TOPLINE:

Most patients with type 2 diabetes (T2D) showed partial non-adherence to antidiabetic therapy, with about one fourth of those prescribed an SGLT2 inhibitor not taking it. Partial non-adherence rose with the number of prescribed antidiabetic agents and was linked to poorer glycaemic control and a higher prevalence of diabetes-related comorbidities.

METHODOLOGY:

• Researchers in the Czech Republic conducted a cross-sectional analysis of 641 outpatients with T2D (mean age, 66.5 years; 37.3% women) to evaluate medication adherence and the clinical impact of partial non-adherence on glycaemic control and complications.
• Patients had been diagnosed with T2D at least 1 year earlier and had remained on stable medication regimens, including metformin, for at least 3 months before enrolment to minimise the inclusion of discontinued medications.
• After an overnight fast, blood samples were taken, and liquid chromatography-mass spectrometry was used to measure plasma concentrations of 13 oral antidiabetic drugs; adherence was defined as the detection of a prescribed drug in plasma at a concentration above the limit of quantification.
• Patients completed a questionnaire covering demographic and lifestyle factors, including education level and employment status; and health-related behaviours, including smoking and physical activity.

TAKEAWAY:

• Metformin showed the highest adherence rate exceeding 98%, whereas other medications showed lower rates — sulfonylurea at 94%, DPP-4 inhibitors at 90%, pioglitazone at 82%, and SGLT2 inhibitors at 73%.
• The majority of non-adherent patients exhibited partial non-adherence, with 93% missing only one prescribed medication; among those prescribed an SGLT2 inhibitor, 25% were selectively non-adherent to that drug.
• Partial non-adherence increased with the number of antidiabetic drugs; no significant link was found between adherence and the lifestyle factors examined.
• Glycaemic control was notably worse in non-adherent patients; 63% of non-adherent vs 37% of adherent patients did not reach target glucose and A1c levels, and diabetic kidney disease was twice as common in non-adherent patients.

IN PRACTICE:

"Our findings emphasize the importance of individualized treatment approaches," the authors of the study wrote.

"Particular attention should be given to drugs with lower adherence rates, ensuring that patients understand their benefits and addressing any misconceptions or concerns that may lead to partial non-adherence," they added.

SOURCE:

This study was led by Vojtěch Škop, MD, Centre for Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic. It was published online on October 10, 2025, in Diabetes, Obesity and Metabolism.

LIMITATIONS:

Plasma drug measurements reflected only a single timepoint and may not have accurately represented long-term adherence. Patient behaviour could have been influenced by blood sampling as some individuals might have taken their medication before their medical checkup despite instructions. The study population consisted exclusively of European participants, potentially limiting the generalisability of the findings to other populations.

DISCLOSURES:

This study was supported by Ministerstvo Zdravotnictví České Republiky: the Institute for Clinical and Experimental Medicine, NextGenerationEU (EXCELES), and Univerzita Karlova v Praze. Some authors reported serving on advisory panels and receiving consulting fees, research support, or honoraria from various pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.