Effect of empagliflozin on copeptin levels in patients with recent acute coronary syndrome and newly detected dysglycaemia: a post-hoc analysis of the SOCOGAMI randomized controlled trial

Abstract Background Copeptin, a surrogate marker for vasopressin secretion, is associated with cardiovascular disease, insulin resistance and dysglycaemia. The cardioprotective effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) may involve vasopressin modulation through fluid redistribution, but whether this effect persists long-term in high-cardiovascular-risk patients with newly detected dysglycaemia remains unknown. Methods In this post-hoc analysis of the SOCOGAMI double-blind, placebo-controlled trial, 42 patients (mean age 67.5 years, 19% females) with impaired glucose tolerance or newly detected type 2 diabetes following an ACS and no heart failure were randomized to empagliflozin 25 mg/day ( n = 20) or placebo ( n = 22) for 7 months. Copeptin was measured during oral glucose tolerance tests (OGTT) at baseline, after 7 months on-treatment, and 3 months after treatment withdrawal. Treatment effects were assessed by repeated-measures ANOVA with treatment × time interaction and linear mixed-effects models. Results Haematocrit, but not copeptin, showed a significant between-group difference at 7 months ( p = 0.03 and p = 0.63, respectively). Both markers returned toward baseline after treatment withdrawal, but the overall treatment × time interaction was not significant for either ( p = 0.72 and p = 0.64 respectively). Results were unchanged after accounting for a baseline imbalance in diuretic use (35% vs. 14%). Copeptin was not associated with the glucose-lowering effect of empagliflozin and no differential copeptin response during the OGTT across groups or visits was observed. In exploratory analyses, copeptin correlated with arterial pulse wave velocity at baseline (rs = 0.40, unadjusted p = 0.03). Conclusions In this post-hoc analysis, empagliflozin treatment was not associated with statistically significant sustained vasopressin secretion in post-ACS patients with newly detected dysglycaemia and preserved cardiac function. Due to the limited power and the absence of early on-treatment sampling these findings cannot exclude AVP modulation and warrant confirmation in adequately powered studies. Trial registration EudraCT number 2015-004571-73.