High risk of IDDM in African-American and Hispanic children in Chicago, 1985-1990.
OBJECTIVE
To determine the incidence of insulin-dependent diabetes mellitus (IDDM) among African-American and Hispanic children < 18 years of age in the city of Chicago. These minority communities are large and heterogeneous with respect to socioeconomic status, length of time since migration, and place of origin, so that correlates of IDDM risk can be examined with precision.


METHODS
Cases occurring during the years 1985-1990 were drawn from records at 37 hospitals in Cook County. African-American and Hispanic patients using insulin, residing within the city limits, and < 18 years old at onset were included. Three secondary sources of cases were used: medical records of clinics associated with the Chicago Department of Health, a survey of unaffiliated neighborhood clinics, and lists of children attending diabetes camps. Overall ascertainment was estimated at 86%.


RESULTS
There were 413 new cases during this 6-year interval. The average incidence of IDDM was 12.0/100,000 annually among African-American males, 12.1 among African-American females, 9.1 among Hispanic males, and 10.2 among Hispanic females. Mean age at onset was 11.1, 11.0, 10.7, and 10.1 years for African-American males, African-American females, Hispanic males, and Hispanic females, respectively. Fewer cases occurred during the summer months. Diabetes among the first-degree relatives of children from both ethnic groups was commonly noted on the medical charts.


CONCLUSIONS
The incidence rates in Chicago fall near the upper limits of reports for both African-origin and Hispanic populations worldwide. The relatively early age at onset may point to an environmental factor associated with this high incidence of the disease. Further studies will provide valuable data on comorbid conditions, unusual diabetic syndromes, and family dynamics in childhood chronic disease.
D000293:Adolescent; D001741:Black or African American; D002641:Chicago / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis / Q000208:ethnology*; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007407:Interviews as Topic; D008297:Male; D010375:Pedigree; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution