Trend of Obesity in School Age Children in Seoul Over the Past 23 Years / 소아과

PURPOSE: The aim of this study was to evaluate the change in prevalence and the epidemiology of obesity in school age children of Seoul, Korea during the last 23 years with coherency and under the same standards. METHODS: We used the new 1998 standard weight for height to calculate obesity on the personal data from five years and produced a coefficient of correlation that could be applied to previous obesity prevalence results. RESULTS: From age six to 17, the average body mass index increased 5.7 in boys and 6.2 in girls. The prevalence of obesity according to age peaked around age 11 and age 13-14, and increased again at 16-17 in boys. In girls, there was a peak at the age of 10 and a second peak which was at age 16 in 1979, but the age of the second peak gradually came down to a younger age, to age 13, in 2002. Obesity in girls increased steadily after the second peak. In 1979 and 1981, there were many more underweight children than obese. In boys, obesity had risen to 11.0% by 1997 and rose abruptly to 17.9% by 2002 and in girls, to 9.0% by 1997 and 10.9% by 2002. Mild, moderate, and severe obesity also increased with the increase of obesity. CONCLUSION: As Korea became developed, obesity became more frequent than underweight. Obesity increased rapidly and the increase rate accelerated in boys, whereas though it increased, the increase rate slowly decreased in girls.

Change of Cerebral Blood Flow during Tilt Tests in Children with Vasovagal Syncope

PURPOSE: Syncope appears to be common. However, the mechanism of syncope is not clear. Increased vagal activity and withdrawal of sympathetic stimulation cause hypotension, bradycardia and finally loss of consciousness. The purpose of this study was to evaluate changes of cerebral blood flow velocity, blood pressure, and heart rate during tilt test in children with vasovagal syncope. METHODS: Sixty four children with a past history of syncope were evaluated. The stand up test was performed for 15 minutes after a rest at supine position for 10 minutes, followed by an 80 degrees tilt test lasting 45 minutes. If presyncope(lightheadedness, nausea, blurred vision, or sweating) or syncope occurred, the study was discontinued. 12-lead electrocardiography, echocardiography, and electroencephalography were performed. Transcranial Doppler study was performed at the middle cerebral artery with 2 MHz continuous Doppler probe in 10 children with positive tilt test. Systolic, diastolic, mean cerebral blood flow velocity, integral, and pulsatility index were measured with blood pressure, heart rate, and O2 saturation. RESULTS: The positive rate of tilt test was 31.3%(20/64). Systolic, diastolic, and mean cerebral blood flow velocity decreased significantly in absence of hypotension or bradycardia during presyncope. Time velocity integral of cerebral artery also decreased significantly. CONCLUSION: Decreased cerebral blood flow velocity can predict the presyncope manifestation. Impairment of autoregulation of cerebral blood flow might play an important role in the pathophysiology of vasovagal syncope.