Abstract P619: Teen Obesity Leads To Changes In The Circulatory T Lymphocyte Profile

Abstract

Increasing evidence indicates that inflammatory markers exist in cardiovascular patients years prior to disease diagnosis. In addition, obesity is a major risk factor for cardiovascular disease, especially among African Americans. We hypothesized that obesity would lead to different circulating T lymphocyte profiles and activation status in Caucasian and African American teenagers. Lean (BMI < 60th percentile) and obese (BMI ≥ 95th percentile) teenagers (14-20 years-old; n=23-67/group) of both genders and races were recruited from public schools of Augusta, GA. Circulating immune cell phenotypes and activation status were analyzed by fluorescence-activated cell sorting (FACS), and total whole blood cell (WBC) counts were also determined. Obesity was associated with significant reduction of circulating T lymphocyte percentages in white individuals independently of gender (lean vs. obese; CD3+, CD4+ and CD8+ cells, respectively: 29.40±8.14 vs. 25.58±7.53% (p=0.007), 28.51±7.29 vs. 25.95±6.04% (p=0.049) and 5.12±2.6.0 vs. 4.04±1.64% (p=0.013)). A significant decrease in percentages of circulating CD8+ and activated CD8+ cells was also observed in black males (lean vs. obese, CD8+ and CD8+/CD69+: 5.16±2.45 vs. 5.51±2.27% and 0.53±0.49 vs. 0.60±0.55%), but not in black females, indicating that activation of CD8+ cells may be important in the increased prevalence of cardiovascular disease in female African Americans. Interestingly, WBC counts were found to be increased in obese subjects (obese vs. lean: 6.67±2.16 vs. 5.67±1.62 x103/mm3), and, when results were normalized to these counts, obesity was associated with significantly elevated absolute values of circulating CD3+ and CD4+ cells, independently of gender and race. Our analysis also indicates a positive correlation between circulating CD4+ cell percentage and HDL cholesterol (HDLc) in obese whites (r=0.34), and a negative correlation between activated T cells (CD3+/CD69+) percentage and HDLc in obese black males (r=-0.42). In conclusion, teen obesity leads to changes in the circulatory T lymphocyte profile. Moreover, these changes could help to recognize at-risk cardiovascular patients and could be used to prevent the development of the disease in these individuals.