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

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.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.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).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).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.This study looked at how different types of obesity affect inflammation in older adults who have quit smoking cigarettes and using tobacco. Other studies have found that Black adults tend to have higher levels of inflammation than White adults, and that this might be due to Black adults being more obese than White adults and having less education. Researchers in this study compared Black and White older adults who had similar education, age, income, and smoking history to look at how weight, body mass index, and waist circumference (all forms of obesity) were related to inflammation, which was measured by C-reactive protein (CRP), and how it changed over time. In the sample, CRP decreased over an 8-year period, and weight was the only factor that was related to CRP changing. Specifically, weight gain led to higher levels of CRP. Importantly, in this sample, even though CRP levels were higher for Black adults at the beginning of the study, there were no differences in how CRP changed or how obesity affected CRP between Black and White adults. These findings highlight the importance of understanding how obesity is related to differences in inflammation between Black and White older adults.