Zinc nutritional status in obese children and adolescents

Studies in animals and humans have corroborated that zinc (Zn) metabolism is altered in obesity. The present work intends to evaluate the Zn nutritional status in obese children and adolescents by the determination of some biochemical parameters and analyses of the diets. The investigation was carried out in a group of obese children and adolescents (n=23) and compared to a control group (n=21), both between 7 and 14 yr of age. A software analyzed diet information from 3-d food records. Body composition was evaluated by body mass index, bioelectrical impedance, and skinfold measurements. Zinc nutritional status was evaluated by Zn determination in plasma, erythrocyte, and 24-h urine, by atomic absorption spectrophotometry (γ=213.9 nm). Diets consumed by both groups had marginal concentrations of zinc. Zinc concentrations in plasma and erythrocytes were significantly lower in the obese group. Urinary zinc excretion was significantly higher in the same group. The results allowed one to conclude that zinc nutritional status in obese individuals is altered.     

Zinc status in plasma of obese individuals during glucose administration

To know whether plasma zinc status is altered under acute hyperglycemic state, the interrelationships among plasma glucose, insulin, and zinc concentrations during oral glucose tolerance test (OGTT) in obese individuals and their lean controls were studied. Plasma glucose and insulin concentrations under fasting as well as those values in response to OGTT were significantly higher in obese individuals than those in lean controls. On the other hand, the obese had lower fasting plasma zinc concentrations compared to lean controls (13.5 vs 18.1 Μmol/L,p < 0.005). Under fasting, plasma zinc concentrations in overall individuals inversely correlated to their body mass index (BMI) (r = -0.516), plasma glucose (r = -0.620), and plasma insulin (r = -0.510). However, there were no significant changes in plasma zinc and copper values during OGTT in both obese individuals and lean controls. This study showed that plasma zinc values had no changes during OGTT in obese individuals. The results also indicated that lower fasting plasma zinc concentrations in obese individuals were not the short-term metabolic result.     

The relationships between oral status, physical and mental health, nutritional status and diet type in elderly Japanese women with dementia

Objectives: To suggest methods for maintaining an adequate nutritional status for elderly patients with dementia by evaluating the relationships between oral status, physical and mental health, and feeding conditions. Background: Feeding difficulties in dementia patients are related to food intake, and failure to eat may be associated with weight loss in long‐term care facilities. The relationship between compromised oral function and diet is still unclear. Materials and methods: A cross‐sectional study of 94 elderly women with dementia (mean age 89.6 ± 5.6 years) from a nursing home was undertaken to investigate their oral, physical and mental and nutritional status. Results: There were significant differences in serum albumin (p = 0.0284), N‐ADL (p = 0.0005), NM scale (p = 0.0004) and HDS‐R (p = 0.0004) between denture wearers and non‐denture wearers. However, there were no significant differences in body mass index between denture wearers and non‐denture wearers. Conclusion: A suitable type of diet and assistance with feeding could maintain the nutritional status of elderly patients with dementia if they are still feeding themselves. The nutritional support team will benefit from the participation of a dentist.     

Improved oxidative stress and cardio-metabolic status in obese prepubertal children with liver steatosis treated with lifestyle combined with Vitamin E

Abstract

In obese adults with non alcoholic fatty liver disease (NAFLD), treatment with Vitamin E has resulted in an improvement in liver histology, whereas variable and limited results are available in children. Our aim was to assess whether lifestyle combined with supplementation with Vitamin E might reduce oxidative stress and improve cardio-metabolic status in obese children with NAFLD.

24 obese prepubertal children (16M) followed a 6-month lifestyle intervention combined with Vitamin E supplementation (600 mg/day) and they were compared with 21 age and sex-matched obese peers who underwent lifestyle intervention only. At baseline and after 6-month urinary prostaglandin F2α (PGF-2α), endogenous secretory receptor for advanced glycation end products (esRAGE), high sensitivity C-reactive protein (hs-CRP), alanine aminotransferases (ALT), lipid profile, glucose, and insulin were assessed.

The two groups were comparable for age (8.3 ± 1.6 vs 8.4 ± 1.3 yr), sex and BMI SDS (2.16 ± 0.29 vs 2.13 ± 0.28). At the beginning of the study, PGF2-α, esRAGE hsCRP, ALT, lipid profile and HOMA-IR levels were similar between the two groups (all p > 0.05). After 6-month treatment, levels of PGF2-α (p < 0.001) significantly decreased and esRAGE significantly increased (p < 0.001) in children treated with Vitamin E. A significant reduction was also found in ALT (p = 0.001), lipid profile and HOMA-IR (p < 0.001). In contrast, no significant change in any of these markers was detected in the lifestyle only group.

In conclusion, Vitamin E supplementation was associated with a significant reduction in oxidative stress and improved cardio-metabolic alterations. These data suggest that Vitamin E supplementation could represent a valuable treatment in obese children affected by NAFLD.     

Assessment of copper and lipid profile in obese children and adolescents

The aim of this study was to assess erythrocyte and plasma copper concentrations and correlate them with the lipid profile of overweight and obese children and adolescents. The study was performed with 15 over-weight and 30 obese children and adolescents, and the results were compared to the control group (21), aged 6–16 yr. Anthropometric assessment was carried out using body mass index (BMI). Total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride serum levels were investigated. Erythrocyte and plasma copper levels were determined by atomic absorption spectrophotometry. Greater alterations in the lipid profile were observed in HDL-cholesterol, LDL-cholesterol, and triglyceride levels, with distinctions according to gender. The plasma copper concentrations in the overweight and obese male groups were significantly higher than those in the control group (p=0.0006). Negative correlations between plasma copper and total cholesterol (r=−0.54) and LDL cholesterol (r=−0.59) were observed in the obese male group. There was no statistical difference in copper erythrocyte concentrations. The obesity associated to disorders in lipid metabolism predisposes to changes in copper plasma concentrations, but there was no alteration in intracellular reserves, which suggests an important homeostatic control to compensate for plasma oscillations and metabolic alterations of the disease.     

Alzheimer's disease,oral function and nutritional status

Objectives: To study differences in nutritional, dental status and oral function between institutionalised patients with Alzheimer's disease and cognitively healthy elderly people living in the community. Design: Comparison was made between two groups, Alzheimer's disease sufferers and healthy controls, using established criteria for anthropometric, mental and dental state. Setting: An institution and residential area in Stockholm, Sweden. Subjects: Forty patients with Alzheimer's disease living in a nursing home and 40 age-and gender-matched control subjects living independently. Intervention: Dental status and anthropometric variables. Results: Overnutrition was less frequent among the demented than the controls and more demented were undernourished. Dental status was similar in the two groups with few edentulous subjects but only 2 of 7 edentulous subjects with Alzheimer's disease wore dentures. Having natural teeth and many functional oral zones is important for food consistency choice, but not for nutritional status. In the Alzheimer group, the stage of dementia has a strong association to the ability to eat unaided and an association with dental status. Conclusion: There are differences in nutritional status between Alzheimer's patients in institutions and cognitively healthy elderly living at home. The choice of food consistency is correlated to dental status but nutritional status is not shown to be influenced by dental status. However, the ability to eat unaided is strongly correlated to cognitive status.     

Alzheimer's disease,oral function and nutritional status

Objectives: To study differences in nutritional, dental status and oral function between institutionalised patients with Alzheimer's disease and cognitively healthy elderly people living in the community. Design: Comparison was made between two groups, Alzheimer's disease sufferers and healthy controls, using established criteria for anthropometric, mental and dental state. Setting: An institution and residential area in Stockholm, Sweden. Subjects: Forty patients with Alzheimer's disease living in a nursing home and 40 age-and gender-matched control subjects living independently. Intervention: Dental status and anthropometric variables. Results: Overnutrition was less frequent among the demented than the controls and more demented were undernourished. Dental status was similar in the two groups with few edentulous subjects but only 2 of 7 edentulous subjects with Alzheimer's disease wore dentures. Having natural teeth and many functional oral zones is important for food consistency choice, but not for nutritional status. In the Alzheimer group, the stage of dementia has a strong association to the ability to eat unaided and an association with dental status. Conclusion: There are differences in nutritional status between Alzheimer patients in institutions and cognitively healthy elderly living at home. The choice of food consistency is correlated to dental status but nutritional status is not shown to be influenced by dental status. However, the ability to eat unaided is strongly correlated to cognitive status.     

Mg2+ as an indicator of nutritional status in marine bacteria

Cells maintain an osmotic pressure essential for growth and division, using organic compatible solutes and inorganic ions. Mg²⁺, which is the most abundant divalent cation in living cells, has not been considered an osmotically important solute. Here we show that under carbon limitation or dormancy native marine bacterial communities have a high cellular concentration of Mg²⁺ (370–940 m) and a low cellular concentration of Na⁺ (50–170 m). With input of organic carbon, the average cellular concentration of Mg²⁺ decreased 6–12-fold, whereas that of Na⁺ increased ca 3–4-fold. The concentration of chlorine, which was in the range of 330–1200 m and was the only inorganic counterion of quantitative significance, balanced and followed changes in the concentration of Mg²⁺+Na⁺. In an osmotically stable environment, like seawater, any major shift in bacterial osmolyte composition should be related to shifts in growth conditions, and replacing organic compatible solutes with inorganic solutes is presumably a favorable strategy when growing in carbon-limited condition. A high concentration of Mg²⁺ in cells may also serve to protect and stabilize macromolecules during periods of non-growth and dormancy. Our results suggest that Mg²⁺ has a major role as osmolyte in marine bacteria, and that the [Mg²⁺]/[Na⁺] ratio is related to its physiological condition and nutritional status. Bacterial degradation is a main sink for dissolved organic carbon in the ocean, and understanding the mechanisms limiting bacterial activity is therefore essential for understanding the oceanic C-cycle. The [Mg²⁺]/[Na⁺]-ratio in cells may provide a physiological proxy for the transitions between C-limited and mineral nutrient-limited bacterial growth in the ocean''s surface layer.     

Root colonization and iron nutritional status of a Pseudomonas fluorescens in different plant species

Root colonization and induction of an iron stress regulated promoter for siderophore production by Pseudomonas fluorescens 2-79RLI was studied in vitro and in the rhizosphere of different plant species. P. fluorescens 2-79RLI was previously genetically modified with an iron regulated ice nucleation reporter, which allowed calibration of ice nucleation activity with siderophore production. Initial experiments examined ice nucleation activity and siderophore production under different growth conditions in vitro. These studies demonstrated that P. fluorescens 2-79RLI could utilize both Fe-citrate and Fe-phytosiderophore as iron sources, suggesting that production of these compounds by plants would increase iron availability for P. fluorescens 2-79RLI in the rhizosphere. Fe demand and Fe stress were further shown to be a function of nutrient availability and were reduced when carbon was limiting for growth. Subsequent experiments extended these observations to rhizosphere cells. Cells were sampled from the rhizosphere and the rhizoplane. Results of a soil microcosm experiment showed that Fe stress was reduced for P. fluorescens 2-79RLI in the barley rhizosphere as compared to the cells in the rhizosphere.of lupin. In lupin, relative Fe stress of P. fluorescens 2-79RLI was greater at the root tip than in the lateral root zone. In a second experiment comparing zucchini and bean, iron stress was greater for P. fluorescens 2-79RLI associated with zucchini than with bean. In a third experiment with rape plants under P deficient conditions, addition of soluble P was shown to increase Fe stress for P. fluorescens 2-79RLI located at the root tip, but not in the lateral root zone. This study showed that Fe stress of P. fluorescens 2-79RLI in the rhizosphere may be influenced by plant species, P source, root zone and localization of the cells within the rhizosphere.     

Zinc mediated normalization of histoarchitecture and antioxidant status offers protection against initiation of experimental carcinogenesis

The present study evaluated the inhibitory effects of zinc on colonic antioxidant defense system and histoarchitecture during 1,2 dimethylhydrazine (DMH) induced colon carcinogenesis in male Sparque Dawley rats. The rats were segregated into four groups viz., normal control, DMH treated, zinc treated, DMH + zinc treated. Colon carcinogenesis was induced through weekly subcutaneous injections of DMH (30 mg/kg body weight) for 8 weeks. Zinc (in the form of zinc sulphate) was supplemented to rats at a dose level of 227 mg/l in drinking water, ad libitum for the entire duration of the study. Increased lipid peroxidation was accompanied by a decrease in reduced glutathione (GSH), glutathione reductase (GR), glutathione-s-transferase (GST), superoxide dismutase (SOD), and catalase. Administration of zinc to DMH treated rats significantly decreased the lipid peroxidation levels with simultaneous enhancement of GSH, GR, GST, SOD, and Catalase. Histopathological studies from DMH treated rats revealed disorganization of colonic histoarchitecture. However, zinc treatment to DMH treated rats greatly restored normalcy in the colonic histoarchitecture, with no apparent signs of abnormality. Energy Dispersive X-Ray Fluorescence (EDXRF) studies revealed a significant decrease in tissue concentrations of zinc in the colon following DMH treatment, which upon zinc supplementation were recovered to near normal levels. In conclusion, the results of this study suggest that zinc has a beneficial effect during the initiation of key events leading to the development of experimentally induced carcinogenesis.     

Plasma zinc levels during pregnancy and its relationship to maternal and neonatal characteristics: a longitudinal study

Forty consecutive healthy pregnant women aged 17–38 yr who attended the antenatal clinic of the Department of Obstetrics and Gynecology, Ankara University in their first trimester participated in the study. The pregnant women were followed up longitudinally until the end of their pregnancy. Forty healthy age-matched nonpregnant women were used as a control group. Each pregnant woman was interviewed and a special questionnaire recording dietary history (3-d recall) and socioeconomic status (SES) was used. Birth weight, height, and head circumference of the newborn were measured and a complete physical examination was done for each neonate by the same observer. Blood samples were obtained at each trimester and zinc determinations were made using flame atomic absorption spectrophotometer. The results of plasma Zn measurements were available in 39 pregnant women. There were 23 women of low SES (mean plasma Zn level: 59.0 ± 6.9 μg/dL) and 16 of high SES (mean plasma Zn: 70.3 ± 5.2 μg/dL). The difference between the mean plasma Zn levels of these two groups was significant (p<0.001). The nutritional status in our study appeared to be an important factor responsible for low plasma Zn levels during pregnancy. However, we did not find any correlation between plasma Zn levels and anthropometric parameters of the newborn and pregnancy outcome. Further studies using larger sample sizes are needed to clarify the role of plasma Zn levels on maternal features and fetal outcomes in Turkey.     

Relationship between nutritional status and tooth loss in an older population from Sri Lanka

doi: 10.1111/j.1741‐2358.2011.00518.x Relationship between nutritional status and tooth loss in an older population from Sri Lanka Objective: To determine the relationship between tooth loss and nutritional status in older individuals in Sri Lanka. Background: In developing countries, both the prevalence of malnutrition and oral disease are high among older individuals. Materials and methods: Four hundred and eighty subjects aged 60 years and above were selected to be included in the sample, of which 437 responded giving an overall response rate of 91%. Data were collected by means of an interviewer administered questionnaire, an oral examination and a physical examination to determine height and weight to calculate the body mass index (BMI). Results: Based on the WHO cut‐offs for BMI, 62, 20 and 18% of the sample were normal, under‐ and over‐weight, respectively. A multinomial logistic regression analysis with normal weight as the reference category revealed that missing teeth and denture status were associated with being underweight but not with being overweight. Conclusion: In older individuals, tooth loss is significantly associated with being underweight.     

Effects of zinc supplementation on the plasma glucose level and insulin activity in genetically obese (ob/ob) mice

The effects of zinc supplementation (20 mM ZnCl₂ from the drinking water for eight weeks) on plasma glucose and insulin levels, as well as its in vitro effect on lipogenesis and lipolysis in adipocytes were studied in genetically obese (ob/ob) mice and their lean controls (+/?). Zinc supplementation reduced the fasting plasma glucose levels in both obese and lean mice by 21 and 25%, respectively (p < 0.05). Fasting plasma insulin levels were significantly decreased by 42% in obese mice after zinc treatment. In obese mice, zinc supplementation also attenuated the glycemic response by 34% after the glucose load. The insulin-like effect of zinc on lipogenesis in adipocytes was significantly increased by 80% in lean mice. However, the increment of 74% on lipogenesis in obese mice was observed only when the zinc plus insulin treatment was given. This study reveals that zinc supplementation alleviated the hyperglycemia of ob/ob mice, which may be related to its effect on the enhancement of insulin activity.     

Nutritional status and eating habits of bus drivers during the day and night

The aim of this study was to compare anthropometry and food intake patterns in bus drivers working during the day and night. One hundred and fifty males (81 night workers and 69 day workers) participated in the study. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Measurements of height, weight, waist circumference (WC), systolic and diastolic blood pressure, blood glucose, and lipid profile were obtained. A significant difference between groups was observed for mean WC (98.5?±?10.7?cm in day workers versus 103.2?±?9.7?cm in night workers; p?=?0.005). Night workers had higher prevalence of being overweight and obese (BMI?≥?25?kg/m²) than day workers (78.2% day workers versus 90.2% night workers; p?=?0.004) and increased WC (>94?cm) (72.4% day workers versus 86.4% night workers; p?=?0.03). Significant differences were found for meat consumption (2.3 servings ±0.9 for night workers versus 2.0 servings ±0.7 day workers, p?=?0.04) and fruit intake (0.9 servings ±0.4 for night workers versus 0.7 servings for day workers ±0.5; p?=?0.006). Night workers had a lower intake of vegetables than recommended compared to day workers (100 versus 92.7%, respectively, p?=?0.01) and higher intake of oil (40.7 versus 24.6%, p?=?0.03). Multivariate logistic regression analysis indicated that night work was associated with being overweight (OR?=?2.94, 95% IC: 1.14–7.66, p?=?0.03) and abnormal values of WC (OR?=?2.82, 95% IC: 1.20–6.69, p?=?0.009) after adjusting for potential confounders. It is concluded that night workers had a higher prevalence and risk of being overweight/obese and increased WC compared with day workers. Night workers also presented a higher proportion of inappropriate intakes of food groups when compared to day workers, even though both groups were eating poor diets. These results demonstrate the need of lifestyle-intervention programs in these workers.     

Socioeconomic status, height, and obesity in children

The substantial increase in the prevalence of child obesity over recent decades and its association with a number of negative health and economic outcomes suggests its strong potential as an influence on the lifecourse development of health and productivity. This paper evaluates interactive effects between family socioeconomic status (SES) and height on child obesity in the United States. Using the 1999-2006 National Health and Nutrition Examination Surveys (NHANES), the results of this paper confirm previous findings that taller children exhibit greater propensity towards obesity as measured by body mass index (BMI) and that obesity is inversely related to family SES as measured by poverty status. The analysis adds to the existing literature by showing that the magnitude of the SES-obesity association is larger in taller children. Age and sex patterns are evaluated that suggest the SES-height interaction persists through childhood and adolescence in males but is only evident in females during adolescence. Interaction effects are also shown to be most evident in white males and Hispanic females. Policy implications are discussed and directions for future work are suggested.     

Vitamin D status in a Brazilian cohort of adolescents and young adults with perinatally acquired human immunodeficiency virus infection

The purpose was to determine the prevalence and related factors of vitamin D (VitD) insufficiency in adolescents and young adults with perinatally acquired human immunodeficiency virus. A cohort of 65 patients (17.6 ± 2 years) at the Federal University of Rio de Janeiro, Brazil, were examined for pubertal development, nutrition, serum parathormone and serum 25-hydroxyvitamin D [s25(OH)D]. s25(OH)D levels < 30 ng/mL (< 75 nmol/L) were defined as VitD insufficiency. CD4⁺ T-cell counts and viral load, history of worst clinical status, immunologic status as nadir, current immunologic status, and antiretroviral (ART) regimen were also evaluated as risk factors for VitD insufficiency. Mean s25(OH)D was 37.7 ± 13.9 ng/mL and 29.2% had VitD insufficiency. There was no difference between VitD status and gender, age, nutritional status, clinical and immunological classification, and type of ART. Only VitD consumption showed tendency of association with s25(OH)D (p = 0.064). Individuals analysed in summer/autumn season had a higher s25(OH)D compared to the ones analysed in winter/spring (42.6 ± 14.9 vs. 34.0 ± 11.9, p = 0.011). Although, the frequency of VitD insufficiency did not differ statistically between the groups (summer/autumn 17.9% vs. winter/spring 37.8%, p = 0.102), we suggest to monitor s25(OH)D in seropositive adolescents and young adults, especially during winter/spring months, even in sunny regions.     

Zinc and Selenium Nutritional Status in Vegetarians

A vegetarian diet may have beneficial effects on human health, however when it is not well-balanced may be deficient in some nutrients, as minerals for example. The aim of the present study was to assess the nutritional status of zinc and selenium in vegetarians in the city of São Paulo. A cross-sectional study was performed, and the inclusion criteria were age ≥ 18 years, both gender, no use of food or pharmaceutical supplements. Thirty vegetarian, of both genders, mean age of 27 years and 4,5 years of vegetarianism had performed the study, and their mean BMI was 21,5. Zinc plasma concentration was 71 and 62,5 μg/dL for men and women and erythrocyte concentration was 37 μg/gHb for both genders. Selenium concentration was 73,5 and 77,3 μg/L in plasma and 51,4 and 66,9 μg/L in erythrocytes for men and women, respectively. These biochemical values show that, according to the references, selenium blood levels are adequate and zinc concentration in erythrocytes is deficient in the studied population. For this reason, vegetarians should be constantly assessed and receive nutritional support to reduce the effects of inadequate zinc status.     

Zinc Nutritional Status in Adolescents with Down Syndrome

Studies have evidenced that zinc metabolism is altered in presence of Down syndrome, and zinc seems to have a relationship with the metabolic alterations usually present in this syndrome. In this work, the Zn-related nutritional status of adolescents with Down syndrome was evaluated by means of biochemical parameters and diet. A case–control study was performed in a group of adolescents with Down syndrome (n = 30) and a control group (n = 32), of both sexes, aged 10 to 19 years. Diet evaluation was accomplished by using a 3-day dietary record, and the analysis was performed by the NutWin program, version 1.5. Antropometric measurements were performed for evaluation of body composition. The Zn-related nutritional status of the groups was evaluated by means of zinc concentration determinations in plasma and erythrocytes, and 24-h urinary zinc excretion, by using the method of atomic absorption spectroscopy. The diet of both groups presented adequate concentrations of lipids, proteins, carbohydrates, and zinc. The mean values found for zinc concentration in erythrocytes were 49.2 ± 8.5 μg Zn/g Hb for the Down syndrome group and 35.9 ± 6.1 μg Zn/g Hb for the control group (p = 0.001). The average values found for zinc concentration in plasma were 67.6 ± 25.6 μg/dL for the Down syndrome group and 68.9 ± 22.3 μg/dL for the control group. The mean values found for zinc concentration in urine were 244.3 ± 194.9 μg Zn/24 h for the Down syndrome group and 200.3 ± 236.4 μg Zn/24 h for the control group. Assessment of body composition revealed overweight (26.7%) and obesity (6.6%) in the Down syndrome group. In this study, patients with Down syndrome presented altered zinc levels for some cellular compartments, and the average zinc concentrations were low in plasma and urine and elevated in erythrocytes.     

在不同营养状态下东方田鼠对陌生食物选择学习的研究

通过不同饥饿处理 ,研究了东方田鼠在不同营养状态下 ,对陌生食物尝试和选择的行为模式。结果表明 ,初次遇到陌生食物时 ,各处理组对陌生食物的采食量分别为饱食 6.9± 1 .8g,饥饿组为 4.8± 1 .6g,饥饿 食物短缺组为 3.4± 1 .4g。各处理组动物对陌生食物的摄入量间差异极为显著 ( P=0 .0 0 4 3)。饱食组、饥饿组及饥饿 食物短缺组动物初次遇到陌生食物时 ,所摄入的陌生食物量占总摄入量的百分比分别为72 %、38%与 1 2 %。说明 ,在实验室条件下饱食动物较饥饿和饥饿 食物短缺的动物学习选择摄食陌生食物的倾向较强。     

Zinc supplementation on serum levels and hepatic conversion of thyroid hormones in obese (ob/ob) mice

The supplemental effects of zinc on thyroid status in obese (ob/ob) mice were studied. Four-week-old obese mice and their lean controls were fed either a basal diet or a zinc-supplemented diet (200 mg/kg diet) for 8 wk. Following the 8-wk basal diet, obese mice had lower serum T4 values, as well as hepatic T4 and T3 values, than lean mice (p < 0.05). A significant decrease in hepatic 5′-deiodinase activity was also observed in obese mice. Dietary zinc supplementation significantly reduced serum T4 levels in both the obese and lean mice. However, the zinc-supplemented effects on diminishing hepatic T4 and T3 values, as well as on 5′-deiodinase activities, were found only in obese mice (p < 0.05). Furthermore, the 5′-deiodinase activities in hepatic microsomal pellets after incubation with various zinc concentrations (0.5, 1.0, and 2.5 mM) were also examined. The 5′-deiodinase activities, in hepatic samples from all mice, were significantly attenuated by zinc treatments. However, this effect was more predominant in obese mice following the addition of 0.5 mM zinc. This study suggests that a lower hepatic 5′-deiodinase activity, resulting from a higher zinc level, might be related to abnormal energy metabolism in theob/ob mice.