Social disadvantage linked to diabetes through chronic inflammation.

Chronic inflammation explained a quarter to a third of the association between social adversity and type 2 diabetes in a longstanding cohort from the UK.

The Whitehall II study has been tracking the health of selected government employees since 1985. The new analyses modelled data from 6387 men and women who did not have diabetes when tested between 1991 and 1993.

A lifetime of social adversity from childhood to middle age was significantly associated with risk of diabetes during the next 18 years (adjusted hazard ratio comparing lowest with the highest lifetime scores of socioeconomic status 1.96, 95% CI 1.48 to 2.58).

Markers of chronic inflammation – serum concentrations of C reactive protein and interleukin 6 – accounted for 25% of the association (95% CI 16% to 48%), mostly through pro inflammatory lifestyles such as smoking, inactivity, poor diet and obesity.

Once unhealthy lifestyles were accounted for, chronic inflammation alone explained 10% of the association between social adversity and diabetes. These independent effects may be genetic say the authors. It is known that social circumstances can alter the regulation of genes that control the body’s inflammatory responses.

Downwardly mobile social trajectories were associated with diabetes in this study, but upwardly mobile trajectories were not. This suggests that any early effects of social adversity may be reversible, say the authors.

Source: PLoS Med 2013;10.e1001479.