Abstract
Family studies in adults suggest the presence of familial aggregation in obstructive sleep apnoea. Whether the presence of OSA in either or both parents affect disease occurrence in their offspring is unclear. In this study we aimed to investigate if OSA in either parent is a risk factor for childhood OSA, after controlling for the effect of tonsillar size.
A total of 124 trios with a child / adolescent aged 6-18 years as index case were recruited. All cases and their parents underwent in-hospital and home nocturnal polysomnography respectively. Tonsillar size of the index subjects was assessed with the standard Brodsky grading system. Significant interaction was observed between tonsillar size of index subjects and family history of OSA (p=0.015), therefore index cases who had minimal (grade I) or no tonsils (grade 0) and those with prominent tonsils (grade II to IV) were analyzed separately.
Within the group of minimal or no tonsils, twenty-three out of a total of 46 index subjects had at least one parent with moderate-to-severe OSA (defined as an obstructive apnoea hypopnoea index (OAHI) of 15/h or more). Compared to those without parental moderate-to-severe OSA, subjects whose parent with the disease had a significantly higher OAHI [0.4/h (0-0.8) c.f. 1.2/h (0.3-3.4), p=0.036] as well as a higher prevalence of OSA (defined as an OAHI>1/h, 21.7% c.f. 52.2%, p=0.032), while the two groups had similar age, body size and sex ratio. These findings were not seen in subjects with prominent tonsils.
Our results suggest that parental OSA is a significant risk factor for the presence of disease in children with minimal tonsillar enlargement.
- © 2014 ERS