Six-minute walk distance in overweight children and adolescents: effects of a weight-reducing program.

OBJECTIVE: To assess the significance of consecutive six-minute walk tests (6MWTs) during a weight reduction program. STUDY DESIGN: Overweight children and adolescents (n = 113; mean ± standard deviation age, 12.9 ± 2.0 years; 64 girls) performed a standardized 6MWT at the beginning and end of an in-patient weight reduction program consisting of exercise, diet, and educational and psychological support. Their 6-minute walk distance (6MWD) was compared with age- and sex-matched normal-weight children (n = 353). RESULTS: Preintervention 6MWD averaged 93% of control subjects (631 ± 88 m versus 675 ± 70 m, P < .001) and increased significantly to 667 ± 90 m (P < .001) after 27 ± 7 days of intervention (99% of control subjects; P = .260). Participants reduced their body weight from 80.9 ± 19.8 kg to 75.6 ± 19.0 kg, body mass index (BMI) percentile from 98.2 ± 2.1% to 96.8 ± 3.8%, and BMI-standard deviation score from 2.37 ± 0.6 to 2.13 ± 0.6 (P < .001 for each variable). BMI-standard deviation score, height, and the change in heart rate during the 6MWT were significant independent predictors of the 6MWD at preintervention and at post intervention time points (P < .001 each). CONCLUSIONS: The 6MWD increases during a weight reduction program, indicating improvement of physical fitness and decreased metabolic demand during daily activities in overweight children. The 6MWT represents a practical and reliable assessment tool for exercise performance in overweight children and adolescents.

Six-minute walk test in children and adolescents.

OBJECTIVE: To evaluate the 6-minute walking distance (6MWD) for healthy Caucasian children and adolescents of a population-based sample from the age of 3 to 18 years. STUDY DESIGN: Two hundred and eighty boys and 248 girls completed a modified test, using a measuring wheel as incentive device. RESULTS: Median 6MWD increased from the age of 3 to 11 years in boys and girls alike and increased further with increasing age in boys (from 667.3 m to 727.6 m), whereas it essentially plateaued in girls (655.8 m to 660.9 m). After adjusting for age, height (P = .001 in boys and P < .001 in girls) remained independently correlated with the 6MWD. In the best fitting and most efficient linear and quadratic regression models, the variables age and height explained about 49% of the variability of the 6MWD in boys and 50% in girls. CONCLUSION: This modified 6-minute walk test (6MWT) proved to be safe, easy to perform, and highly acceptable to children. It provides a simple and inexpensive means to measure functional exercise capacity in children, even of young age, and might be of value when conducting comparable studies.

Homozygous familial hypercholesterolemia: Summarized case reports.

BACKGROUND AND AIMS: Homozygous familial hypercholesterolemia (hoFH) is a rare genetic disorder with potential severe atherosclerosis in the pediatric age. METHODS: We report on 9 patients with hoFH, who had been diagnosed within the last 30 years and who were consequently treated with apheresis and drugs. RESULTS: Two deaths occurred: one at age 36 years and the other at age four and a half years before effective treatment was commenced. All other patients are still in good clinical condition today, although four of them have proven aortic stenosis or arterial plaques. CONCLUSIONS: Our case report highlights that adequate treatment should start as early as possible to delay the onset of clinical manifestations of atherosclerosis. It can be assumed that the introduction of new drugs can improve the outcome and possibly lengthen the life expectancy of patients affected by hoFH.

FTIR kinetic, product, and modeling study of the OH-initiated oxidation of 1-butanol in air.

A kinetic and product study was performed on the reaction of OH radicals with 1-butanol in a 480 L indoor photoreactor and also in the EUPHORE outdoor smog chamber in Valencia, Spain. Long path in situ FTIR spectroscopy and gas chromatography with photoionization detection were used to analyze reactants and products. Using a kinetic relative rate technique, a rate coefficient of k(OH + 1-butanol) = (8.28 +/- 0.85) x 10(-12) cm3 s(-1) was measured in 740 Torr synthetic air at 298 +/- 2 K. The reaction products observed and their fractional molar yields were (in percent) butanal (51.8 +/- 7.1), propanal (23.4 +/- 3.5), ethanal (12.7 +/- 2.2), and formaldehyde (43.4 +/- 2.4). In addition, the results support the probable formation of 4-hydroxy-2-butanone. Propanal, ethanal, and formaldehyde could also be formed in secondary reactions of some of the primary aldehydic products. However, under the conditions employed in the experiments, the contribution from secondary reactions is very minor. On the basis of the product studies, a detailed atmospheric degradation mechanism was constructed and tested against experimental data by chemical box model calculations. Measured and simulated concentration-time profiles for selected reactants were in excellent agreement.