Abstract
OBJECTIVES: The cardiotonic steroid, marinobufagenin (MBG), has been shown to play a physiological natriuretic role in response to salt intake. However, recent studies in clinical and animal models demonstrated possible links between elevated levels of endogenous MBG and increased arterial stiffness. Large artery stiffness is a known predictor of future cardiovascular disease. We, therefore, investigated whether large artery stiffness relates to 24-h urinary MBG excretion in young apparently healthy black and white adults. METHODS: This study included data of 711 participants (black 51%, men 42%, mean age 24.8 ± 3.02 years). We measured the carotid-femoral pulse wave velocity (cfPWV), 24-h urinary MBG and sodium excretion. RESULTS: In single, partial and multivariable adjusted (Adj.) regression analyses, we found a persistent positive association between cfPWV and MBG excretion in women [Adj. R = 0.23; standardized (std.) β = 0.15; P = 0.002], but not men (Adj. R = 0.17; std. β = 0.06; P = 0.31). Multiple regression models were adjusted for ethnicity, age, waist-to-height ratio, mean arterial pressure, high-density lipoprotein cholesterol, C-reactive protein, γ-glutamyl transferase and glucose. CONCLUSION: In conclusion, already at a young age heightened endogenous MBG levels may contribute to large artery stiffness in women via pressure-independent mechanisms, increasing their risk for future cardiovascular disease.