Diabetes mellitus and mortality from all-causes, cancer, cardiovascular and respiratory disease: evidence from the Health Survey for England and Scottish Health Survey cohorts

Abstract

Background: Diabetes mellitus is associated with differing rates of all-cause and cause-specific mortality compared with the general population; although the strength of these associations requires further investigation. The effects of confounding factors, such as overweight and obesity and the presence of co-morbid cardiovascular disease (CVD), upon such associations also remain unclear. There is thus a need for studies which utilise data from nationally-representative samples to explore these associations further.

Methods: A cohort study of 204,533 participants aged 16+ years (7,199 with diabetes) from the Health Survey for England (HSE) (1994-2008) and Scottish Health Survey (SHeS) (1995, 1998 and 2003) linked with UK mortality records. Odds ratios (ORs) of all-cause and cause-specific mortality and 95% confidence intervals were estimated using logistic and multinomial logistic regression.

Results: There were 20,051 deaths (1,814 among those with diabetes). Adjusted (age, sex, and smoking status) ORs for all-cause mortality among those with diabetes was 1.68 (95%CI 1.57-1.79). Cause-specific mortality ORs were: cancer 1.26 (1.13-1.42), respiratory diseases 1.25 (1.08-1.46), CVD 1.96 (1.80-2.14) and 'other' causes 2.06 (1.84-2.30). These were not attenuated significantly after adjustment for generalised and/or central adiposity and other confounding factors. The odds of mortality differed between those with and without comorbid CVD at baseline; the ORs for the latter group were substantially increased.

Conclusions: In addition to the excess in CVD and all-cause mortality among those with diabetes, there is also increased mortality from cancer, respiratory diseases, and 'other' causes. This increase in mortality is independent of obesity and a range of other confounding factors. With falling CVD incidence and mortality, the raised risks of respiratory and cancer deaths in people with diabetes will become more important and require increased health care provision.

Keywords: All-cause; Cancer; Cardiovascular disease; Diabetes; Respiratory disease.