Epidemiology of diabetes mellitus in children in Hong Kong: the Hong Kong childhood diabetes register.

OBJECTIVES: To establish a registry for Chinese children with onset of type 1 (insulin dependent) diabetes mellitus before 15 years of age and to determine the incidence of childhood onset type 1 diabetes mellitus in Chinese children in Hong Kong. RESEARCH DESIGN AND METHODS: A registry was established in 1997 to collect childhood diabetes cases retrospectively from all districts in Hong Kong. The study included all newly diagnosed cases of diabetes with onset < 15 yr of age from 1st January 1984 to 31 December 1996. Primary ascertainment was based on review of medical records at all regional public hospitals in Hong Kong and survey of all the registered practitioners in Hong Kong. The secondary source of validation was made impractical, if not impossible, because of the recent implementation of the Personal Data Privacy Ordinance in Hong Kong. RESULTS: A total of 255 diabetic cases were identified, 227 type 1 diabetes mellitus (218 were Chinese), 18 type 2 diabetes mellitus and 11 secondary diabetes. 246 patients were Chinese and 9 non-Chinese. The age-standardized incidence of type 1 and type 2 diabetes mellitus in southern Chinese children in Hong Kong was 1.4/100,000/yr and 0.1/100,000/yr respectively for children < 15 yr of age during the study period. The incidence rates for type 1 diabetes were 0.9, 1.5 and 1.7 per 100,000/yr for 0-4 years, 5 to 9 years and 10 to 14 years age-groups respectively. The incidence for males was 1.2/100,000/yr and for females 1.7/100,000/yr. A significant increase in the incidence was demonstrated during the study period by simple linear regression (slope 0.14/100,000/year, r2 = 0.73, p = 0.0002) CONCLUSIONS: A diabetic registry is established in Hong Kong. This study documents a very low incidence rate of childhood type 1 diabetes mellitus in southern Chinese children in Hong Kong and we have seen an increasing incidence of the disease in the past 13 years.