Association between obesity, cardiometabolic disease biomarkers and innate immunity-related inflammation: Relevance of vitamin D.

Abstract

Background and Objectives: Obesity is associated with a state of chronic inflammation and increased cardiometabolic disease risk. The present study examined the relationship between body mass index (BMI) and cardiometabolic and inflammatory biomarkers among normal weight, overweight, and obese subjects. Methods: Subjects (n = 1,805, aged 18 to 79 years) from Canada were examined for associations between BMI, cardiometabolic markers [apolipoprotein (Apo) A1, ApoB, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol, total:HDL-C ratio, triglycerides, and glycosylated hemoglobin (HbA1c)], inflammatory factors [C-reactive protein (CRP), fibrinogen, and homocysteine), and 25-hydroxyvitamin D [25(OH)D]. Bootstrap weights for variance and sampling weights for point estimates were applied to account for the complex survey design. Linear regression models adjusted for age, sex, physical activity, smoking status, and ethnicity (in addition to season of clinic visit for vitamin D analyses only) were used to examine the association between cardiometabolic markers, inflammatory factors, and BMI in adults. Results: All biomarkers were significantly associated with BMI (P≤0.001). ApoA1 (β= 0.31, P<0.0001), HDL-C (β=-0.61, P<0.0001), and 25(OH)D (β=-0.25, P<0.0001) were all inversely associated with BMI, while all other biomarkers showed positive linear associations. Different patterns of significant associations were noted for all biomarkers among normal weight, overweight, and obese groups, excluding CRP which was consistently correlated with BMI and showed a significant positive association in the overall population (β=2.80, P<0.0001) and in the normal weight (β=3.20, P=0.02), overweight (β=3.53, P=0.002) and obese (β=2.22, P=0.0002) groups. Interestingly, plasma vitamin D levels were significantly inversely correlated with BMI (β=-0.25±0.06, P<0.0001). Conclusions: There is a distinctive profile of cardiometabolic and inflammatory biomarkers that emerges with obesity as BMI increases from normal weight to obesity. Elucidating these profiles may permit developing an effective approach for early risk prediction of cardiometabolic disease and its prevention based on modulating the corresponding metabolic phenotype in each BMI stage., e.g., by micronutrients such as vitamin D.