Insomnia symptoms as a cause of type 2 diabetes incidence: a 20 year cohort study

Green, M. J. , Espie, C. A., Popham, F. , Robertson, T. and Benzeval, M. (2017) Insomnia symptoms as a cause of type 2 diabetes incidence: a 20 year cohort study. BMC Psychiatry, 17, 94. (doi:10.1186/s12888-017-1268-4) (PMID:28302102) (PMCID:PMC5356374)

[img]
Preview
Text
132236.pdf - Published Version
Available under License Creative Commons Attribution.

571kB

Abstract

Background: Insomnia symptoms are associated with type 2 diabetes incidence but are also associated with a range of potential time-varying covariates which may confound and/or mediate associations. We aimed to assess whether cumulative exposure to insomnia symptoms has a causal effect on type 2 diabetes incidence. Methods: A prospective cohort study in the West of Scotland, following respondents for 20 years from age 36. 996 respondents were free of diabetes at baseline and had valid data from up to four follow-up visits. Type 2 diabetes was assessed at the final visit by self-report, taking diabetic medication, or blood-test (HbA1c ≥ 6.5% or 48 mmol/mol). Effects of cumulative insomnia exposure on type 2 diabetes incidence were estimated with traditional regression and marginal structural models, adjusting for time-dependent confounding (smoking, diet, physical inactivity, obesity, heavy drinking, psychiatric distress) as well as for gender and baseline occupational class. Results: Traditional regression yielded an odds ratio (OR) of 1.34 (95% CI: 1.06-1.70) for type 2 diabetes incidence for each additional survey wave in which insomnia was reported. Marginal structural models adjusted for prior covariates (assuming concurrently measured covariates were potential mediators), reduced this OR to 1.20 (95% CI: 0.98-1.46), and when concurrent covariates were also included (viewing them as potential confounders) this dropped further to 1.08 (95% CI: 0.85-1.37). Conclusions: The association between cumulative experience of insomnia and type 2 diabetes incidence appeared confounded. Evidence for a residual causal effect depended on assumptions as to whether concurrently measured covariates were confounders or mediators.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Popham, Dr Timothy and Espie, Professor Colin and Green, Dr Michael and Benzeval, Dr Michaela
Authors: Green, M. J., Espie, C. A., Popham, F., Robertson, T., and Benzeval, M.
College/School:College of Medical Veterinary and Life Sciences > Institute of Health and Wellbeing > MRC/CSO Unit
College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
Journal Name:BMC Psychiatry
Publisher:BioMed Central
ISSN:1471-244X
ISSN (Online):1471-244X
Copyright Holders:Copyright © 2017 The Authors
First Published:First published in BMC Psychiatry 17:94
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
727651SPHSU Core Renewal: Measuring and Analysing Socioeconomic Inequalities in Health Research ProgrammeAlastair LeylandMedical Research Council (MRC)MC_UU_12017/13IHW - MRC/CSO SPHU