Physical and psychological characteristics in adolescence and subsequent gastrointestinal disease risk in adulthood

Physical fitness has been associated with risk for many chronic diseases; lately it has been suggested to be protective against inflammatory disorders. Current research also indicates that psychological stress may still be relevant to the risk and course of gastrointestinal (GI) diseases. Low stress resilience, as an indication of greater susceptibility to stress in general, is relevant to how an individual responds to stressful exposures. Animal models indicate that early life exposures influence the development and persistent function of the Hypothalamic-Pituitary-Adrenal (HPA) axis, a feedback regulatory system that responds to stress. The persistence of stress resilience in animals suggests that this could also be a characteristic that remains across the life-course in humans. This project uses this theoretical framework in hypothesising how low stress resilience renders individuals more susceptible to stressful exposures experienced in everyday life. As there is notable variation in stress susceptibility between individuals, this characteristic may be a useful tool to elucidate the role of psychosocial stress in gastrointestinal diseases.

The research project will utilise data from a representative general population-based cohort study of approximately 250,000 Swedish men born between 1952 and 1956. These men were followed from late adolescence until 31^st December 2009 (up to 57 years). Data were systematically collected for all young men during assessments for Swedish military enlistment. The enlistment assessments spanned two days with examinations of health, physical fitness and cognitive ability. In addition, a certified psychologist assessed whether they had the psychological requirements for serving in war.

Aim: To examine associations between physical fitness and stress resilience in adolescence with gastrointestinal disease in adulthood. Outcomes include peptic ulcer disease (PUD), inflammatory bowel disease (IBD) and gastrointestinal infections.  

Significance: Prospectively collected physical fitness and stress susceptibility measures recorded many years prior to disease onset could provide an important insight into the pathways that underlie some gastrointestinal disease risks. This information may in turn be used to develop intervention strategies to reduce disease risk.