Lesley McKarney, PhD, Editorial Director, Geriatrics & Aging
The Canadian Geriatrics Society held its annual scientific meeting from May 28–30, 2004 at the Delta Chelsea Hotel in Toronto. The first day comprised a clinical and scientific conference for physicians working in the field of geriatrics, followed by a day and a half of research presentations and discussions on recruitment and training in geriatric education. The following are some highlights from day one of the meeting.
Management of Type 2 Diabetes in the Elderly
The conference opened with Dr. Bernard Zinman’s overview of the type 2 diabetes epidemic in North America and the latest Canadian Diabetes Association practice guidelines for management of the disease.
Diabetes, Zinman reminded the audience, is the fourth leading cause of death due to disease and a major cause of premature disability.
As stipulated in the Canadian Diabetes Association guidelines, the target for hemoglobin A1C levels in type 2 diabetic patients is less than seven. However, in the United States, Canada, and Europe, the majority of type 2 diabetes patients have an A1C level well above seven and thus have inadequate glycemic control. Zinman cited the United Kingdom Prospective Diabetes Study (UKPDS) as clearly demonstrating the benefits of decreased A1C levels in type 2 diabetes patients: a 1% reduction in A1C resulted in significant reductions in diabetes mellitus endpoints, death related to diabetes, and all-cause mortality among participants. The study also showed that diabetes is a progressive disease: with traditional monotherapy, the patients’ condition deteriorated over time due to continued loss of beta cell function, and after three years of therapy, patients needed more than one pharmacological agent for adequate glycemic control. A key conclusion of this extensive clinical trial, Zinman noted, was that multiple agents are likely to be required for glycemic control, and physicians need to more aggressively initiate combination therapies or administer a second drug at the diagnosis of type 2 diabetes in order to decrease the risk of complications.
According to Zinman, the old methods of managing type 2 diabetes failed to control or reduce A1C to a satisfactory level in the early stages of the disease. The new CDA recommendations focus on a diabetes treatment paradigm by A1C level, and involve diet and exercise when the A1C level is seven or lower, followed by monotherapy (A1C >8), combination oral agents (A1C >9), and insulin therapy when A1C reaches 10 or higher. Furthermore, the most recent Canadian Diabetes Association guidelines (CDA 2003) recommend that if glycemic targets are not achieved using lifestyle management within two to three months, antihyperglycemic agents should be initiated, and if a single antihyperglycemic agent is not able to achieve target A1C level, agents from other classes should be added. The aim is to reach target A1C level of less than seven within 6–12 months of treatment to reduce the risk or micro- and macro-vascular complications. The new guidelines have also upgraded thiazolidinediones from third-to second-line therapy for type 2 diabetes because of their ability to decrease plasma insulin, ambulatory blood pressure, hyperglycemia, and visceral fat, in addition to their positive effects on HDL and endothelial function.
In addition to encouraging better metabolic control, using therapeutic interventions that target pathophysiology, using additive or combination therapy earlier, and targeting lipid and blood pressure abnormalities for better management of diabetes, the CDA advocates lifestyle interventions and weight reduction/nutrition therapy for those at risk in the 40+ age group. Moreover, relatively healthy older patients with diabetes should be treated to achieve the same glycemic, blood pressure, and lipid profiles as younger patients. The
full list of recommendations can be found on the CDA website (www.diabetes.ca/cpg2003/).
Quality of Life, COPD, and the Elderly
Dr. Roger Goldstein’s presentation focussed on chronic obstructive pulmonary disease (COPD) in the older population and took the form of a question-and-answer session.
The first question related to why the symptoms of COPD appear much later in life after a long history of smoking, or even many years after an individual has quit. The most likely explanation for this, Goldstein replied, was that the lungs have a tremendous capacity to be “insulted,” and there can be a large degree of damage to the airways and lung parenchyma before symptoms occur; why symptoms appear later, he offered, is a combination of both the chronic inflammatory changes that progress and age-associated changes, such as diminished elasticity. In addition, the FEV1 declines at the rate of about 40cc per year; if a patient is a heavy smoker and is susceptible to cigarette smoke, their FEV1 is declining at an accelerated rate of 80–120cc per year, and the reduced flow of air becomes much more problematic in later life when chronic inflammatory changes become more evident.
The next question put forward by a member of the audience regarded the projected prevalence of COPD among the older population. In terms of disability-adjusted life years, Goldstein replied, the World Bank estimates that COPD will be the fifth leading cause of disability by 2020. While no firm numbers are available, people aged 65 and over account for two-thirds of those reporting COPD as their main disabling condition. COPD in Canada mirrors the global situation; however, there is an epidemic of COPD among Canadian women, according to Goldstein, which can be attributed more to the high rate of smoking in this population rather than to greater longevity. In 1999, he added, more women were diagnosed with COPD than men in Canada, and data from Health Canada suggest that between now and 2020 women will outrank men with this disease globally.
Regarding the influence of urban pollution and second-hand smoke on the development of COPD, Goldstein suggested that while the medical community in general is confident that both factors play a role in COPD, the data do not provide strong evidence for increased morbidity related to these factors. However, these factors should not be disregarded completely, he stressed.
Goldstein closed by discussing the value of pulmonary rehabilitation for COPD patients. He explained that the effectiveness of this therapy, which was previously only supported anecdotally, has been verified recently by well-controlled trials that show significant improvement in various outcomes, including increased exercise capacity, improved quality of life, increased pulmonary capacity, and fewer hospital admissions when rehabilitation is used. Pulmonary rehabilitation is now increasingly recognized as an important component of the comprehensive management of patients with COPD in the older population. The real challenge, he concluded, was to prevent the diminutive benefit over time of rehabilitation and maintain patient adherence to the program.
Prevention and Management of Stroke 2004
Dr. Frank Silver presented a talk on the management of stroke in terms of secondary prevention following transient ischemic attack. Most older adults, he reminded the audience, are less fearful of dying of stroke than of becoming disabled by the condition. Stroke is the leading cause of adult disability in North America, costing Canadian society three billion dollars annually, in addition to
the intangible costs to families and caregivers.
MRI remains a very important tool for diagnosing stroke, said Silver, but vigilance regarding secondary stroke prevention post-transient ischemic attack is crucial. Depending on underlying comorbidities, the risk of recurrent stroke within 30 days of the initial stroke event is 3–8%; within five years of the first stroke, the risk is 25–40%. Carotid endartectomy is the mainstay of secondary stroke prevention. Older patients derive greater benefit from such stroke treatment, particularly older men and when there is a high degree of stenosis. Silver also noted that the sooner that carotid endartectomy is performed (i.e., within two weeks), the better the outcome; while the surgical risk of operating is the same at seven days as compared to seven weeks, earlier surgery significantly reduces the risk of a second stroke. As a preventative measure, he emphasized the importance of referral to a specialist as soon as possible when the patient presents with symptomatic carotid disease. Regarding treatment, most patients with small vessel disease where the underlying mechanism of the stroke is not known, or who have large vessel disease, will be treated with antiplatelet therapy; warfarin should only be prescribed when there are clear cardiac sources of stroke (e.g., prosthetic valves or atrial fibrillation).
Silver is commonly asked what the optimum dose of ASA for stroke prevention is. Recent studies have shown that a lower dose of ASA (e.g., 81mg/day) prevents stroke just as effectively as larger doses. Current alternatives to ASA include dipyridamole, ASA and dipyridamole in combination, clopidogrel, and ticlopidine, although the latter is generally not prescribed for new patients because of the associated risk of bleeding. Silver drew attention to the recent results of the Management of Athrombosis with Clopidogrel in High-Risk Patients with Recent Ischemic Attack or Ischemic Stroke (MATCH) trial, presented at this year’s 13th European Stroke Conference, which demonstrated that ASA in combination with clopidogrel did not confer any advantage over clopidogrel alone in preventing recurrent ischemic events. In fact, the combination of ASA and clopidogrel significantly increased the patient’s risk of a life-threatening hemorrhage.