Mexican descent: effects on selected blood constituents and on progress and outcome of pregnancy

As a follow-up of our study of pregnant women, we report effects of zinc supplementation during pregnancy in another population of 138 Hispanic teenagers in Los Angeles. Teenagers were randomized (double-blind) to a control or zinc-supplemented group and received similar daily vitamin and mineral supplements except for 20 mg zinc added to the zinc-supplemented group's capsules. Initially, mean dietary zinc intakes of both groups were about 50% of the Recommended Dietary Allowance and their mean serum zinc levels did not differ significantly (69.8 +/- 11.2 micrograms/dl in control and 69.0 +/- 11.4 micrograms/dl in zinc-supplemented group). Zinc supplementation did not maintain mean serum zinc levels during pregnancy but, as in our earlier study, it reduced (p = 0.018) the number of low serum zinc values (less than or equal to 53 micrograms/dl) in late pregnancy. Zinc supplementation did not affect outcome of pregnancy but serum zinc levels were lower (p = 0.038) in teenagers with pregnancy-induced hypertension than in normotensives.

Association between urinary zinc excretion and lymphocyte dysfunction in patients with lung cancer

Patients with bronchogenic carcinoma often have low serum zinc concentrations and sometimes have markedly elevated renal zinc losses. Since normal zinc metabolism is critical for the proper function of T lymphocytes and natural killer cells, the effect of zinc status on T cell phytohemagglutinin response and peripheral blood lymphocyte natural killer cell activity was studied in patients with lung cancer. Mean (± SEM) serum zinc concentration in 75 patients with cancer was 67.4 ± 2.2 μg/dl versus 96.0 ± 8.0 μg/dl for normal subjects. Patients with low serum zinc levels (less than 70 μg/dl) had significantly higher urine zinc excretion than patients with normal serum zinc levels (1,385 ± 240 μg per 24 hours versus 392 ± 107 μg per 24 hours) (p <0.001). This pattern of zinc concentrations (i.e., low serum zinc in combination with high urine zinc) is typical of patients with mild zinc deficiency, and suggests that a mild chronic zinc deficiency state was present in some of these patients. When lymphocyte data were analyzed according to serum zinc concentrations and urinary zinc excretion, low serum zinc concentration and high urine zinc excretion both correlated with depressed T cell phytohemagglutinin response (p <0.005 and p <0.001, respectively). For instance, mean maximal phytohemagglutinin response in patients with urinary zinc excretion of more than 700 μg per 24 hours was 22,132 ± 3,201 cpm (n = 14) compared with 68,130 ± 6,850 cpm for patients with normal zinc excretion (n = 7). Peripheral blood lymphocyte natural killer cell activity did not correlate with either serum or urine zinc values. Oral zinc sulfate (220 mg, three times daily for six weeks) was then administered to patients with hyperzincuria (mean = 992 μg per 24 hours). Zinc-supplemented patients had normalization of T cell phytohemagglutinin response after zinc therapy, whereas control patients demonstrated continued T cell dysfunction. Natural killer cell activity did not change in either group during the study period. These data suggest that a mild subclinical zinc deficiency state may exist in some patients with lung cancer and may be an important cause of abnormal T cell function. Furthermore, zinc supplementation may be useful to improve lymphocyte function in selected patients. Whether zinc supplementation would alter the course of the disease or the patient's prognosis is presently unknown.

1261 RETENTION AND ELIMINATION OF 65Zn IN ACRODERMATITIS ENTEROPATHICA: A STUDY WITH WHOLE BODY COUNTING

Hypozincemia is a constant finding in patients with acrodermatitis enteropathica (AE). Oral supplementation with large doses of zinc corrects both hypozincemia and clinical manifestations. We measured changes in serum zinc values in 3 healthy subjects and 4 patients with AE after an oral dose of zinc sulphate (1 mg/kg); increments were identical in patients and controls. We then studied zinc retention and elimination after a tracer dose of 37 kBq (1 μCi) of carrier-free ZnCl2 in 4 patients (aged 5-40 years, 1 male) and four controls (32-41 years, 2 males) using whole body counting technique. The radiation dose was accepted by the Institute for Radiation Protection and remained clearly below the background radiation dose. Body distribution of the label was similar in patients and controls. Zinc retention and biological half-life were calculated for counts between 7 and 120 days of the study by fitting single exponential function to the data. The patients showed a 23±1% retention (mean±SE) and 109±11 days' biological half-life. In female controls the values were 81±1% and 159±16 days, and in male controls 45±1% days, respectively. We conclude that tracer amounts of zinc are poorly absorbed in AE, and that the turnover of zinc appears to be faster in the patients than in controls also while patients are on zinc supplementation.

Serum zinc and urinary zinc excretion of trauma patients

Eight male patients who had suffered severe trauma were longitudinally monitored for serum zinc, total protein, alkaline phosphatase and urea nitrogen. Daily urinary zinc and creatinine excretion were also measured. The trauma patients were followed from less than 24 hours to 240 hours after admission. The initial mean serum zinc concentration at less than 24 hours after admission was significantly lower (P<.05) than the concentrations at 97–168 and 169–240 hours post admission. The initial mean serum zinc of 41 ug/dl was also lower than the mean of 87 ug/dl observed in twelve healthy males. By 240 hours after admission 6 of the 8 patients had serum zinc values comparable to the healthy males. Serum zinc concentration was significantly correlated (P <.05) with serum alkaline phosphatase but not with serum total protein, albumin or urea nitrogen. An increase in urinary zinc excretion compared to that observed in the twelve healthy men did not occur until 97–168 hours post admission. An increase in urinary creatinine excretion also occurred at this time period, which suggests that the increased loss of zinc was due to muscle catabolism. The initial decrease in serum zinc below values observed for the healthy males was not accompanied by a decrease in serum albumin or an increase in urinary zinc excretion.

Effect of dietary linoleic acid on the tissue levels of zinc and copper, and serum high density lipoprotein cholesterol

The effects of dietary linoleic acid on the serum level of high density lipoprotein (HDL) cholesterol and its relationship with the tissue status of zinc and copper were examined in adult male rats fed diets differing in the amount of linoleic acid. One group of 9 animals was fed a diet containing hydrogenated coconut oil (4%) and the other was fed a diet containing coconut oil (3.4%) plus linoleic acid (0.6%). Both diets were isocalorically formulated with the equal levels of minerals and other nutrients and contained cholesterol at 1% level. During a 6-week experiment, no differences were observed in food intake and body weight between the two groups. The feeding of linoleic acid produced a significant decrease in serum HDL cholesterol level at 6 weeks and no changes in other lipoproteins and total serum cholesterol and triglyceride. Dietary linoleic acid also significantly lowered the concentrations of zinc in serum and tibia at 6 weeks, while it had no effect on copper contents in these tissues. No changes were observed in the concentration of either zinc or copper in the liver. Linear regression analysis of the 18 pairs of serum zinc and HDL values at 6 weeks indicated a significant positive correlation ( r = + 0.65; P < 0.01) between the two parameters. No such relationships were shown between tibia zinc and serum HDL, and between tissue copper and serum HDL. The results indicate that dietary linoleic acid at a relatively low level produces a decrease in serum HDL cholesterol without significantly lowering total serum cholesterol and that the decrease in HDL cholesterol due to linoleic acid feeding is significantly correlated with the reduction in serum zinc level.

Effect of Dietary Zinc Sources and Pregnancy on Zinc Utilization in Adult Women Fed Controlled Diets

Five nonpregnant and 10 pregnant women participated in 21-day confined metabolic studies. Two diets each providing 16 mg of zinc per day were fed. In one diet 70% of the total zinc was provided by animal products and 30% was contributed by plant sources. In the second diet the proportions were reversed. Apparent absorption of zinc was determined using the balance technique. During the last 15 days of the study, zinc intake was only slightly greater than the amount of zinc excreted in feces. Mean apparent absorption values did not exceed 5% and did not vary due to diet or pregnancy. Zinc bioavailability was also assessed by measuring the apparent absorption of a stable isotope of zinc (70Zn) added to the diet. There was no significant effect of either diet or pregnancy on 70Zn absorption, which averaged about 25%. Serum zinc values were normal throughout the study and did not change significantly as a function of diet. The pregnant women, however, maintained values that were 19-27% lower than those of the nonpregnant women. In summary, the substitution of animal sources of zinc by plant products did not reduce zinc bioavailability or alter zinc utilization.

Zinc absorption in patients with compensated alcoholic cirrhosis.

Zinc absorption was measured by whole-body counting in 10 patients with compensated alcoholic cirrhosis without steatorrhoea and in 8 healthy subjects. After oral administration of 65Zn the absorption was measured at regular intervals until a straight time/activity retention curve was obtained in a semilogarithmic system, whereafter it was calculated by extrapolation to time zero. Cirrhotic patients had a median absorption of 69% (27-90%), compared with 42% (25-67%) in healthy subjects (P less than 0.01). Median T1/2 of 65Zn as calculated from the retention curve was 156 days (83-280 days) in cirrhotic patients and 103 days (72-132 days) in healthy subjects (P less than 0.05). Median serum zinc value was 11 mumol/l (9-17 mumol/l) in cirrhotic patients and 16 mumol/l (12-17 mumol/l) in healthy subjects (P less than 0.01). Median erythrocyte zinc value was 224 mumol/l (205-281 mumol/l) in cirrhotics and 223 mumol/l (188-275 mumol/l) in healthy subjects (P less than 0.1). Six cirrhotic patients, of whom four took diuretics, had increased urinary zinc excretion (greater than 15 mumol/24 h). Zinc absorption seems intact in compensated alcoholic cirrhosis. The increased absorption and prolonged T1/2 of 65Zn might be compensatory to a moderate zinc depletion.

Dietary cholesterol decreases the serum level of zinc: further evidence for the positive relationship between serum zinc and high-density lipoproteins

The previous finding (Am J Clin Nutr 1981;34:2376-81) that the serum level of high-density lipoprotein (HDL) cholesterol is positively correlated with the serum concentration of zinc (r = +0.81; p less than 0.01) led us to evaluate further the zinc-HDL relationship as affected by dietary cholesterol. The two diets, one control diet containing no cholesterol and the other containing 1% cholesterol, were isocalorically formulated with an equal but adequate level of zinc. Cholesterol feeding produced a significant decrease in the serum level of HDL cholesterol at 8th wk of dietary treatment and a significant increase in very low density lipoprotein cholesterol at 4th and 8th wk. At the same intervals of dietary treatment, significant decreases in serum zinc levels were observed in cholesterol-fed rats; no changes were noted in the serum levels of other related elements such as copper, calcium, and magnesium. Linear regression analysis of the 44 pairs of serum HDL and zinc values revealed a significant positive correlation (r = +0.57; p less than 0.01) between the two parameters. The rather selective lowering of serum zinc due to cholesterol feeding and the observation of the positive serum zinc-HDL relationship observed in the present and previous studies warrant further investigation into the role of zinc in cholesterol and high-density lipoprotein metabolism.

Zinc supplementation during pregnancy: zinc concentration of serum and hair from low-income women of Mexican descent

The effect of zinc supplementation on concentrations of zinc in hair and serum of 213 pregnant Hispanic women attending a clinic in Los Angeles was assessed using a random, double-blind experiment. Both the treatment (T) and control (C) groups received similar vitamin and mineral supplements except that 20 mg zinc was added to the supplements for the treatment group. Nutrient intakes were calculated from 24-h recalls. The initial mean dietary zinc intake of both groups was about 50% of the Recommended Dietary Allowance (9 +/- 5 mg). Initially there were no significant differences between the two groups in mean zinc levels in serum (66 +/- 11 micrograms/dl, C, and 65 +/- 12 micrograms/dl, T) or in hair (184 +/- 41 micrograms/g, C, and 175 +/- 38 micrograms/g, T). Zinc supplementation did not alter mean zinc levels in serum or hair but significantly (p less than 0.05) reduced the number of low serum zinc values (less than or equal to 53.3 micrograms/dl) toward the end of pregnancy. Although serum zinc levels do decline in pregnancy, our results suggest that severely depressed levels (less than or equal to 50 to 55 micrograms/dl) indicate inadequate zinc status.

Serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin concentrations in infants receiving intravenous zinc and copper supplementation

One hundred twenty-seven newborn infants requiring parenteral nutrition were randomly assigned to receive differing amounts of zinc (40 to 400 micrograms/kg/day) and copper (20 or 40 micrograms/kg/day) supplementation within five birth weight groups (600 to 2,500 gm). The serum zinc concentration remained relatively constant in the group receiving the most zinc supplementation after two weeks of therapy, but declined sharply in the groups receiving less supplementation. No effect of increased copper intake was noted on ceruloplasmin values, but a difference in serum copper concentrations was noted at two weeks. No correlation was noted between serum zinc and copper values or among those for serum zinc, retinol-binding protein, and prealbumin. Reference ranges were defined for serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin in the preterm infant.

ESTUDO SOBRE O ESTADO NUTRICIONAL EM RELAÇÃO AO ZINCO NA AMAZÔNIA. I. Níveis de Zinco no Sôro e Ingestão de Zinco em Operários de Manaus, 1978 ()

SUMÁRIO O objetivo deste estudo foi verificar se a baixa ingestão de zinco relatada para a população da área urbana da cidade de Manaus, no Estado do Amazonas, está associada com niveis balxos de zinco sérico. O estudo foi realizado com trabaIhadores percebendo salários baixos, em quatro fábricas de Manaus. Duas destas fábricas forneciam alimentação e assistência médica. A média e a mediana da ingestão de zinco dietético, foi 54.7% e 49.3% respectivamente das recomendações diárias. americanas. A ingestão de zinco foi mais alta nos trabalhadores nascidos em Manaus, que possuiam um meIhor nível de escolaridade e que tinham renda familiar mais alta, mas essas diferenças foram evidentes unicamente nas fábricas que não forneciam refeição. A ingestão de zinco diminui com a idade em ambos os sexos, sendo mais alto nos homens do que nas mulheres em todos os grupos por idade. Essa tendência foi observada em todas as fábricas. Não houve diferença significativa do nível de zinco sérico entre homens e mulheres. Porém o valor de zinco no soro tende a declinar também com a idade em ambos os sexos. A média do nível de zinco sérico de trabalhadores com renda familiar baixa e média foi significativamente mais baixa do que trabalhadores com renda familiar alta (P&lt;.001. P&lt;.05). 34% de todos os trabalhadores com renda familiar baixa, 26% com renda familiar média e 17% com renda familiar alta, tinham níveis de zinco sérico deficientes (&lt; 11.5 μmol/l). A concentração de zinco no soro foi relacionada com ingestão de zinco do sexo masculino (r=0.26 p&lt;.02) mas não em operários do sexo feminino (r=0.11 p&lt;.1). A ingestão de zinco em trabalhadores de ambos os sexos com nível de zinco sérico déficiente foi significativamente mais baixa do que aqueles com nível de zinco sérico normal. A ingesta de zinco nos homens foi mais alta do que nas mulheres para todos os níveis de zinco sérico.

Serum copper and zinc values and copper/zinc ratio in acute leukemia and relation to prognosis: [formula omitted], [formula omitted], [formula omitted], [formula omitted], [formula omitted], Pediatrics Oncology and Hematology Research Unit (TUBITAK) School of Medicine Ankara University, Ankara - Turkey

Serum copper and zinc values and copper/zinc ratio in acute leukemia and relation to prognosis: [formula omitted], [formula omitted], [formula omitted], [formula omitted], [formula omitted], Pediatrics Oncology and Hematology Research Unit (TUBITAK) School of Medicine Ankara University, Ankara - Turkey

Serum zinc levels and urinary zinc excretion in patients with bronchogenic carcinoma: Effects of tumor resection

Low serum zinc levels and high urinary zinc excretion were found in 25 patients with bronchogenic carcinoma. Twenty of them underwent successful removal of the tumor by lobectomy or pneumonectomy; in the other 5 patients surgical exploration revealed unresectable pulmonary lesions. The latter had significantly lower serum zinc and higher urinary zinc levels than the patients in whom surgical removal of the tumor could be performed. Tumor resection was followed by restoration of serum and urinary zinc to normal. In contrast, in the inoperable patients a further decrease in serum zinc and no significant change in urinary zinc excretion were noted 15 days after thoracic exploration. In both patient groups a significant negative correlation existed between preoperatively obtained values of serum and urinary zinc. Hypozincemia in patients with bronchogenic carcinoma may result from an increase in urinary zinc losses, probably related to a decrease in zinc binding to plasma proteins. Determination of serum and urinary zinc may be useful in evaluating the prognosis of primary lung cancer.

Trace metals in cystic fibrosis.

Serum zinc and copper concentration, 24 hrs urinary zinc and copper excretion, plasma selenium and red blood cell glutathione peroxidase activity were measured in 13 cystic fibrosis patients aged 6 to 15 years. The mean serum zinc value +/- S.D. (17.3 mumol/l +/- 4.6) did not differ from that of the control group (17.9 mumol/l +/- 3.1). Urinary zinc excretion in 12 out of 13 patients was within the normal range (1.53-13.8 mumol/24 hrs). The mean serum copper +/- S.D. (23.8 mumol/l +/- 4.2) was not significantly elevated as compared to the value found in the control group (19.2 mumol/l +/- 3.5), but 4 children, including 1 with documented portal hypertension, showed an urinary copper excretion greater than 0.94 mumol/24 hrs (normal: 0.16-0.80 mumol/24 hrs). Mean plasma selenium +/- S.D. (0.84 mumol/l +/- 0.25) was significantly reduced as compared to the control group (1.0 mumol/l +/- 0.15) (p less than 0.05). The correlation between selenium concentration and RBC glutathione peroxidase activity was significant (p less than 0.01). A negative correlation was also found between plasma selenium and 24 hrs faecal fat excretion (p less than 0.05). It is concluded that CF children with severe dysfunction of the exocrine pancreas are at increased risk to develop symptoms of subclinical or manifest zinc and/or selenium deficiency. Appropriate supplementation should therefore systematically be considered.

Relationship between the nutritional status of zinc and cholesterol concentration of serum lipoproteins in adult male rats

The effect of zinc status on the distribution of serum cholesterol among the major serum lipoproteins was assessed in adult male rats fed a zinc-deficient diet (0.37 ppm Zn) as compared with those of pair-fed and ad libitum-fed zinc-supplemented controls (41 ppm Zn). All data were collected within the first 4 wk of dietary treatment before the manifestation of any external symptoms of zinc deficiency. The acute zinc depletion produced a significant reduction in total serum cholesterol; the reduction was primarily due to the selective decline in high-density lipoprotein-cholesterol. Zinc depletion per se produced no significant alterations in very low-density lipoprotein- or low-density lipoprotein-cholesterol level. In addition, linear regression analysis based on the 36 pairs of serum zinc and high-density lipoprotein-cholesterol values showed a significant positive correlation (r = + 0.81; p less than 0.01) between these two parameters. The data also indicated a significant correlation between the ratio of zinc/copper and total serum cholesterol. This relationship was, however, solely dependent upon serum zinc status rather than serum copper. The serum levels of copper were not affected by zinc depletion over the period of 4 wk. These results present new evidence for the close association between the nutritional status of zinc and high-density lipoprotein concentration in adult male rats and draw attention to the potential significance of zinc nutriture in relation to cardiovascular health.

Zinc nutrition in Crohn's disease.

A prospective evaluation of zinc status was made in 63 randomly selected patients with Crohn's disease. In the patients, mean serum and 24-hr urinary zinc values--105 microgram/dl and 383 microgram/day, respectively--were not different from controls. However, 46% of these patients had less than normal serum zinc and 36% had low urinary zinc excretions. Simultaneous reductions in both serum and urinary zinc were detected in 19% of patients. A direct correlation (P = 0.01) was found between serum levels of zinc and the concentration of albumin, the major zinc-binding protein, in outpatients but not in hospitalized patients or patients with Crohn's disease as a whole. Intake of zinc was surprisingly good--a mean intake of 13.4 +/- 1.4 mg/day. A significant (P = 0.006) association was found between urinary zinc and the Crohn's disease activity index but not between serum zinc concentration and this index. No association was found between zinc measurements and the presence or absence of fistulas, use of prednisone or sulfasalazine (Azulfidine), large bowel resections, and length of small bowel resected.