Morphological features of elderly patients with obstructive sleep apnoea syndrome: a prospective controlled, comparative cohort study

Objectives: To investigate the pharyngeal morphologic features and its pathogenic role on obstructive sleep apnoea syndrome in the elderly population. Design: Prospective controlled, comparative cohort study. Setting: Territory referral centre. Participants: We enroled 320 consecutive patients with complaints of snoring who visited Nagoya University Hospital from January 2004 to December 2007. We also collected 26 control subjects aged over 60 years from community-dwelling people. Main outcome measures: We underwent a morphological evaluation, measurement of nasal resistance, assessment of daytime sleepiness and nocturnal polysomnography. Results and conclusions: Two hundred and ninety-two patients were analysed. The constitution ratio of men, the body mass index and Epworth sleepiness scale were decreased with ageing. Tonsil size was reduced progressively with ageing. Retroglossal space was wider, and soft palate was lower in >= 60 year group than in < 40 year group. Retroglossal space was wide in elderly patients with sleep apnoea compared with control subjects. Tonsil size was not correlated to apnoea/hypopnoea index in >= 60 year group unlike the other generations. Modified Mallampati Score and tongue size were significantly but mildly correlated only in >= 60 year group. Width of fauces was correlated in all the groups. Multiple regression analysis showed that body mass index, age, gender, tonsil size and width of fauces were independent factors for apnoea/hypopnoea index. Conclusions: Morphologically, the tonsil could play a minor role but the width of fauces could play relatively a major role. Additionally, wide retroglossal space, low positional soft palate and large tongue size may be characteristics for elderly patients of obstructive sleep apnoea syndrome.