Low Plasma Zinc Levels Research Articles

創傷治ゆ過程における生体内亜鉛量の変動

In a dermatological experiment, the plasma and tissue levels of zinc in rats undergoing healing of artificially created wounds was investigated. In groups of animals not pretreated with zinc, tissue and plasma zinc concentrations showed no appreciable changes during the initial stage of inflammation, then increased at the climax of local inflammatory reaction, with noticeable elevation in the injured skin as well, but returned to initial levels as epidermal regeneration took place with increased collagen synthesis. In rats pretreated with zinc, local inflammatory reactions were less intense, together with a hastening of the healing process to cutaneous regeneration. These animals demonstrated low tissue and plasma zinc levels during inflammation despite pretreatment with zinc, and there was a gradual accumulation of zinc in their organs as epidermal regeneration progressed. The results indicate the necessity for zinc in the healing process of wounds, and points out the decreased duration of the healing process when zinc is utilized.

Studies of marginal zinc deprivation in rhesus monkeys. III. Effects on vitamin A metabolism

The relationship between dietary zinc, vitamin A, and retinol-binding protein (RBP) was studied in pregnant rhesus monkeys. Beginning on day 0 of gestation, monkeys were divided into three groups; 1) eight ad libitum-fed controls (AL) fed a diet containing 100 µg/g zinc, 2) 15 zinc-deprived (ZD) fed a diet containing 4 & #x00B5;g/g zinc, 3) 11 pair-fed controls (PF) fed the 100 µg/g control diet in amounts equal to those consumed by ZD animals. ZD monkeys had lower plasma zinc levels than did the AL and PF groups at day 135 of gestation, and at 1 and 3 months gestation. A positive correlation between plasma vitamin A and plasma zinc was observed (r = 0.5150, p < 0.05) and between RBP and zinc (r = 0.883, p < 0.001) in the ZD group at day 135 of pregnancy. By 3 months postpartum, plasma zinc levels increased in all groups; a positive correlation between zinc and vitamin A was observed in the ZD group (r = 0.5162, p < 0.05) and in the PF group (r = 0.6353, p < 0.05); however, no correlation between zinc and RBP was observed. In ZD monkeys, the ratio of RBP to vitamin A was higher (p < 0.05) than in controls at day 135 of pregnancy. Polynomial regression of the interaction between plasma vitamin A and zinc, and the RBP/vitamin A and zinc, indicated a curvilinear relationship between plasma zinc and these two parameters. These results suggest that there is an interrelationship among zinc, vitamin A, and RBP, and indicate that marginal zinc status may alter vitamin A metabolism, with potentially important implications for pregnant women whose dietary intakes may be less than adequate.

FAILURE TO THRIVE AND ZINC DEPLETION IN BREAST-FED INFANTS: COMPLICATIONS OF UNPLANNED PREGNANCY IN NURSING MOTHERS

In a study of failure to thrive, 3 infants with a similar pattern of growth deviation were encountered. Weight gain ceased at 6 months in two and at 8 months in the 3rd. Breast milk was the main source of calories for all infants and refusal of milk supplements and lack of interest in solids was reported. Dietary analysis for a 6 month girl showed an average intake of 580 ml breast milk and 100 kcal daily from solids. The zinc content of breast milk was in the normal range (0.49 - 0.64 mg/l) for the stage of lactation. Total daily zinc intake approximated only 0.9 mg however, or 18% of the RDA. In a 9 month male, dietary intake consisted of frequent short bouts of nursing and 280 kcal from solids. In this infant, anorexia and poor weight gain persisted for 6 additional months until zinc supplements were provided and catch-up growth occurred. Low plasma zinc levels (57 & 67 μg/dl) were found when assayed in two of the infants. Retrospectively it was realized that the mothers became pregnant at the time the growth failure began in the infants. Unexpected pregnancy should be considered if breast-fed infants show an unexplained failure to gain weight. Zinc may furthermore cause anorexia and delay catch-up growth until supplements are provided to correct the depletion.

The importance of dietary protein in the zinc deficiency of uremia

The pathogenesis of zinc deficiency and its relationship to hypogeusia were studied in three chronic dialysis units in Toronto. The difference between low plasma zinc levels at two of the hospitals compared to the normal levels in the third hospital was significantly related to levels of dietary zinc intake which in turn was due to the levels of dietary protein intake. Thus one cause of zinc deficiency in chronic uremia is dietary protein deprivation. In addition, in the hospital with normal plasma levels there was a small but significant rise in plasma zinc postdialysis in contrast to the other two hospitals where there was no change. Thus slight leaching of zinc from dialysis equipment could help prevent zinc deficiency in such patients. Hypogeusia was more common in zinc-deficient patients.

Acrodermatitis Enteropathica: Zinc Levels and Cell-Mediated Immunity

Acrodermatitis enteropathica (AE) is a rare vesicobullous skin disorder.1 Genealogic data suggest an autosomal recessive mode of inheritance. The onset of symptoms is generally insidious. In breastfed infants, the disorder may be precipitated on weaning to cow's milk. The frequent occurrence of secondary infections, particularly with opportunistic fungi and bacteria, led to the suspicion that AE is associated with immunodeficiency. "Dysgammaglobulinemia" has been reported in one infant2 and defective chemotaxis in another three patients.3 Limited autopsy observations showed atrophic thymus, tonsils, germinal centers, and Peyer patches.2,4 We report variable impairment of cell-mediated immunity in ten patients with AE of whom eight had low plasma zinc levels.

Plasma zinc and its relationship to clinical symptoms and drug treatment in rheumatoid arthritis.

Total plasma zinc levels in patients with rheumatoid arthritis on different therapeutic treatments were determined in conjunction with total serum proteins, serum albumin and globulin, and articular index of joint tenderness, erythrocyte sedimentation rate, rheumatoid factor, serum copper, and serum iron. There were significantly lower zinc levels in patients with rheumatoid arthritis on nonsteroidal anti-inflammatory drugs than in patients on levamisole and penicillamine. Zinc levels correlated positively with serum albumin, and there was an inverse correlation between zinc levels and both ESR and globulin concentration in all rheumatoid patients. However, the correlation coefficient varied in the different treatment groups. The results of this study support the hypothesis that low plasma zinc level in rheumatoid arthritis is one of the nonspecific features of inflammation.

1097 ZINC EXCRETION AND PLASMA ZINC LEVEL IN CHILDREN WITH NEPHROTIC SYNDROME

According to earlier reports albuminuria is accompanied by an increased excretion of zinc and corticosteroid treatment causes a precipitous fall in serum zinc level. These questions were examined in 92 children with nephrotic syndrome and in 33 controls in whom zinc studies were performed at time of initial diagnosis during Prednisone treatment and after treatment was terminated. The plasma zinc content was low in all children with active nephrosis, mean 51.7 μg/100 ml, with values as low as 22 μg/100ml. A slow increase was observed with improvement of the disease. It remained low, however, even in cases of complete and long-lasting remission (69 μg/100 ml).For all groups the quantitative zinc excretion was not significantly different from the controls except for patients undergoing massive diuresis and those in long-lasting remission. During the polyuric phase our patients excreted up to 2500 μg zinc/24 hrs (mean 1770 μg/24 hrs). The zinc excretion of patients in remission was twice the control value (mean 860 μg/24 hrs). The correlation between plasma and urinary zinc and total protein, albumin and α2-globulin concentrations was studied also. The hair zinc level was low in all cases of nephrotic syndrome.A significant urinary zinc loss is not observed in nephrotic syndrome. The low plasma zinc level is not caused by either zinc excretion or corticosteroid administration and can not be explained by changes in serum protein or its fractions. Additional factors will have to be investigated.

Oral zinc therapy in geriatric patients with selected skin manifestations and a low plasma zinc level

A geriatric population comprising 585 inhabitants of an institution for the aged was studied. Twenty-six persons with a mean age of 82 years were selected because of skin manifestations suggestive of chronic zinc deficiency. In 10 of the patients a subnormal plasma zinc level was found. This hypozincaemic group underwent a 4 week trial with zinc sulphate tablets, 0.6 g daily. The therapy failed to alleviate the skin condition in any of the patients, thus indicating that the changes were not caused by zinc deficiency. In the hypozincaemic group, plasma albumin was subnormal in all patients and significantly lower than in the normozincaemic subjects. The correlation between plasma zinc and plasma albumin levels in all 34 patients studied was highly significant (rs = 0.69, p less than 0.001). As plasma albumin tends to fall to subnormal concentrations with age, this explains why plasma zinc may be low in the elderly without indicating a state of zinc deficiency. After 2 and 4 weeks' zinc therapy, the mean plasma zinc concentration of the hypozincaemic group rose significantly from 9.5 to 17.6 and 23.4 mumol/1. This increase is higher than the rise observed in younger patients receiving an identical zinc sulphate dosage.

REVERSAL OF URÆMIC IMPOTENCE BY ZINC

In eight impotent hæmodialysed men with low plasma-zinc levels sexual function, including potency, frequency of intercourse, libido, and plasma testosterone, follicle-stimulating hormone, and luteinising hormone levels, was determined before and after therapy with zinc (four patients) or placebo (four patients). Dialytic administration of zinc strikingly improved potency in all patients and raised the plasma-testosterone to normal in the two with low pretreatment plasma-testosterone levels. Placebo did not improve sexual function in any patient. Zinc deficiency is a reversible cause of gonadal dysfunction in uræmia.

NUTRITIONAL EVALUATION OF HEAD START CHILDREN WITH SHORT STATURE

Twenty-nine children in the Head Start program were referred for evaluation of short stature after preliminary screening by nutrition aides, three months after starting school. This group comprised 18 Hispanos, 3 Negroes and 8 Anglos (15 males and 14 females) with a mean age of 4.4 years (range 3.2-6.4 years). The height was <3P in 26/29 children and weight <3P in 19/29. Physical abnormalities included multiple cavities (4/29), hepatomegaly (4/29), cardiac murmurs (4/29), stigmata of rickets (4/29), and skin or mucosal changes compatible with Vitamin A deficiency in 5/29. Normal laboratory parameters included: hematocrits (39.8% ± 2.65), urinalyses, serum Ca, Alk. Phos., BUN, total protein and serum albumin. Vitamin A levels were <30μg% in 18 patients and <20μg% in 9 of these. Vitamin C levels were <.5mg% in 2. The mean hair zinc concentration was 105 ± 4ppm, lower than control children of similar age (p <0.01). Low hair zinc levels (<70ppm) were present in 8 and low plasma zinc levels (<70μg/100ml) in 4 children.The present study demonstrates inadequate vitamin and trace mineral nutrition or metabolism in 50% of this Head Start group of children with short stature, emphasizing the need for medical and nutritional attention in this high risk group.

Plasma and urinary zinc in patients with malabsorption syndromes or hepatic cirrhosis.

Plasma and urinary zinc have been measured in 19 patients with malabsorption and 21 patients with hepatic cirrhosis. The results have been compared with those of 20 control subjects and 23 patients with a variety of other diseases. The diurnal variation in plasma zinc levels has been confirmed and is of such magnitude that this must be taken into account in comparing results in groups of subjects. Plasma zinc levels, both fasting and after a meal, are significantly lower in patients with cirrhosis (71 and 60 mug/100 ml) and malabsorption (76 and 64 mug/100 ml) than in controls (97 and 81 mug/100 ml). In the patients with cirrhosis or malabsorption similar correlations exist between plasma zinc and plasma albumin, suggesting that the low plasma zinc levels may be, at least in part, dependent on the plasma albumin level. Urinary zinc excretion is increased in cirrhosis, but not in malabsorption, indicating that increased urinary loss is unlikely to explain the low plasma levels.

Zinc, Copper, Magnesium, and Calcium in Dialyzed and Nondialyzed

Increasingly, long-term hemodialysis is being implicated causally in the development of metabolic disturbances. Complications such as bone disease and neuropathy have been observed and the role of trace metals in their development has been questioned. In 15 uremic patients who underwent hemodialysis, plasma and erythrocyte content of zinc, copper, magnesium, and calcium was determined before and after a single dialysis and compared to values obtained in seven nondialyzed uremics. Uremic patients receiving severely restricted protein intake and not dialyzed had low plasma zinc and normal copper levels, high plasma and erythrocyte magnesium and low plasma and erythrocyte calcium levels. In dialyzed uremic patients with more liberal protein intake the plasma zinc levels approached normal. The effect of a single dialysis on these values was not striking; the role of the diet could not be ascertained.

Growth and Sexual Development of Adolescent Egyptian Village Boys : Effects of Zinc, Iron, and Placebo Supplementation

Two hundred and seventy-nine boys attending the Sindion Preparatory School in the United Arab Republic were examined for growth retardation, delayed sexual development, and signs of nutritional deficiencies. One-third, or 90 boys, were found to be greater than two standard deviations below the Iowa mean for height. One quarter of the boys showed signs of B-complex deficiency. Eighty percent were infected with Schistosoma hematobium and complained of intermittent hematuria or dysuria, or both. Hookworm infection was uncommon. All of the boys 2 standard deviations below the Iowa mean for height and a randomly selected control group of 30 of the taller boys were studied in greater detail. Periodic physical examinations were done and included heights, weights and clinical findings. Blood specimens were collected for hemoglobin, hematocrit, serum iron, plasma zinc, and alkaline phosphatase determinations. Urinary riboflavin levels were also determined. X-Rays were taken for bone age. Serial photographs were taken to assess genital development. The examinations were performed at intervals of 3-5 months for a year. The laboratory examinations showed hypoferremia and low plasma zinc levels. Bone age was retarded 2-3 years in both the physically retarded boys and in the controls. Height age was more severely retarded than bone age in the retarded boys. The onset of puberty was slightly delayed in the physically retarded boys by American standards. A double-blind therapeutic trial was carried out giving a daily supplement of 300 mg reagent grade FeSO4·7H2O, 60 mg reagent grade ZnSO4·7H2O, and a placebo. The therapeutic trial was continued for 5½ months. No other additional foods or nutritional supplements were given, and the basic village diet remained unchanged. At the end of 1 year, there was no difference in growth, as measured by increase in height, and no difference in sexual development, as measured by analysis of the clinical examinations and serial photographs, between the three therapeutic groups. The supplements of zinc and iron were effective in raising the serum levels of zinc and iron, respectively, and thus were absorbed. A diet survey using the recall method was done and showed that the diets of the retarded boys were limiting in calories, vitamin A, riboflavin, and possibly calcium and ascorbic acid. Composite food samples were also collected and analyzed and showed the same deficiencies. The zinc content of the diets was normal. Phytate may have interfered with absorption, however.

Zinc Levels and Blood Enzyme Activities in Egyptian Male Subjects with Retarded Growth and Sexual Development

Zinc deficiency in animals results in a retardation of growth and sexual development. An attempt has been made during previous investigations to correlate low plasma zinc levels in rural male Egyptians with retarded growth and sexual development. Our present studies have revealed that plasma zinc levels in rural male Egyptians with normal maturation are also low. Normal Egyptians and Americans living in Cairo have normal plasma zinc levels. Egyptian "hypogonadal dwarfs" have been demonstrated to ultimately obtain sexual maturity and a normal stature without treatment or change in their low plasma zinc levels. Thus the significance of plasma zinc level as a reflection of maturation or zinc deficiency remains unclear.