CPAP treatment saves lives of sleep apnea patients with type 2 diabetes
Patients with both T2D (type 2 diabetes) and OSA (obstructive sleep apnea) who were treated with CPAP (continuous positive airway pressure) achieved an approximately 26% lower risk of death over a 14-year period compared to patients who had never received CPAP.
The findings were presented on Sept. 8, 2025 at the Annual Meeting of the European Association for the Study of Diabetes (EASD 2025).
“Despite the substantial impact of obstructive sleep apnea on cardiovascular disease and survival, it often goes undiagnosed in people with type 2 diabetes and is not routinely addressed as part of diabetes management,” said lead author Dr Jonas Aghome from Linköping University in Sweden. “What’s more, the impact of treatment with CPAP on survival in people with T2D hasn’t been clear.”
As background to the new study, the investigators noted that obstructive sleep apnea coexists with type 2 diabetes at a prevalence rate of between 50% and 80%.
The aim of the new study was to determine whether T2D patients with confirmed OSA who were prescribed CPAP demonstrate improvement in long-term survival compared to T2D patients who were never prescribed CPAP and whose OSA status is unknown.
The researchers said, “The rationale for this grouping is that, despite potential dilution from including OSA free individuals in the control group, the high estimated prevalence of OSA among T2D – together with the higher baseline risk associated with T2D-OSA comorbidity – should allow any clinically relevant associations of CPAP to be detected. Consequently, this approach would theoretically provide a conservative estimate of such an association.”
The investigators extracted and linked data from five Swedish national health registers. Adults with T2D were enrolled without any exclusions.
They compared outcomes of T2D subjects with OSA and ever-prescribed CPAP (n=12,388) to T2D patients (of unknown OSA status) who were never prescribed CPAP (n=737,911).
The CPAP group was younger (mean 58 years vs. 65 years) but had a higher mean BMI (34.7 vs. 30.6 kg/m2).
The researchers used standard statistical tools to adjust the data for fixed baseline differences (age, sex, prior cardiovascular disease) and time-varying factors (BMI, smoking, cholesterol, kidney function, blood pressure, and pharmacological treatment).
The primary endpoint was all-cause mortality.
During the 14-year follow-up, 212,336 deaths occurred in the non-CPAP group and 764 in the CPAP group.
Compared with patients who had never received CPAP during the 14-year follow-up, subjects with both T2D and OSA who had been treated with CPAP achieved a 26% lower risk of dying from any cause over the 14-year period. The difference was statistically significant.
The authors concluded, “These findings suggest that patients with comorbid T2D and OSA who were prescribed CPAP had an approximately 26% lower risk of death over a 14-year period, compared with T2D patients who never received CPAP. However, rigorous causal inference methods are needed to determine the causal effect of CPAP treatment.”
Aghome added, “This new study using real-world data highlights the potential benefits of CPAP in people with T2D and obstructive sleep apnea, a clinical conundrum that has long awaited answers. The findings suggest that CPAP may play an important role in improving patient outcomes and survival, and they underline the value of early OSA diagnosis in people with T2D. Still, more rigorous research is needed to determine the causal effect of CPAP treatment.”
