Abstract Body (Do not enter title and authors here): Introduction: Cardiovascular disease (CVD) complications are the leading cause of mortality in individuals with type 2 diabetes (T2D). Abnormal extracellular matrix (ECM) remodelling leads to the release of ECM protein fragments into circulation, reflecting these complications. Endotrophin, a pro-fibrotic and -inflammatory hormone, released during collagen type 6 formation, has been linked to adverse outcomes in T2D, but not previously in a long-term perspective.
Aim: To assess the 12-year prognostic value of circulating endotrophin levels, measured by PRO-C6, to predict the risk of major adverse cardiovascular events (MACE) in a large cohort of individuals with T2D.
Methods: Endotrophin levels were measured with the NordicPRO-C6™ ELISA in 909 serum samples from the Thousand & 2 study, which was initiated in 2011 and examined individuals with T2D, with and without known CVD. Clinical data were collected at baseline. Follow-up was 100% complete and performed on the 1^st of May 2024 with the registration of data on MACE from the Danish national registers. The primary outcome was MACE, defined as incident events of hospital admission for ischemic heart disease, heart failure, stroke, or all-cause mortality. PRO-C6 was split into tertiles and examined for survival probability by Kaplan-Meier analysis. Univariate Cox proportional hazard regression analysis was conducted to examine the association between PRO-C6 and the risk of MACE. A multivariable Cox model was additionally conducted, adjusted for age at baseline, sex, systolic blood pressure, duration of diabetes, HbA1c, estimated glomerular filtration rate, use of statins, albuminuria status, and current or prior smoking.
Results: The baseline mean (±SD) age of the cohort was 64 (±10) years, 66% were males, mean (±SD) PRO-C6 was 11.9 (±7.01) ng/ml, the median follow-up time was 10.6 years, and number of MACE recorded was 472. The risk of experiencing MACE was significantly higher in the third tertile compared to the first and second tertile (Log-Rank p < 0.001). In the univariate Cox model, the estimated hazard ratio (HR), corresponding to a 2-fold increase of PRO-C6, was HR [95% Confidence Interval(CI)] = 2.1 [1.8-2.4], P <0.001. In the fully adjusted Cox model, PRO-C6 remained significantly associated with the risk of MACE (HR [95% CI] = 1.5 [1.2-1.8], P <0.001).
Conclusion: Elevated circulating endotrophin is associated with MACE in T2D, independent of common risk factors.