Risk trajectories of complications in over one thousand newly diagnosed individuals with type 2 diabetes

Abstract

Although the increased risk of complications of type 2 diabetes (T2D) is well known, there is still little information about the long-term development of comorbidities in relation to risk factors. The purpose of the present study was to describe the risk trajectories of T2D complications over time in an observational cohort of newly diagnosed T2D patients, as well as to evaluate the effect of common risk factors on the development of comorbidities. This national cohort study investigated individuals with T2D in the Swedish National Diabetes Register regarding prevalence of comorbidities at the time of diagnosis, and the incidence of cardiovascular disease (CVD), chronic kidney disease (CKD) and heart failure in the entire patient cohort and stratified by HbA1c levels and age at baseline. Multivariable Cox regressions were used to evaluate risk factors predicting outcomes. We included 100,878 individuals newly diagnosed with T2D between 1998 and 2012 in the study, with mean 5.5 years follow-up (max 17 years). The mean age at diagnosis was 62.6 ± SD12.5 years and 42.7% of the patients were women. Prevalent CVD was reported for 17.5% at baseline. Although the prevalence of comorbidities was generally low for individuals 50 years or younger at diagnosis, the cumulative incidence of the investigated comorbidities increased over time. Newly diagnosed CVD was the most common comorbidity. Women were shown to have a lower risk of developing comorbid conditions than men. When following the risk trajectory of comorbidities over a period of up to 15 years in individuals with type 2 diabetes, we found that all comorbidities gradually increased over time. There was no distinct time point when onset suddenly increased.

Figure 1

Cumulative incidence of complications. Line plots illustrating cumulative incidence (CI) (%) stratified by age (A–C) or HbA1c levels (D–F) at the time of diagnosis for cardiovascular disease (CVD), heart failure (HF), and chronic kidney disease (CKD). CI is presented on the y-axis and time from diagnosis on the x-axis (years). Note different scales on Y axes.