There are approximately 1 billion OSA patients worldwide. Recent data suggest that when the apnea-hypopnea index (AHI) is ≥ 15 events per hour, the incidence rate of moderate-to-severe OSA is 49.7% in men and 23.4% in women. Common clinical symptoms include snoring during sleep, recurrent abrupt awakenings, increased nocturia, morning headaches, and daytime sleepiness. However, patients often ignore these symptoms and lack time management strategies. OSA is a syndrome with metabolic and endocrine complications that can lead to cardiovascular damage, metabolic disorders, abnormal hormone levels, cognitive function decline, and behavioral abnormalities, significantly impacting the workability and quality of life.

The thyroid is a gland responsible for the functioning of many vital functions, from the heartbeat to the frequency of our breathing. It is also the organ responsible for the production of thyroid hormones, which are related to metabolism. When there is an imbalance associated with the production of these hormones, the person may experience hypothyroidism or hyperthyroidism.

Hypothyroidism is characterised by reduced thyroid activity, which decreases the production of hormones and consequently causes a slow metabolism. Associated causes include deficiency in iodine consumption, removal (total or partial) of the thyroid, use of some medications, the postpartum period, among others.

When a patient has hypothyroidism, their body becomes less active. As a result, they may feel tired more easily and be quite drowsy. The diagnosis of this disease is typically made through a physical examination by an endocrinologist and confirmed by blood tests and a thyroid ultrasound.

It is known that people with hypothyroidism are at a greater risk of developing OSA due to multiple factors involving breathing, such as decreased ability to react to chemical changes and the muscles involved in breathing.

Symptoms of difficulty or stopping breathing, excessive tiredness during the day, excessive drowsiness, apathy, headaches, difficulty concentrating, among others, are related to both hypothyroidism and OSA.

Patients diagnosed with primary sleep apnea, who are not subjected to thyroid function analysis, are underdiagnosed and inappropriately treated as having OSA due to the failure to detect hypothyroidism. These same patients experience temporary symptom improvement with treatments recommended for OSA, but inevitably fail in the long term. This temporary improvement can be avoided if the diagnosis of hypothyroidism is not delayed.

In other words, it is necessary to identify the origin of the symptoms, and not just treat them. Some patients undergo OSA treatment and receive short-term improvement in symptoms, but the real cause of the breathing disorder actually lies in the thyroid.

The cause of a low respiratory rate at night may, in fact, be related to the metabolic function of the thyroid and originate from hypothyroidism.

Therefore, it cannot be said with certainty that one causes the other. However, what is known is that there is indeed a correlation between these two factors, as OSA can occur in between 25% and 100% of patients who have hypothyroidism.

For more information please contact Grupo HPA Saude on (+351) 282 420 400.