Response Letter to Gazzaruso and Colleagues

We’d like to thank Dr Gazzaruso and colleagues for their thought-provoking letter which suggests that our conclusion, that a HbA1c target of 8.0% may be lower than necessary for maintaining function in nursing home eligible elders, may be premature for 2 reasons. (1) First, they note that our study results run counter to previous studies where hyperglycemia was associated with disability. However, both of the cited studies were cross-sectional, raising the possibility that the observed association was due to reverse causation. Specifically, providers may have appropriately decreased the intensity of glycemic treatments for disabled patients, since these patients are often older with a higher burden of comorbidities putting them at higher risk for hypoglycemia. (2, 3) Thus, we believe our longitudinal study is an important advance from previous studies. Second, Dr Gazzaruso and colleagues note that our studies occurred before the widespread use of dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide 1 (GLP-1) agonists. We acknowledge that newer agents hold the promise of tighter glycemic control in older adults with less hypoglycemia. However, there is currently little data to suggest that these newer medications lead to improved patient outcomes such as decreased functional decline. Since these newer medications cost many times more than older medications and long-term safety is unknown, we believe that older medications should be tried first in the vast majority of older patients with diabetes. For healthier elders with an extended life expectancy, we agree with Dr Gazzaruso that a reasonable HbA1c target would be 7.0 – 7.5%, as recommended by the International Association of Gerontology and Geriatrics (IAGG). (4) However, our study and conclusions focused on nursing home eligible elders for whom consensus statements recommend less stringent glycemic targets. The IAGG panel states that “in cases of functional dependence, care home residence…and other high dependency states, [HbA1c target] may need to be adjusted to reduce the risk of hypoglycemia and enhance patient safety.” (4) Further, a recent American Diabetes Association and European Association for the Study of Diabetes consensus statement recommended that “…less stringent goals—e.g. 7.5 – 8.0% or even slightly higher—are appropriate for patients with…a limited life expectancy [or] extensive comorbid conditions.” (5) Thus, for elders with functional limitations and limited life expectancy, expert consensus statements appear to support our conclusion that a HbA1c target of 8.0% may be lower than necessary to maintain function.