Type 1 Diabetes In type 1 diabetes mellitus, body cells fail to produce insulin due to a compromised immune system causing damage to the cells where production of insulin takes place.
The cause and prevention of type 1 diabetes are not particularly known; however, it is suspected to be a consequence of certain genetic factors.
First stage – a genetic predisposition, due to the presence of certain antigens in the HLA system, as well as genes of chromosomes 11 and 10.
Second stage – the initiation of the autoimmune process in islands of B cells influenced with viruses, cytotoxic agents and any other unknown factors.
Genetic susceptibility is linked with particular genes of HLA systems, which are considered markers of such a predisposition.
Patients with a genetic predisposition to IDDM have an altered response to environmental factors.The most common occurrence of IDDM clinically is preceded by the following viral infections: measles (rubella virus has a tropism to the islets of the pancreas, accumulates, and can be replicated in them), Coxsackievirus and hepatitis B virus (can be replicated in the insular apparatus), mumps (1-2 years after the epidemic of mumps, the incidence of IDDM in children dramatically increases), infectious mononucleosis, cytomegalovirus, influenza virus, etc.The role of viral infection is confirmed by seasonality in the incidence of IDDM development (often, the first diagnosed cases of IDDM among children occur in autumn and winter months, with a peak incidence in October and January), the detection of high titers of antibodies to the virus in the blood of patients with IDDM, and the detection by immunofluorescent methods for studying viral particles in the islets of Langerhans in people who have died of IDDM.For mothers who had gestational diabetes during their first pregnancy, the probability that it will occur in subsequent pregnancies is approximately two-thirds.Furthermore, some patients may subsequently develop type 2 diabetes.They are associated with the HLA system (D-locus), which determines the individual, genetically determined response of the body and B cells to various antigens.The hypothesis of polygenic inheritance of IDDM suggests that diabetes is caused from two mutant genes (or two groups of genes) that have a recessive inherited predisposition to autoimmune lesions of the insular apparatus or increased sensitivity of B cells to viral antigens or attenuated antiviral immunity.Its length depends on the severity and degree of B cell damage, their ability to regenerate, and the level of residual insulin secretion, as well as the severity and frequency of related viral infections.Sixth stage – the complete destruction of b-cells, and a complete lack of insulin secretion and C-peptide.Type 2 Diabetes In type 2 diabetes mellitus, there is low production of insulin by the body cells or the body does not effectively make use of the produced insulin.Type 2 diabetes is known to be the commonest type of diabetes; in fact, 90% of diabetes sufferers have type 2 diabetes (World Health Organization, 1999).