Long-term prognostic effect of serum albumin concentration in diabetic patients with stable coronary artery disease: A multicenter cohort study

Background: Diabetes and insulin resistance alter the physiological state of serum albumin (SA), which is a prognostic marker for stable coronary artery disease (CAD). However, whether the SA concentration is associated with long-term cardiovascular (CV) outcomes in diabetic patients with stable CAD remains unclear. Methods: In total, 1148 patients were retrospectively identified from a nationwide multicenter cohort study on patients with stable CAD. They were categorized into four groups according to their diabetes mellitus (DM) status and SA concentration (cutoff: 4 g/dL). Results: The patients’ mean age was 62.5 years, and 83.5% were male. Of the total patients, 405 were included in group 1 (SA ≥4/non-DM), 322 in group 2 (SA <4/non-DM), 201 in group 3 (SA ≥4/DM), and 220 in group 4 (SA <4/DM). Group 4 had the oldest age and a higher prevalence of prior myocardial infarction and stroke. During the median 4.5-year follow-up (interquartile range: 1.5-6.7 years), the highest and lowest survival rates in terms of all-cause and CV mortality were found in groups 1 and 4, respectively. However, no prognostic differences were noted in nonfatal stroke and myocardial infarction among the groups. The data were consistent after covariate adjustment. Using group 1 as the reference, hazard ratio (HRs) (95% CIs) for all-cause mortality in groups 2, 3, and 4 were 3.64 (1.22-10.83), 3.26 (0.95-11.33), and 5.74 (1.92-16.95), respectively, and those for CV mortality were 2.8 (0.57-13.67), 2.62 (0.40-17.28), and 6.15 (1.32-28.58), respectively. Conclusion: In diabetic patients with stable CAD, a low SA concentration (<4 g/dL) was associated with increased long-term mortality regardless of all-cause or CV reasons but not nonfatal CV events.