Obesity in Switzerland: a critical assessment of prevalence in children and adults.

The objective was to analyze the situation in Switzerland regarding the prevalence of overweight or obesity in children, adolescents and adults. The data were compared with France, an adjacent much larger country. The results showed that there is a definitive lack of objective information in Switzerland on the prevalence of obesity at different ages. As in other European studies, the fact that many national surveys are classically based on subject interviews (self-reported weights and heights rather than measured values) implies that the overweight/obesity prevalence is largely underestimated in adulthood. For example, in a recent Swiss epidemiological study, the prevalence of obesity (BMI greater than 30 kg/m(2)) averaged 6-7% in young men and women (25-34 y), the prevalence being underestimated by a factor of two to three when body weight was self-reported rather than measured. This phenomenon has already been observed in previous European studies. It is concluded that National Surveys based on telephone interviews generally produce biased obesity prevalence results, although the direction of the changes in prevalence of obesity and its evolution with repeated surveys using strict standardized methodology may be evaluated correctly. Therefore, these surveys should be complemented by large-scale epidemiological studies (based on measured anthropomeric variables rather than declared) covering the different linguistic areas of Switzerland. An epidemiological body weight (BMI) monitoring surveillance system, using a harmonized methodology among European countries, would help to accurately assess differences in obesity prevalence across Europe without methodological bias. It will permit monitoring of the dynamic evolution of obesity prevalence as well as the development of appropriate strategies (taking into account the specificity of each country) for obesity prevention and treatment.

Sex-dependent variations and timing of thyroid growth during puberty.

Marked changes in thyroid function occur during puberty as an adaptation to body and sexual development. Characteristics of thyroid growth were investigated in 259 healthy adolescents (110 girls and 149 boys), aged 11--17 yr, in an urban area of Switzerland with sufficient iodine supply. The thyroid volume determined by ultrasonography was correlated with chronological age, body weight, body height, cervical circumference, body mass index, and body surface area (BSA). Iodide concentration was measured in urine. The increase in thyroid volume mainly occurred between 11--15 yr (age at maximum thyroid growth rate, 12.5 yr) and was best correlated with BSA in both genders (girls, r(2) = 0.38; boys, r(2) = 0.49). The BSA-related thyroid growth was almost constant throughout puberty in boys and similar in girls up to menarche, but 14.5% larger in girls after menarche (P < 0.01). Percentiles of thyroid volume were lower than WHO reference values despite low normal urinary iodide concentration (median, 0.75 micromol/L). These findings suggest that physiological thyroid growth during puberty is mainly influenced by growth factors involved in somatic development and further modulated by sex steroid secretion profiles. The thyroid growth spurt coinciding with menarche in girls may contribute to a higher incidence of goiter during mid- to late puberty.

[Vaccination against hepatitis B in school: factors influencing acceptance and evaluation of general vaccination coverage ]. / Vaccination contre l'hépatite B à l'école: facteurs influençant l'acceptation et bilan de la couverture vaccinale générale.

The second vaccination campaign against Hepatitis B in Lausanne concerned 1243 students of the seventh grade. This campaign was actively supported by personalized information given to each adolescent in the class room. The decisions were collected in the same way, and in necessary the nurse phoned the parents for further information. In comparison with the previous year, the coverage had grown from 63.5% to 78.5%, but varied in each class between 42% and 92%, whatever the class type. The factors which influence acceptance of the vaccination are coverage for the other vaccines, origin, and class, which has up to five times more effect than the other factors. Assessment of the vaccination coverage against Diphteria, Tetanus, Poliomyelitis, Pertussis, Measles and MMR is given in relation to the acceptance of the Hepatitis B vaccination and the class type.

[Iodine nutrition and prevalence of goiter in adolescents in the Canton of Vaud]. / Apport iodé et prévalence du goitre chez les adolescents dans le canton de Vaud.

Iodine deficiency disorders virtually disappeared in Switzerland after iodized salt was introduced in 1922 and the iodine content increased from 3.75 to 7.5 mg/kg in 1962 and to 15 mg/kg in 1980. However, a decreasing iodine intake has recently been reported again. The status of iodine nutrition in the Canton of Vaud was therefore assessed in 348 representative adolescents aged 11 to 17 years from the urban area of Lausanne in 1995. Thyroid size was estimated by inspection and palpation and thyroid volume measured by ultrasonography. Iodine concentration was determined in urine. Thyroid enlargement, as assessed by clinical examination, was found in 15% of the adolescents (stage 1a: 12.9%, 1b: 1.8%, 2: 0.3%), but its positive predictive value was low. The goitre prevalence determined by ultrasonography was only 1.4%. In addition, 4% of the adolescents had nodular or diffuse echo-structure abnormalities. Percentiles of thyroid volume as a function of sex, chronological age and body surface area were lower than WHO reference values. Median iodine concentration in urine was 92 micrograms/l (56.6% < 100 micrograms/l), slightly below WHO recommendations. Iodized cooking salt was consumed by 82% of the adolescents. In conclusion, the adolescents living in the Canton of Vaud had a low normal iodine intake with subclinical thyroid abnormalities. These findings support the recent decision to increase the salt iodine content to 20-30 mg/kg in order to prevent iodine deficiency during puberty and pregnancy. Percentiles of thyroid volume determined in the present study can be used as local reference.

[Nutritional balance of breakfast of children 7 to 11 years of age: comparison between school health education and eating behavior at home]. / Equilibre nutritionnel du petit-déjeuner d'enfants de 7 á 11 ans: comparaison entre une action de santé á l'école et l'alimentation au domicile.

Following the favourable impact of a health education programme carried out in a school setting concerning "healthy eating at breakfast", the consumption of food at home for all meals, and separately at breakfast time was evaluated by using a "food-frequency" questionnaire. These results were then compared with the results of the school health education programme which focused primarily on breakfasts. The results of the survey, which included 80 children between 7 and 11 years old, show a great stability in the choice of foods, and during the action interesting variations concerning the respective proportions of nutriments according the recommended dietary allowances. We noticed an increase in the consumption of glucides, starch, vegetable proteins, and certain micronutriments. These changes are minor, but they may have a great importance if they spread to the whole nutrition. One can advise to generalise such school health education interventions.