AUTHOR=Wu Bo , Qiu Lanlan , Lin Yun , Lin Qian , Pan Yuxiong 

TITLE=The association between the dietary inflammatory index and cardiorespiratory fitness in United States young adults: a cross-sectional study from the National Health and Nutrition Examination Study, 1999–2004

JOURNAL=Frontiers in Nutrition

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1442710

DOI=10.3389/fnut.2024.1442710

ISSN=2296-861X

ABSTRACT=<sec><title>Background</title><p>Cardiorespiratory fitness (CRF) is a vital indicator of overall health and cardiovascular efficiency. Systemic inflammation significantly impacts CRF, and reducing systemic inflammation may serve as an effective strategy to improve CRF. Diet plays a crucial role in systemic inflammation, but daily dietary intake typically involves multiple elements rather than a single nutrient. The Dietary Inflammatory Index (DII) provides an overall assessment of dietary inflammation on the basis of the anti-inflammatory and pro-inflammatory effects of the nutrients consumed. However, the relationship between DII and CRF is not yet well understood.</p></sec><sec><title>Aims</title><p>To examine the association between the DII and CRF.</p></sec><sec><title>Method</title><p>This study analyzed 3,087 participants from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2002. The study subjects were divided into three distinct groups by DII tertile: T1 (<italic>n</italic> = 1,027), T2 (<italic>n</italic> = 1,029), and T3 (<italic>n</italic> = 1,031). The associations between DII levels and CRF were examined via logistic regression analysis and restricted cubic splines (RCSs).</p></sec><sec><title>Results</title><p>Elevated DII scores were significantly linked to low CRF levels. Compared with those in the lowest tertile, participants in the highest DII tertile exhibited a greater prevalence of low CRF (T1: 10.85%, T2: 16.32%, T3: 19.31%). In the model with full adjustments, elevated scores on the DII were consistently linked with a heightened likelihood of low CRF (OR: 1.17, 95% CI: 1.07–1.28; <italic>P</italic> &lt; 0.001). Compared with those in the T1 group, participants with higher DIIs had an increased risk of lower CRF (T2: OR: 1.42, 95% CI: 1.01–2.01, <italic>P</italic> = 0.046; T3: OR: 1.71, 95% CI: 1.22–2.40, <italic>P</italic> = 0.003). Additionally, a significant interaction (<italic>P</italic> = 0.045) between sex and the DII for low CRF was observed within the population.</p></sec><sec><title>Conclusion</title><p>A higher DII score is linked to an elevated risk of low CRF. Moreover, sex can impact CRF, with women being more prone to low CRF.</p></sec>