Edited by Frank J. Snoek and T. Chas Skinner
Diabetes in Older Adults
4.3 Symptoms and their Representation
Because the symptoms of diabetes in older adults are often slow to develop, less severe and longer lasting, and because they appear against a more complex background of somatic sensations, older persons may have difficulty distinguishing illness specific symptoms from those attributed to normal ageing, creating unnecessary risk for morbidity and mortality.
Indeed, Kart16 has suggested that physicians, as well as older adults themselves, overestimate the changes that are caused by biological ageing, physicians often assuming that physical and intellectual debilitation necessarily come with age and should be expected as a consequence of ageing. One consequence of older adults’ acceptance of symptoms as signs of ageing is that they fail to report these symptoms to health care professionals.17 This type of misattribution could be important if it leads to the discounting and ignoring of diabetes symptoms or of delay in diagnosis and treatment.18….
Experimental evidence of the existence of an age-illness rule was reported by Prohaska et al.19 They presented participants with scenarios depicting symptoms of varying severity and duration and found that the likelihood of attributing symptoms to ageing was greater for mild than severe symptoms. Attributions of symptoms to age rather than illness also occurred more frequently for older than younger participants regardless of the severity and duration of the symptoms. Participants who attributed symptoms to age also reported less emotional distress and more delay in care-seeking than participants who attributed symptoms to illness — this held for participants of all ages. The data was also clear in showing that all patients were more likely to delay care-seeking when they initially attributed symptoms to ageing.
Extrapolation from these data suggests that older individuals with diabetes may be at greater risk because they are somewhat more likely to make ageing attributions and, because older persons are less robust and resistant to pathogens, they may suffer more if they do delay in seeking care for their illness. Thus, while stimuli, such as gradual onset of symptoms, that lead to ageing attributions and their behavioral consequences are similar for younger and older persons,20 negative health consequences of errors induced by such attributions are more likely for the older individual with diabetes.
In contrast to these findings, however, it is of interest to note that work with people with type 2 diabetes has shown that they are more likely than healthy controls to report a greater frequency and severity of memory problems, which do not appear to be supported by objective memory testing.21 This subjective, yet apparently erroneous, symptom reporting is potentially worrying in that it has also been associated with poorer diabetes-specific problem solving in type 2 patients.22 Clinicians may hence benefit from the knowledge that their elderly patients with type 2 diabetes may over-emphasize memory problems, which, although not objectively evident, may well moderate attempts to self-manage successfully.
The clinical picture of type 2 diabetes differs from that of type 1 in several important aspects. The older age of onset of most patients has already been mentioned. Just over 50 per cent of cases present with classical hyperglycemic symptoms, but with rare exceptions (e.g. during intercurrent illness) the features of diabetic ketoacidosis are absent. Many type 2 patients do not complain of obvious diabetic symptoms, and the disease is detected either opportunistically, for example by screening at medical examinations or during hospital visits, or when patients present with intercurrent infections, usually genital candidisis (particularly in women) or of the urinary tract or skin. Some present with complications of diabetes itself, such as myocardial infarction or peripheral vascular disease, or with microvascular disease, most commonly retinopathy, which may be discovered by an optician during a routine eye test. The high proportion of incidental diagnoses in apparently asymptomatic people emphasizes the fact that type 2 diabetes runs an insidious course; various studies have estimated that significant hyperglycemia is present on average for 5-7 years before the diagnosis is made. These data also indicate that many patients with overt type 2 diabetes still remain undiagnosed, and several surveys that have systematically screened defined populations suggest that up to 50 per cent of all cases have not yet been detected.23
Older adults with diabetes are susceptible to all the usual complications of diabetes. Although clinical outcomes of many of the diabetes complications including end-stage renal disease, loss of vision, myocardial infarction, stroke, peripheral vascular disease, and peripheral neuropathy all increase with age in the absence of diabetes, their incidence and co-occurrence are all exaggerated by the presence of diabetes. Indeed, there is substantial evidence that the presence of diabetes in an older adult increases risk for adverse outcomes. Overall, it is estimated that a diagnosis of diabetes is associated on average with a 10-year reduction in life expectancy. However, this figure becomes progressively reduced at advanced old age, when risks of competing causes of mortality rise exponentially. Nonetheless, diabetes is associated with a higher mortality rate at any age, approaching twice the rate in older people of comparable age without diabetes in some studies. Similarly, the rates of myocardial infarction, stroke, and end-stage renal disease, are increased approximately twofold, and the risk of visual loss is increased by approximately 40 per cent in older people with diabetes. This level of increased relative risk may appear modest on an individual level. However, since the elderly population has by far the highest rates of these conditions, the increase in absolute risk is more substantial. Thus a twofold relative risk increase represents a very large number of added adverse outcomes. The risk for lower extremity amputation is dramatically increased in older people with diabetes, approximately 10-fold greater than that for older people without diabetes.
The individual with type 2 diabetes is more likely to be affected by arterial disease, partly because type 2 diabetes generally appears at a time of life when arteriosclerotic problems are frequent even in the non-diabetic population. In addition, these patients frequently have many other adverse arteriosclerotic risk factors such as obesity, hyperlipidemia, hypertension (which is more common in diabetic people24) and smoking. The grouping of these risk factors has long been recognized and has been given the title of ‘syndrome X’ by Reaven,25 who has suggested that insulin resistance in various tissues can explain its key features.
Obesity is a major predisposing factor to insulin resistance and is also an important obstacle to the effective management of type 2 diabetes. In the UK and other westernized countries, at least 50 per cent of men and 70 per cent of women are 120 per cent of the ideal body weight at presentation;26 truncal obesity, which is associated with hypertension, dyslipidemia and cardiovascular disease is particularly common.27
Coronary artery disease is the main complication of type 2 diabetes. Angina affects17 per cent or more of patients7 and ultimately nearly 60 per cent die from ischemic heart disease as compared with 15 per cent of patients with type 1 diabetes.28 Myocardial infarction is more common in diabetes and also carries a worse prognosis;29,30 the mortality rate is about twice that in non-diabetic individuals. Peripheral vascular disease may cause intermittent claudication and gangrene of the foot or leg, sometimes requiring amputation. Together with neuropathy, it is a major cause of diabetic foot syndrome, a source of considerable morbidity and cost to the health services. Cerebrovascular disease presents as transient ischemic attacks or stroke, which is more common amongst diabetic patients and carries a higher mortality than in the non-diabetic population.28,29
7. Gill GC. Type 2 diabetes – is it ‘mild diabetes’? Practical Diabetes 1986; 3: 280–282.
16. Kart C. Experiencing symptoms: attribution and misattribution of illness among the aged. In Haug MR. (ed.), Elderly Patients and Their Doctors. New York: Springer, 1981, pp 70–78.
17. Brody EM, Kleban MH. Physical and mental health symptoms of older people: who do they tell? J Am Geriatr Soc 1981; 29: 442–449.
18. Leventhal H, Diefenbach M. The active side of illness cognition. In Skelton JA, Croyle RT. (eds), Mental Representation in Health and Illness. New York: Springer, 1991, pp 247–272.
19. Prohaska TR, Keller ML, Leventhal EA, Leventhal H. Impact of symptoms and aging attribution on emotions and coping. Health Psychol 1987; 6: 495–514.
20. Keller ML, Leventhal H, Prohaska TR, Leventhal EA. Beliefs about aging and illness in a community sample. Res Nursing Health 1989; 12: 247–255.
21. Tun P, Perlmuter LC, Russo PA, Nathan DM. Memory self-assessment and performance in aged diabetics and non-diabetics. Exp Aging Res 1987; 13 (3): 151–157.
22. Asimakopoulou KG, Hampson SE. Cognitive function and diabetes self management in older patients with type 2 diabetes. Diabetes Spectrum 2002; 15: 116–121.
23. Fujimoto WY. A national multicenter study to learn whether type II diabetes can be prevented: The Diabetes Prevention Program. Clin Diabetes 1997; January/February: 13–15.
24. Barrett-Connor E, Criqui MH, Klauber MR, Holdbook M. Diabetes and hypertension in a community of older adults. Am J Epidemiol 1981; 113: 276–284.
25. Reaven GM. Role of insulin resistance in human disease. Diabetes 1988; 37: 1595–1607.
26. UKPDS Group. United Kingdom Prospective Diabetes Study. Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). Lancet 1998; 352: 837–853.
27. Bjorntorp P. Abdominal obesity and the development of non-insulin-dependent diabetes mellitus. Diabetes Metab Rev 1988; 4: 615–622.
28. Marks HH, Krall LP. Onset, course, prognosis and mortality of diabetes mellitus. In Marble A, Proctor E (eds), Joslin’s Diabetes Mellitus, 11th edn. Philadelphia PA: Lea and Febiger, 1971, pp 209–254.
29. Rytter L, Troelsen S, Beck-Nielsen H. Prevalence and mortality of acute myocardial infarction in patients with diabetes. Diabetes Care 1985; 8: 230–234.
For more information on this book and how to get a copy, just follow this link to Amazon.com, Psychology in Diabetes Care (Practical Diabetes).
Copyright © 2005 by John Wiley & Sons, Ltd.