[Physical activity and health in young persons]. / Activité physique et santé chez les jeunes.

Epidemiological studies highlighted an inverse relationship between the level of usual physical activity and the risk of cardiovascular accident. Physical inactivity during childhood and adolescence is believed to be a significant risk factor for various health disorders in later life. One makes a clear distinction between on the one hand, exercise and physical fitness and, on the other hand, activity and health. An investigation into the life style (practice of out-of-school physical and sports activities, their frequency, their duration, practice in club and competitive practice) of young Europeans was carried out in nine countries or areas. In the French Community of Belgium, 730 boys and 726 girls of 12 and 15 years were administered an internationally validated questionnaire. The results obtained in all the countries were in agreement with the data of the literature. More than 50% of the girls participated in physical activities only with a very limited frequency and at a low intensity. This is an obvious deficit when compared with the recommendations concerning exercise for health. One can predict without much risk of error that in the adulthood, they will be also classified among the sedentary people.

[Bronchial reactivity in diabetic patients]. / Réactivité bronchique chez les patients diabétiques.

The data of the literature concerning bronchial reactivity in diabetic patients are controversial. Therefore, we studied the influence of the presence of a diabetic cardiac autonomic neuropathy (CAN) on the ventilatory parameters measured during a methacholine-induced bronchoconstriction test. Ten insulin-dependent diabetic patients without CAN, ten insulin-dependent diabetic patients with CAN and ten healthy volunteers, all non-smokers and free of respiratory symptoms, have undergone a functional respiratory check-up before the methacholine test. The presence of CAN was classically studied by the decrease in heart rate changes during three standardized tests (deep breathing at 6 cycles/min, Valsalva manoeuver, orthostatism) which all mainly explore the parasympathetic function. The bronchial response to methacholine was similar in the healthy subjects and in the diabetic patients without CAN. However, the fall in forced expiratory volume in 1 second induced by the highest dose of methacholine was significantly less marked in the diabetic subjects with CAN than in the two other groups. These results suggest that the diabetic autonomic neuropathy also involves the vagal innervation of the respiratory tract.