Abstract 5073: Relationship of Physical Activity with Circulating Progenitor Cell Counts and Adiponectin Levels in Healthy Non-Obese Individuals
Background: Physical activity is a determinant of cardiovascular performance and a predictor of risk. Levels of progenitor cells that contribute to repair of tissues including the cardiovascular system are modulated by cardiovascular risk factors and disease. Similarly, adiponectin levels, an anti-inflammatory adipokine, may be modulated by the sedentary state. We hypothesized that the benefits of physical activity may include enhancing the circulating progenitor cell counts and raising adiponectin levels. We investigated this relationship in healthy subjects.
Methods: We studied 61 healthy, non-obese subjects free of risk factors (age 43±13 years, BMI 24.2±3.4 kg/m2). Levels of light (<3 METS), moderate intensity (3– 6 METS), vigorous (>6 METS) and total physical activity, expressed as MET-minutes/day of energy expenditure, were derived from the validated Cross-Cultural Activity Participation Study (CAPS) Typical Week Activity questionnaire. Levels of CD34+ hematopoetic progenitor cells and the sub-populations enriched for endothelial progenitors including CD34+/CD133+, CD34+/KDR+ and CD34+/CD133+/KDR+ cells were measured by flow cytometry. Adiponectin was measured by ELISA (n= 32).
Results: The CD34+ count correlated with light (r = 0.30, p<0.05), vigorous (r = 0.30, p<0.05) and total physical activity (r = 0.28, p<0.05), independent of age and gender. The 34 subjects who fulfilled the CDC criteria for vigorous physical activity had higher CD34+/KDR+ (1.41±0.77 vs. 1.0±0.82 cells/μL, p<0.05) and CD34+/CD133+/KDR+ counts (0.68±0.36 vs. 0.50±0.38 cells/μL, p<0.05) compared to the 27 subjects who did not meet those criteria. There was a positive correlation between adiponectin levels and moderate-intensity physical activity (r=0.41, p<0.05).
Conclusion: We show for the first time in a healthy, non-obese population that vigorous physical activity is associated increased levels of hematopoeitic and endothelial progenitors. Greater activity is also associated with increased adiponectin levels. These findings provide insights into the mechanisms underlying the protective role of regular exercise in cardiovascular and metabolic health.