Association between Dietary Inflammatory Index (DII) and sarcopenia in ischemic heart disease: an 1999-2004 NHANES study of 1088 US individuals.

Background: The aim of this study was to investigate the relationship between DII and sarcopenia in individuals with ischemic heart disease (IHD).

Methods: This was a retrospective study utilizing data of the National Health and Nutrition Examination Survey (NHANES) from 1999-2004. Adults aged ≥50 years diagnosed with IHD, having complete 24-hour dietary recall data, and dual energy X-ray absorptiometry (DEXA)-measured muscle mass were eligible for inclusion. Association between DII and sarcopenia, defined by reduced appendicular skeletal muscle mass, was determined by the logistic regression analyses.

Results: Data of 1088 individuals were analyzed, with the mean age of 68.1±0.5 years. Significantly higher DII was observed in the sarcopenic group compared to the non-sarcopenic group (0.24 vs. -0.17, P=0.020). After adjusting for relevant confounders in the multivariable analysis, each unit increase in DII was significantly associated with higher odds of sarcopenia (adjusted odd ratio [aOR]=1.07, 95% confidence interval: 1.00-1.14, P value = 0.040). In stratified analyses, among patients with a Body Mass Index (BMI) ≥30 kg/m², both DII tertile 2 and tertile 3 were significantly associated with greater odds of sarcopenia (tertile 2 vs. tertile 1: aOR=2.85, 95% CI: 1.56-5.23, P=0.001; tertile 3 vs. tertile 1: aOR=3.11, 95% CI: 1.53-6.31, P=0.002), whereas no significant associations was observed among patients with a BMI<30 kg/m².

Conclusions: This study has established a significant independent association between a higher DII and an increased risk of sarcopenia in US adults with IHD regardless of type of IHD. BMI appears as a moderating factor in this association.