Effects of Weight Loss and Exercise on GlycA Levels in Middle-Aged Adults

Abstract

GlycA is a novel inflammatory biomarker that measures systemic inflammation. Inflammation accompanies atherosclerosis, leading to cardiovascular disease (CVD). The effects of a combined exercise-plus-diet intervention on GlycA levels is not well-versed in the current literature. The purpose of this study was to evaluate the effects of weight loss and exercise on GlycA levels in obese adults, to investigate potential mediators that contribute to GlycA reduction, and to determine a possible association between GlycA and the well-established CRP. GlycA, body composition, fitness, and blood lipids were measured in 30 sedentary, overweight and obese adults (30-65 years) before and after the weight loss intervention. Participants underwent The Prescribed Exercise to Reduce Recidivism After Weight Loss Pilot (PREVAIL-P) study's 10-week combined intervention of aerobic treadmill exercise (2-3 times/week for 30-50 minutes) and an OPTIFAST diet regimen to achieve a clinically significant weight loss (CWL) of 7%. Baseline GlycA was associated with CRP (r = 0.61, p=0.001), insulin (r = 0.41, p = 0.031), absolute VO2 (r= -0.40, p=0.030), relative VO2 (r = -0.46, p = 0.01), and fat mass (r = 0.46, p = 0.011), but was not associated with BMI, total cholesterol, HDL, LDL, triglycerides, or glucose levels (all ps < 0.05). The 10-week combined intervention significantly reduced GlycA (mean [delta]: -27.9 [plus-minus] 15.2 [mu]956;mol/L, p[less=than]0.05), but not CRP (mean [delta]: -0.3 [plus-minus] 0.8 mg/dL, p=0.41). Significant improvements in body compositional, fitness, and blood lipid variables did occur. However, changes in GlycA were not significantly correlated with changes in our suspected mediators. The current study effectively reduced weight and GlycA levels, indicative of better health scores; however, the mediators of GlycA's change still remain unknown.