Diabetes-associated HLA genotypes affect birthweight in the general population.

• Aims/hypothesisThe aim of our study was to test the hypothesis that HLA genotypes conferring risk of diabetes, cord blood autoantibodies, or both are associated with increased birthweight. Methods: HLA genotypes were determined in dried blood spots of cord blood from a total of 16,709 children born to healthy mothers in the Diabetes Prediction in Skane (DiPiS) study, a population-based observational clinical investigation of newborn children. Children born to mothers with diabetes or gestational diabetes were excluded. Autoantibodies to glutamic acid decarboxylase (GAD65Ab) and insulinoma-associated protein 2 were determined in standard radioligand binding assays. Birthweight was adjusted for gestational age and divided into quartiles. The upper quartile was defined as high relative birthweight (HrBW) and the lower quartile as low relative birthweight (LrBW). Results: Genotypes conferring risk of type 1 diabetes were strongly associated with relative birthweight (rBW) (p=0.01). The high-risk HLA-DQ2/8, DQ8/0604 and DQ8/X genotypes were associated with HrBW (odds ratio [OR] [95% CI]=1.20 [1.08-1.33], p=0.0006). The HLA-DQB1*0603 allele, which is negatively associated with type 1 diabetes, was also associated with HrBW (p=0.025), confirming a previous report on DQB1*0603-linked HLA-DR13. GAD65Ab were negatively associated with HrBW (OR [95% CI]=0.72 [0.56-0.93], p=0.01). Regression analysis showed that the HLA-associated increase in rBW was independent of confounding factors. Conclusions/Interpreation: HLA genotypes may be associated with intrauterine growth independent of type 1 diabetes risk. The epidemiological observation that high birthweight is a risk factor for type 1 diabetes could possibly result from a moderating effect on intrauterine growth of HLA genotypes conferring a high risk of diabetes.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Endokrinologi och diabetes (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Endocrinology and Diabetes (hsv//eng)

Keyword

IA-2 autoantibodies

HLA-DQ8

HLA

GAD65 autoantibodies

birthweight

diabetes mellitus

insulin-dependent diabetes

screening

type 1 diabetes

HLA-DQ2

Publication and Content Type

art (subject category)

ref (subject category)