Because type 2 diabetes (T2D) is related to obesity, it is often associated with obstructive sleep apnoea syndrome (OSAS), although OSAS is also frequently diagnosed in patients with type 1 diabetes (T1D) and may promote gestational diabetes. Thus, this systematic review of the scientific evidence aimed to evaluate the epidemiological association between OSAS and all forms of diabetes, the current understanding of the pathophysiological mechanisms behind these associations, the expected benefits and limitations of OSAS treatment in patients with diabetes and, finally, to propose which patients require screening for OSAS.

A panel comprising French expert endocrinologists and pneumologists was convened. Two of these experts made a search of the relevant literature for each subpart of the present report; all panel experts then critically reviewed the entire report separately as well as collectively.

There is little evidence to support the notion that OSAS treatment improves glycated haemoglobin, although it may improve nighttime blood glucose control and insulin sensitivity. However, there is robust evidence that OSAS treatment lowers 24-h blood pressure.

The high prevalence of OSAS in patients with T1D and T2D justifies screening for the syndrome, which should be based on clinical symptoms, as the benefits of OSAS treatment are mainly improvement of symptoms related to sleep apnoea. There are also several clinical situations wherein screening for OSAS seems justified in patients with diabetes even when they have no symptoms, particularly to optimalize control of blood pressure in cases of resistant hypertension and microvascular complications.