Background: Klotho protein is a membrane-based circulating protein that regulates cell metabolism, as well as the lifespan modulating activity of Fibroblast Growth Factors (FGFs). Higher plasma circulating Klotho levels reduce cardiovascular risk, suggesting Klotho has a protective role in cardiovascular diseases. Brain natriuretic peptide is a prognostic marker in coronary artery disease (CAD) patients, and in particular in CAD patients with heart failure. Aerobic exercise reduces the risk of cardiovascular events and mortality in patients with proven coronary artery disease (CAD), thus, S-Klotho serum levels were assessed in order to find out whether exercise can modulate its activity. Purpose: to assess the impact of 12 weeks exercise training program on S-Klotho and pro- BNP levels in coronary artery disease patients, and to assess possible correlation between S-Klotho and pro-BNP II.
Methods: S-Klotho and pro-BNP serum were assessed in 2 groups: gr. A = 41 coronary artery disease patients (CAD), age 59.6 years ± 2.2 sd, all with recent (< 45 days) aorto coronary by- pass surgery (CABG) years, myocardial infarction (MI), or percutaneous intervention (PCI) who were recruited to a 12 weeks supervised aerobic exercise program (45 min/4-5 sessions/week), and gr. B, a control group consisting of 17 CAD patients, age 61 years ± 2.4sd who continued their usual treatment and lifestyle with no active exercise intervention. Assessment was done twice, prior to exercise program and at the end of 12 weeks intervention. Blood samples were drawn from a forearm vein after overnight fasting, s-Klotho levels in the serum were analyzed using an α-klotho enzyme linked immunosorbent assay Elisa kit (IBL, Immuno-Biological Laboratories Co., Japan) and the pro- BNP was measured as well by an immunoassay method using the Cobas e - 411 analyzer, Roche Diagnostics, Mannheim, Germany.
Results: No significant (p= 0.27) difference was found at baseline for S-Klotho levels between the two groups, 770.49pg/ml +/- 202.20 sd and 727.54pg/ml +/- 207.83 sd respectively, while a significant difference was found following exercise intervention, 863.39 pg/ml +/- 213.66 sd in gr. A compared to 677.71pg/ml +/- 167.46 sd in gr. B, p <0.01. S-Klotho and BNP showed an inverse correlation at baseline in group A, r = -0.803, P<0.01 and in group B, r = - 0.850, p <0.01, with similar values post 12 weeks, r = -0.829 & -0.834 respectively.
Conclusions: Aerobic exercise may modulate S-Klotho activity, thus conferring a possible mechanism for the enhanced survival of coronary artery patients participating in an exercise based cardiac rehabilitation program.