RESUMO
Obesity is associated with several metabolic and endocrine disorders; and changes in plasma concentrations, secretion patterns, and clearance of various hormones are observed in obese patients. In this context, recent research has shown that overweight can influence the function of the thyroid gland, usually leading to increased thyrotropin concentrations and changes in the ratio between the hormones triiodothyronine and thyroxine, though within the normal range. The etiology of these changes is still unclear; however, several mechanisms have been proposed including the adaptive process to increase energy expenditure, hyperleptinemia, changes in the activity of deiodinases, the presence of thyroid hormones resistance, chronic low-grade inflammation, and insulin resistance. Although the clinical implications have not been clarified, studies suggest that these changes in the thyroid function of obese individuals may contribute to the worsening of metabolic complications and the development of diseases in the thyroid gland.
Assuntos
Obesidade/patologia , Obesidade/fisiopatologia , Glândula Tireoide/patologia , Glândula Tireoide/fisiopatologia , Metabolismo Energético , Humanos , Inflamação/patologia , Resistência à Insulina , Hormônios Tireóideos/metabolismoRESUMO
INTRODUCTION: Zinc deficiency has been associated with damage and oxidative changes in DNA that may increase an individual's risk of cancer. Furthermore, zinc metabolism may be affected in cancer patients, leading to alterations in its distribution that would favor carcinogenesis. Plasma and erythrocyte zinc levels in women with breast cancer were evaluated in this cross-sectional, controlled study. MATERIAL AND METHODS: Fifty-five premenopausal women of 25 to 49 years of age with and without breast cancer were divided into two groups: Group A, composed of women without breast cancer (controls, n = 26) and Group B, composed of women with breast cancer (cases, n = 29). Plasma and erythrocyte zinc levels were measured by flame atomic absorption spectrophotometry at γ = 213.9 nm. Diet was assessed using the 3-day diet recall method and analyzed using the NutWin software program, version 1.5. Student's t-test was used to compare means and significance was established at p = 0.05. RESULTS: Mean plasma zinc levels were 69.69 ± 9.00 g/dL in the breast cancer patients and 65.93 ± 12.44 g/dL in the controls (p = 0.201). Mean erythrocyte zinc level was 41.86 ± 8.28 µgZn/gHb in the cases and 47.93 ± 7.00 µgZn/gHb in the controls (p < 0.05). In both groups, dietary zinc levels were above the estimated average requirement. CONCLUSIONS: The present results suggest that zinc levels are lower in the erythrocyte compartment of pre-menopausal women with breast cancer.
Assuntos
Neoplasias da Mama/sangue , Eritrócitos/metabolismo , Zinco/sangue , Adulto , Biomarcadores , Estudos de Casos e Controles , Estudos Transversais , Dieta , Eritrócitos/química , Feminino , Humanos , Pessoa de Meia-Idade , Pré-Menopausa , PrognósticoRESUMO
INTRODUCTION: Chronic kidney disease promotes changes in the zinc nutritional status and in the antioxidant defense system. This study assessed the relationship between the parameters of the zinc nutritional status and the activity of superoxide dismutase in patients with chronic renal failure who are receiving hemodialysis. METHODS: 134 individuals, aged between 18 and 85 years, were divided into two groups: case group (hemodialyzed patients, n = 63) and control group (n = 71). Zinc concentrations in plasma and erythrocytes were determined using the flame atomic absorption spectrophotometry technique. The activity of superoxide dismutase enzyme was determined according to Ransod kit. RESULTS: The mean values of plasma zinc were 62.02 ± 13.59 µg/dL and 65.58 ± 8.88 µg/dL, and for erythrocytary zinc the values were 54.52 ± 22.82 µgZn/gHb and 48.01 ± 15.08 µgZn/gHb for the chronic renal patients and the control group, respectively. The activity of superoxide dismutase was significantly lower in patients when compared with the control group (p < 0.05). CONCLUSION: The activity of superoxide dismutase in patients with chronic renal failure undergoing hemodialysis, which is influenced by zinc concentracions, was significantly lower. There was an inadequate response of this enzyme to oxidative stress in patients undergoing hemodialysis.