Epidemiology and public health aspects of non-insulin-dependent diabetes mellitus.

NIDDM is the predominant form of diabetes mellitus in all populations, almost exclusively so in some. Its prevalence varies enormously, with particularly high rates in populations whose lifestyle has drastically changed since World War II. Epidemiologic data from the developed countries of Europe and North America are not adequate to determine whether their incidence rates have also increased. Genetic factors are clearly implicated in the etiology of NIDDM, but their location and mode of expression remain to be determined. The two variables most strongly related to the incidence of NIDDM are age and degree of obesity, although there is emerging evidence of an independent association with fat distribution. Whether the nature of the habitual diet and the degree of physical activity influence the incidence of NIDDM remains uncertain and should be further researched. Cardiovascular disease is strongly associated with NIDDM in most populations, but there are between-population differences in the degree of association and the relative excess in the two sexes. There is increasing evidence, in particular for coronary heart disease, that increased risk precedes the onset of hyperglycemia; the implication of this is that NIDDM and atherosclerosis share common antecedents. The specific complications of NIDDM--eye and renal disease--are important causes of morbidity and mortality and for those populations, often relatively poor, in which NIDDM is already or is becoming very common will pose substantial problems in provision of health care.