Multidimensional Predictors of Tirzepatide Efficacy: Clinical, Genetic, and Molecular Biomarkers for Glycemic,...

Tirzepatide, a dual glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist, demonstrates robust efficacy in glycemic control and weight reduction. However, substantial interindividual variability in treatment response is observed in clinical practice. In this narrative review, we summarize current evidence on clinical, genetic, and molecular predictors of tirzepatide response and discuss their implications for a precision medicine framework. Data from pivotal clinical trials, post hoc analyses, and relevant preclinical and clinical studies were evaluated to identify determinants of glycemic and weight loss responses, as well as hepatic and renal protective effects. Key clinical predictors include tirzepatide dose, duration of diabetes, β-cell function, baseline glycated hemoglobin, sex, age, race, concomitant therapies, and early treatment response. Genetic factors implicated in treatment variability include variants in GLP-1 receptor, GIP receptor, β-arrestin 1, transcription factor 7-like 2, fat mass and obesity-associated protein, and melanocortin 4 receptor, although tirzepatide-specific validation remains limited. Molecular biomarkers such as branched-chain amino acids, insulin-like growth factor-binding protein-1 and -2, the adiponectin-to-leptin ratio, high-sensitivity C-reactive protein, and interleukin-6 show potential as pharmacodynamic indicators of metabolic response. For organ-specific outcomes, procollagen type III N-terminal peptide and magnetic resonance imaging-proton density fat fraction are supported for assessing hepatoprotective effects, while cystatin C-based estimated glomerular filtration rate and urine albumin-to-creatinine ratio are validated markers of renoprotection. Additional candidates-including tumor necrosis factor receptor 1/2, kidney injury molecule-1, and neutrophil gelatinase-associated lipocalin-are promising but require prospective validation. Overall, predicting response to tirzepatide's multifaceted therapeutic effects necessitates an integrated, multidimensional approach that incorporates clinical characteristics, genetic variation, and molecular profiling. Ongoing validation and harmonization of these predictors may help establish a precision medicine framework for optimizing tirzepatide therapy.