INTRODUCTIONType 2 diabetes mellitus (T2DM) is associated with comorbidities, particularly in the cardiovascular, renal, and metabolic (CVRM) spectrum. Given the complexity of CVRM spectrum diseases and the treatment landscape, treatment guidelines have been established to assist physicians in selecting the most appropriate treatment based on not only patients' primary disease but also their comorbidities. However, the impact of adherence to treatment guidelines on associated outcomes remains unclear.METHODSA systematic literature review was conducted to evaluate the impact of guideline-based treatment on clinical, economic, and quality-of-life (QoL) outcomes and related comorbidities in the CVRM spectrum or heart failure (HF) alone in individuals with T2DM. The MEDLINE, MEDLINE In-Process, Embase, Cochrane Central Register of Controlled Trials, and EconLit electronic databases were searched to identify relevant peer-reviewed studies published in the United States, Canada, or Germany. The studies were screened and selected for inclusion or exclusion based on populations, interventions, comparators, and study design (PICOS) criteria.RESULTSOf the 622 records identified, 28 publications met the inclusion criteria. In total, 11 and 16 studies reported adherence to clinical guidelines for T2DM and HF management, respectively. Adherence to T2DM and HF treatment guidelines decreased all-cause mortality and all-cause hospitalizations; furthermore, adherence to T2DM guidelines decreased hospitalizations due to HF, myocardial infarction, and stroke, and reduced T2DM-related long-term complications, while adherence to HF guidelines reduced hospitalizations due to HF. Evidence gaps were identified, including the need to assess the impact of guideline adherence on economic outcomes, the impact of adherence to diagnosis and monitoring guidelines, and the impact of guideline adherence on QoL outcomes.CONCLUSIONSAdherence to disease management guidelines improves the outcomes of patients with T2DM or HF and reduces disease-related complications and hospitalizations; however, key evidence gaps exist, particularly regarding patients with T2DM along with comorbidities in the CVRM spectrum.