Sleep disturbances may contribute to day-to-day glucose instability in type 2 diabetes mellitus (T2DM). A study in Metabolism Open evaluated how subjective sleep quality relates to CGM-based glycemic variability.

The study included 62 adults with T2DM who provided at least 3 days of valid CGM data. Sleep quality was assessed using the PSQI. Glycemic variability was expressed as coefficient of variation (%CV).

Lower sleep efficiency was significantly associated with higher glycemic variability (%CV) (r = 0.28; P = .03). Greater sleep disturbances correlated with lower time-below-range (TBR) (r = −0.27; P = .04). A %CV threshold of 32.3 was suggested to differentiate stable and unstable glucose patterns, although this needs further validation.

Multivariable analyses showed that reduced sleep efficiency (β = 7.77; P = .002) remained significantly linked to greater glycemic variability after adjusting for HbA1c and diabetes complications. Sleep-medication use (β = −2.12; P = .01) also showed a significant association.

These findings indicate that improving sleep quality may be a practical strategy for enhancing daily glucose stability in T2DM.