The rising incidence of type 1 diabetes mellitus and the role of environmental factors--three decade experience in a primary care health center in Saudi Arabia.

Background: The incidence of type 1 diabetes has been increasing all over the world including Saudi Arabia and environmental factors have been suggested to play an important role in its etiology.

Objective: The aim of this study was to evaluate if there are any contributory roles of various environmental factors in the rising incidence of type 1 diabetes in children in the Eastern Province of Saudi Arabia.

Methods: We conducted a retrospective study of Saudi Arab subjects (n = 119) diagnosed between 1980 and 2009 with type 1 diabetes and these subjects were classified to six groups on the basis of the onset of diabetes.

Results: 119 subjects (61 boys and 58 girls) with confirmed diagnosis of type 1 diabetes met the study eligibility criteria. 89 children (74%) presented with ketoacidosis. The mean age of onset was 4 3/4 years for Group II and age of onset increased to above 8 years on subsequent years. Excessive weight gain was noted in all study groups. No etiological influences of maternal age at birth, birth order, birth weight, early introduction of cow's milk and cereals, infections and vaccines as well as nitrate levels in drinking water were noted in any of the groups. The predicted doubling of diabetes in young children below 5 years as in previous studies was not found in our study.

Conclusions: The rising incidence of type 1 diabetes over the last 30 years is not proved to have been influenced by various environmental factors.