Obstructive Sleep Apnea and Glycemic Variability in People With Diabetes: A Systematic Review and Meta‐Analysis

ABSTRACT Obstructive sleep apnea (OSA) is common among people with diabetes, but its association with glycemic variability (GV), an important indicator for glycemic control, remains unknown. This review synthesised and quantified the association between OSA and GV in people with diabetes. The review was registered in PROSPERO (CRD42022331493). Seven databases were searched from inception to March 2023 and updated in September 2025. Meta‐analyses were performed to pool findings from interventional studies on continuous positive airway pressure (CPAP) treatment of OSA using a random‐effects model. Studies that could not be pooled were narratively synthesised. Fourteen studies were included: nine interventional and five cross‐sectional studies. Only one study included people with type 1 diabetes (T1D). In single‐arm studies, CPAP treatment was associated with a significant reduction in nocturnal standard deviation (SD) (mean difference = −0.37, 95% CI [−0.58, −0.15], p = 0.001, I 2 = 82.19%) and a marginally significant reduction in nocturnal mean amplitude of glycemic excursions (MAGE) (mean difference = −0.23, 95% CI [−0.46, 0.00], p = 0.050, I 2 = 79.11%). In contrast, the pooled estimates for 24 h SD and MAGE were nonsignificant either from single‐arm or controlled studies. Findings from studies examining mean of daily difference, mean of nocturnal glucose difference, and BG diff showed significant reductions after CPAP, while coefficient of variation findings were inconsistent. Cross‐sectional studies also revealed possible associations between OSA severity and GV. In conclusion, current findings suggest the potential impact of OSA on glucose metabolism in type 2 diabetes. More RCTs and studies in T1D are needed.