Do sociodemographic, health behaviors, and clinical factors predict levels of hs-CRP stratified by race and ethnicity?

Purpose: Health disparities between different racial and ethnic groups exist for many preventable chronic conditions, such as cardiovascular disease and diabetes. High- sensitivity C- reactive protein (hs-CRP) is a marker of systemic inflammation, and it is known that inflammation is one of the many components associated with physiologic deterioration, or chronic illness. Research has shown disparities in elevations of hs-CRP within different races and ethnicities. Furthermore, research has also demonstrated which factors can lead to elevations in hs-CRP within the general population. However, there is a need to determine factors and clarify relationships predictive of elevated HS-CRP for different racial and ethnic groups. The purpose of this analysis was to identify sociodemographic, health behavior, and clinical factors that predict hs-CRP by race / ethnicity.

Methods: A secondary analysis of the 2017-2020 National Health and Nutrition Examination Survey (NHANES) was conducted. Briefly, the NHANES is a nationally representative survey assessing physical activity, chronic disease, and other health behaviors among adults 18 years of age and older in the United States. The outcome variable was hs-CRP levels, which was log-transformed due to non-normal distributions. Covariates included demographics (e.g., age, biological sex, education, marital status), insurance, BMI, sleep, depression, alcohol drinks, physical activity, and number of chronic conditions. Due to missing data, 5 datasets were imputed and combined in a multivariate manner using Rubin’s rules. Regression analyses were conducted stratified by race/ethnicity (non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, Mexican American, Other Hispanic, and Other/Multi-Racial) to determine significant risk factors. Analyses were weighted to be representative of the U.S. population.

Results: The analytic sample consisted of 15,476 adults ages 18 years or older (M= 38.5,SE =0.19). Diverging patterns emerged regarding hs-CRP levels, such that significant risk factors included BMI, biological sex (female), and health status. For white individuals, identifying as female (b = 0.13), increased BMI (b = 0.07), and poor sleep (b = 0.07) were significant predictors of inflammation. Regarding Black individuals, increased age (b = 0.01), identifying as female (b = 0.19), and increased BMI (b = 0.07) were significant predictors of inflammation. Pertaining to Mexican American individuals, identifying as female (b = 0.44), reporting good/fair/poor health (b = 0.28), and increased BMI(b = 0.08) were significant predictors of inflammation. Good/fair/poor health (b = 0.33) and increased BMI (b = 0.07) were significant predictors of inflammation for Other Hispanic individuals, while never being married decreased the risk for inflammation (b = -0.45). For Asian individuals, increased poverty (b= 0.08) and increased BMI (b = 0.09) were significant predictors. Finally, for multi-racial individuals, identifying as female (b = 0.37) and increased BMI (b = 0.04) were significant predictors of inflammation.

Conclusion: This study identified racial/ethnic differences in sociodemographic, health behavior, and clinical factors that predict hs-CRP. Understanding disparities in risks for elevated hs-CRP could help clinicians identify potential biomarkers and intervene to reduce the impact of elevated inflammation among racial/ethnic minorities. Future research should include other social determinants of health such as environment, shift work, and nutrition.