ABSTRACT
AIM: The aim of this study, which is part of the ongoing DIABFIN project, was to correlate HLA class II genotypes, classified for their effect on susceptibility to Type 1 diabetes (T1D), with various risk factors during pregnancy and the neonatal period. METHODS: Cord blood was collected from 4349 neonates; 1.0% were at high HLA risk (HR), 9.0% at moderate HLA risk (MR), and 90.0% at low HLA risk (LR) for T1D. Information about the mother's pregnancy, type of delivery, the neonates' clinical features at birth, and family history for autoimmune diseases were collected. RESULTS: Significant correlations were found between the different HLA risk categories and length of gestation, even when adjusted for sex, weight and length at birth of the neonate, birth order and mother's age (adjusted P = 0.007). The male : female ratio tended to increase from the LR to the HR category, from 1.00 and 1.21, respectively, in the LR and MR groups, to 1.62 in the HR group (P = 0.05). CONCLUSIONS: Length of gestation is inversely correlated with HLA risk categories for T1D. The higher the HLA risk for T1D, the shorter the gestational age, especially in male neonates.
Subject(s)
Diabetes Mellitus, Type 1/genetics , Genetic Predisposition to Disease , Histocompatibility Antigens Class II/genetics , Pregnancy in Diabetics/genetics , Female , Genotype , Gestational Age , Humans , Infant, Newborn , Pregnancy , Risk Factors , Sex FactorsABSTRACT
BACKGROUND AND AIMS: An epidemiological retrospective study and a recent prospective study from Finland have both concluded that vitamin D3 supplementation at birth protects individuals from type 1 diabetes later in life. Moreover, it is thought that vitamin D3 supplementation, in particular its activated form, 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], may act as an immunomodulator, facilitating the shift from a Th1 to a Th2 immune response. The aim of this surveillance study was to measure levels of both 25-hydroxyvitamin D3 (25OHD3) and 1,25-dihydroxyvitamin D3 in patients with newly diagnosed type 1 diabetes as compared to normal subjects. METHODS: We measured plasma levels of 25-hydroxyvitamin D3 [25OHD3] and 1,25-dihydroxyvitamin D3 by radioimmunoassay in 88 consecutive patients with newly diagnosed type 1 diabetes (mean age 14.6 years; diagnosis within the last week), and in 57 healthy age and sex-matched subjects (mean age 16.5 years) born and residing in the Lazio region of continental Italy. RESULTS: Mean levels of both 25OHD3 and 1,25-(OH)2D3 were significantly lower in patients compared to controls (p < 0.01 and p < 0.03, respectively). There was no correlation between 1,25-(OH)2D3 plasma level and metabolic control status at disease diagnosis, age, gender, or most importantly, seasonality of disease diagnosis. This new observation endorses the findings of the Finnish study, even though Italy is a geographic area with more hours of sunlight than Finland. CONCLUSIONS: These findings suggest that vitamin D3 may be an important pathogenic factor in type 1 diabetes independent of geographical latitude, and that its supplementation should be considered not only at birth, but also at diagnosis of type 1 diabetes with the aim of favouring a Th2 immune response and protecting residual beta cells from further destruction.
