Sex and ethnic-origin specific BMI cut points improve prediction of 40-year mortality: the Israel GOH study.

BACKGROUND: Although obesity has been associated with a higher risk for premature death, the sex and ethnic-origin specific body mass index (BMI) levels that are associated with increased mortality are controversial. We investigated the 40-year cumulative all-cause mortality, in relation to the BMI in adult life, among men and women originating from Yemen, Europe/America, Middle East and North Africa, using sex and ethnic-origin specific BMI cut points. METHODS: A random stratified cohort (n = 5710) was sampled from the central population registry and followed since 1969 for vital status. Weight, height and blood pressure were measured, and smoking status was recorded at baseline. BMI was analysed according to conventional categories and according to sex and ethnic-origin specific quintiles. RESULTS: Elevated and significant mortality hazard ratios (HRs) of 1.21 [95% confidence interval (CI) 1.00-1.45] for women and 1.22 (95%CI 1.03-1.44) for men were found for the highest origin-specific BMI quintile. In men, the lowest ethnic-origin specific quintile was also significantly associated with increased mortality (HR of 1.22 95% CI 1.03-1.45), adjusting for age, smoking and blood pressure. Obesity was associated with mortality in non-smokers (HR = 1.29, 95% CI 1.04-1.61 in men and HR = 1.46, 95% CI 1.19-1.79 in women), whereas leanness was associated with mortality only among smoking men (HR = 1.39, 95% CI 1.09-1.77). CONCLUSION: Refinement of BMI categories using country of origin specific quintiles demonstrated significantly increased mortality in the upper quintile in both sexes, while according to the conventional values this association did not prevail in men. We propose the establishment of sex and origin-specific BMI categories when setting goals for disease prevention.

Spectacle use and reduced unaided vision in third grade students: a comparative study in different educational settings.

BACKGROUND: The development of myopia is influenced by hereditary factors, environmental factors and gene-environment interaction. Reading and near-work activity are associated with myopia and myopic progression. This study sought to determine and compare the prevalence of reduced unaided vision and spectacle use among third grade Israeli students from three different educational settings. METHOD: A sample of 917 students (mean age 8.5 years, range seven to 10 years) was drawn from the three Israeli educational streams: secular, Orthodox and ultra-Orthodox. Children in the ultra-Orthodox education pathway begin studying at the age of three years and their daily reading involves sustained near work with increased accommodative effort accompanied by head-rocking movements. Reduced distance vision was used to indicate the likely development of or an increase in the amount of myopia. Spectacle lenses were measured to determine the prevalence of myopia. RESULTS: Of the 917 students studied, 103 (11.2 per cent) wore spectacles (14.2 per cent of the males and eight per cent of the females); 82.5 per cent of those who wore spectacles were myopic. Males from ultra-Orthodox schools had the highest rate of reduced unaided vision (72.5 per cent) compared with males from secular schools (27.3 per cent), males from Orthodox schools (59.3 per cent) or with females from all three groups (average of 34.8 per cent, p < 0.0001, chi squared). Males had a higher rate of reduced unaided vision, especially in the Orthodox and ultra-Orthodox schools. CONCLUSIONS: Our study suggests that Jewish ultra-Orthodox males have a higher prevalence and degree of myopia. The study habits of young children, including exposure to prolonged near tasks, high accommodative demands and possibly optical defocus induced by body sway, may contribute to the development of myopia.