studysleep apnoea: a community based Ambulatory blood pressure in children with

ABSTRACTBackground: Childhood obstructive sleep apnoea (OSA)is increasingly being recognised. Its effects on bloodpressure (BP) elevation and hypertension are stillcontroversial.Objective: To evaluate the association between OSA andambulatory BP in children.Methods: Children aged 6–13 years from randomlyselected schools were invited to undergo overnight sleepstudy and ambulatory BP monitoring after completing avalidated OSA questionnaire. OSA was diagnosed if theobstructive apnoea–hypopnoea index (AHI) was .1, andnormal controls had AHI ,1 and snoring ,3 nights perweek. Children with OSA were subdivided into a mildgroup (AHI 1–5) and moderate to severe group (AHI .5).Results: 306 subjects had valid sleep and daytime BPdata. Children with OSA had significantly higher BP thannormal healthy children during both sleep and wakeful-ness. BP levels increased with the severity of OSA, andchildren with moderate to severe disease (AHI .5) wereat significantly higher risk for nocturnal systolic (OR 3.9(95% CI 1.4 to 10.5)) and diastolic (OR 3.3 (95% CI 1.4 to8.1)) hypertension. Multiple linear regression revealed asignificant association between oxygen desaturation indexand AHI with daytime and nocturnal BP, respectively,independent of obesity.Conclusions: OSA was associated with elevated day-time and nocturnal BP, and is an independent predictor ofnocturnal hypertension. This has important clinicalimplications as childhood elevated BP predicts futurecardiovascular risks. Future studies should examine theeffect of therapy for OSA on changes in BP.In adults, obstructive sleep apnoea (OSA) is anindependent risk factor for hypertension and isinvolved in the initiation and progression of othercardiovascular diseases.