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


CONCLUSIONS
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.
Department of Pediatrics, Section of Diabetes and Endocrinology, Texas Children's Hospital, Baylor College of Medicine, Houston, TX 77030, USA. redondo@bcm.edu
Maria J
MJ
Redondo
Luisa M
LM
Rodriguez
Mirna
M
Escalante
E
E
O'Brian Smith
Ashok
A
Balasubramanyam
Morey W
MW
Haymond
D001741:Black or African American; D001323:Autoantibodies / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000208:ethnology* / Q000276:immunology / Q000503:physiopathology; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D050417:Insulin-Secreting Cells / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009765:Obesity / Q000150:complications; D050177:Overweight / Q000150:complications; D011627:Puberty; D044465:White People
D001323:Autoantibodies; D001786:Blood Glucose; D002096:C-Peptide