The association of dietary inflammatory potential with skeletal muscle strength, mass, and sarcopenia: a meta-analysis

AIMS: Evidence suggested that dietary inflammatory potential may be associated with age-related skeletal muscle decline, but the results remained controversial. To summarize the evidence for the relationships between dietary inflammatory potential and skeletal muscle strength, mass, and sarcopenia in adults we conducted this meta-analysis. METHODS: Embase, Pubmed, and Web of Science were searched from inception up to 12 March 2023 for studies that evaluated the associations of dietary inflammatory potential [estimated by the Dietary inflammatory index (DII)] with skeletal muscle strength, mass, and sarcopenia. A meta-analysis was then performed to calculate the pooled regression coefficient (β) and odds ratio (OR). The non-linear dose-response relation between DII and sarcopenia was assessed using random-effects dose-response meta-analysis. RESULTS: This meta-analysis included 24 studies involving 56,536 participants. It was found that high DII was associated with low skeletal muscle strength [OR 1.435, 95% confidence interval (CI) 1.247–1.651, P < 0.001, I(2) = 4.97%]. There was a negative association of DII with skeletal muscle strength (β−0.031, 95% CI −0.056 to −0.006, P = 0.017, I(2) = 72.69%). High DII was also associated with low skeletal muscle mass (OR 1.106, 95% CI 1.058–1.157, P < 0.001, I(2) = 0%). DII had a negative relationship with skeletal muscle mass with high heterogeneity (β−0.099, 95% CI −0.145 to −0.053, P < 0.001, I(2) = 88.67%); we downgraded the inconsistency in the subgroup analysis of overweight/obese participants (β−0.042, 95% CI −0.065 to −0.019, I(2) = 12.54%). Finally, the pooled results suggested that high DII was significantly associated with sarcopenia with significant heterogeneity (OR 1.530, 95% CI 1.245–1.880, P < 0.001, I(2) = 69.46%); age and BMI may contribute partially to the heterogeneity since heterogeneity was decreased in the subgroup of older age (OR 1.939, 95% CI 1.232–3.051, I(2) = 0%) and the group of overweight/obesity (OR 1.853, 95% CI 1.398–2.456, I(2) = 0%). There was a non-linear dose-response association between DII and sarcopenia (P = 0.012 for non-linearity). CONCLUSION: This meta-analysis suggested that higher dietary inflammatory potential was significantly associated with lower skeletal muscle strength, mass, and risk of sarcopenia. Future studies with consistent assessment and standardized methodology are needed for further analysis.