Abstract 1379: Endothelial Progenitor Cells Are Up-regulated in the Severely Obese
Obesity is a major global health concern with a strong association to higher cardiovascular incidence. However, the obesity paradox describes the phenomenon where obese patients with established cardiovascular diseases (CVD) have a better prognosis than do patients with ‘ideal’ body weight. While a reduction in number and function of endothelial progenitor cells (EPC) has been demonstrated in subjects with various CVD and also in moderately obese subjects, EPC number and function in the severely obese have not been explored and they may account for the higher cardiovascular incidence, or alternatively, the obesity paradox. This study thus aimed to determine EPC number and EPC colony-forming capacity (EPC-CFU) in the severely obese. 63 severely obese patients (age 46.3±1.1 yrs, BMI 45.2±0.7 kg/m2, 42% men), together with 26 age- and gender-matched healthy non-obese controls (age 48.1±2.3 yrs, BMI 25.5±0.5 kg/m2, 52% men), were recruited. Circulating EPC level was determined by FACS counting of percentage of AC133+/KDR+ cells in 10^6 Ficoll-density isolated peripheral mononuclear cells, and EPC-CFU was assessed using a standard EPC-colony forming unit assay. Plasma leptin, adiponectin, hs-CRP and VEGF were measured by ELISA. EPC number and EPC-CFU were respectively 1.7-fold (0.089±0.011 versus 0.051±0.011, p=0.04) and 3.4-fold (11.1±1.9 versus 3.3±1.1, p=0.03) higher in the severely obese compared to controls. In obesity, plasma leptin and CRP were ~2-fold higher (leptin: 59.0±6.9 versus 20.5±3.6, p<0.0001; CRP: 4.8±0.6 versus 1.3±0.3, p<0.0001) and adiponectin ~40% lower (16.1±2.4 versus 25.6±3.1, p=0.0191), while VEGF trended towards an increase (94.3±20.4 versus 54.6±13.3). This study demonstrates that EPC number and EPC-CFU are significantly higher in severely obese subjects compared to age- and gender-matched healthy non-obese controls. It provides a potential cellular mechanism in elucidating a better outcome of established CVD in severe obesity.