Abstract 3696: Decreased Number Of Circulating Progenitor Cells In Obesity -Beneficial Effects Of Weight Reduction
Aims: Cardiovascular risk factors are associated with decreased levels of circulating progenitor cells (CPC). The aim of this study was to determine whether the number of CPC is an independent correlate of Body-Mass-Index (BMI) and whether weight loss leads to an increase of CPC.
Methods: CD34 positive and KDR/CD34, CD133/CD34 and CD117/CD34 double positive cells were measured by FACS in peripheral blood of 149 volunteers (52.5±0.1 years, BMI 21.5–52.7 kg/m2, mean 31.6±0.03 kg/m2) participating in a weight reduction program offered by German pharmacies. In addition, carotid intima media thickness and brachial artery flow mediated dilatation were determined. After a diet and sports program for 6 months, 86 representing subjects were re-evaluated (mean weight loss 5.8±0.1 kg).
Results: There was an inverse correlation between BMI and CPC. For subjects with BMI>34.1 compared to BMI<28.1 (4th vs. 1st quartile) cell counts were: CD34+: 137.7±1.6 vs. 187.0±1.8; KDR/CD34: 17.3±0.7 vs. 55.8±2.0; CD133/CD34: 70.2±1.6 vs. 129.2±1.7; CD117/CD34: 93.1±2.1 vs. 142.7±1.7, all per million leucocytes; p< 0.01 for all parameters). The decrease in CPC in obesity held true not only for the absolute cell numbers, but also for the relative fractions of KDR, CD133 and CD117 positive cells within the CD34 + cells, indicating a specific down regulation of these progenitor cell types. Intima media thickness increased in dependence from BMI (p< 0.001) and was inversely correlated with the number of circulating CD34 positive cell (p< 0.05). After diet, there was a significant increase of CD34 and CD117/CD34 positive cells in subjects whose reduction in BMI was greater than 2.5 kg/m2 (4thquartile), which was accompanied by a decrease in intima media thickness (p< 0.05) and an improvement in forearm dilatory response (p < 0.01). Increase in the number of CPC was independent from whether weight loss was achieved by increased physical exercise or by reduced calory intake only.
Conclusions: Obesity is associated with decreased numbers of CPC, increased intima media thickness and impaired endothelial function. Diet and weight loss lead to an increase in circulating progenitor cell count, which might contribute to regression of intima media thickness and improved endothelial function.