Smoking induces oropharyngeal narrowing and increases the severity of obstructive sleep apnea syndrome.
OBJECTIVE
Smoking is a known risk factor for snoring, and is reported to be associated with an increased prevalence of obstructive sleep apnea syndrome (OSAS). The purpose of this was to determine the relationship of smoking to the severity of OSAS and examine what local histological changes in the uvular mucosa of OSAS patients might influence this relationship.


METHODS
Fifty-seven OSAS subjects were included and classified according to smoking history and OSAS severity. Twenty-eight subjects were heavy smokers and 29 were nonsmokers; these 57 patients were divided according to moderate or severe OSAS. Histologic changes in the uvular mucosa were evaluated in all subjects as well as smoking duration and OSAS severity.


RESULTS
Among smokers, moderate-to-severe OSAS was more common, and apnea, hypopnea, and oxygen desaturation indices were higher. Moreover, smoking duration and OSAS severity were significantly correlated. Increased thickness and edema of the uvular mucosa lamina propria were observed in moderate and severe OSAS patients, and only smokers had significant changes in uvular mucosa histology. Positive staining for calcitonin gene-related peptide (CGRP), a neuroinflammatory marker for peripheral nerves, was increased in the uvular mucosa of smokers.


CONCLUSIONS
Our results suggest that smoking may worsen OSAS through exacerbation of upper airway collapse at the level of the uvula, and that histological changes of the uvular mucosa correlated with smoking might be due to increased CGRP-related neurogenic inflammation.
Department of Otolaryngology and Head & Neck Surgery, Chung-Ang University, College of Medicine, Seoul, Korea.
Kyung Soo
KS
Kim
Jun Hee
JH
Kim
Sung Yoon
SY
Park
Ho-Ryun
HR
Won
Hyun-Jin
HJ
Lee
Hoon Shik
HS
Yang
Hyun Jik
HJ
Kim
D000293:Adolescent; D000328:Adult; D000368:Aged; D003251:Constriction, Pathologic / Q000139:chemically induced; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000187:drug effects / Q000473:pathology; D009960:Oropharynx / Q000187:drug effects* / Q000473:pathology; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000209:etiology* / Q000473:pathology; D012907:Smoking / Q000009:adverse effects* / Q000473:pathology; D014609:Uvula / Q000187:drug effects / Q000473:pathology; D055815:Young Adult