The influence of neighbourhood-level socioeconomic deprivation on developing type 2 diabetes in older men: a longitudinal analysis of the British Regional Heart Study cohort data

Abstract

BackgroundEvidence from the British longitudinal studies on the influence of neighbourhood-level socioeconomic deprivation in older men on developing type 2 diabetes mellitus is scarce. This study investigates the prospective associations of neighbourhood-level deprivation and individual socioeconomic position with type 2 diabetes mellitus incidence in older men. MethodsThe British Regional Heart Study comprises a cohort of 4252 men aged 60–79 years in 1998–2000 from 24 towns across the UK. Neighbourhood-level deprivation was based on the country specific 2004–05 Index of Multiple Deprivation (IMD) quintiles for participants' postcode of residence at baseline. Individual socioeconomic position was defined as occupational social class based on longest-held occupation at recruitment. Participants with prevalent diabetes were excluded. The incidence of type 2 diabetes mellitus was ascertained from biannual reviews of primary care records over 18 years of follow-up. Cox proportional hazard models were undertaken to examine associations. FindingsThe incidence of type 2 diabetes mellitus cases observed was 368 (9·9%), amongst the 3706 male participants. Age-adjusted rates of type 2 diabetes mellitus increased from IMD quintile 1 (least deprived) to quintile 4 (second most deprived), before decreasing in quintile 5. Compared with quintile 1, the age and individual social class adjusted hazard ratio (aHR) in quintile 4 was 1·52 (95% CI 1·09–2·13), remaining significant after further adjustments for obesity and family history of type 2 diabetes mellitus. Participants in the lowest social class had the highest rates of type 2 diabetes mellitus. The aHR by age and IMD scores for type 2 diabetes mellitus in the lowest social class compared with the highest social class was 2·12 (95% CI 1·15–3·89). InterpretationNeighbourhood-level and individual-level socioeconomic factors remain important predictors of developing type 2 diabetes mellitus in older men, demonstrating that inequalities persist in later life. Inequalities in diabetes and its underlying modifiable risk factors need to be addressed to reduce the burden of this disease in socioeconomically deprived older-age populations. FundingNone.