My 90-year-old grandfather was the first person to teach me how to use a glucometer. He developed diabetes thirty years after his 3-vessel CABG, and the necessity of daily blood glucose checks seemed like an inevitable aspect of managing his new disease. As a diligent patient, he underwent the painful experience of pricking his finger and recording his measurements daily, and taught me how to help him as he lost dexterity with age. The experience left me questioning whether glucose monitoring is necessary for all patients with diabetes, especially older patients with late-onset, stable disease like my grandfather.
Diabetes mellitus is common disease among older adults; in the U.S., 1 in 4 persons over age 65 are affected. Cardiologists recognize diabetes management as integral to overall cardiovascular health. However in older adults, aggressive glycemic control can be burdensome and at times dangerous. Evidence from large randomized control trials including ADVANCE, ACCORD and VADT suggests that avoiding dangerously low blood sugars (hypoglycemia) may be more beneficial than achieving aggressively low hemoglobin a1c (HbA1c) targets. Based on available evidence, the American Geriatrics Society recommends higher Hba1c targets for older adults – between 7-8.5% depending on comorbidity burden and prognosis. There remains, however, a lack of strong evidence on the optimal frequency of home glucose monitoring in this group of patients. An individualized discussion the benefits, risks and alternatives provides a framework for this discussion.
There is a clear need to avoid hypoglycemia, and self-glucose monitoring may provide a mechanism to screen for low blood sugars. Accordingly, the Endocrine Society indicates that glucose monitoring may benefit type 2 diabetics taking medications that put them at risk for hypoglycemia, including insulin or sulfonylureas. This may be especially important during medication initiation or uptitration. However, in patients with stable disease with no clear risk for hypoglycemia, the Endocrine Society and the Society of General Internal Medicine both recommend against routine multiple daily self-glucose monitoring. Home monitoring is nonetheless overprescribed; CDC health behavior data indicate that a majority (63%) of non-insulin dependent diabetics are checking finger sticks at home at least daily, and Veterans Affairs data found that test strips were prescribed to a large number of patients with stable non-insulin type-2 diabetes. Potential harms associated with daily self-monitoring of blood glucose monitoring include pain of needle sticks, cost, and general therapeutic burden, all of which can adversely influence quality of life. While needle-free glucose monitors are a potentially promising alternative, they remain under development.
In summary, in the absence of clear guidelines, decisions about initiation, frequency and discontinuation of self-monitoring of blood glucose in older adults with type 2 non-insulin dependent diabetes requires an informed discussion between clinician and patient, with particular attention to patient goals. For most older patients with cardiovascular disease, in whom sulfonylureas should be avoided, routine glucose monitoring is reasonable for a brief period during medication titration, and subsequent intermittent monitoring may be helpful to determine whether symptoms of hypoglycemia correlate with low blood glucose. However, for most patients with stable disease on oral agents, discontinuing routine (daily) home glucose checks can improve quality of life and reduce health care costs.
By: Tanya Wilcox, MD