Tenascin X and Tenascin C Serum Levels in Relation to Age and Cardiometabolic Risk Parameters

Tenascin C (TNC) and tenascin X (TNX) are extracellular matrix glycoproteins in the same family but with reportedly distinct functions: TNC is acutely up-regulated during tissue damage, whereas TNX maintains structural connective tissue stability. Recently, recurring pathogenic variants in the TNX gene (TNXB) were linked to Ehlers–Danlos syndrome in patients with congenital adrenal hyperplasia, yet the regulation and clinical function of TNX remain poorly understood. In this retrospective cohort study, serum TNX and TNC were measured by ELISA in 274 patients with prevalent cardiovascular risk factors. In bivariate analyses, TNX levels correlated negatively with age and cardiometabolic risk parameters (blood pressure, glucose) and positively with kidney function; in multivariable regression, TNX was independently associated with age, sex, and height, whereas the associations with cardiometabolic parameters were no longer significant. TNX levels remained unchanged following acute glucocorticoid administration. TNC levels correlated negatively with age and glycated hemoglobin and positively with kidney function in bivariate analyses. These findings support distinct but overlapping roles for TNX and TNC in connective tissue function and extend current knowledge, suggesting both proteins as candidate systemic biomarkers for aging. A further investigation of TNX and TNC in a clinical context could reveal new mechanisms for the detection or prevention of cardiometabolic disease.