Nineteen studies comprising 438 patients were included. SMA type 2 was most represented (55.5%), followed by type 1 (25.3%) and type 3 (14.8%). SDB prevalence was highest in SMA type 1 (64.4–100%), frequent in type 2 (26.67–100%), and variable in type 3 (14.29–100%). Obstructive patterns predominated (64.3%), followed by mixed (18.2%) and pseudo-obstructive (14.7%) patterns. Sleep architecture alterations occurred in 78.7% of patients, most commonly reduced total sleep time, low sleep efficiency, and abnormal REM distribution. Apnea-hypopnea index (AHI) varied across SMA types, with severe OSA in 43.8% of type 1 patients. Nocturnal hypoxemia and hypercapnia were frequent. Most studies had moderate methodological quality.

SDB and sleep architecture disturbances are highly prevalent across SMA phenotypes, particularly in severe forms, and often precede daytime respiratory failure. Routine sleep evaluation and early ventilatory support are essential. Future studies should assess the impact of disease-modifying therapies on sleep outcomes.