Beta cell function and BMI in ethnically diverse children with newly diagnosed autoimmune type 1 diabetes

Pediatr Diabetes. 2012 Nov;13(7):564-71. doi: 10.1111/j.1399-5448.2012.00875.x. Epub 2012 May 30.

Abstract

Objective: To examine the relationship between BMI and beta-cell function at diagnosis of autoimmune type 1 diabetes (T1D) in a large group of ethnically diverse children.

Methods: Cross-sectional analysis of 524 children (60.8% White, 19.5% Hispanic, 14.5% African-American, 5.2% other non-Hispanic; mean age = 9.8 yr [SD = 2.5]) with newly diagnosed autoimmune T1D.

Results: As much as 22.2% of children were overweight or obese. Median random serum C-peptide was 0.40 ng/mL (25th-75th percentiles = 0.3-0.8), with median glycemia of 366 mg/dL (25th-75th percentiles = 271-505). Median C-peptide was 0.3, 0.5, 0.7, and 0.85 ng/mL, respectively, in underweight, normal weight, overweight, and obese children (p < 0.0001, Kruskal-Wallis). In the final model (p < 0.0001), the odds of having preserved C-peptide (≥0.6 ng/mL) were increased by 2.4-fold (95% CI = 1.2-4.9, p < 0.015) and 4.1-fold (1.9-8.5, p < 0.0001), respectively, in overweight and obese compared to lean children; 1.3-fold per each year of age; 2.5-fold in girls compared to boys; 4-fold in children who presented without, compared to with, diabetes ketoacidosis (DKA); and decreased by 21% for each point increase in HbA1c. Tanner stage, race/ethnicity, glycemia, and number of anti-islet antibodies expressed were not independently associated with preserved C-peptide. The association between BMI and C-peptide levels was significant in children with and without preserved C-peptide. Excluding patients who presented with DKA and/or using BMI obtained 5 wk after diagnosis did not alter the results.

Conclusion: Obese and overweight children compared to lean children have greater beta-cell function at the onset of autoimmune T1D. Prospective studies on the relationships among BMI, beta-cell function, and progression to clinical T1D are warranted.

MeSH terms

  • African Americans
  • Autoantibodies / blood
  • Blood Glucose / metabolism
  • Body Mass Index*
  • C-Peptide / blood
  • Child
  • Diabetes Mellitus, Type 1 / ethnology*
  • Diabetes Mellitus, Type 1 / immunology
  • Diabetes Mellitus, Type 1 / physiopathology
  • European Continental Ancestry Group
  • Female
  • Hispanic Americans
  • Humans
  • Insulin-Secreting Cells / immunology
  • Insulin-Secreting Cells / metabolism
  • Insulin-Secreting Cells / physiology*
  • Male
  • Obesity / complications
  • Overweight / complications
  • Puberty

Substances

  • Autoantibodies
  • Blood Glucose
  • C-Peptide