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Postgrad Med J 88:679-683 doi:10.1136/postgradmedj-2012-130877
  • Original article

Falling mortality rates in Type 2 diabetes mellitus in the Wirral Peninsula: a longitudinal and retrospective cohort population-based study

  1. Banjo Adekunle Afolabi3
  1. 1Department of Community and Child Health, University of Chester, Chester, Cheshire, UK
  2. 2Department of Medicine, Wirral University Teaching Hospital Foundation NHS Trust, Upton, Merseyside, UK
  3. 3Department of Statistics, Aintree University Hospitals NHS Foundation Trust, Liverpool, Liverpool, UK
  1. Correspondence to Dr Chukwuemeka Nwaneri, Department of Community and Child Health, University of Chester, Chester, CRV 253, Riverside Campus, Cheshire CH11SL, UK; c.nwaneri{at}chester.ac.uk
  1. Contributors HC, DBJ, and CN designed and planned the study. KC had done preliminary evaluations on the study. All authors developed the protocol. CN and BA did the statistical analyses and alongside other authors interpreted the data and prepared the manuscript. All authors contributed to the review and writing of the paper.

  • Received 21 February 2012
  • Accepted 23 July 2012
  • Published Online First 17 August 2012

Abstract

Objectives To determine the life expectancy and mortality rates in patients with type 2 diabetes mellitus when compared with the UK general population; to measure the years of life lost.

Design Longitudinal and retrospective cohort study.

Setting The Wirral Peninsula in the northwest of England.

Participants Total of 13 620 patients with type 2 diabetes mellitus on the Wirral Diabetes Register.

Main Outcome measure All-cause mortality, from 1 January 2000 to 31 December 2007.

Results Over the 8-year period of the study, there were a total of 16 692.5 person-years lived and 3888 deaths; 2041 (52.5%) males and 1847 (47.5%) females with corresponding mean ages at death of 75.6±10.3 years and 80.2±10.2 years, respectively. Although prevalence rates increased linearly (from 1.06% in 2000 to 4.39% in 2007) a decrease in mortality rates (from 117 to 46 per 1000 population) in both sexes was observed. This coincided with a progressive fall in cardiovascular risk factors in this population. A survival time curve of life lived until death showed that males had 8.0 years reduction in life span and females' life span was reduced by 9.6 years when compared with UK general population. In both sexes, life expectancy was reduced by between 2 and 11 years dependent on the age of diagnosis, with males showing a greater degree of reduction.

Conclusion Type 2 diabetes mellitus is associated with a significant reduction in life expectancy, more markedly in men, and in those diagnosed before age 70 years. However, annual mortality rates have fallen progressively in our population and may contribute to longer survival and life expectancy in future years.

Footnotes

  • Funding Dr Nwaneri is a Gladstone Doctoral Fellow at the University of Chester.

  • Competing interests None.

  • Ethics approval The study protocol was approved by the local ethics committee of the University of Chester and Integrated Research Application System (IRAS) exemption.

  • Provenance and peer review Not commissioned; externally peer reviewed.