Ubiquinone and
ubiquinol represent the oxidized and reduced forms of
Coenzyme Q10 (
CoQ10).
CoQ10 is present in membranes of almost all human tissues and organs, with highest concentration in the heart. In patients with
heart failure, serum levels of the N-terminal pro-
brain natriuretic peptide (
NT-proBNP) are an
indicator of disease severity. Here, we investigated the relationship between serum levels of
CoQ10 and
NT-proBNP in healthy volunteers of an elderly study population (mean age 52 years, n = 871). We found a negative association between serum levels of
ubiquinol and
NT-proBNP (P < 0.001). Accordingly, the
CoQ10 redox state (% oxidized form of
CoQ10) is positively associated with serum
NT-proBNP level (P < 0.001). Compared to patients who survived a
myocardial infarction (n = 21), healthy subjects have lower
NT-proBNP level (500.39 ± 631.28 pg/ml vs. 76.90 ± 120.27 pg/ml, P < 0.001), higher
ubiquinol serum level (0.43 ± 0.19 µmol/L vs. 0.71 ± 0.32 µmol/L; P < 0.001), and a lower
CoQ10 redox state (27.6 ± 13.8% vs. 17.6 ± 10.1%; P < 0.001). Interestingly,
ubiquinol supplementation (150 mg/day; 14 day; n = 53) slightly reduces the expression of CLCN6, a gene related to
NT-proBNP level. In summary, higher serum levels of
ubiquinol are associated with lower serum
NT-proBNP levels in healthy elderly subjects. However, to what extent a high serum level of
ubiquinol is a protective factor for
heart failure remains to be elucidated in prospective studies.