Vikas Grover1, Rebecca B. Lipton2, Stanley L. Sclove3.   Seasonality of month of birth among African American children with Diabetes Mellitus in the City of Chicago. Journal of Pediatric Endocrinology & Metabolism, 17 (2004), 289-296.

Short Title:   Seasonality of month of birth among children with diabetes

1. Division of Epidemiology & Biostatistics, University of Illinois at Chicago, School of Public Health, Chicago USA. Current Affiliation: Resident, Department of Internal Medicine, State University of New York, Buffalo, USA.
2. Division of Epidemiology & Biostatistics, University of Illinois at Chicago, School of Public Health, Chicago USA. Current Affiliation: University of Chicago, Division of Pediatric Endocrinology, Chicago, USA
3. Department of Information and Decision Sciences, University of Illinois at Chicago, Chicago USA

Address for correspondence and reprints:
Rebecca B. Lipton, Associate Professor of Pediatrics, University of Chicago, 5841 S. Maryland Ave. (MC 1027), Chicago, IL 60637 USA
Tel: +1-773-834-8313 Fax: +1-773-834-8315 Email: lipton@uchicago.edu
Word Count: 255 (Abstract); 1776 (Article)

Acknowledgments: This work was supported by NIH Grants 1R29DK44752 and 1R01DK44752, and would have been impossible without the efforts of the Chicago Childhood Diabetes Study Group, whose members are listed in the Appendix. Ms Antigone Christakos of the Chicago Department of Public Health gave invaluable help in procuring the population birth data. Members of the research staff, whose work was essential to the conduct of this study, were Esther Alva, Kamal el Deirawi, Martha Schnell, and Michael Walsh.

ABSTRACT

AIM: To study the seasonality of month of birth among African American children with insulin- treated diabetes in the city of Chicago, in order to determine if perinatal exposures play a significant role in diabetes risk among non-European-origin children.

METHOD: The Chicago Childhood Diabetes Registry ascertains new cases of insulin-treated diabetes among minority children <18 years of age; these cases were compared with birth certificate data for the general African-American population in Chicago. The Chi square test and Poisson regression were used to compare the pattern of month of birth of children with diabetes (n=604) to that of the general population (n=758,658) over the same period of years (1968-1995).

RESULTS: In a month-by-month comparison, there were significantly fewer children who later developed diabetes born during October (chi-square = 6.74, 1 df).   This seasonal pattern was stronger among males (n=284) than females (n=320), and among those who apparently developed Type 2 diabetes (n=155) as compared to those who developed Type 1 diabetes (n=449).   Children who were diagnosed between 15-17 years of age (n=131) demonstrated significant seasonality (chi-square = 27.6, 11 df) compared to the general population.

CONCLUSIONS: The apparent protective effect of October birth, and the significant overall seasonality among those diagnosed at ages 15-17, suggests the possibility that seasonal environmental factors at conception, during pregnancy or in the neonatal period may affect diabetes risk in adolescence. The greater impact of month of birth in adolescent Type 2 diabetes patients is surprising and seems to indicate a role for mechanisms other than the immunological ones previously suggested.

KEY WORDS:   Insulin dependent diabetes mellitus, Seasonality; Type 1 Diabetes Mellitus; Children and Adolescents; African Americans; Perinatal Exposures; Environmental Risk Factors


Created 2003: April 18     Updated   2004: July 27