Biomedical subjects
Publications and source records attributed to Jenny L Jeffries.
Severe obstructive sleep apnea in children leads to congestive heart failure. We studied the early changes in left ventricular function across a range of severity of the disorder. A dose-dependent decrease in diastolic function with increased severity of obstructive apnea was demonstrated.
Obstructive sleep apnea causes intermittent elevation of systemic blood pressure (BP) during sleep. To determine whether obstructive apnea in children has a tonic effect on diurnal BP, 24-hour ambulatory blood pressure was obtained from 60 children with mean age of 10.8 +/- 3.5 years. Thirty-nine children had obstructive apnea and 21 had primary snoring. Children with obstructive apnea had significantly greater mean BP variability during wakefulness and sleep, a higher night-to-day systolic BP, and a smaller nocturnal dipping of mean BP. Variability of mean arterial pressure during wakefulness was predicted by the desaturation, body mass, and arousal indices, whereas variability during sleep was predicted by apnea-hypopnea and body mass indices. Nocturnal BP dipping was predicted by the desaturation index. There were no significant differences in systolic, diastolic, or mean arterial BP during sleep between the groups. Diastolic BP during wakefulness was significantly different between the groups and correlated negatively with apnea-hypopnea index. We conclude that obstructive apnea in children is associated with 24-hour BP dysregulation and that, independent of obesity, the frequency of obstructive apnea, oxygen desaturation, and arousal contributes to abnormal BP control.
Obstructive sleep apnea (OSA) has been shown to be an independent risk factor for cardiovascular disease in adults. However, there are severe limitations in the extent to which the cardiovascular consequences of OSA are being studied in children. To investigate the echocardiographic changes in children with OSA, right and left ventricular (RV, LV) dimensions and LV mass index and geometry were measured in 28 children with OSA and 19 children with primary snoring (PS). The study showed that LV mass index and relative wall thickness were greater in the OSA group compared with those with PS (p = 0.012 and p < 0.0001, respectively). An apnea-hypopnea index of more than 10 per hour was significantly associated with RV dimension above the 95th percentile (odds ratios, 6.7; 95% confidence interval, 1.4-32) and LV mass index above the 95th percentile (odds ratios, 11.2; confidence interval, 1.9-64). Abnormality of LV geometry was present in 15% of children with PS compared with 39% of children with OSA. We conclude that OSA in children is associated with increased LV mass.