CHICAGO-- It has become increasingly apparent in recent years that sleep-disordered breathing can have major health consequences: impaired physical and mental functioning, reduced quality of life, and medical illness. However, the role that rhinitis plays in causing sleep-disordered breathing is often overlooked by physicians and patients alike.

"Over 75% of patients with rhinitis report impaired sleep," said Eli O. Meltzer, MD, a clinical professor of pediatric allergy at the University of California, San Diego. In fact, nasal disease is one of the leading causes of sleep-disordered breathing. Yet few physicians ask their rhinitis patients about sleep problems, Dr. Meltzer noted.

"Nasal symptoms impair sleep quality and lead to snoring, which may be accompanied by apnea and hypopnea; in severe cases of nasal obstruction, impairment of airflow can cause hypoxia," explained Dr. Meltzer, who discussed the relationship between rhinitis and sleep complications at the annual meeting of the American College of Allergy, Asthma, and Immunology. "The lowered oxygen levels can cause a change in the respiratory drive center," he noted. "By nature, humans will choose to breathe over choosing to sleep. The consequence of too much sleep fragmentation is daytime sleepiness."

NASAL SYMPTOMS LINKED TO SLEEP DISTURBANCES

What is the connection between rhinitis and sleep-disordered breathing? First, nasal symptoms are more common in the night and early morning, according to Dr. Meltzer. Second, allergen exposure may be increased when patients are in bed; third, people with nasal obstruction must breathe harder to get adequate airflow. At night, the combination of accelerated airflow and reduced muscle activity leads to snoring and difficulty breathing.

Several studies underscore the importance of nasal air function relative to sleep-disordered breathing. In one study, eight healthy men had their noses packed, which resulted in an increased percentage of light sleep.[1] "These men had an increase in sleep-obstructive events and increased awakenings," Dr. Meltzer reported. In a different study, seven men who had postsurgical nasal packing experienced increased apnea episodes.[2] Furthermore, four of the seven men had more than 50 events per hour.

In another trial that evaluated 14 patients with allergic rhinitis, all patients experienced disordered breathing with hypopnea and apnea episodes.[3] Microarousals averaged 50 per hour, compared with only five episodes per hour in the control population. Furthermore, three of the 14 patients complained of difficulty falling asleep, and four patients reported excessive daytime sleepiness. "Although this sleepiness has previously been attributed to tumor necrosis factor, interferons, and other cytokines, it may very well be due to the nasal congestion causing sleep-disordered breathing and secondary poor sleep," Dr. Meltzer speculated.

Finally, a seasonal study showed that patients who experienced symptoms had increased nasal airway resistance during the allergy season and decreased nasal obstruction afterward.[4] "During the season, these patients had higher numbers of apnea episodes per hour and longer durations," Dr. Meltzer said.

IDENTIFYING THE SYMPTOMS

Diagnosing sleep-disordered breathing requires taking a comprehensive patient history. "If you don't ask the question, you don't get the answer," Dr. Meltzer stressed. "We need to ask about hours of sleep, difficulty in falling asleep, and difficulty staying asleep. Does the patient report restless nighttime behaviors or snoring? A history of nasal congestion has also been linked to habitual snoring. Because nasal symptoms are related to snoring and snoring to sleepiness, the association between rhinitis and sleepiness may be explained by the sleep-disordered breathing and also by the direct effects of the symptoms in causing cortical arousal and fragmented sleep," Dr. Meltzer said.

Asking about daytime functioning is also important. For example, does the patient report memory impairment, personality changes, decreased motivation, or decreased libido? "We spend one third of our life in sleep; but if the quantity and quality of sleep is compromised, cognitive ability and performance skills may be impaired," noted Dr. Meltzer.

Other symptoms that suggest nighttime problems include agitation, depression, stress, and performance impairment. Obesity, a family history of sleep disorders, or the presence of a chronic medical condition, such as asthma or rhinitis, may also contribute to disordered sleep. Use of prescription or over-the-counter medications, caffeine, and alcohol may also affect sleep patterns.

"Bed-partner questionnaires can be very useful," Dr. Meltzer suggested, particularly since patients themselves may not be aware of their snoring. He also advocates using sleep laboratories, which allow practitioners to accurately gauge the magnitude of a patient's sleep problem. "If the patient has significant sleep disability, it will not only affect his daytime activities, but could even affect his mortality," Dr. Meltzer pointed out. "Patients with an apnea index of fewer than 20 episodes per hour are going to survive longer than those who have more than 20 episodes per hour.

TIMING INFLUENCES TREATMENT OUTCOME

Allergic rhinitis can be treated with an antihistamine, a decongestant, and/or an intranasal corticosteroid. However, the effects of these medications can vary markedly, depending on whether they are administered in the morning or the evening. "For example, the duration and time to peak effect … of terfenadine varies according to administration time," Dr. Meltzer said. Other antihistamines have also been shown to be more effective if given around dinnertime. Therefore, "perhaps our oral antihistamines should be given at nighttime instead of in the morning to improve early morning rhinorrhea, nasal blockage, and sneezing."

In particular, first-generation antihistamines should not be given during the day because they often cause drowsiness. "If we give a patient who's already sleepy from not having a good night's sleep a first-generation antihistamine, we are going to impair that patient even more," Dr. Meltzer said.

On the other hand, some medications, such as oral sympathomimetics, "can, in fact, cause stimulation at night and make it more difficult for patients to fall asleep," he said. "If we give patients 120 mg of pseudoephedrine at nighttime, the prevalence of insomnia will be 10% to 25%."

CORTICOSTEROIDS IMPROVE SYMPTOMS

Nasal corticosteroids have a significant effect on nasal obstruction in both seasonal and perennial allergic rhinitis. A study of intranasal corticosteroids in patients with allergic rhinitis showed that patients given placebo had some improvement in nasal obstruction, but the improvement was not as great as that experienced by those who took an intranasal corticosteroid.[5] In addition, sleep quality and daytime sleepiness were also improved in patients taking corticosteroids. "By improving the nasal airway, we can improve the ability to sleep," Dr. Meltzer explained.

--Bob Kronemyer

References
1. Olsen KD, Kern EB, Westbrook PR. Sleep and breathing disturbance secondary to nasal obstruction. Otolaryngol Head Neck Surg. 1981;89:804-810.
2. Taasan V, Wynne JW, Cassisi N, Block AJ. The effect of nasal packing on sleep-disordered breathing and nocturnal oxygen desaturation. Laryngoscope. 1981;91:1163-1172.
3. Lavie P, Gertner R, Zomer J, Podoshin L. Breathing disorders in sleep associated with "microarousals" in patients with allergic rhinitis. Acta Otolaryngol. 1981;92:529-533.
4. McNicholas WT, Tarlo S, Cole P, et al. Obstructive apneas during sleep in patients with seasonal allergic rhinitis. Am Rev Respir Dis. 1982;126:625-628.
5. Craig TJ, Teets S, Lehman EB, et al. Nasal congestion secondary to allergic rhinitis as a cause of sleep disturbance and daytime fatigue and the response to topical nasal corticosteroids. J Allergy Clin Immunol. 1998;101:633-637.