Growing disparities in atopy between the Finns and the Russians: A comparison of 2 generations

Background and objective: Western lifestyle has consistently been associated with the current asthma and atopy epidemics. We examined the occurrence and risk factors of atopy among schoolchildren and their mothers in 2 geographically adjacent areas with fundamental differences in living conditions and lifestyles. Methods: A population-based study of 2 generations was carried out in eastern Finland and in western Russia. Randomly selected schoolchildren aged 7 to 16 years (367 in Finland and 446 in Russia) and their mothers (365 and 437, respectively) were enrolled. Data were obtained by using a modified International Study of Asthma and Allergies in Childhood questionnaire and by performing skin prick tests against 14 common airborne and food allergens. Results: In children a 4-fold higher risk for atopy (>= 1 positive prick test result) was found in Finland compared with Russia. Sensitization rates in Finland were generally higher among children compared with those of their mothers, whereas in Russia the opposite trends emerged. Parental farming in early life (< 1 year) in Finland (odds ratio [OR], 0.53; 95% CI, 0.28-0.99) and in Russia (OR, 0.47; 95% CI, 0.22-1.03) and currently in Finland (OR, 0.45; 95% CI, 0.22-0.91) conferred protection against atopy. Having pets, dogs in Finland (OR, 0.57; 95% CI, 0.35-0.95) and cats in Russia (OR, 0.43; 95% Cl, 0.24-0.80), in early life was also inversely associated with atopy. Conclusion: Atopy was several-fold more common in Finland compared with in Russia, and disparities in sensitization rates between the countries have further increased during these generations. The similarity of explanatory variables of atopy in both countries suggests that determinants of atopy are shared, at least in similar geoclimatic conditions.