Altered Monocyte Subtype Profiles Following High Intensity Exercise in Obese Children: 2657 Board #180 June 3, 9: 30 AM - 11: 00 AM.

Obesity is associated with chronic inflammation. Intermediate monocytes (iMn) are a pro-inflammatory leukocyte subpopulation implicated with cardiovascular (CV) disease. While exercise improves CV health via modulation of inflammatory processes, its effects on circulating iMn of obese patients are unknown. Understanding the changes in iMn for children may optimize the effectiveness of exercise interventions. PURPOSE: To evaluate the changes in circulating iMn in obese (Ob), overweight (Ow), and normal weight (Nw) children (10-17 yr) following a high-intensity interval cycling. METHODS: 11 Ob (BMI ≥ 95%), 6 Ow (BMI 85-94%), and 5 Nw (BMI < 85%) underwent a high-intensity, cycle ergometer interval exercise (10 x 2-min @ 80% peak VO2). Baseline, end-exercise, and 1 hour post exercise blood samples were used to determine ratios of classical (cMn, CD14++CD16-) vs. iMn (CD14++CD16+) subtypes by flow cytometry. RESULTS: At baseline, relative abundance of iMn correlated positively with BMI% (r=0.48, p=0.02). In all groups, exercise induced a significant (p<0.001) but similar (3850%) increase in the iMn %. Values returned to baseline by 1 hr post exercise. The abundance of iMn was 1.6-1.8x greater in the ob vs. Nw children throughout the study (end exe: 13±2% vs 8±1%, p<0.05). CONCLUSION: Ob children have a higher % of pro-inflammatory iMn proportional to the severity of obesity. This systematically greater inflammation could contribute to obesity-related CV problems later in life. Investigating iMn responses across different exercise paradigms and few hours following exercise may help identify how inflammation is modulated in pediatric obesity and other dysmetabolic conditions. Support: NIH NICHD P01HD048721 & UL1 TR000153