What are the Risks Associated with Obstructive Sleep Apnea and Patients with Obesity?
— By Dawn M. Sweet, Ph.D
Obstructive sleep apnea is associated glucose intolerance and insulin resistance, thus exacerbating health risks for patients with obesity.
Research supports the importance of quality sleep for overall well-being, noting its crucial role in mental health, cognitive functioning, metabolic health, and cardiovascular healh.1 One less talked about contributor to poor sleep quality is an unhealthy weight. As research on sleep quality continues to grow, we are learning more about the health risks of poor sleep quality for patients with obesity.
For patients with obesity, fat deposits found in the upper respiratory system cause a narrowing of the airway which in turn leads to decreased muscle activity in the muscles groups implicated in breathing.2 These fat deposits — coupled with decreased muscle activation — lead to intermittent hypoxia, which leads to compromised breathing and oxygen levels, as well as sleep fragmentation and systemic inflammation.3 Because of the risks to metabolic functioning, it is important to consider this relationship further and explore strategies for mitigating obstructive sleep apnea.
Obstructive Sleep Apnea and Type 2 Diabetes
Type 2 diabetes and obstructive sleep apnea are risks factors for each other — their relationship is bidirectional.1 As reported in a 2018 study3, there is a greater risk of type 2 diabetes in patients with moderate to severe obstructive sleep apnea.
Hypoxic episodes that lead to sleep fragmentation cause hormonal changes that activate the sympathetic nervous system (SNS). As catecholamine is released during SNS activation, glycogenesis occurs along with insulin sensitivity decreases.3 Increased cortisol levels due to hypothalamic-pituitary-adrenal axis stimulation also increases insulin resistance. Inflammatory markers such as TNFα and IL-6 and oxidative stress are also implicated in the inflammatory processes that lead to metabolic syndrome.3 As reported in a 2016 study4, in male cohort without type 2 diabetes, obstructive sleep apnea independently predicted the development of insulin resistance. In a longitudinal study with participants from North America, Australia, and Europe an increased risk of type 2 diabetes was observed in those participants with moderate to severe obstructive sleep apnea.
Screening and Treating Obstructive Sleep Apnea
Because patients with obesity and type 2 diabetes have an elevated risk of obstructive sleep apnea, they should be screened.3 This screening should include assessments for snoring, daytime sleepiness, and observed apneic events per the International Diabetes Federation Task Force on Epidemiology and Prevention.3 Because weight or BMI do not account for body fat distribution, they should not be considered sole assessment metrics.3 Admittedly, snoring and daytime sleepiness are not foolproof indicators. Poor sleep quality in patients with obesity and type 2 diabetes may also result from diabetic neuropathy. Doctors who work with patients who are at risk of obstructive sleep apnea should consider recommending sleep centers for a more thorough assessment or at home devices to screen for obstructive sleep apnea.3
Lifestyle modifications such as diet and exercise that will reduce caloric intake while increasing energy expenditure should be considered. A 2016 meta-anaysis5 found that exercise benefitted patients with obstructive sleep apnea. In addition to exercise, health care providers should work with their at-risk patients to develop a Low Calorie Diet (LCD) or Very Low Calorie Diet (VLCD) that is tailored their weight loss goals and needs. Decreasing energy intake and increasing energy expenditures coupled with obstructive sleep apnea screening can help mitigate the associated health risks for patients with diabetes and obesity.
- Obstructive sleep apnea and obesity: Implications for Public Health
- Sleep is essential to health: an American Academy of Sleep Medicine position statement
- Obesity, obstructive sleep apnea and type 2 diabetes mellitus: Epidemiology and pathophysiologic insights
- Sleep apnea in Type 2 diabetes
- Effect of exercise training on sleep apnea: a systematic review and meta-analysis