Examining the causal effect of type 2 diabetes on ischemic heart disease – A longitudinal study with four measurements (1980–2017). (April 2023)

• Record Type: Journal Article
• Authors: Jansåker, Filip; Ekström, Ola; Memon, Ashfaque A.; Hansson, Ola; Johansson, Sven-Erik; Sundquist, Kristina
• Is Part Of: Diabetes research and clinical practice. Volume 198(2023)
• Publication Date: 2023-04
• Subjects: Causal effect -- Epidemiology -- Ischemic Heart Disease -- Type 2 Diabetes; BMI Body Mass Index -- CI Confidence Intervals -- HR Hazard Ratio -- ICD International Classification of Diseases -- IHD Ischemic Heart Disease -- IPTW Inverse Probability Treatment Weights; Diabetes -- Periodicals; Diabetes Mellitus -- Periodicals; 616.462
• DOI: 10.1016/j.diabres.2023.110595
• Languages: English
• ISSNs: 0168-8227

Abstract

Abstract: Objective: This longitudinal study examines a possible causal effect between type 2 diabetes and ischemic heart disease (IHD) by using measurements on four occasions from the Swedish Statistics on Income and Living Conditions (SILC) together with nationwide healthcare registers. Methods: This was a longitudinal study based on a random sample of men and women (n = 2014) from the Swedish population with four measurements in the SILC every eight years. Baseline was 1980/81 and the participants were followed for up to 37 years. The mean age and age range at baseline were 36.5 and 20–59 years, respectively. The study used Marginal Structural Modeling (MSM-Cox) to account for time-varying exposures by implementing inverse probability weighting (IPTW). MSM-Cox with IPTW was compared with Cox proportional hazard modelling. Results: The hazard ratio (HR) for IHD (369 cases) with 95% confidence interval (CI) in participants with type 2 diabetes (11.1%) compared to participants without type 2 diabetes (88.9%) was significantly higher (1.99; CI = 1.15 – 3.44) when using MSM-Cox with IPTW after adjustments for clinical and sociodemographic risk factors. When applying Cox proportional hazard models adjusted for the same variables, the HR was lower and non-significant at 1.34 (CI = 0.94 – 1.98). Conclusions: This longitudinal study with four measurements assessed a possible causal association between type 2 diabetes and IHD by applying MSM-Cox with IPTW. Although causality cannot be determined due to the remaining risk of residual bias, the results may help to elucidate a potential causal relationship between type 2 diabetes and IHD. Further causal studies on possible underlying mechanisms are, however, needed.