Diabetes mellitus, especially type 2, is a major clinical and public health problem in Kuwait. It has shown a climbing prevalence, being 23% in 2013 from 15% in 1998. So, considering that an average family consists of 4-5 members, this means that diabetes affects almost each household in Kuwait. The risk accumulates considering a significant proportion of the population suffering from borderline-diabetes (known as glucose intolerance). This can further affect another one-fifth of the Kuwaiti population.
Diabetes is highly linked to obesity and overweight, which have around 50% and 80% prevalence in Kuwait, respectively. As obesity affects most of diabetics (around two-third), it has several implications on the respiratory system. Obese patients may suffer from breathing disorders, mainly including sleep apnea and asthma. Other disorders include a condition called obesity hypoventilation syndrome, and impaired lung mechanics secondary to increased fat content in the chest wall and abdomen.
Obstructive sleep apnea is a disorder characterized by recurrent closure of upper airways during sleep causing reduction in oxygen concentration in the blood and leading to stresses on heart, lung, and brain. Research has shown that while sleep apnea causing a chronic state of intermittent reductions of low levels in the blood, it leads to raised blood pressure (hypertension), increased levels of stress hormones in the blood (known as catecholamines), impaired liver functions, and insulin resistance. The latter complication is closely related to diabetes, particularly type 2. Different mechanisms are postulated about this relationship, all are being studied at present time.
Sleep apnea can affect the endocrine system in the human body at many levels, beside diabetes. Sleep apnea was found to be associated with abnormal regulation of the functions of the thyroid gland, mainly being suppressed. The relationship was found in a way that treatment with thyroid hormones was found to ameliorate sleep apnea, which was found to be more complicated if the thyroid disease was left untreated. Sleep apnea was also found to be associated with growth hormone dysfunction (gigantism).
Treating this condition with surgery, radiation, and hormonal therapy was found in research studies to improve the sleep apnea. In addition, sleep apnea had been reported to have an association with sex hormones’ abnormal regulation. The involvement is primarily through the axis of the sex hormones pathways in the human body. In all relationships with the endocrine glands, sleep apnea was found to complicate any hormonal disease with raising the blood pressure.
Not only that sleep apnea is associated with insulin resistance, this relationship is independent of obesity. So even lean diabetics are found to have double the risk of suffering from sleep apnea those non-diabetics. The same is applied on those with borderline diabetes (glucose intolerant patients). This can be explained through different mechanisms. Traditionally, sleep apnea is linked to increased sleepiness in the affected individuals leading to physical inactivity, reduced exercise, and subsequent weight gain.
Sleep apnea is also linked to decreased slow-wave (deep/dreaming) sleep. All of these factors increase insulin resistance and prevalence of diabetes. Diabetes itself can lead to sleep apnea through autonomic dysfunction, which causes irregular breathing pattern. This is more profound during sleep leading to chocking and snoring, the manifestations of sleep apnea.
Treatment of sleep apnea has different elements. As obesity is the major risk factor, it is highly recommended that affected patients should adopt a lifestyle modifications focusing on weight loss through healthy nutrition and increased physical activity. When applicable, we highly recommend that patients quit smoking as this can lead to chronic inflammation of the upper airways narrowing their diameter and limiting passage of air through them. We also advise patients to sleep in a quiet and dim environment to avoid external factors inhibiting them from having a deep sleep.
In addition to these items, it is recommended that patients with sleep apnea use nasal wash and spray regularly to clear their breathing passages. The mainstay treatment is through the assurance of smooth breathing during sleeping time. This is usually done through providing the patients with a machine (usually called CPAP) that blows air at extra pressure during sleep to maintain normal oxygen delivery and level in the blood. Other treatment options, which are less efficacious than CPAP include surgery and mouth guards. Surgical treatments are confined to a subset of patients that can have a localized abnormality, which can be fixed with a procedure. A recent study has shown that implantation of tongue nerve pacemaker is equivalent to CPAP, but this treatment is not yet available for public.
Treatment of sleep apnea is efficacious in controlling blood sugar, blood pressure, and preventing diabetes-heart complications. Besides treating sleep apnea, CPAP was found to reduce blood pressure and glycated hemoglobin to significant levels. CPAP also reverses diabetes and its related diseases including high cholesterol levels.
Finally, screening of sleep apnea has been recommended by the international health authorities. It was found based on research that treatment of sleep apnea is cost-effective. The estimates of medical costs of untreated sleep apnea in Kuwait are around 10 million KD.
This is in addition to the cost of unnecessary use of medical services and indirect costs due to driving accidents and disability. Actual treatment costs of Kuwaiti patients would definitely save lots of these costs, improve population productivity and quality of life, treat major health disorders, and prevent significant complications.