Circulating Heavy Molecular Weight Adiponectin is Inversely Associated with Arterial Stiffness in Apparently Healthy Young Adults Without Obesity

Aortic stiffness, measured by carotid-femoral pulse wave velocity (cf-PWV), contributes to subclinical end-target organ damage and is a robust independent predictor of clinical cardiovascular disease (CVD) events in adults. Adiponectin (ApN) is primarily an adipocyte-derived protein (i.e., adipokine) that is abundant in plasma and has high biological activity, including the ability to influence vascular remodeling via effects that include reduced smooth muscle cell proliferation and intimal hyperplasia, promoting endothelial nitric oxide synthesis, and by tempering excess extracellular matrix production. Thus, low circulating ApN is related to increased cf-PWV in clinical populations such as in obesity, diabetes, and heart failure, and exercise training-related reductions in cf-PWV are accompanied by training-induced increases in circulating ApN in aging adults. However, whether these associations extend to young adults free of disease or are dependent on physical activity is unclear. PURPOSE: To investigate the relationship between circulating ApN and PWV in healthy young adults and whether this association is dependent on physical activity levels. We hypothesized that (1) there would be an inverse association of ApN concentrations with cf-PWV and (2) that the strength of this association would be dependent on moderate-to-vigorous intensity physical activity (MVPA) level. METHODS: Thirty-five apparently healthy young adults without obesity (25 females, 10 males; 24±4 y; 24±4 kg/m2) provided a venous blood sample for measurement of heavy molecular weight ApN by ELISA, completed the international physical activity questionnaire (IPAQ) to assess weekly MVPA levels, and had cf-PWV assessed. Multiple linear regression was used to examine the relation of ApN with cf-PWV while controlling for age, sex, BMI, and mean arterial pressure. Moderation analysis was used to determine whether the magnitude of the relation of ApN with cf-PWV was dependent on MVPA level. RESULTS: There was a significant independent association between ApN and PWV (β = -0.29, p = 0.024). Moderation analysis confirmed the effect of ApN on PWV (p < 0.001), but this effect was not significantly moderated by MVPA (p = 0.26). DISCUSSION: These preliminary analyses indicate that circulating ApN is related with aortic stiffness in apparently healthy adults without obesity, irregardless of self-reported MVPA levels. These preliminary findings could be bolstered by objective measurements of MVPA and by examining whether training-induced improvements in arterial stiffness may be linked with increases in ApN in healthy young adults. Funding was provided by the Injury Prevention Research Center at the University of Iowa. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.