Protocol for a systematic review and meta-analysis: the effects of atorvastatin on interleukin-1β (IL-1β) levels in patients

Background: Atorvastatin is a lipophilic 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor with potential pleiotropic anti-inflammatory effects. Interleukin-1β (IL-1β) is a pro-inflammatory cytokine implicated in cardiovascular, metabolic, and autoimmune diseases. However, evidence regarding the effect of atorvastatin on IL-1β concentrations is inconsistent. Objective: To systematically evaluate the effect of atorvastatin on IL-1β concentrations in human participants. Methods: This protocol follows PRISMA-P guidelines. We will search PubMed, Scopus, Web of Science, and Embase for English-language, peer-reviewed studies published from January 2005 through October 2025. Eligible studies will include randomized controlled trials, controlled non-randomized studies, and uncontrolled longitudinal before-after studies of atorvastatin monotherapy that report IL-1β at baseline and follow-up, change scores, or comparable endline values in the intervention and comparator groups. We will synthesize results separately by study design and comparator structure. If appropriate after assessing clinical and methodological comparability, we will conduct cross-design synthesis only as an exploratory analysis. Mean differences (MD) or standardized mean differences (SMD) will be pooled using random-effects models. We will assess heterogeneity using I 2 and evaluate the certainty of the evidence using GRADE. Outcomes: We will estimate whether atorvastatin changes IL-1β concentrations and explore whether the dose, treatment duration, clinical condition, study design, and assay method modify the estimated effect. Ethics and dissemination: Ethical approval is not required because we will use only publiclyavailable data. We will submit findings to a peer-reviewed journaland present them at scientific meetings.