Arquivos brasileiros de endocrinologia e metabologia最新文献

Objective: The objective of this study was to evaluate the association between insulin-resistance and fasting levels of ghrelin and PYY in Wistar rats.

Materials and methods: A total of 25 male Wistar rats, weighing 200-300 g, was included in this study. The animals were maintained in cages with a 12/12h light-dark cycle and fed standard chow and water ad libitum. After 12-h overnight fasting, ghrelin, PYY, insulin and glucose values were determined. Insulin resistance was assessed by means of the HOMA-IR, which was ranked and the median was used as a cut-off value to categorize insulin-resistance. HOMA-IR values equal and above 2.62 were considered insulin-resistant (IR) while values below 2.62 were considered insulin sensitive (IS). Differences between means were determined using the Student t-test. Multiple regression and Pearson's correlation test were used to evaluate the association between variables.

Results: HOMA-IR median IQ range values for IS and IR groups were, respectively, 1.56 (0.89 - 2.16) vs. [4.06 (3.50 - 4.61); p < 0.001]. The IR group presented increased levels of fasting ghrelin, PYY and insulin respectively: [50.35 (25.99 - 74.71) pg/mL vs. 12.33 (8.77 - 15.89) pg/mL; p = 0.001]; [54.38 (37.50 - 71.26) pg/mL vs. 33.17 (22.34 - 43.99) pg/mL; p = 0.016]; [18.04 (14.48 - 21.60) uU/mL vs. 7.09 (4.83 - 9.35) uU/mL; p = 0.001]. Ghrelin, but not PYY, correlated linearly and positively with HOMA-IR: ghrelin vs. HOMA-IR (r = 0.52; p = 0.008), and PYY vs. HOMA-IR (r = 0.22; p = 0.200). This correlation was independent of body weight.

Conclusion: Fasting ghrelin and PYY serum levels are increased in lean, relatively insulin resistant Wistar rats, and this increase is independent of weight.

The gut microbiota obtained after birth is composed of a large range of bacteria that play different roles in the human host, such as nutrient uptake, protection against pathogens and immune modulation. The intestinal bacterial content is not completely known, but it is influenced by internal, and mainly by external factors, which modulate its composition and function. Studies indicate that the gut microbiota differs in lean and obese individuals, and in individuals with different food habits. There is evidence that the relationship between diet, inflammation, insulin resistance, and cardiometabolic risk are, in part, mediated by the composition of intestinal bacteria. Knowledge about the gut microbiota may result in different strategies to manipulate bacterial populations and promote health. This review discusses the relevance of understanding the role of dietary factors or patterns in the composition of the microbiota, as well as pathophysiological mechanisms of chronic metabolic diseases, and the potential of prebiotics and probiotics on the cardiometabolic risk profile.

Objective: To evaluate the performance of percent body fat (%BF) and waist circumference (WC) in predicting metabolic abnormalities indicating cardiovascular risk in adolescents.

Subjects and methods: Cross-sectional study with a probabilistic sample of 573 adolescents aged 12 to 19 years from state public schools in Niterói, RJ. The Receiver Operating Characteristic Curve was used to evaluate the accuracy of WC and %BF in predicting alterations in blood pressure, lipid profile, and blood glucose.

Results: The best %BF cutoff points were 21% for boys, and 23% for girls, with sensitivity (SE) and specificity (SP) of approximately 60%. The best WC cutoff points were 71 cm for boys, and 66 cm for girls (SE: 55% to 70%; SP: 55% to 78%).

Conclusion: Even the best cutoff points misidentified high proportions of adolescents with metabolic abnormalities. Caution is recommended in the use of these indicators for cardiovascular risk screening in this age group.

Objective: To establish serum TSH reference values for a population of Brazilian elderly, and to compare them to those found in the adult population.

Subjects and methods: Healthy volunteers aged 70 to 85 years, without known thyroid disease or risk factors for thyroid dysfunction, who did not use any medication that could potentially interfere with TSH, were selected. Subjects with goiter, palpable thyroid nodules, anti-thyroperoxidase antibodies, or altered free T4 were excluded. The sample consisted of 360 older adults (180 per sex).

Results: TSH values corresponding to the 2.5th and 97.5th percentile of the sample were 0.2 and 4.62 mIU/L, respectively. TSH > 2.5 mIU/L was seen in 25.26% of the volunteers, > 3 mIU/L in 15.26%, and > 4 mIU/L in 6.1% of them. TSH values were slightly higher than those previously reported for adults (18-60 years).

Conclusion: This study suggests an upper limit for normal TSH of approximately 4.6 mIU/L for the Brazilian elderly population.

Objective: To evaluate the association of the PTPN2 rs1893217 polymorphism with T1DM and/or its clinical and laboratory characteristics in a Caucasian population from Southern Brazil.

Subjects and methods: Four hundred and eighty six patients with T1DM and 484 non-diabetic subjects were included in the study. Genotyping of the PTPN2 rs1893217 was performed by real-time PCR.

Results: Genotype frequencies did not differ between T1DM patients and non-diabetic subjects (P = 0.265). The C allele was observed in 14.5% of the T1DM sample and 12.2% of the non-diabetic group (P = 0.152). Moreover, the frequencies of this variant did not differ statistically between T1DM patients and non-diabetic subjects when assuming recessive, dominant, or additive inheritance models. The clinical and laboratory characteristics of T1DM patients did not differ significantly among the three genotypes of the rs1893217 polymorphism, either.

Conclusion: The PTPN2 rs1893217 polymorphism is not significantly associated with T1DM in Caucasian subjects from Southern Brazil.

Objective: To compare the age at menarche obtained by recall method according to the time elapsed since the event, in order to verify the importance of the recall bias.

Subjects and methods: Were evaluated 1,671 girls (7-18 years) at schools in Campinas-SP regarding the occurrence of menarche by the status quo method (menarche: yes or no) and the recall method (date of menarche, for those who mentioned it). The age at menarche obtained by the status quo method was calculated by logit, which considers the whole group, and the age obtained by the recall method was calculated as the average of the mentioned age at menarche. In this group, the age at menarche was obtained by the difference between the date of the event and the date of birth. Girls who reported menarche (883, 52.8%) were divided into four groups according to the time elapsed since the event. To analyze the results, we used ANOVA and logistic regression for the analysis, with a significance level of 0.05.

Results: The age at menarche calculated by logit was 12.14 y/o (95% CI 12.08 to 12.20). Mean ages obtained by recall were: for those who experienced menarche within the previous year 12.26 y/o (±1.14), between > 1-2 years before, 12.29 y (±1.22); between > 2-3 years before, 12.23 y/o (±1.27); and more than 3 years before, 11.55y/o (±1.24), p < 0.001.

Conclusion: The age at menarche obtained by the recall method was similar for girls who menstruated within the previous 3 years (and approaches the age calculated by logit); when more than 3 years have passed, the recall bias was significant.

The term Marine-Lenhart syndrome describes the association between Graves' disease and autonomously functioning thyroid nodules (AFTN), such as toxic adenoma or toxic multinodular goiter. The two diseases may coexist or may be present at different moments in the same patient. In the literature, there are many reports on the development of Graves' disease after radioiodine treatment for AFTN, but very little information may be found on the occurrence of AFTN after radioiodine therapy for Graves' disease. We describe here the case of a female patient with Graves' disease who was successfully treated with radioiodine for Graves' disease, returning to normal thyroid function. Three years later, biochemical analysis and ultrasound examination identified a thyroid nodule that progressively increased in size. The 99mTc-pertechnetate scintigraphy showed avid uptake in the right lobule, which corresponded to a nodular lesion consistent with AFTN.

Solitary fibrous tumor (SFT) is an uncommon spindle-cell neoplasm that most often involves the pleura, rarely occurring in extra-thoracic locations. Twenty-six cases of SFT arising in the thyroid gland have been described. We report a case of a 60-year-old woman presenting an 8-month history of enlargement of the neck associated with dysphagia. The patient underwent a right hemithyroidectomy and SFT of the thyroid was diagnosed. Immunohistochemistry showed positivity for CD34 marker, and the high number of mitoses and the presence of cellular atypia suggested that the tumor was malignant. To our knowledge, this is the second case of malignant SFT of the thyroid gland ever reported. Due to the rarity of these tumors, the indication of adjuvant therapy and prognosis are uncertain. Long-term follow-up after surgical resection seems to be advisable.

Objective: This study aimed to determine whether a hypercholesterolemic diet induces hepatic steatosis, alterations in mRNA expression of NADPH oxidase subunits, and antioxidant defenses.

Materials and methods: Fischer rats were divided into two groups of eight animals according to the treatment, control (C) and hypercholesterolemic diet (H). Those in group C were fed a standard diet (AIN-93M), and those of the group H were fed a hypercholesterolemic diet (25% soybean oil and 1% cholesterol).

Results: The hypercholesterolemic diet did not affect body weight, but resulted in the accumulation of lipids in the liver, increased serum activities of aminotransferases and cholesterol levels. Biomarker of lipid peroxidation (TBARS) and mRNA expression of NADPH oxidase subunits p22(phox) and p47(phox) were increased in the liver of animals in group H. Besides, the activity and expression of antioxidant enzymes were altered.

Conclusion: The results show increased mRNA expression of NADPH oxidase subunits and changes in antioxidant enzyme activities in diet-induced hepatic steatosis.