Sleep apnoea and excessive daytime sleepiness

What is it
all about?

Obstructive Sleep Apnoea Hypopnoea Syndrome (OSA) is characterised by the onset during sleep of abnormally frequent interruptions of ventilation (apnoea) or significant reductions in ventilation (hypopnoea). These episodes of apnoea and hypopnoea lead to hypoxaemia (reduced haemoglobin oxygen saturation) and micro-awakenings.

These repeated micro-awakenings, which are often not perceived by the patient, lead to a fragmentation of sleep.
OSA is a common condition which is still widely underdiagnosed 1, 2, 3

According to a huge international study published in 2019, almost a billion adults aged 30-69 years are affected by this chronic pathology which fragments sleep and affects activities of daily living as well as patients’ state of health.4

Continue reading

According to a study published in 2018 in the European Respiratory Journal5, OSA affects 175 million people in Europe.

According to this study, if we consider the moderate-to-severe forms, defined by 15 episodes of apnoea or hypopnoea or more per hour, the prevalence is 4.8% in France.

Thus, at least two million French people would appear to be affected. These figures will no doubt continue to progress, in particular due to the rise in obsesity, a major risk factor for OSA (70% of obese patients are affected), but also thanks to progress in diagnosis of the condition3. t should also be noted that a good number of patients suffering from this sleep disorder with possible consequences for their short- and long-term health are unaware of their illness.

'Alongside fatigue, excessive daytime sleepiness is the most frequently reported symptom by patients, with a considerable impact on daily quality of life and safety'

Jean-Charles Schwartz

Scientific director and co-founder of Bioprojet

Drowsiness, fatigue
and impaired alertness

OSA has a major impact on patient’s daily lives, in terms of quality of life, health and safety. It leads to daytime sleepiness which affects daily life.

Somnolence is defined as an intermediate state between sleep and wakefulness. It is characterised by overwhelming drowsiness when the person is not stimulated. It leads to attention and memory impairments which can affect patients’ work and social activities.

Impaired alertness associated with drowsiness increases the risk of accidents at home, at work and when driving.

Double the risk of crashes 6

A study carried out on patients with OSA published in 2006 in the European Respiratory Journal showed the effects of the disease on breaking time, with reduced responsiveness and a lengthening of the vehicle’s stopping distance of 8.8 m at 40 km/h and 22 metres at 130 km/h, as well as twice as many collisions compared with the general population.

Fatigue, one of patients’ main complaints, is manifested through physical or psychological weakness, making it difficult and uncomfortable to engage in effort or activities.

First-line Treatment with
Continuous Positive Airway Pressure

Treatment involves continuous positive airway pressure (CPAP) which has proven to be effective in the vast majority of cases. CPAP allows you to remove the airway obstruction. It is applied using a pressurised air generator with an adjustable level. The therapeutic efficacy of CPAP depends on adherence to treatment and the number of hours of use. It is difficult to set a minimum threshold, but, when used for less than 4-5 hours a night, the improvement in drowsiness and quality of life cannot always be achieved.

Poor adherence to therapy is often linked to comfort issues, ill-fitting masks, insufficient humidification, the presence or air leaks or chronic rhino-sinusitis which makes ventilation with the nasal mask uncomfortable.

The effectiveness of CPAP on the apnoea-hypopnoea score is generally regularly assessed by the respiratory physician.

Persistent daytime sleepiness
despite properly administered CPAP

A certain number of patients continue to present with excessive daytime sleepiness despite CPAP, explains Professor Pépin, a respiratory physician at Grenoble University Hospital. These patients complain not only of drowsiness, but also fatigue, symptoms of depression and an impaired quality of life.

The prevalence of residual excess sleepiness (RES) on CPAP varies according to the studies from 4.4% to 34%, with a mean estimate of around 13%7

These characteristics were found in another study in which half of the patients with RES complained of sometimes severe fatigue as well as headaches on waking8.


  1. Young T et al. The occurrence of sleep disordered breathing among middle aged adults. N Engl J Med 1993; 328: 1230-35
  2. C. Fuhrman et al. Le syndrome d’apnées du sommeil en France : un syndrome fréquent et sous diagnostiqué. BEH 44-45. November 20, 2012
  3. Peppart P et al. Increased prevalence of sleep disordered breathing in adults. Am J Epidemiol 2013; 177: 1006-1014
  4. Benjafield A et al. Estimation of the global prevalence and burden of osbtructivesleep apnoea: a litterature based analysis. Lancet Resp 2019; 7: 687-98
  5. Malhotra A et al. Breaking Abstract – European prevalence of OSA in adults: Estimation using currently available data, European Respiratory Journal 2018 52: OA4961
  6. Mazza S et al. Driving ability in sleep apnoea patients before and after CPAP treatment: evaluation on road safety platform. Eur Respir J 2006; 28 : 1020-1028
  7. Pépin JL et al. Pitolisant for residual excessive daytime sleepiness in OSA patients adhering to CPAP. Chest 2021; 159: 1598-1609
  8. Pépin JL et al. Prevalence of residual excessive sleepiness in CPAP-treated sleep apnoea patients: the French multicentre study. Eur Respir J 2009; 33: 1062-1067

Useful links

Alliance Apnées [Apnoea Alliance]

Réseau Morphée [Morpheus Network]