Macrovascular and microvascular complications in US Medicare enrollees with type 2 diabetes with and without atherosclerotic cardiovascular disease

Abstract

Aims: To assess the incidence of macrovascular and microvascular complications in US Medicare enrollees diagnosed with T2D with and without established ASCVD.

Materials and methods: We conducted a retrospective cohort study using Medicare fee-for-service claims data from 1 January 2006, through 31 December 2021. Baseline demographic and clinical characteristics were assessed in the 1-year prior to indexing. Cumulative incidences of various diabetes complications were assessed until the first microvascular or macrovascular complication of interest, the end of the study period or death.

Results: A total of 2 326 726 patients and 640 666 patients met study inclusion/exclusion criteria for the T2D cohort and T2D + ASCVD sub-cohort, respectively. The incidence rate of any macrovascular event was 483.34 per 10 000 person-years in the T2D cohort. Overall, the 1-year cumulative incidence rate of any macrovascular event was 3.90%. Coronary heart disease (T2D, 3.24%; T2D + ASCVD, 8.10%) and peripheral artery disease (T2D, 1.97%; T2D + ASCVD, 7.33%) were the macrovascular events with the greatest 1-year cumulative incidence. Patients developed microvascular complications at a rate of 1569.28 per 10 000 person-years in the T2D cohort and 1859.80 per 10 000 person-years in the T2D + ASCVD sub-cohort. The 1-year cumulative incidence of any microvascular event was 16.88% in the T2D cohort and 21.16% in the T2D + ASCVD sub-cohort. Neuropathy and nephropathy were the microvascular events with the greatest 1-year cumulative incidence in both cohorts: T2D, 8.34% and 7.02%; T2D + ASCVD, 10.65% and 9.12%, respectively.

Conclusions: The frequencies of macrovascular and microvascular complications highlight the importance of annual cardiovascular risk assessment in patients with T2D, especially those with established ASCVD.

Plain language summary: What is the context and purpose of this research study? People with type 2 diabetes (T2D), especially those with hardening of the arteries or atherosclerotic cardiovascular disease (ASCVD), are at risk of developing problems with large and small blood vessels throughout their bodies. These problems can lead to serious health risks and death. We wanted to determine how many Medicare people with T2D, with and without ASCVD, developed problems with their large and small blood vessels over time. What was done? We used Medicare claims data to measure how many people with T2D, and a subset with T2D+ASCVD, developed problems with these blood vessels from January 1, 2006, through December 31, 2021. What were the main results? In the year after developing T2D, we found that 3.90% of patients developed problems with their large blood vessels. The most common large blood vessel problems that occurred within the first year of developing T2D (or T2D+ASCVD) were coronary heart disease (T2D, 3.24%; T2D+ASCVD, 8.10%) and peripheral artery disease (T2D, 1.97%; T2D+ASCVD, 7.33%). In the year after developing T2D (or T2D+ASCVD), we found that 16.88% of people with T2D and 21.16% of people with T2D+ASCVD developed problems with their small blood vessels. The most common small blood vessel problems were nerve damage (T2D, 8.34%; T2D+ASCVD, 10.65%) and kidney disease (T2D, 7.02%; T2D+ASCVD, 9.12%) in the first year. What is the originality and relevance of this study? This was the first study where we measured large and small blood vessel problems in people with T2D+ASCVD in a Medicare population. This study also provides an update to previous studies that measured large and small blood vessel problems in people with T2D. By highlighting the frequency of large and small blood vessel problems in people with T2D, we hope to raise awareness about the importance of annual screening in people with T2D, especially people with existing ASCVD, and manage according to the established guidelines.

Keywords: diabetes complication; diabetic nephropathy; diabetic neuropathy; macrovascular disease; real‐world evidence; type 2 diabetes.

FIGURE 1

Cumulative incidence of macrovascular diseases among a cohort of patients with T2D and a sub‐cohort of patients with T2D + ASCVD. A, ischaemic stroke or transient ischaemic stroke (year 0 n at risk, T2D, 2 084 448; T2D + ASCVD, 541 876). B, myocardial infarction (year 0 n at risk, T2D, 2 198 950; T2D + ASCVD, 591 064). C, Peripheral artery disease (year 0 n at risk, T2D, 1 816 843; T2D + ASCVD, 449 834). D, other cardiovascular disease (year 0 n at risk, T2D, 1 933 414; T2D + ASCVD, 514 349). E, coronary heart disease (year 0 n at risk, T2D, 1 467 989; T2D + ASCVD, 337 299). F, lower extremity amputation (year 0 n at risk, T2D, 2 324 089; T2D + ASCVD, 639 844). G, atherosclerosis of the brain (year 0 n at risk, T2D, 1 849 057; T2D + ASCVD, 442 601). H, atherosclerosis of the heart (year 0 n at risk, T2D, 1 458 254; T2D + ASCVD, 317 175). I, atherosclerosis of the major arteries (year 0 n at risk, T2D, 1 816 159; T2D + ASCVD, 449 065). ASCVD, atherosclerotic cardiovascular disease; T2D, type 2 diabetes.

FIGURE 2

Cumulative incidence of microvascular diseases among a cohort of patients with T2D and a sub‐cohort of patients with T2D + ASCVD. A, end‐stage kidney disease (year 0 n at risk, T2D, 2 242 937; T2D + ASCVD, 616 725). B, diabetic nephropathy (year 0 n at risk, T2D, 1 771 699; T2D + ASCVD, 449 272). C, diabetic neuropathy (year 0 n at risk, T2D, 1 694 289; T2D + ASCVD, 407 154). D, diabetic retinopathy (year 0 n at risk, T2D, 1 987 858; T2D + ASCVD, 506 649). ASCVD, atherosclerotic cardiovascular disease; T2D, type 2 diabetes.