Rudy Bilous, MD, FRCP
Richard Donnelly, MD, PHD, FRCP, FRACP
There is a steep age-related increase in the prevalence of diabetes and impaired glucose tolerance which applies equally to both sexes. Overall, diabetes prevalence is higher in men, but there are more women with diabetes. In developing countries, most people with diabetes are in the 45–64-year age band, whereas in developed countries the majority of people with diabetes are aged> 64 years (Figure 29.1 ). There is a particularly high frequency of type 2 diabetes in certain susceptible ethnic groups such as black Americans and Mexican Americans (about 30% of the elderly)….
By the year 2030, it is estimated that the number of people with diabetes over 64 years of age will be >82 million in developing countries and >48 million in developed countries (Figure 29.2). In future years, a bigger proportion of the diabetes population will be elderly. This will have a number of effects on clinical practice. The presentation, management and outcomes of diabetes are different in older patients, especially if diabetes occurs in the context of other co-morbidities, frailty, physical and cognitive impairment and multiple drug therapies.
The presentation of diabetes in older people is often insidious and the diagnosis is often delayed. The symptoms can be non-specific and vague, such as fatigue, urinary incontinence or change in mental state (e.g. depression, confusion and apathy) (Box 29.1). Many cases are detected by finding incidental hyperglycaemia during the investigation of co-morbidities, such as a delayed recovery from specific illnesses, repeated infections or cardiovascular disease; the latter may present with atypical features, such as painless myocardial infarction, manifested as breathlessness, lassitude or falls. Acute metabolic disturbance is a further, rarer presentation: about 25% of cases of hyperosmolar nonketotic hyperglycemic coma (HONK, see Chapter 12) occur in people with previously undiagnosed type 2 diabetes. The tendency to hyperosmolarity may be worse in elderly people, who may not perceive thirst or drink enough to compensate for the osmotic diuresis of diabetes, and who are often taking diuretics.
Elderly patients with diabetes require treatment mainly to alleviate symptoms, to reduce the risk of hyperglycaemic crises, to prevent and manage vascular and other complications and to achieve a normal life expectancy whenever possible (Box 29.2). Strict glycemic control may not always be appropriate. Diets rarely produce weight loss in the elderly and may be unjustifiably burdensome in the frail. Short-acting sulphonylureas such as gliclazide, or DPP-4 inhibitors, are preferred because of the likelihood in the elderly of impaired renal function, poor nutrition, impaired counterregulatory responses and cognition, and other factors that increase the risk of hypoglycaemia. Metformin is best avoided in many elderly subjects because of its increased tendency to cause lactic acidosis with renal impairment and hepatic or cardiac failure.
Simple insulin regimens are usually the most appropriate in diabetes of old age. Twice-daily injections of premixed insulins for type 1 diabetes or NPH insulin in type 2 patients are preferred. However, the practical difficulties of administration can limit their use in some patients and once-daily insulin, though unlikely to produce good control, may be more suitable for the very old and frail. The use of once- or twice-daily injections of the long-acting insulin analogues glargine or detemir may be advantageous and practical. The traditional multiple-dose, basal-bolus regimen for achieving near normoglycemia is probably only suitable for the comparatively few well-motivated, mobile and mentally alert patients who are independent in self-care and have no other medical disorders.
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Rudy Bilous MD, FRCP, Professor of Clinical Medicine, Newcastle University, Honorary Consultant Endocrinologist, South Tees Foundation Trust, Middlesbrough, UK
Richard Donnelly MD, PHD, FRCP, FRACP, Head, School of Graduate Entry Medicine and Health, University of Nottingham, Honorary Consultant Physician, Derby Hospitals NHS Foundation Trust, Derby, UK
A John Wiley & Sons, Ltd., Publication This edition first published 2010, © 2010 by Rudy Bilous and Richard Donnelly. Previous editions: 1992, 1999, 2004
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