Cardiovascular Complications, Hypoglycemia Common in Older Patients with Diabetes
Data from a large cohort study of older patients with diabetes confirm recent treatment recommendations for this population—that focusing on blood pressure and cholesterol goals may be more beneficial than focusing on glycemic targets.
"Physicians often meet older patients for the first time at different stages of disease. The clinical course of diabetes is quite different for older patients depending on how old they are and how long they have had diabetes. Our findings indicate that longer diabetes is associated with higher rates of hypoglycemia and microvascular complications. Older age is associated with higher rates of hypoglycemia, cardiovascular complications, and mortality," said lead author Elbert S. Huang, MD, Associate Professor of Medicine, University of Chicago, Chicago, IL.
"Hypoglycemia has emerged as one of the most common complication of diabetes, especially for patients who are older and have long-standing diabetes—it is now the 2nd or 3rd ranked complication," said Dr. Huang, MD. "The incidence rates of hypoglycemia exceed rates of renal failure and amputation in this study," he said. The findings were published online ahead of print in JAMA Internal Medicine.
Findings Validate American Geriatric Society Guidelines
"The findings from Huang et al validate the American Geriatric Society [AGS] guidelines, which recommend that treatment should be individualized for older adults and shouldn't solely be focused on trying to achieve intensive blood sugar control because of the risk for hypoglycemia," said Dr. Moreno, co-chair of the interdisciplinary panel of experts who developed the AGS guidelines.
The macrovascular benefits of treating blood pressure and cholesterol can be seen within 2 to 3 years in older adults, while the microvascular benefits of targeting glucose levels take much longer and have to be balanced against the risks for side effects of glucose-lowering medications as the study by Huang et al shows, Dr. Moreno said. In addition, "intensive treatment of blood glucose levels has not consistently been found to be associated with reduction in cardiovascular complications in randomized clinical trials," said Dr. Moreno, who is also Assistant Clinical Professor in Family Medicine at the University of California-Los Angeles.
Large Cohort Study
The study authors compared rates of diabetes complications and mortality across categories of age and duration of diabetes. The study included 72,310 adults with type 2 diabetes age 60 years and older who were enrolled in the Kaiser Permanente Northern California (Kaiser) Diabetes Registry. The patients were followed for 7 years (2004-2010).
As expected, the incidence of all complications increased with longer disease duration, regardless of age. However, for a given disease duration, rates of hypoglycemia, cardiovascular complication (coronary artery disease, congestive heart failure, and cerebrovascular disease) and mortality increased markedly with greater age while rates of microvascular complications remained stable or declined.
Among older adults who had diabetes for a shorter duration (≤9 years), nonfatal cardiovascular complications had the highest incidence, followed by diabetic eye disease and acute hypoglycemic events. In older adults with longer disease duration (≥10) hypoglycemia was the most common complication with rates similar to those of coronary artery disease and cerebrovascular disease.
"The rates of microvascular and cardiovascular complications in older patients with diabetes are now much lower than they were in the 1990s," Dr. Huang said. "The implication is that the treatments that we are administering are making a difference. For example, in 1995 the incidence of ischemic heart disease was 181.5/1000 person years. It is now 24.09/1000 person-years in our sample," he said.
AGS Guideline Recommendations
In addition to the increased focus on blood pressure and cholesterol treatment over blood glucose control, the AGS guidelines stress that older adults are heterogeneous as far as duration of diabetes, comorbidities, functional and cognitive status, frailty, and life expectancies. Thus, tailoring goals of therapy to patient preferences is important, Dr. Moreno said.
Similar to the recent American College of Cardiology/American Heart Association's clinical practice guidelines for the treatment of dyslipidemia, the AGS guidelines emphasize treating elevated cholesterol levels with statins, but not necessarily treating to specific target levels. In addition, the AGS guidelines, no longer recommend the use of aspirin for primary prevention of cardiovascular disease because recent studies show that the increased risk of bleeding outweighs the reduction in cardiovascular events. Furthermore, the guidelines encourage lifestyle modification for healthy older adults with diabetes, based on increased evidence supporting the importance of exercise and weight loss.