|Disease||Diabetes mellitus, Type I (juvenile)|
|Blood Group Link||In general, Type I diabetes has a highly significant overall association with Blood Types A and AB, and this is especially strong in males versus females. What is especially interesting is the fact that the percentage of Blood Type A over Blood Type O in diabetes appears to increase with age. This association has been confirmed in several large independent studies, looking at literally thousands of people.|
It may be that the link with Blood Type A and diabetes results from the ability of certain serum lectins to bind to both the A antigen and the insulin-producing Langerhans cells of the pancreas. This complex has been shown to stimulate the activation of the antibody IgE at the site, thereby resulting in inflammation and cell death. This would explain why both blood types that carry an A antigen are at risk.
One of the strongest risk factors for juvenile diabetes, almost the same risk as having a mother with diabetes, is a maternal-child blood group incompatibility. As we have seen, the immune consequences of maternal-fetal incompatibility are the worst if the mother is Blood Type O and the child is Blood Type A. This association was particularly strong for children of
ABO incompatible mothers, who went on to develop diabetes within the first five years of life. Diabetes may have exerted a powerful environmental effect on the delayed occurrence of Blood Type A in any large numbers. This begs the question: If diabetes is a fairly deadly disease without insulin replacement, how could it have persisted genetically through the earlier times in which there was no effective life saving therapy? Several theories have been advanced, including the observation that women who have a hereditary tendency toward diabetes tend to be more fertile than normal women, and apparently begin to menstruate at a younger age.
In the late 1950s, diabetes was placed in a broader anthropological context. In Paleolithic times, when humankind lived on a low carbohydrate, low calorie diet, diabetes would have only rarely developed to the point that the greater fertility would have maintained the frequency of the gene. One researcher went so far as to call diabetes a thrifty gene, which may have had some advantage to those possessing it, especially during times of starvation. Diabetes may have been advantageous under certain primitive conditions. But today, with the availability of adequate, or more than adequate, carbohydrate-rich diets, it now provokes a different sort of result altogether.
This is especially interesting in light of research which seems to indicate that, though the overall incidence of diabetes is higher in Blood Type A, the percentage of Blood Type O rises in diabetics who are below average in weight.
As with stress, high blood pressure, and myocardial disease, there are substantial differences between Blood Type A and Blood Type O diabetics with regard to the rheology (fluidity) of their blood. Blood Type A diabetics have significantly higher levels of clotting factors in their blood when compared with Blood Type O or Blood Type B diabetics. This may be an important risk factor in determining the probability of developing cardiovascular complications due to diabetes. It is more often Blood Type A individuals who have borderline diabetes. Their insulin levels are low, but not frankly absent.
ABH non secretors, and especially Lewis negative individuals, are at a greater risk of developing diabetes (especially adult onset diabetes); and they might be at a greater risk of developing complications from diabetes. Findings suggest that an increased proportion of non-secretors are found among patients with diabetes, particularly of the insulin-dependent diabetes type. (14,15)
The Lewis negative (Le a-b-) red blood cell phenotype appears to confer the greatest risk of developing diabetes. This blood type is observed more than three times more frequently (29%) in diabetics irrespective of their clinical type. Non-diabetics categorized as low insulin responders to glucose are also significantly more likely to be Lewis negative. (16)
Among individuals with juvenile diabetes mellitus, the prevalence of severe retinopathy (a side effect of diabetes) is lower in ABH secretors than in the ABH non-secretor group. (17)
The MN variation of the MN blood grouping subtype is associated with a higher incidence of diabetes
Non-diabetic individuals who are non-secretors of blood group antigens are prone to superficial infections by Candida albicans. In this study, 216 patients with diabetes mellitus who were denture wearers were examined for the presence or absence of denture stomatitis. There was an overall trend for non-secretors to be prone to denture stomatitis compared with secretors. Stepwise linear discriminant analysis was used to dissect the contribution of secretor status and other variables to the development of the disease. Secretor status was found to be a contributory factor among patients with non-insulin dependent diabetes but not among those with insulin-dependent diabetes. The possible reasons for this are discussed. Xx)
|Special Note||A matched case-control study was carried out analysing about 20 perinatal variables concerning mother and child. A total of 2757 infants who became diabetic during the period 1978-1988 were analysed. For each case infant three control children were randomly selected from among all infants born in the same year and at the same delivery unit as the case infant. The following statistically significant risk factors were identified for Type 1 diabetes with an onset before 15 years of age: maternal diabetes (OR = 3.90), maternal age above 35 (OR = 1.36), maternal non-smoking (OR = 1.54), pre-eclamptic toxaemia (OR = 1.19), caesarian section (OR = 1.32), and maternal-child blood group incompatibility (OR = 1.61). When the analysis was restricted to Type 1 diabetes with an onset before the age of 5 years, most odds ratios were increased - for blood group incompatibility OR = 3.86 (95% confidence interval 1.54-9.65). Icterus without blood group incompatibility was not a significant risk factor. When each risk factor was analysed after standardization for all other risk factors, the odds ratios remained significantly increased. Scrutiny of medical records for cases and control children with a diagnosis of blood group incompatibility verified the diagnosis in close to 90% of children. The more severe cases needing phototherapy and/or blood transfusion were found to have a greater risk than milder cases.|
|References||1. Patrick AW, Collier A. An infectious aetiology of insulin-dependent diabetes mellitus? Role of the secretor status. FEMS Microbiol Immunol 1989 Jun;1(6-7):411-416|
2. Peters WH, Gohler W. ABH-secretion and Lewis red cell groups in diabetic and normal subjects from Ethiopia. Exp Clin Endocrinol 1986 Nov;88(1):64-70
3. Melis C, Mercier P, Vague P, Vialettes B. Lewis antigen and diabetes. Rev Fr Transfus Immunohematol 1978 Sep;21(4):965-71
4. Eff C, Faber O, Deckert T. Persistent insulin secretion, assessed by plasma C-peptide estimation in long-term juvenile diabetics with a low insulin requirement. Diabetologia 1978 Sep;15(3):169-72
5. Epidemiol Infect 1991 Apr;106(2):355-363 Chronic atrophic oral candidiasis among patients with diabetes mellitus--role of ABH secretor status. Aly FZ, Blackwell CC, MacKenzie DA, Weir DM, Elton RA, Cumming CG, Sofaer JA, Clarke BF
6. Diabetologia 1992 Jul;35(7):671-675 Maternal-child blood group incompatibility and other perinatal events increase the risk for early-onset type 1 (insulin-dependent) diabetes mellitus. Dahlquist G, Kallen B, Department of Pediatrics, University of Umea, Sweden.