Genetic predisposition and environmental factors leading to the development of insulin-dependent diabetes mellitus in Chilean children

Abstract

This study was designed to examine the hypothesis that some environmental factors increase the risk for insulin-dependent diabetes mellitus. Data on dietary history was collected from 80 diabetic children from the Santiago de Chile Registry and from 85 nondiabetic control subjects who were comparable in terms of age, sex, and ethnic characteristics. Early exposure was defined as the ingestion of food sources other than maternal milk before 3 months of age. To define genetic susceptibility to insulin-dependent diabetes mellitus each subject was typed in terms of HLA DQA1 and DQB1, and the possible conformation of susceptible heterodimers was considered as a risk marker. Fewer children were exclusively breast fed in the diabetic group than in the control group (21.55 +/- 15.05 vs 33.95 +/- 20.40 weeks, P<0.01). In addition, exposure to cow's milk and solid foods occurred earlier in the diabetic group than in the control group (15.90 +/- 10.95 vs 21.15 13.65 and 16.85 +/- 10.25 vs 21.20 +/- 12.35 weeks, P<0.05). Our data show that a short duration of breast-feeding and early exposure to cow's milk and solid foods may be important factors in the development of insulin-dependent diabetes mellitus. The high relative risk observed in individuals genetically predisposed indicates an interaction effect between genetic and environmental components.

Short-term exclusive breastfeeding predisposes young children with increased genetic risk of Type I diabetes to progressive beta-cell autoimmunity

“…Also, the different susceptible or protective HLA risk alleles, or both, could affect the influence of specific environmental factors in initiating and promoting the autoimmune process. It has been implied that an even stronger association between breastfeeding and diabetes might have been detected in previous case-control studies, if the cases and control subjects had been genetically matched [8] and this hypothesis has actually been confirmed by a Chilean study [22]. Those children who tested positive for all four diabetes-associated autoantibodies most probably have an ongoing beta-cell destructing process in their pancreatic islets.…”

Environmental Triggers and Determinants of Type 1 Diabetes

“…So far, there are only a few examples of gene-environmental interactions implicated to play a role in the development of type 1 diabetes. The findings in two case-control studies suggested that there might be an interaction between increased genetic disease susceptibility, based on HLA class II alleles, and an early introduction of supplementary milk feeding during infancy on the risk of type 1 diabetes (88,89). A Finnish study indicated that the increased relative risk associated with childhood milk consumption may be higher among siblings of affected children carrying HLA class II genotypes conferring strong or moderate disease susceptibility than among those with low or decreased risk genotypes (63).…”

Breastfeeding and the Use of Human Milk

“…Some studies suggest decreased rates of sudden infant death syndrome in the first year of life [49][50][51][52][53][54][55] and reduction in incidence of insulin-dependent (type 1) and non-insulin-dependent (type 2) diabetes melli- [56][57][58][59] lymphoma, leukemia, and Hodgkin disease, 60-62 overweight and obesity, 19,63-70 hypercholesterolemia, 71 and asthma [36][37][38][39] in older children and adults who were breastfed, compared with individuals who were not breastfed. Additional research in this area is warranted.…”