Innate and adaptive immune parameters and adiposity in non-obese adults

Introduction Excess body weight, mainly resulting from high body fat mass, is known to negatively affect immune system functioning due to the proinflammatory and prooxidative roles of adipose tissue. In general, most studies have documented the immunosuppressive role of adiposity by comparing selected immune markers between individuals of normal weight and those with obesity. Study aims This study investigates whether the amount of adipose tissue observed in overweight individuals may already negatively affect immune function. Methods We examined a broad panel of immunological parameters – both innate (WBC, neutrophil count, phagocytic uptake, respiratory burst, complement activity, lysozyme activity) and adaptive (total IgA, total IgG, CD3 count, CD19 count, the strength of antibody response to flu vaccination), in 85 women and 98 men aged 18–37 years, with a BMI between 18.5 and 29.99. As measures of adiposity, we used BMI on a continuous scale, BMI categorized as normal weight or overweight, and body fat mass percentage. Results In women, CD3 count was positively associated with continuous BMI (p = 0.03) and categorized BMI (p = 0.006). CD19 was positively associated with continuous BMI (p = 0.03), categorized BMI (p = 0.01), and fat mass percentage (p = 0.02). In men, categorized BMI was positively associated with phagocytic uptake (p = 0.04). However, none of these relationships would remain statistically significant after applying corrections for multiple comparisons. Conclusion Our results suggest that there is no relationship between adiposity and the analyzed immunity markers in non-obese (normal weight and overweight) adults.