All-Cause, Cardiovascular and Respiratory Mortality in People with Type 2 Diabetes and Chronic Obstructive Pulmonary Disease (COPD) in England: A Cohort Study Using the Clinical Practice Research Datalink (CPRD)

Abstract

Background

Type 2 diabetes (T2D) and chronic obstructive pulmonary disease (COPD) are common non-communicable diseases. Both have an inflammatory nature and similar risk factors, and there is overlap and interaction between them. To date, there is a lack of research on outcomes in people that have both conditions. The aim of this study was to investigate whether the presence of COPD in people with T2D was associated with an increased risk of all-cause, respiratory-cause and cardiovascular-cause mortality.

Methods

A three-year cohort study (2017–19) was done using the Clinical Practice Research Datalink Aurum database. The study population was 121,563 people with T2D aged ≥40. The exposure was COPD status at baseline. Incident rates for all-cause, respiratory-cause and cardiovascular-cause mortality were calculated. Poisson models for each outcome were fitted to estimate rate ratios for COPD status adjusted for age, sex, Index of Multiple Deprivation, smoking status, body mass index, prior asthma and cardiovascular disease.

Results

COPD was present in 12.1% people with T2D. People with COPD had a higher all-cause mortality rate (448.7 persons per 1000 person years) compared with people without COPD (296.6 persons per 1000 person years). People with COPD also had substantially higher respiratory mortality incidence rates and moderately raised cardiovascular mortality rates. Fully adjusted Poisson models showed that people with COPD had a 1.23 (95% CI 1.21, 1.24) times higher rate of all-cause mortality as compared with those without COPD and a 3.03 (95% CI 2.89, 3.18) times higher rate of respiratory-cause mortality. There was no evidence of an association with cardiovascular mortality after adjusting for existing cardiovascular disease.

Conclusion

Co-morbid COPD in people with T2D was associated with increased mortality overall and particularly from respiratory causes. People with both COPD and T2D are a high-risk group who would benefit from particularly intensive management of both conditions.

Keywords:

• type 2 diabetes
• chronic obstructive pulmonary disease
• mortality
• respiratory
• cardiovascular

Data Sharing Statement

Data are available on request from the CPRD. Their provision requires the purchase of a license, and this license does not permit the authors to make them publicly available to all. This work used data from the version collected in December 2020 and have clearly specified the data selected within the Methods section. To allow identical data to be obtained by others, via the purchase of a license, the code lists will be provided upon request. Licenses are available from the CPRD (http://www.cprd.com): The Clinical Practice Research Datalink Group, The Medicines and Healthcare products Regulatory Agency, 10 South Colonnade, Canary Wharf, London E14 4PU.

Ethics Approval

In the UK, the protocol for this research was approved by the Independent Scientific Advisory Committee (ISAC) for MHRA Database Research (protocol number 22_001961) and the approved protocol was made available to the journal and reviewers during peer review. This study is based in part on data from the Clinical Practice Research Datalink obtained under licence from the UK Medicines and Healthcare products Regulatory Agency. The data is provided by patients and collected by the NHS as part of their care and support. The interpretation and conclusions contained in this study are those of the author/s alone. Linked pseudonymised data was provided for this study by CPRD. Data is linked by NHS Digital, the statutory trusted third party for linking data, using identifiable data held only by NHS Digital. Select general practices consent to this process at a practice level, with individual patients having the right to opt-out. This study is based in part on data from the Clinical Practice Research Datalink (CPRD) obtained under licence from the UK Medicines and Healthcare products Regulatory Agency. The data is provided by patients and collected by the National Health Service (NHS) as part of their care and support. The Office for National Statistics (ONS) was the provider of the ONS Data contained within the CPRD Data and maintains a Copyright © 2019, re-used with the permission of The Health & Social Care Information Centre, all rights reserved. The interpretation and conclusions contained in this study are those of the authors alone.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

Abdul Sattar Raslan is now an employee of IQVIA. All of his work for this project was done at Imperial College London. The authors report no other conflicts of interest in this work.