The Link Between Obstructive Sleep Apnoea And Type 2 Diabetes

Obstructive Sleep Apnoea (OSA) is a chronic treatable sleep disorder and a frequent comorbidity in patients with type 2 diabetes. The primary features of obstructive sleep apnoea include sleep fragmentation and frequent cessation of breathing resulting in hypoxia have been linked to abnormal glucose metabolism in various experiments. OSA is also strongly associated with the development of incident type 2 diabetes. So why do those with type 2 diabetes appear to have a greater risk of developing obstructive sleep apnoea?

Article Highlights: -Obstructive sleep apnoea and type 2 diabetes commonly occur simultaneously -The relationship between sleep apnoea and type 2 diabetes is bidirectional -Treatment of obstructive sleep apnoea with CPAP has not yet been shown to effectively manage the symptoms of type 2 diabetes, however, this may be partially due to compliance issues

-If you have type 2 diabetes, it is important to be vigilant under the supervision of your doctor and/or sleep specialist to watch for signs of obstructive sleep apnoea The precise link between OSA and type two diabetes is still being defined, however, it is clear that there is indeed a relationship between these conditions. It has been suggested that the nature of this relationship is bidirectional; meaning that the outcomes of diabetes contribute to obstructive sleep apnoea, and the outcomes of obstructive sleep apnoea contribute to diabetes. It is likely that there is a lot more going on than just disordered breathing in those with comorbid OSA and type 2 diabetes as trials looking at the use of CPAP treatment on glucose metabolism have been inconsistent. Researchers suggest that one aspect of this inconsistency is CPAP treatment compliance. It is possible that failing to use CPAP consistently or effectively can influence the findings of these studies.

When untreated, obstructive sleep apnoea causes intermittent oxygen starvation, CO2 build up, cortical microarousals, increased oxidative stress, inflammation, and sleep fragmentation. These effects are important factors in metabolic disorders (diabetes, cancer, cardiovascular disease) and neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease). The prevalence of OSA is increasing in-step with the obesity epidemic. Carrying excess weight is a risk factor for both type 2 diabetes and OSA. Overweight leads to metabolic dysfunction and also places pressure on the upper airways and weakens the diaphragm, making apnoea events more likely. It is possible that obstructive sleep apnoea is more prevalent in men because they tend to store fat on the abdomen, placing more pressure on the muscular structures that facilitate breathing. It has also been hypothesised that diabetic neuropathy (loss of feeling and signal transduction in the central nervous system) may also contribute to the cessation of breathing during sleep, causing apnoea events. For these reasons, the nature of the relationship between type 2 diabetes and obstructive sleep apnoea is seen as bidirectional.

Many studies have shown a clear and robust relationship between the severity of OSA and the extent of insulin resistance in those with type 2 diabetes. Even in healthy volunteers, induced sleep fragmentation and intermittent hypoxia quickly leads to glucose dysregulation; the hallmark of pre-diabetes. Sleep fragmentation resulting from apnoea events throughout the night cause a disruption to sleep architecture. This prevents the natural flow of sleep and often disrupts REM sleep, or ‘dream sleep’. REM sleep is the section of sleep that appears to have the greatest impact on lowering blood sugar levels, so loss of REM sleep is likely to have a substantial impact on metabolic health, particularly when it is due to a chronic, untreated breathing disorder such as obstructive sleep apnoea.

If you have been diagnosed with type 2 diabetes and have signs of obstructive sleep apnoea, it is important to speak with your doctor and/or sleep specialist. If clinically necessary, they may recommend having a sleep study, where electrodes are attached to your body to monitor your sleep. Sleep studies can determine the presence of a sleep disorder, its severity, and provide guidance regarding treatment options. The most common treatments for obstructive sleep apnoea include CPAP treatment, Mandibular Advancement Splints (MAS), positional sleep devices and weight loss. If left untreated, obstructive sleep apnoea can increase one’s risk of cardiovascular disease, type 2 diabetes, stroke, hypertension and depression.

Sove CPAP Clinic is a leading, independent and comprehensive provider of Respiratory & Sleep Disorder services with a network of clinics nationwide. We have a comprehensive team of Respiratory & Sleep Physicians and CPAP Consultants and provide eligible patients with access to bulk billed sleep studies, Respiratory/Sleep specialist consultations and sleep apnoea treatment services.* Speak with your doctor or contact Sove CPAP Clinic on 1300 76 29 39 or email info@thecpapclinic.com.au * Medicare criteria apply