Keywords: Obesity, cohort, adolescent, young adults, cardiovascular risk Internship Duration: 30/11/-1 - 30/11/-1
Head of the hosting team: Elisabete Ramos
Website: Click here
Address of the host laboratory: ISPUP Team EPIUnit - Epidemiology Research Unit Rua das Taipas 135 4050-600 Porto Portugal
Supervisor: Joana AraujoE-mail: joana.araujo@ispup.up.pt Phone: +351222061820
We expect the intern to work on a research paper on a specific question under the topic of dynamics of adiposity and cardiometabolic profile throughout the lifecourse, to be published in a scientific international journal. Evidence on obesity trends shows that from 1980 to 2013 the prevalence of overweight and obesity increased the most in children (47.1% and 27.5%, in children and adults, respectively). Additionally, the comparison of obesity prevalence of successive birth cohorts according to the age strata showed that peak prevalence of obesity moved to younger ages in developed countries. The exposure to obesity at increasingly younger ages will have impact on the burden of disease, both at short and long-term. Childhood obesity is associated with the development of obesity-related complications, such as cardiovascular risk factors detectable as early as childhood. Moreover, it also increases the risk of cardiovascular risk factors or events in adulthood. This highlights the importance of understanding the determinants that might explain cohort effects in obesity prevalence, leading to higher prevalence in younger cohorts, and its progression throughout paediatric age. Although majority of subjects living with obesity develop complications such as dyslipidemia, hypertension and type 2 Diabetes, some individuals with obesity do not present the risk profile of adverse metabolic effects, and remain insulin-sensitive and metabolically healthy. This sub-group has been designated as metabolically healthy obese (MHO). The MHO subjects present increased risk of outcomes, such as cardiovascular events and mortality, in comparison to those who are metabolically healthy normal weight, but still lower risk than the metabolically unhealthy obese group. The association with all-cause mortality is not as consensual as for the other outcomes. The very heterogeneous definition of the MHO phenotype across studies may contribute to explain these differences in the association with clinical outcomes. Definitions vary in terms of risk factors considered (metabolic syndrome features, insulin resistance indicators, inflammation markers, etc...) and with regard to the maximum number of risk factors allowed in the metabolically healthy status definition. The exposure to obesity across life, namely different adiposity trajectories, duration of obesity or degree of obesity, may contribute to explain this phenotype. Nevertheless, some individuals still remain MHO after several years living with obesity, and other factors may be related to this phenotype, such as lifestyle factors or adipose tissue biology and function. Consistent evidence in these complex relationships between the role of different factors and obesity duration on the role of MHO is still lacking.
Our group uses mostly population-based cohorts to address the following topics: 1. To study the dynamics of adiposity and its impact on the cardiometabolic profile using a lifecourse approach; 2. To study different adiposity measures to summarize exposure to adiposity; 3. To evaluate cohort effects on the occurrence and trajectories of obesity; 4. To evaluate the mediating effect of chronic inflammation on the obesity effects; 5. To explore how diet and physical activity can modulate undesired effects of adiposity, namely through potential pro- and anti-inflammatory mechanisms.
Araujo J, Barros H, Ramos E, Li L. Trajectories of total and central adiposity throughout adolescence and cardiometabolic factors in early adulthood. Int J Obes (Lond). 2016;40(12):1899-905. Araujo J, Severo M, Barros H, Ramos E. Duration and degree of adiposity: effect on cardiovascular risk factors at early adulthood. Int J Obes (Lond). 2017;41(10):1526-30. Craveiro V, Ramos E, Araújo J. Metabolically healthy overweight in young adulthood: is it a matter of duration and degree of overweight? Nutr Metab Cardiovasc Dis. 2021 Feb 8;31(2):455-463.
