Age, sex, and ethnicity may modify the influence of obesity on inflammation

Many medical concerns associated with obesity are due to chronic inflammation, but factors underlying the development or maintenance of obesity-associated inflammation remain unclear. This study investigated how age, sex, and ethnicity may modify the interplay of subclinical inflammation and obesity in nationally representative contexts.

Using National Health and Nutrition Examination Survey data from 1999 to 2008, we assessed the role of these demographic factors on immunological markers of subclinical inflammation (such as total white blood cell counts, white blood cell subpopulation counts, and C-reactive protein [CRP] levels) in both obese and nonobese individuals. Approximately 9756 individuals were included in the analysis after removing individuals with confounding conditions.

The CRP levels, total white blood cell count, and white blood cell subpopulation counts increased with increasing body mass index (BMI). After controlling for BMI, female subjects had greater levels of most inflammatory markers compared with male subjects. After controlling for age, sex, and ethnicity, the following inflammatory markers significantly increased with increasing BMI: CRP and white blood cell, lymphocyte, monocyte, and neutrophil counts. Basophil and eosinophil counts also increased with increasing BMI but not significantly.

Factors, such as age, sex, and ethnicity, may modify the influence of obesity on subclinical inflammation at the population level.