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).
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.
Fourth stage – the progressive reduction of insulin secretion stimulated by glucose (1-phase secretion of insulin).
Fifth stage – clinical diabetes (the manifestation of diabetes).