Researchers Highlight the Connection Between Type 2 Diabetes and Comorbid Insomnia and Sleep Apnea

Clinicians have traditionally viewed insomnia and obstructive sleep apnea as separate disorders that may coexist in some patients. However, emerging evidence suggests a more complex relationship, particularly in individuals with type 2 diabetes. A commentary in the Journal of Clinical Sleep Medicine by Abdulghani Sankari, a pulmonologist at the John D. Dingell VA Medical Center and Wayne State University, argues that the relationship between diabetes and a condition known as comorbid insomnia and sleep apnea (COMISA) should be studied as a distinct clinical issue.

The commentary accompanies a significant epidemiological analysis from TURKAPNE, a Turkish sleep apnea cohort, which indicates that diabetes is linked to both a higher prevalence and severity of COMISA. This is notable as COMISA is common among sleep disorder patients; many with obstructive sleep apnea report chronic insomnia symptoms and vice versa. However, this overlap often goes unrecognized in clinical settings, where insomnia can mask sleep apnea or be dismissed as secondary to a primary apnea diagnosis, leaving patients without adequate treatment for all underlying issues.

COMISA’s biological implications extend to its impact on metabolic health, as research shows a unique pattern of sleep disruption resulting from the combination of the two disorders. This pattern includes characteristics of both insomnia’s prolonged sleep-onset difficulties and the cycles of upper airway collapse and oxygen desaturation seen in sleep apnea. Studies indicate that the intermittent hypoxia caused by sleep apnea can impair glucose metabolism, providing a mechanistic link between the conditions.

Patients with insomnia who experience short sleep durations also show higher risks for conditions such as hypertension and diabetes. Consequently, the metabolic burden of insomnia may compound the effects of sleep apnea, creating a feedback loop that exacerbates both sleep fragmentation and insulin resistance.

Cardiovascular risks linked to the combination of diabetes, insomnia, and sleep apnea reinforce the need for integrated treatment approaches. An analysis from a sleep registry found that diabetic patients with both insomnia and sleep apnea faced greater cardiovascular risks than those with only one or neither condition. Furthermore, findings regarding hypoxic burden suggest that this may better predict cardiovascular disease-related mortality than traditional measures of sleep apnea severity.

The TURKAPNE study also highlights the bidirectional relationship between diabetes and COMISA. While diabetes can exacerbate the severity of COMISA, the disorder itself may negatively influence glycemic control, potentially sustaining a loop where fragmented sleep leads to weight gain and worsening diabetes. Treating both disorders simultaneously may be necessary to break this cycle.

Recent trials have explored treatment options, such as tirzepatide, which has shown promise in reducing apnea severity among patients with obstructive sleep apnea and obesity. However, safety concerns remain regarding the use of hypnotics and anxiolytics, particularly in older adults with multiple comorbidities. Cognitive behavioral therapy for insomnia is recommended as a first-line treatment, while positive airway pressure therapy is key for managing sleep apnea, despite adherence challenges in patients suffering from comorbid insomnia.

Screening for both conditions is another area for improvement, especially in women and in diabetic patients, where classic symptoms may not always be present. Clinicians are encouraged to evaluate patients reporting sleep difficulties for potential sleep-disordered breathing. Simple screening tools could be implemented in primary care settings at low cost to improve early detection of these interrelated conditions.

The central argument of the commentary is the need to rethink the treatment approach for patients with diabetes, insomnia, and sleep apnea, viewing their interplay as an integrated issue rather than isolated conditions. Continued research tracking sleep patterns and related health outcomes is essential for establishing the most effective treatment strategies.