To investigate the association between biomarkers of inflammation and metabolic dysregulation
and cancer mortality by obesity status. Data from the Reasons for Geographic and Racial
Differences in Stroke (REGARDS) cohort was used to examine the associations between
baseline biomarkers of inflammation (IL-6, IL-8, IL-10, and CRP) and metabolism (adiponectin,
resisting and lipoprotein (a)) with cancer mortality among 1,822 participants cancer-free
at baseline. Weighted Cox proportional hazard regression with the robust sandwich
method was used to estimate the hazard ratios and 95% confidence intervals (CIs) adjusting
for baseline covariates and stratified by BMI (normal, overweight/obese) given the
significant interaction between biomarkers and BMI ( P <0.1). During a mean follow-up
of 8 years, there were statistically significant associations between cancer mortality
and being in the highest vs. lowest tertile of IL-6 (HR: 5.3; 95% CI: 1.6, 17.8),
CRP (HR: 3.4; 95% CI: 1.0, 11.2) and resistin (HR: 3.7; 95% CI: 1.2, 11.2) among participants
with normal BMI. IL-6 was also associated with a 3-fold (HR: 3.5; 95% CI: 1.5, 8.1)
increased risk of cancer mortality among participants with overweight/obesity; however,
neither CRP nor resistin was significantly associated with cancer mortality in this
group. Higher baseline inflammatory and metabolic biomarkers were associated with
significantly increased risk of cancer mortality after adjusting for baseline risk
factors and the associations varied by BMI. Cancer patients may benefit from interventions
that modulate inflammatory and metabolic biomarkers.