Markers of Chronic Inflammation in Overweight and Obese Individuals and the Role of Gender: A Cross-Sectional Study of a Large Cohort

Objective: During the last decade, obesity has become an epidemic. As obesity is now considered a state of low-grade inflammation, the purpose of this study was to assess the prevalence of four common elements of inflammation, in individuals with increased BMI. These findings were compared to those of subjects with normal BMI. The effect of gender was also noted.

Methods: Data were collected from medical records of individuals examined at a screening center in Israel between the years 2000-2014. Cross-sectional analysis was carried out on 7526 men and 3219 women. White blood cell count (WBC); platelet (PLT) count; erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were assessed in four BMI categories: normal, overweight, obese and morbidly obese.

Results: Mean (SD) age of the study sample was 47.5 (9.7) and 46.7 (9.8) years for men and women, respectively. The prevalence of each inflammatory marker increased significantly when comparing abnormal to normal BMI (p<0.0001). The odds ratio (OR) of the prevalence of increased inflammatory markers was compared between subjects with overweight, obese and morbid obesity and subjects with normal BMI. This study showed that the higher the BMI, the higher the OR. For those in the morbid obesity group, the OR for the different inflammatory markers adjusting for age, diabetes mellitus hypertension and kidney function were as follows: WBC levels, 5.1 (2.9-8.7) and 4.7 (2.4-9.1) for men and women, respectively; PLT levels, 1.7 (0.3-8.5) and 2.0 (0.6-7.2) for men and women, respectively; ESR levels, 4.2 (3.2-5.4) and 4.6 (3.2-6.6) for men and women, respectively, and CRP levels, 13.4 (10.0-18.2) and 19.2 (12.9-28.6) for men and women, respectively.

Conclusion: Inflammatory markers are significantly higher in subjects with abnormal compared to normal BMI. This difference was found to be greater in women than in men.