Kelly West Lecture 1991 Challenges in Diabetes Epidemiology—From West to the Rest

Abstract

The application of epidemiology to the study of non-insulin-dependent diabetes mellitus (NIDDM) is providing new insights into many aspects of this major public-health problem, including its natural history, prevalence, incidence, morbidity, and mortality in diverse populations around the globe. The main impetus came from the late Kelly West's book Epidemiology of Diabetes and its Vascular Lesions. These studies are providing direction for research into the possible molecular defect or defects and biochemical mechanism or mechanisms underlying NIDDM and important information on the extrinsic (social, cultural, environmental) risk determinants. Studies have highlighted the importance of regional adipose tissue distribution, particularly upper-body obesity, and physical inactivity in enhancing risk of NIDDM. These findings have important implications for the primary prevention of NIDDM, particularly in populations with increased genetic susceptibility such as Polynesians, Micronesians, American and Asian Indians, Mexican Americans, and Australian aborigines.Hyperinsulinemia and insulin resistance may be present many years before the onset of NIDDM and clearly play an important role in its etiology. There is some evidence to support the contention that hyperinsulinemia and insulin resistance may also play an important causal role in hypertension, dyslipidemia, upper-body obesity, and, through these risk factors, coronary artery disease. Hyperinsulinemia and/or insulin resistance may be a central factor in the etiology of glucose intolerance, hypertension, dyslipidemia, upper-body obesity, and atherosclerosis, which has very important implications for the primary prevention of these disorders. That both weight reduction and exercise reduce insulin resistance and reduce the levels of some of the other risk factors for coronary artery disease provides strong support for an integrated approach to the primary prevention of NIDDM and cardiovascular disease, although it seems paradoxical that prevention is now a possibility, whereas, the molecular and biochemical mechanisms involved in the etiology of these disorders are not fully understood. EPIDEMIOLOGICAL APPROACH TO NON-INSULIN-DEPENDENT DIABETES MELLITUS (NIDDM) -There has been a remarkable upsurge in interest and activity in studies relating to the epidemiology of diabetes mellitus

Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus

“…Insulin resistance may improve with weight reduction and/or pharmacological treatment of hyperglycemia but is seldom restored to normal (36 -40). The risk of developing this form of diabetes increases with age, obesity, and lack of physical activity (29,41). It occurs more frequently in women with prior GDM and in individuals with hypertension or dyslipidemia, and its frequency varies in different racial/ethnic subgroups (29,30,41).…”

“…The risk of developing this form of diabetes increases with age, obesity, and lack of physical activity (29,41). It occurs more frequently in women with prior GDM and in individuals with hypertension or dyslipidemia, and its frequency varies in different racial/ethnic subgroups (29,30,41). It is often associated with a strong genetic predisposition, more so than is the autoimmune form of type 1 diabetes (42,43).…”

Are there ethnic differences in the association between body weight and resistance, measured by bioelectrical impedance?

“…1±3 However, few studies have examined the effects of ethnicity on the relationship between body size and body composition. Although the prevalence of obesity-related complications, such as hypertension and non-insulin dependent diabetes varies widely among ethnic groups, 4 data on body fatdisease vs overweight-disease relationships, is not available. Bioelectrical impedance analysis is an attractive tool in epidemiology for the assessment of body composition, due to its portability, low cost and ease of use for a large number of subjects.…”

Reduction of risk factors for cardiovascular diseases in morbid-obese patients following biliary-intestinal bypass: 3 years' follow-up

“…Patients affected by abdominal obesity, often affected by hypertension, dyslipidaemia and impaired glucose metabolism, suffer from cardiovascular disease (CVD) for reasons that are, in part, still unclear. 5 The clustering of impaired glucose metabolism, elevated triglycerides, low HDL cholesterol and abdominal obesity has been variously labelled as, syndrome X, 6 insulin resistance syndrome 7 or metabolic syndrome. 7 Alone, each component of the cluster conveys an increased risk of CVD, but as a combination they become much more powerful and severe.…”

“…5 The clustering of impaired glucose metabolism, elevated triglycerides, low HDL cholesterol and abdominal obesity has been variously labelled as, syndrome X, 6 insulin resistance syndrome 7 or metabolic syndrome. 7 Alone, each component of the cluster conveys an increased risk of CVD, but as a combination they become much more powerful and severe. 8 Obese patients show an increased prevalence of hypertension, 9 dyslipidaemia, hyperglycaemia and fibrinogen excess, 10 in addition to CVDs such as coronary heart disease and stroke.…”