Demographic and psychological factors in type 2 diabetes risk and progression

Demographic and positive psychological factors are relevant to Type 2 Diabetes (T2D) risk and progression, but the biological underpinnings are unclear. This PhD consists of four studies aiming to better understand the role of demographic and positive psychological factors on T2D risk and progression, and the biological mechanisms involved. Study 1 used data from a nationally representative cohort to examine a) the relationship between different types of subjective well-being and T2D incidence in initially healthy participants and b) the amount of association explained by sociodemographic, behavioural, and clinical characteristics. Hedonic but not eudaimonic well-being predicted lower T2D rate over 12 years. Sociodemographic, behavioural, and clinical factors together accounted for 36% of the association. Studies 2 and 3 used data from a laboratory stress testing study. Study 2 tested sex differences in inflammatory stress responses in people with existing T2D. Results showed that women with T2D produced larger interleukin(IL)-6 stress responses compared with men. Study 3 examined the association between hedonic well-being and inflammatory stress responses in individuals with T2D. Hedonic well-being was associated with lower inflammatory markers pre- and post-stress. Inflammatory stress responses did not differ in people varying in hedonic well-being. Study 4 is a 7.5-year follow-up of this laboratory study. Study 4 looked at the possible mediating role of IL-6 stress (re)activity in associations linking sex or hedonic well-being with health outcomes in participants with T2D. Results showed that women with T2D experienced worse mental health-related quality of life at follow-up and greater IL-6 stress responses at baseline predicted diminished mental health-related quality of life. IL-6 stress responsivity did not mediate the link between sex and mental health at follow-up. These findings highlight the role of hedonic well-being in T2D development. The relationship between sex or hedonic well-being with T2D outcomes may be mediated via increased inflammatory (re)activity