Postnatal early overnutrition (EO) is a risk factor for obesity in adult life. Rats raised in a small litter can develop hyperinsulinaemia, hyperphagia, hyperleptinaemia and hypertension as adults. Since leptin regulates the hypothalamic-pituitary-thyroid axis and the metabolism of thyroid hormones, we studied the leptin signalling pathway in pituitary and thyroid glands of the postnatal EO model. To induce EO, at the third day of lactation the litter size was reduced to three pups per litter (SL group). In control litters (NL group), the litter size was adjusted to 10 pups per litter. Body weight and food intake were monitored. Rat offspring were killed at 21 (weaning) and 180 days old (adulthood). Plasma thyroid hormones, thyroid-stimulating hormone (TSH) and leptin were measured by radioimmunoassay. Proteins of the leptin signalling pathway were analysed by Western blotting. Body weight of offspring in the SL group was higher from the seventh day of lactation (+33%, P < 0.05) until 180 days old (+18%, P < 0.05). Offspring in the SL group showed higher visceral fat mass at 21 and 180 days old (+176 and +52%, respectively, P < 0.05), but plasma leptin was higher only at 21 days (+88%, P < 0.05). The SL offspring showed higher plasma TSH, 3,5,3 -triiodothronine (T 3 ) and thyroxine (T 4 ) at 21 days (+60, +91 and +68%, respectively, P < 0.05), while the opposite was observed at 180 days regarding thyroid hormones (T 3 , −10%; and T 4 , −30%, P < 0.05), with no difference in TSH levels. In hypothalamus, no change was observed in the leptin signalling pathway at 21 days. However, lower janus thyrosine kinase 2 (JAK2) and phosphorilated-signal transducer and activator of transcription-3 (p-STAT3) content were detected in adulthood. In pituitary, the SL group presented higher leptin receptors (Ob-R), JAK2 and p-STAT3 content at 21 days and lower JAK2 and STAT3 content at 180 days old. In contrast, in thyroid, the Ob-R expression was lower in young SL rats, while the adult SL group presented higher Ob-R and JAK2 content. We showed that postnatal EO induces short-and long-term effects upon the hypothalamic-pituitary-thyroid axis. These changes may help to explain future development of metabolic and endocrine dysfunctions, such as metabolic syndrome and hypothyroidism.

No abstract

Experimental and clinical studies have demonstrated that early postnatal overnutrition represents a risk factor for later obesity and associated metabolic and cardiovascular disturbance. In the present study, we assessed the levels of glucose transporter 4 (GLUT-4), GLUT-1, insulin receptor (IR), IR substrate 1 (IRS-1), phosphatidylinositol 3-kinase (PI3K) and Akt expression, as well as insulin-stimulated glucose transport and Akt activity in adipocytes from adult rats previously raised in small litters (SL). The normal litter (NL) served as control group. We also investigated glycemia, insulinemia, plasma lipid levels, and glucose tolerance. Our data demonstrated that early postnatal overfeeding induced a persistent hyperphagia accompanied by a significant increase in body weight until 90 days of age. The SL group also presented a significant increase (w42%) in epidydimal fat weight. Blood glucose, plasma insulin, and lipid levels were similar among the animals from the SL and NL groups. While insulin-stimulated glucose uptake was approximately twofold higher in adipocytes from the NL group, no stimulatory effect was observed in the SL group. The impaired insulin-stimulated glucose transport in adipose cells from the SL rats was associated with a significant decrease in GLUT-4, IRS-1 and PI3K expression, and Akt activity. In contrast, IR and Akt expression in adipocytes was not different between the SL and NL groups. Despite these alterations, our results showed no differences in glucose tolerance test in rats raised under different feeding conditions. Our findings reinforce a potent and long-term effect of neonatal overfeeding, which can program major changes in the metabolic regulatory mechanisms.

Epidemiological and experimental studies have associated development of metabolic syndrome with stressful events (nutritional, hormonal, or environmental) in early life. This phenomenon is known as programing and changes in adipokines levels in early life, especially leptin, seem to be involved with its development. We have shown that neonatal hyperleptinemia on lactation programs for leptin resistance, hyperthyroidism, and higher corticosterone and catecholamines levels with cardiovascular consequences. In the present study, we evaluated the effect of hyperleptinemia during lactation on the glucose and lipid metabolism and liver morphology of adult rats, which were saline or leptin-treated (8 microg/100 g of body weight) daily, for the first 10 days of life. Leptin group had lower body mass during treatment, but higher body mass and hyperleptinemia at adulthood, without difference in fat mass. We showed that the probable source of hyperleptinemia is the higher leptin content in the subcutaneous adipose tissue. The programed rats showed hyperinsulinemia and hypoadiponectinemia with higher expression of the hypothalamic Suppressor of Cytokine Signaling 3 (SOCS3), suggesting insulin resistance. Besides, they presented higher liver glycogen and hypertriglyceridemia. We also observed liver microsteatosis in the leptin-programed adult rats. Our data show that neonatal hyperleptinemia alters glucose metabolism, which seems to be partially compensated by the hyperinsulinemia. However, changes in the lipid metabolism are not compensated. It is probable that these changes induced by neonatal hyperleptinemia result from a selective tissue specific resistance both to insulin and leptin at adulthood, and the increase of SOCS3 may play an important role in this process.

Objectives: to analyze characteristics of homeless people and factors associated with living on the streets. Methods: a census-type sectional survey carried out between 2015 and 2018, in the municipality of Maringá-Paraná. A total of 701 homeless answered a structured questionnaire with sociodemographic data, living conditions, and drug use. We used Pearson’s correlation test for the association analysis of the variables at a 95% confidence level. Results: men (90.7%) the average age of 37.7 years had been homeless for an average of 5.39 years. Most had little education (54.2%), and homelessness was due to drug use (47.2%) and family disagreements (38.9%). Conclusions: drug use and family disagreements were the main reasons for homelessness. Time on the street, gender, and drugs were associated with a negative correlation to be homeless; and age, mean daily income, the number of daily meals, having been in prison, and having an income source were associated with positive correlation.