Salivary Alpha-Amylase Activity, a New Biomarker in Heart Failure?

Salivary α-amylase activity is an increasingly investigated biomarker for the activation of the autonomic nervous system. Autonomic imbalance is associated to several diseases, one of which is heart failure, and the aim of the present study was to test if salivary α-amylase activity might be a new biomarker in patients with chronic heart failure. Methods: In this pilot study, 48 elderly men (range 59-89 years), 24 patients with established chronic heart failure in NYHA class I to III, and 24 controls were included. In all participants, saliva was collected for three consecutive days at three time points (at awakening, 30 minutes later and in the late afternoon), and blood was sampled for analysis of NT-proBNP. Results: Within the whole group of participants, a statistically significant positive correlation between morning salivary α-amylase activity levels and serum NT-proBNP could be found, which was strongest for the measurement taken 30 minutes after awakening, as well as a significant negative correlation of awakening α-amylase activity levels with arterial blood pressure. Within the control group separately, higher daily salivary α-amylase activity output correlated with increasing levels of NT-proBNP, while within the patients, the strongest association of α-amylase activity measures were found to be a negative correlation with blood pressure. Conclusions: Our data supports the idea that sAA activity has the potential as a non-invasive index of adrenergic activity in specific pathological conditions, though for heart failure in particular the results were merely modest, which was likely due to the specific intake of beta-receptor blocking drugs by all patients. Due to the large variability of sAA activity levels, we expect a greater potential for monitoring its changes over time, which could prove a valuable surrogate biomarker for cardiovascular diseases, including heart failure.