Accumbal µ-opioid receptors and salt taste-elicited hedonic responses in a rodent model of prenatal adversity, and their correlates using human functional genomics.

Prenatal adversity is associated with behavioral obesogenic features such as preference for palatable foods. Salt appetite may play a role in the development of adiposity and its consequences in individuals exposed to prenatal adversity, and sodium consumption involves individual differences in accumbal µ-opioid receptors function. We investigated the hedonic responses to salt and the levels of µ-opioid receptors and tyrosine hydroxylase in the nucleus accumbens (Nacc) of pups from an animal model of prenatal dietary restriction. In children, we evaluated the interaction between fetal growth and the genetic background associated with the accumbal µ-opioid receptor gene (OPRM1) expression on sodium consumption during a snack test. Sprague-Dawley dams were randomly allocated from pregnancy day 10 to receive an ad libitum (Adlib) or a 50% restricted (FR) diet. The pups' hedonic responses to a salt solution (NaCl 2%) or water were evaluated on the first day of life. FR and Adlib pups differ in their hedonic responses to salt, and there were decreased levels of accumbal µ-opioid and p-µ-opioid receptors in FR pups. In humans, a test meal and genotyping from buccal epithelial cells were performed in 270 children (38 intrauterine growth restricted-IUGR) at 4 years old from a Canadian prospective cohort (MAVAN). The OPRM1 genetic score predicted the sodium intake in IUGR children, but not in controls. The identification of mechanisms involved in the brain response to prenatal adversity and its consequences in behavioral phenotypes and risk for chronic diseases later in life is important for preventive and therapeutic purposes.

The impact of poor fetal growth and chronic hyperpalatable diet exposure in adulthood on hippocampal function and feeding patterns in male rats.

Poor fetal growth affects eating behavior and the mesocorticolimbic system; however, its influence on the hippocampus has been less explored. Brain insulin sensitivity has been linked to developmental plasticity in response to fetal adversity and to cognitive performance following high-fat diet intake. We investigated whether poor fetal growth and exposure to chronic hyperpalatable food in adulthood could influence the recognition of environmental and food cues, eating behavior patterns, and hippocampal insulin signaling. At 60 days of life, we assigned male offspring from a prenatal animal model of 50% food restriction (FR) to receive either a high-fat and -sugar (HFS) diet or standard chow (CON) diet. Behavioral tests were conducted at 140 days, then tissues were collected. HFS groups showed a diminished hippocampal pAkt/Akt ratio. FR-CON and FR-HFS groups had higher levels of suppressor of cytokine signaling 3, compared to control groups. FR groups showed increased exploration of a novel hyperpalatable food, independent of their diet, and HFS groups exhibited overall lower entropy (less random, more predictable eating behavior) when the environment changed. Poor fetal growth and chronic HFS diet in adulthood altered hippocampal insulin signaling and eating patterns, diminishing the flexibility associated with eating behavior in response to extrinsic changes in food availability in the environment.

Lifestyle, health characteristics and alcohol abuse in young adults who are non-daily smokers / Estilo de vida, características de saúde e consumo excessivo de álcool em adultos jovens que são fumantes esporádicos

CONTEXT AND OBJECTIVES: Despite the decline in the prevalence of tobacco use in many countries, including Brazil, there are growing numbers of smokers who continue to smoke at a low daily rate, or less frequently (non-daily smokers). This group needs to be better characterized in order to direct preventive actions and public health policies. The aim here was to compare lifestyle, health characteristics and alcoholism problems among young adult smokers, non-daily smokers and non-smokers. DESIGN AND SETTING: This was a cross-sectional study in which volunteers from the university community and its surrounds in Santa Maria, State of Rio Grande do Sul, Brazil, were included between October 2007 and January 2008. METHODS: Out of 1240 volunteers initially contacted in a university cafeteria, a total of 728 participants of mean age 22.45 ± 3.32 years were selected for final analysis. Data were collected using structured questionnaires. RESULTS: In general, it was observed that the non-daily smokers showed intermediate characteristics in relation to the smokers and non-smokers. However, there was a significant association between non-daily smoking and alcohol abuse. The non-daily smokers presented an odds ratio of 2.4 (95 percent confidence interval: 1.10-5.48) in relation to the daily smokers and an odds ratio of 3.3 (confidence interval: 1.7-6.5) in relation to the non-smokers, with regard to presenting a positive CAGE test, thereby indicating alcohol abuse or dependence. CONCLUSION: The study suggested that non-daily smoking and alcohol consumption were concomitant behaviors.

CONTEXTO E OBJETIVO: Apesar do declínio na prevalência do tabagismo em diversos países, incluindo o Brasil, existe um número crescente de fumantes que continua a fumar em baixa quantidade diária ou com menor frequência (fumantes esporádicos). Esse grupo precisa ser mais bem caracterizado para que se possa direcionar ações preventivas e políticas de saúde pública. O objetivo foi comparar o estilo de vida, características de saúde e problemas de alcoolismo entre fumantes, fumantes esporádicos e não fumantes entre adultos jovens. TIPO DE ESTUDO E LOCAL: Estudo transversal em que se incluíram voluntários da comunidade universitária e do seu entorno entre outubro de 2007 a janeiro de 2008 em Santa Maria, Rio Grande do Sul, Brasil. MÉTODOS: A partir de um contato inicial com 1.240 voluntários numa cafeteria universitária, 728 participantes com idade média de 22.45 ± 3.32 anos foram selecionados para análise final. Os dados foram coletados através de um questionário estruturado. RESULTADOS: Em geral, foi observado que os fumantes esporádicos apresentaram características intermediárias em relação aos fumantes e não fumantes. Entretanto, foi encontrada uma associação significativa entre fumo esporádico e abuso de álcool. Os fumantes esporádicos apresentaram uma razão de chance de 2,4 vezes (intervalo de confiança de 1,10-5,48) em relação aos fumantes diários e uma razão de chance de 3,3 (intervalo de confiança de 1,7-6,5) em relação aos não fumantes de apresentar um teste CAGE positivo indicador de abuso ou dependência de álcool. CONCLUSÃO: O estudo sugere que o tabagismo esporádico e o consumo de álcool são comportamentos concomitantes.