Insulin-dependent diabetes mellitus: strategy for prevention and management

Insulin-dependent diabetes mellitus (IDDM) is inherited in a multifactorial manner with polygenes and environmental factors contributing to its emergence in a particular individual. The evidence for such a mode of inheritance is reviewed. One of the most important genetic roles is that played by the HLA genes on chromosome 6 and the different alleles which increase or decrease susceptibility in Caucasians, Japanese, Singapore Chinese and Shanghai Chinese are described. It is inferred that these alleles are different in different ethnic groups. The other genes which are important are unknown. The environmental influences are less well known although viral infections may act as triggers. Because the morbidity and mortality are still extremely serious in IDDM patients in spite of insulin therapy, it is proposed that preventive measures should be instituted in families prone to IDDM. The role of prenatal diagnosis is discussed especially in those families with multiple HLA susceptibility genes present. Great care paid to management of hyperglycemia from onset of the disease may reduce future morbidity and mortality.