Effect of combination pioglitazone with sodium‐glucose cotransporter‐2 inhibitors or glucagon‐like peptide‐1 receptor agonists on outcomes in type 2 diabetes: A systematic review, meta‐analysis, and real‐world study from an international federated database

AbstractAimsTo evaluate the efficacy and cardiovascular outcomes of combination pioglitazone with either a glucagon‐like peptide‐1 receptor agonist (GLP‐1RA) or a sodium‐glucose cotransporter‐2 (SGLT2) inhibitor in individuals with type 2 diabetes (T2D) by conducting a systematic review, meta‐analysis, and analysis of a large international real‐world database.MethodsWe searched MEDLINE, SCOPUS and Web of Science to identify relevant articles for inclusion (PROSPERO [CRD: 42023483126]). Nineteen studies assessing pioglitazone + SGLT2 inhibitors or GLP‐1RAs versus controls were identified, 16 of which were randomized controlled trials. Risk of bias was assessed using Cochrane‐endorsed tools and quality of evidence was assessed using GRADE. We additionally performed a retrospective cohort study of all individuals aged 18 years or over with T2D, using the TriNetX platform. We included propensity‐score‐matched individuals who were treated for at least 1 year with pioglitazone and a GLP‐1RA or pioglitazone and an SGLT2 inhibitor, compared against GLP‐1RA and SGLT2 inhibitor monotherapy. Outcomes were all‐cause mortality, heart failure, chronic kidney disease and composite stroke and transient ischaemic attack.ResultsThe average follow‐up in the included studies ranged from 24 to 52 weeks. Combination of pioglitazone with a GLP‐1RA reduced glycated haemoglobin (HbA1c) and weight greater than in controls: mean differences −1% (95% confidence interval [CI] −1.27, −0.74) and −1.19 kg (95% CI −1.80, −0.58), respectively. There was no statistically significant difference in systolic blood pressure (SBP) or mortality between groups: mean difference − 1.56 mmHg (95% CI −4.48, 1.35; p = 0.30) and relative risk (RR) 0.29 (95% CI 0.07–1.15; p = 0.08), respectively. Combination of pioglitazone with SGLT2 inhibitors reduced HbA1c, weight and SBP to a greater extent than control treatment: mean differences −0.48% (95% CI −0.67, −0.28), −2.3 kg (95% CI −2.72, −1.88) and −2.4 mmHg (95% CI −4.1, −0.7; p = 0.01), respectively. There was no statistically significant difference in mortality between groups (RR 1.81, 95% CI 0.30–10.97; p = 0.52). The included trials demonstrated a reduction in risk of heart failure with combination treatment. Similarly, from the real‐world database (n = 25 230 identified), pioglitazone and SGLT2 inhibitor combination therapy was associated with reduced risk of heart failure compared to monotherapy alone (hazard ratio 0.50, 95% CI 0.38–0.65; p < 0.001).ConclusionBoth our systematic review/meta‐analysis and the real‐world dataset show that combination of pioglitazone with either GLP‐1RAs or SGLT2 inhibitors is associated with increased weight loss and reduced risk of heart failure compared with monotherapy.