Association of Dietary Fiber and Measures of Physical Fitness with High-Sensitivity C-Reactive Protein

Dietary fiber intake and physical fitness are independently associated with high-sensitivity C-reactive protein (hs-CRP) levels. Nevertheless, the association between dietary fiber intake, measures of physical fitness, and hs-CRP levels has not yet been fully evaluated. We investigated the influence of a combination of dietary fiber intake and measures of physical fitness, including hand grip strength, resistance training, and metabolic equivalents of tasks, on hs-CRP levels. Data collected from the Korea National Health and Nutrition Examination Survey (KNHANES) spanning 2015 to 2018 were used in this study. A total of 16,934 participants (7434 men and 9500 women aged ≥19 years) were included in this study. After adjusting for confounding factors (age, education, income, marital status, smoking status, drinking habits, total energy intake, and aerobic physical activity), we employed a multivariable logistic model to examine the association of dietary fiber intake and measures of physical fitness with hs-CRP levels. Among women, the odds of high hs-CRP levels were lower in those with the highest dietary fiber intake and superior grip strength compared to in women with the lowest dietary fiber intake and weaker grip strength (odds ratio [OR] = 0.40, 95% confidence interval [CI] = 0.24-0.68). The highest dietary fiber intake who participated in resistance exercise at least three times per week had a reduced odds of high hs-CRP levels compared with those with the lowest dietary fiber intake who did not engage in resistance exercise in both men and women (OR = 0.53, 95% CI = 0.32-0.89; OR = 0.40, 95% CI = 0.19-0.84, respectively). Our findings indicate that dietary fiber intake and high levels of physical fitness were associated with reduced odds of elevated hs-CRP levels.