BACKGROUND: Statins reduce LDL cholesterol and cardiovascular events among those with or without diabetes but have been reported to increase new-onset diabetes. The CLEAR Outcomes trial demonstrated that bempedoic acid reduced the risk of major adverse cardiovascular events among statin-intolerant patients at high cardiovascular risk. In this prespecified analysis, our dual aims were to evaluate the cardiovascular benefits of bempedoic acid, an ATP-citrate lyase inhibitor, in individuals with diabetes, and to evaluate the risk of new-onset diabetes and HbA1c among those without diabetes in the CLEAR Outcomes trial. METHODS: CLEAR Outcomes was a randomised, double-blind, placebo-controlled trial conducted across 1250 primary care and outpatient sites in 32 countries. Patients with or without cardiovascular disease who were unwilling or unable to take guideline-recommended doses of statins and an LDL cholesterol of 2·59 mmol/L or more were randomly assigned (1:1) in a double-blinded manner to either bempedoic acid 180 mg once per day or placebo. In this prespecified analysis, the efficacy endpoint was a time-to-event analysis of four-component major adverse cardiovascular event (MACE-4), which is the composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or coronary revascularisation, using the intention-to-treat population stratified by baseline glycaemia status. The prespecified analysis of risk of new-onset diabetes and HbA1c increase was evaluated in patients without diabetes at baseline. The CLEAR Outcomes trial was completed on Nov 7, 2022, and is registered with ClinicalTrials.gov (NCT02993406). FINDINGS: Between Dec 22, 2016, and Nov 7, 2022, 13 970 patients were screened and randomly assigned; 6373 (45·6%) with diabetes, 5796 (41·5%) with prediabetes, and 1801 (12·9%) with normoglycaemia. Over a median of 3·4 years follow up, patients with diabetes had significant relative and absolute cardiovascular risk reductions in MACE-4 endpoints with bempedoic acid (HR 0·83; 95% CI 0·72-0·95; absolute risk reduction of 2·4%) compared to placebo, with no statistical evidence of effect modification across glycaemic strata (interaction p=0·42). The proportion of patients who developed new-onset diabetes were similar between the bempedoic acid and placebo groups, with 429 of 3848 (11·1%) with bempedoic acid versus 433 of 3749 (11·5%) with placebo (HR 0·95; 95% CI 0·83-1·09). HbA1c concentrations at month 12 and the end of the study were similar between randomised groups in patients who had prediabetes and normoglycaemia. Placebo-corrected LDL cholesterol concentrations and high-sensitivity C-reactive protein at 6 months were reduced in each glycaemic stratum (diabetes, prediabtes, and normoglycaemia) for patients randomly assigned to bempedoic acid (all p<0·001). INTERPRETATION: Among patients with diabetes, bempedoic acid reduces LDL cholesterol and high-sensitivity C-reactive protein and risk of cardiovascular events. Patients without diabetes had no increase in new-onset diabetes or worsening HbA1c with bempedoic acid. The efficacy and cardiometabolic safety profile of bempedoic acid makes it a clinical option for those with and without diabetes. FUNDING: Esperion Therapeutics.