Race differences in the effect of obesity on inflammation among Black and White older adults who quit smoking: a longitudinal analysis of the Health and Retirement study.

IMPORTANCE

Race differences in inflammation have been attributed to higher body mass index (BMI); however, few studies have comprehensively examined whether changes in obesity influence changes in C-reactive protein (CRP) by race, particularly following smoking cessation.

OBJECTIVE

As CRP declines after quitting smoking, the current study examined whether longitudinal changes in multiple measures of obesity were differentially associated with CRP change among non-Hispanic Black (NHB) and non-Hispanic White (NHW) older adults who formerly smoked.

DESIGN

This is a longitudinal analysis of the Health and Retirement Study, nationally representative study of US adults. Participants were matched on self-reported demographic, socioeconomic, and behavioral factors using propensity score analysis to control for the effects of social disadvantage. C-reactive protein, waist circumference, body weight, and BMI were assessed in 2006, 2010, and 2014. Linear mixed models examined race differences in the effects of time-varying obesity on CRP change (n = 899 observations).

RESULTS

C-reactive protein significantly declined over time (β = -0.23, p < .0001). However, no differences in CRP change were found between NHBs (n = 146) and NHWs (n = 245). Only weight was positively associated with CRP change over time (β = 0.002, p < .001).

CONCLUSIONS AND RELEVANCE: In our matched sample, there were no race differences in CRP decline among older adults, and only weight was associated with a lessened decline over time. Our findings suggest that weight alone may be an important predictor of CRP in older adults rather than BMI, which has been studied extensively in previous research.