Fasting serum copeptin and asymptomatic peripheral artery disease: No association in patients with type 1 diabetes mellitus

Objective: As copeptin is associated with lower-extremity amputation in patients with type 1 diabetes mellitus (T1DM), our study aimed to address the putative association between copeptin and asymptomatic peripheral artery disease (aPAD) in those patients.

Design and methods: This observational cross-sectional study included 112 patients with T1DM from a larger cohort (ClinicalTrials.gov: NCT02910271), selected (1:2) as per the presence of aPAD (n = 37) or not (n = 75). aPAD was evaluated by ankle-brachial index (ABI), toe-brachial index (TBI), and peripheral Doppler ultrasound. The two groups of patients were matched by age, gender distribution and duration of T1DM. Fasting serum copeptin was measured by high-sensitivity ELISA, and its relationships with clinical and biochemical variables as well as aPAD were evaluated too.

Results: The study population was aged 42 ± 8 years, duration of T1DM was 27 ± 7 years, and mean HbA_1c was 7.7 ± 1.1%. No significant differences in copeptin concentrations were found between patients with or without aPAD (16.9 ± 10.8 vs 17.3 ± 14.7 pmol/L, respectively; P = 0.462). Considering all patients as a whole, copeptin correlated with systolic blood pressure (SBP; ρ = -0.209, P = 0.027), eGFR ρ = -0.271, P = 0.004), and serum sodium (ρ = -0.208, P = 0.027), but not with ABI (ρ = -0.068, P = 0.476). Stepwise multiple linear regression analysis (R²: 0.059; P = 0.035) retained SBP (β: -0.219, 95% CI: -1.391; -0.089) as the only significant predictor of copeptin concentration.

Conclusion: As serum copeptin does not appear to be associated with aPAD in patients with T1DM, further studies are now needed to elucidate whether it has any other potential role to play in the subclinical vascular disease of this patient population.