Sleep disorders (short sleep duration, insomnia, obstructive sleep apnea and circadian rhythm disorders) negatively affect microcirculation, causing endothelial dysfunction, decreased capillary density, and increased inflammation. Nailfold capillaroscopy can detect structural changes in microvessels (tortuosity, avascular zones) and serves as an early marker of vascular impairment. The correction of sleep disorders (e.g., CPAP therapy, sleep schedule normalization) improves microcirculation, and capillaroscopy can be used to monitor treatment effectiveness.
Simanovskiy et al. (Tue,) studied this question.