KCC Chan, AM Li, WCW Chu, RCH Li, SC Ling, HL Yuen, CK Li

Abstract

Objective: This pilot study assessed the prevalence of daytime sleepiness and obstructive sleep apnoea (OSA) from children to young adults with beta-thalassaemia intermedia. Methods: Patients diagnosed with beta-thalassaemia intermedia and attended the four participating hospitals (Prince of Wales, Tuen Mun, Queen Elizabeth and Princess Margaret) for regular evaluations were recruited. All subjects were examined by a paediatrician and underwent overnight polysomnography (PSG). The subjects were also invited to undergo magnetic resonance imaging (MRI) of the upper airway. Serum haemoglobin and ferritin levels were measured after overnight PSG. A detailed sleep apnoea questionnaire and a Chinese version of the Epworth Sleepiness Scale were completed by parents of subjects under 18 years old or by subjects themselves if they were aged 18 or more. Findings: A total of 19 beta-thalassaemia intermedia patients (15 males and 4 females) aged 3-28 years were enrolled. Their mean age at diagnosis was 3.54 years. Four subjects were found to have OSA using obstructive apnoea hypopnoea index (OAHI) >1 as cut-off. Epworth sleepiness score, haemoglobin and ferritin levels, PSG parameters and sleep related symptoms were similar between subjects with and without OSA. All 4 OSA subjects and 7 non-OSA patients underwent MRI, and no significant differences between their upper airway parameters were noted. Conclusion: Prevalence of OSA maybe higher amongst patients with beta-thalassaemia intermedia but this has to be confirmed by further studies with larger sample size.