Incidence of childhood type 1 diabetes worldwide. Diabetes Mondiale (DiaMond) Project Group.
OBJECTIVE
To investigate and monitor the patterns in incidence of childhood type 1 diabetes worldwide.


METHODS
The incidence of type 1 diabetes (per 100,000 per year) from 1990 to 1994 was determined in children < or =14 years of age from 100 centers in 50 countries. A total of 19,164 cases were diagnosed in study populations totaling 75.1 million children. The annual incidence rates were calculated per 100,000 population.


RESULTS
The overall age-adjusted incidence of type 1 diabetes varied from 0.1/100,000 per year in China and Venezuela to 36.8/100,000 per year in Sardinia and 36.5/100,000 per year in Finland. This represents a >350-fold variation in the incidence among the 100 populations worldwide. The global pattern of variation in incidence was evaluated by arbitrarily grouping the populations with a very low (<1/100,000 per year), a low (1-4.99/100,000 per year), an intermediate (5-9.99/100,000 per year), a high (10-19.99/100,000 per year), and a very high (> or =20/100,000 per year) incidence. Of the European populations, 18 of 39 had an intermediate incidence, and the remainder had a high or very high incidence. A very high incidence (> or =20/ 100,000 per year) was found in Sardinia, Finland, Sweden, Norway Portugal, the U.K., Canada, and New Zealand. The lowest incidence (<1/100,000 per year) was found in the populations from China and South America. In most populations, the incidence increased with age and was the highest among children 10-14 years of age.


CONCLUSIONS
The range of global variation in the incidence of childhood type 1 diabetes is even larger than previously described. The earlier reported polar-equatorial gradient in the incidence does not seem to be as strong as previously assumed, but the variation seems to follow ethnic and racial distribution in the world population.
Karvonen
M
M
Department of Epidemiology and Health Promotion, National Public Health Institute, Helsinki, Finland. marjatta.karvonen@ktl.fi
Viik-Kajander
M
M
Moltchanova
E
E
Libman
I
I
LaPorte
R
R
Tuomilehto
J
J
D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D005260:Female; D014943:Global Health; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D012307:Risk Factors; D012737:Sex Factors; D014944:World Health Organization