Aging with Diabetes—An Underappreciated Cause of Progressive Disability and Reduced Quality of Life
This continuing medical education activity is sponsored by the Johns Hopkins University School of Medicine, Baltimore, Maryland. The Johns Hopkins University School of Medicine takes responsibility for the content, quality, and scientific integrity of this CME activity. These examination questions are based on the article “Aging with Diabetes—An Underappreciated Cause of Progressive Disability and Reduced Quality of Life,” which appears on pages 45-53 in this issue of Clinical Geriatrics.
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The Johns Hopkins University School of Medicine designates this education activity for a maximum of 1.0 category 1 credit toward the AMA Physician’s Recognition Award. Each physician should claim only those hours of credit that he/she actually spent in the educational activity.
Valid October 1- December 31, 2004.
Estimated time: 1 hour
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1. To understand the pivotal importance and negative impact of diabetes on functional status, quality of life, development of progressive disability, and life expectancy in older adults
2. To be able to recognize and clinically monitor the six most common geriatric syndromes in older adults with diabetes
3. To learn to implement tools for the assessment of depression, impairment in lower extremity functioning and risk for falls, adverse consequences of polypharmacy, and ability for self- management of diabetes
4. To be able to recommend effective pharmacologic and rehabilitative treatments for older adults with diabetes Instructions
A certificate of completion will be awarded to physicians completing the posttest and evaluation form. Please complete the following examination answer sheet and mail it with your payment of $10 (write the course number OFP# 55-0615 on your check payable to Johns Hopkins-Office of Funded Programs) to: Johns Hopkins University School of Medicine Office of Funded Programs P.O. Box 64749 Baltimore, MD 21264-4749
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In adults 60 years and older, diabetes mellitus (DM) has reached almost epidemic proportions, affecting 8.6 million or 18.3% of the population in the United States.1 When impaired fasting glucose (IFG) is also considered, the prevalence of both DM and IFG in persons over 60 years rises to 33.6%. Commencing at age 60, the lifetime risk of subsequently developing diabetes is also high: 22.4% for women and 18.9% for men.2,3 Because diabetes is a chronic, progressive condition, it is associated with significant disability and tremendous costs. In 2001, total expenditures equaled $132 billion, not to mention the intangible costs to society, families, and patients who struggle to live with this disabling disease.1
Reduced Quality of Life and Functional Status
Because of this epidemic and the disproportionate, progressive decline in the physical and functional status of older adults with diabetes, this population deserves special attention. In a study of 177 elderly persons with diabetes, using a cross-sectional questionnaire evaluating health-related quality of life, patients with diabetes scored worse in 7 of 13 measures,4 including general health perceptions, physical functioning, satisfaction with physical health, pain, sleep problems, and role limitations due to both physical and emotional health. Older age and longer duration of diabetes were both key contributors to the reduced quality of life. The pivotal importance of functional status in persons 70 years and older was reported by Lubitz and co-authors5 using data from the 1992-1998 Medicare Current Beneficiary Survey. Among 16,964 seniors, those reported in “better health” lived longer, and those with no functional limitations at age 70 remained active for 61% of their remaining years. With even one limitation in an activity of daily living, life expectancy was reduced by 2.7 years and activity status was maintained for only 35% of the remaining years. Although diabetes was not considered separately, these data emphasize the importance of functional status. Contributing to their poorer quality of life, older persons with diabetes have higher rates of coronary heart disease (CHD), hypertension, and stroke, and are at greater risk for developing one of the common but frequently overlooked geriatric syndromes than their age-matched nondiabetic counterparts.6,7 These syndromes are depression, cognitive impairment, injurious falls, polypharmacy, persistent pain, and urinary incontinence. Any one of these syndromes can adversely affect quality of life, resulting in a vicious cycle of decline, deterioration in self-management, greater demands on caregivers, loss of independence, and possible institutionalization. As discussed herein, older women with diabetes have disproportionately higher risks for physical and mental disability. When the combined burdens of diabetes, its complications, and the geriatric syndromes are considered, the reduction in life expectancy and number of quality-of-life years lost are estimated to be 7.3 and 11.1 years, respectively, in men, and 9.5 years and 13.8 years, respectively, in women.3 To facilitate successful aging in patients with diabetes, it is important to recognize the heterogeneity of the spectrum of health in this population. Some patients suffer multiple diabetic complications plus other chronic diseases, whereas others have no evidence of end-organ damage or functional disability. Because of this variability, diabetes care for older adults must be patient-centered rather than disease-centered. It is not enough to follow the American Diabetes Association (ADA) guidelines. A broader scope is required, including an assessment of functional status and the presence of the geriatric syndromes. Although glycemic control and prevention of microvascular complications are important, it takes approximately 8 years of improved glucose control to reduce microvascular complications and about 2-3 years of blood pressure and lipid control to reduce macrovascular endpoints.7 Given that a person’s life expectancy may be shorter than the time needed to benefit from an intervention, it is important to prioritize treatment strategies. This task is often overwhelming, even for experienced internists, family physicians, and geriatricians. A diabetes-focused geriatric questionnaire for use during office visits is shown in the Table.
Guidelines for Improving Care of Older Patients with Diabetes
To improve the overall care for the older person with diabetes, the California Healthcare Foundation/ American Geriatrics Society Panel on Improving Care for Elders with Diabetes published evidence-based guidelines in 2003 for those 65 years and older.7 This review, which summarizes the geriatric syndromes in diabetes, offers some practical suggestions for prevention, screening, and treatment.
The Plight of the Older Woman with Diabetes
The prevalence and severity of functional disabilities associated with diabetes are significantly greater in older women than men.8,9 Before dying prematurely, older women with diabetes spend twice as many years disabled as do men and are more likely to reside in nursing homes.8 Women are vulnerable because they tend to be less physically active and have longer life expectancies, with 4 years longer life at age 65 and 3 years longer life at age 75.1,10 Considering that the population of women over age 65 is growing and is estimated to be 37.7 million by 2030, the consequences of diabetes-related disabilities in women represent a serious public health problem. Diabetes magnifies the decline and disability of older women and accentuates the disparity between men and women because of the associated disproportionate reductions in mobility, lower extremity strength, cognitive function, and greater number of geriatric syndromes. Knowledge of these gender differences allows health care providers to anticipate problems in the older woman with diabetes in the early or subclinical stage and to initiate appropriate prevention strategies.
The Geriatric Syndromes and Diabetes Depression
In a recent meta-analysis of 39 studies with 20,218 adults (mean age, 52 years), the presence of diabetes doubled the odds for depression, with a higher prevalence in women with diabetes (28%) than in men with diabetes (18%).11 Major depression was diagnosed in 11% of persons with diabetes, and 31% exhibited depressive symptoms. These observations are similar to data from 1993 showing major depression in 14.7% of patients with diabetes, with an additional 26% suffering depressive symptoms.12 In adults over age 65, the odds of a major depression was 1.6 times greater in subjects with diabetes.13 Depression adds to health care costs and interferes with adherence to medical therapy. The impact on diabetes management can be especially harmful because effective diabetes treatment hinges on the patient’s ability to participate in self-care. Diabetes is one of the most behaviorally and psychologically demanding of all the chronic diseases, requiring 95% of daily care to be conducted by the patient.14 In a primary care sample of 367 elderly persons with diabetes, there was a significant relationship between depression symptom severity and poorer adherence to treatment regimens that included diet, exercise, glucose monitoring, and compliance with medication.14 The most severely depressed group had greater impairment of physical and mental functioning. Depression severity was also associated with 86% higher costs due to higher utilization of primary, emergency, and specialty care.13 Whether depression is associated with poorer glycemic control is an important question as glycemic control is a powerful risk factor for diabetes-related complications.15 In a meta-analysis of 24 studies with 2817 patients, a significant association between A1c levels and depression was noted.16 Extrapolations from these data suggested that treatment of depression could increase the proportion of patients in good control from 41% to 58%.16 The mechanism of the link between depression and diabetes is unclear: hyperglycemia per se may cause depression, or depression may lead to hyperglycemia. In either case, treatment of depression affords an opportunity to improve glycemic control. Two meta-analyses of randomized controlled trials in adults over 55 with diabetes have documented that cognitive behavior therapy and pharmacologic therapy are effective in improving depressive symptoms.17,18 Significant reductions in A1c levels have been directly associated with improvement in depressive symptoms.17,19 Because depression impairs self-management, screening patients at routine visits can be very valuable. A simple question such as “Do you often feel sad?” opens the discussion for a more in-depth interview. Reliable screening can also be conducted using a tool such as the Yesavage Geriatric Depression Scale.20,21
Most studies have reported an association between diabetes and cognitive impairment with an increased risk of dementia.22-24 In a study of 396 adults over 65 with diabetes, the odds ratio for normal cognitive test results was 0.74 compared to those without diabetes.24 In comparison to persons with diabetes without cognitive impairment, patients with lower scores were less able to participate in self-care and had greater need for daily assistance and higher rates of hospitalization. In the Epidemiology of Vascular Aging study,22 cognitive function was assessed in 961 adults with either normal or impaired glucose tolerance or diabetes. At the end of 4 years, adults with diabetes had a significantly lower performance on 4 out of 9 tests. Older adults with diabetes, especially women, also experience a more rapid rate in cognitive decline. In a large prospective study of elderly women ages 65-99 years, diabetes was associated with up to a twofold increased risk of lower cognitive function at baseline and a 74% increased risk of decline over 6 years. Both baseline cognitive impairment and rapidity of decline were associated with duration of diabetes, with the greatest risk seen after 15 years.25 In a follow-up study, women with diabetes taking oral agents performed similarly to nondiabetic women, suggesting a favorable effect of glycemic control on cognitive decline.26
Physical limitations and injurious falls
Diabetes is a major contributor to poor lower extremity function, impaired balance, and reduced mobility. This is not surprising considering the conditions, including cardiovascular disease, obesity, peripheral neuropathy, amputations, and visual deficits, that cluster in diabetes. Data from the Third National Health And Nutrition Examination Survey (NHANES III) and the 1997-1999 National Health Interview Survey (NHIS) have delineated the prevalence and severity of diabetes-associated disabilities.27,28 According to NHANES III, diabetes is associated with a two- to threefold increased risk of being unable to perform mobility-related tasks in adults over age 60.27 Mobility was determined using self-reported assessments of whether a person can walk one-quarter mile, climb 10 steps, or do housework, and frequency of falls.
Three performance tests were also conducted, including walking speed, chair stands, and tandem stand. Among women with diabetes, 63% reported disability on at least one parameter, compared with 39% of men with diabetes and 42% and 25% of nondiabetic women and men, respectively. On the performance tests, 32% of women and 15% of men with diabetes were unable to carry out at least one of the tests. Diabetes was also associated with a 3.6-fold increased risk of not being able to perform any of the three physical tests.27 When applied to the U.S. population, 1.2 million or one-quarter of older adults with diabetes are disabled on all three physical tasks, and more than 2.5 million have some difficulty. Because comorbidities increase the disability risk in diabetes, the NHANES III data were analyzed to control for body mass index (BMI), arthritis, CHD, age, poor vision, stroke, and claudication. Controlling for CHD and BMI in women reduced the diabetes-related odds for disability by 52%, whereas controlling for CHD and stroke in men reduced the odds by 25%. After all variables were considered, diabetes still increased the odds for disability by 46% and 50% in men and women, respectively. In the 1997-1999 NHIS, to estimate the prevalence and types of physical limitations associated with diabetes, participants reported on their ability to perform nine physical tasks and to rank degree of limitation: 0 (not difficult) to 4 (can’t do at all) (Figure).28
In adults with diabetes, 66% had some degree of physical limitation compared with 29% without diabetes. Across all ages and in both sexes, diabetes conferred greater physical limitations. For each physical task shown in the Figure, women suffered greater limitations than men. Approximately 22% of women with diabetes reported the inability to stand, walk, and push as opposed to 14% of men with diabetes. The proportion of women with diabetes reporting any restriction was 72% compared to 34% for nondiabetic women. Physical limitations were greater with diabetes duration of 6 years or longer and for patients using insulin. These observations confirm the greater physical disabilities in older persons with diabetes, especially women, and explain the higher prevalence of loss of independence and institutionalization.
Injurious falls/fractures—greater risk for women with diabetes. Among women with diabetes over age 60—but not men with diabetes—NHANES III demonstrated that diabetes was associated with slower walking speeds, inferior lower extremity function, poorer balance, and an increased risk for falling and injury.27 Peripheral neuropathy, which causes pain, weakness, and gait disturbances, is a major reason why 11% of adults older than 72 years, independent of diabetes, cannot safely cross the street.29 In the office, the “Get Up and Go” test can be used to assess integrated neuromuscular function. This simple tool is a timed performance test in which the patient rises from an armchair, walks 3 meters across the room, turns around, walks back to the chair, and sits down.30 Normally, mobile adults perform it in less than 10 seconds, but those requiring 30 seconds or more are physically limited and require assistance with daily activities. Most adults who complete the test in less than 20 seconds remain physically independent. As one might predict, older women with diabetes experience more falls and a higher rate of fracture.
In a 7-year prospective study of elderly women with diabetes, the risk of falling was increased 68%, with insulin-treated women at highest risk.31 After controlling for other risk factors such as peripheral neuropathy and CHD, the association between falling and non-insulin-treated diabetes was no longer significant, but the association remained high in insulin-treated women. Despite higher bone densities observed in women with diabetes, the risk of hip and proximal humerus fractures was higher in women with diabetes who were not on insulin, whereas foot fractures were more common in those treated with insulin.32 As women with diabetes age, they experience a higher yearly incidence of any functional disability (9.8% vs 4.7%)33 and greater risk for lower extremity disability, a serious long-term complication.34 Strategies to maintain the highest level of physical mobility focus on regular physical activity.
Polypharmacy is defined as taking five or more medications. In diabetes, there are multiple reasons for polypharmacy, because blood pressure, lipids, vascular complications, and glucose levels all require therapy.35 In addition to higher costs, multiple medicines increase the complexity of the medical regimen, risk for error and poor compliance, risk for adverse drug reactions, and the susceptibility for falls, cognitive decline, and depression. Although many patients come with a laundry list of medicines, careful questioning reveals that many drugs, including insulin, are not taken because of side effects, cost, and a perception that the medicine is not beneficial.35 Rather than ask if a medicine is omitted, it is more revealing to ask how often a dose is missed. Inspecting the actual medicine bottles helps ensure adherence and reduce adverse drug reactions.
One of the most serious adverse outcomes in the elderly person with diabetes is hypoglycemia.36,37 As the number of pills increases above five, so does the risk for hypoglycemia. Predisposing factors include missed meals, weight loss, unusual activity, confusion regarding the medication regimen, reduced liver glycogen, renal impairment, alcohol abuse, and a recent hospitalization within 30 days. In a large study of ambulance and emergency room visits, severe hypoglycemia (glucose < 50 mg/dL) occurred more frequently in patients taking glyburide. The risk was greatest in patients who were older (mean age, 79 years), had normal A1c levels (mean, 5.4%), and had evidence of impaired renal function (present in 62%).36 A second large study of over 19,000 elderly Medicaid enrollees confirmed a higher risk of hypoglycemia with glyburide; these patients experienced neuroglycopenic symptoms, vascular injury such as MI, or death.37 Because of glyburide’s prolonged duration of action, renal excretion of active metabolites, and the risk for hypoglycemia, its use in older patients should be avoided. Glipizide has lower rates of hypoglycemia, likely due to its liver inactivation prior to being renally excreted and action by first-phase insulin release.
In selecting an oral agent, physicians should also consider a rapid-acting secretagogue with a shorter duration of action, either nateglinide or repaglinide. Both agents in the class of meglitinides stimulate rapid insulin release in a glucose-dependent manner and can be given preprandially without the need for dose adjustment in renal impairment. The choice of which of the many orally active agents to use must be individualized and based on consideration of kidney and liver function, interaction with other medication, and ability to self-monitor. To minimize the risks of polypharmacy, medicine lists should be reviewed regularly. If there is a minimal response to a drug, it should be discontinued. When treating older persons with diabetes, “less is more” in relation to minimizing the number of pills.
Persistent pain with neuropathy in older persons with diabetes leads to deconditioning, reduced physical functioning, and a downward spiral toward loss of independence.37 Pharmacologic treatment and regular physical activity reduce pain and disability and should be prescribed. A thorough discussion of pain is beyond the scope of this article, but the reader is referred to the AGS guideline on the Management of Persistent Pain in Older Persons.38
Urinary incontinence is increased in diabetes, with women affected twice as often as men.21,38 Conditions contributing to this increased risk include polyuria, glycosuria, Candida vaginitis, neurogenic bladder (particularly an atonic bladder leading to overflow), urinary tract infection, medication side effects, or fecal impaction.7 Persistent urinary incontinence is important to evaluate and treat, as it leads to social isolation, reduced quality of life, and increased risk for institutionalization.5,39
Guidelines for Exercise in Diabetes
Numerous studies in older adults with diabetes have documented that regular physical activity improves glycemic control and significantly reduces the risk for functional disability and CHD.40-44 In an 8-year prospective study from the NHIS of 2896 adults with diabetes, walking at least 2 hours per week was associated with a 39% lower all-cause mortality rate and a 34% reduction in CHD mortality.41 The magnitude of these benefits persisted after controlling for age, sex, obesity, functional limitations, duration of diabetes, or presence of other comorbid conditions. The greatest risk reduction was observed in adults who walked 3 to 3.9 hours per week. Regular exercise also improves lower extremity strength and balance and reduces the risk for falls. Current guidelines from the surgeon general and the Centers for Disease Control and Prevention recommend 30 minutes of physical activity of moderate intensity on most days of the week.10,40,45,46 Periods of activity during the day may be as short as 8-10 minutes. In his editorial discussion regarding aging, disability, disease prevention, and health promotion, Fries suggests that it is never too late to begin!47
Diabetes care in the older adult requires an individualized approach. Life expectancy should be perceived as the relationship between actual age and level of functioning, especially in women. Intensive management of all medical problems may not be feasible or appropriate. Overly aggressive diabetes management may result in polypharmacy, hypoglycemia, and excessive costs. Assessment of physical and cognitive functioning is critically important. Screening for and treating depression, if present, has a positive impact on diabetes control and self-management. Regardless of an individual’s functional status, exercise is “the name of the game” and can reduce disability, injurious falls, and cardiovascular mortality. Physical therapy for gait training, balance, strengthening, and endurance can help to maintain the highest level of mobility, so older persons with diabetes, especially women, can have longer, better lives.