Impact of micro‐ and macrovascular complications of type 2 diabetes on quality of life: Insights from the DISCOVER prospective cohort study

BACKGROUND: The key goals of management in patients with type 2 diabetes (T2D) are to prolong life and improve quality of life. Micro‐ and macrovascular complications of T2D not only increase the risk of morbidity and mortality, but cross‐sectional studies indicate they may also worsen quality of life. We prospectively examined the association of complications that developed during the follow‐up with concurrent changes in quality of life. MATERIALS AND METHODS: DISCOVER is a multinational, prospective, observational cohort study of T2D patients enrolled at initiation of second‐line glucose‐lowering therapy. Quality of life was assessed with the SF‐36 Physical (PCS) and Mental Components Summary (MCS) scores at baseline, 6 months, and 1, 2 and 3 years. Hierarchical repeated measures regression models for PCS and MCS were constructed with complications included as time‐dependent covariates; first each complication was modelled alone and then second including all interval complications (to account for different complications occurring in the same patient). RESULTS: Among 7830 patients with T2D from 30 countries (mean age 56.6 years, 47.6% women, mean duration of T2D 5.6 years), baseline mean SF‐36 PCS was 48.0 ± 7.8 and SF‐36 MCS was 45.5 ± 10.4. At baseline, 1422 (18.2%) patients had a known microvascular complication, and 966 (12.3%) had a macrovascular complication. Over the 3 years of the study, 641 (12.0%) developed a new microvascular complication (most commonly neuropathy) and 372 (5.8%) developed a new macrovascular complication (most commonly coronary disease). New diagnoses of coronary disease, peripheral artery disease, heart failure and neuropathy were each associated with subsequent moderate reductions in SF‐36 PCS (range 0.7 to 1.6 points) and new cerebrovascular disease was associated with a reduction in SF‐36 MCS (2.6 points). Results were consistent when all interval complications were considered in the same model. CONCLUSION: In a prospective, multinational study of patients with T2D, the development of macrovascular complications and neuropathy was associated with decreases in both physical and mental quality of life. Our results provide additional support for clinicians to focus on the prevention, detection and management of the complications of T2D.