AIMS/HYPOTHESIS: The objective of this study was to use Scottish national data to assess the influence of type 2 diabetes on the risk of cancer at 16 different sites, while specifically investigating the role of confounding by socioeconomic status in the diabetes-cancer relationship.
METHODS: All people in Scotland aged 55-79 years diagnosed with any of the cancers of interest during the period 2001-2007 were identified and classified by the presence/absence of co-morbid type 2 diabetes. The influence of diabetes on cancer risk for each site was assessed via Poisson regression, initially with adjustment for age only, then adjusted for both age and socioeconomic status.
RESULTS: There were 4,285 incident cancers in people with type 2 diabetes. RR for any cancers (adjusted for age only) was 1.11 (95% CI 1.05, 1.17) for men and 1.33 (1.28, 1.40) for women. Corresponding values after additional adjustment for socioeconomic status were 1.10 (1.04, 1.15) and 1.31 (1.25, 1.38), respectively. RRs for individual cancer sites varied markedly.
CONCLUSIONS/INTERPRETATION: Socioeconomic status was found to have little influence on the association between type 2 diabetes and cancer.
This work is presented by the named authors on behalf of all members of the Scottish Diabetes Research Network Epidemiology Group. The data used are available for analysis thanks to the hard work of numerous NHS staff who enter the data, and people and organisations (the Scottish Care Information – Diabetes Collaboration [SCI-DC] Steering Group, the Scottish Diabetes Group, the Scottish Diabetes Survey Monitoring Group, the managed clinical network managers and staff in each Health Board) involved in setting up, maintaining and overseeing SCI-DC. Thanks are due also to staff of the Scottish Cancer Registry and to the Information Services Division (ISD) record linkage team.
This work was funded by the European Foundation for the Study of Diabetes (grant number 90768) and the Wellcome Trust through the Scottish Health Informatics Programme (SHIP) Grant (grant number WT086113). Funding for diabetes register linkage was provided by the Scottish Government and the authors acknowledge the financial support of NHS Research Scotland (NRS), through the Scottish Diabetes Research Network.
- Diabetes Mellitus, Type 2/epidemiology
- Middle Aged
- Social Class