To the Editor: In August 2007, an 85-year-old women with diabetes mellitus, for which she was taking pioglitazone 30 mg and glyburide 2.5 mg a day, was seen at a busy urban hospital geriatric clinic. That month, her glycosylated hemoglobin (HbA1c) was 7.7%, and her serum creatinine was stable at 0.9 mg/dL. In December 2007, she was seen again, complaining of a fall in September. Occasional home finger stick testing had indicated glucose levels near 80 mg/dL, and at night she had sometimes been somewhat confused. A glucose finger stick was 60 mg/dL in the office. Glyburide was consequently stopped, and this was explained to the patient and granddaughter. In January 2008, she was again seen. On this visit, she was confused and lethargic and had not eaten that day. The bottles of medication were reviewed, and she still had glyburide among them, although her daughter insisted that she had not been taking it. Her laboratory tests showed a glucose level of 29 mg/dL, HbA1c of 6.4%, and creatinine of 0.8 mg/dL. This patient demonstrates the risks of hypoglycemia with the treatment of diabetes mellitus, seen all too commonly in older adults. In the UK Prospective Diabetes Study Group (UKPDS) trial,1 the subjects had a median age of 54. In the intensive treatment group, average HbA1c was 7%, versus 7.9% in the conventional treatment arm. Over 10 years of follow-up, there were fewer microvascular complications in the intensive treatment group, but there was no difference in the important outcomes of renal failure and blindness, nor was there a difference in mortality, although in the small subgroup of overweight patients given metformin, there was lower mortality and fewer macrovascular complications.2 At continued follow-up, lower mortality was found with the other agents as well, becoming significant at approximately 15 years.3 In the Action to Control Cardiovascular Risk in Diabetes Study Group (ACCORD) trial, the average age of patients was 62. In the tightly controlled group, with an HbA1c of 6.4%, versus 7.5%, at 3.5 years, greater mortality was noted, and intensive therapy was discontinued.4 In the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) Trial, the average age was 66. Tight control to an HbA1c of 6.5%, versus 7.3%, over 5 years reduced the development of micro- and macroalbuminuria, with no significant effect on mortality.5 In the Veterans Affairs Diabetes Trial, average age was 60. Tight control to an HbA1c of 6.9%, versus 8.4%, over 5 years resulted in lower increases in albuminuria and two step increases in retinopathy, but no difference in progression to proliferative retinopathy or glomerular filtration rates was noted, and mortality was no lower.6 In the groups receiving more-intensive treatment, there was a greater incidence of hypoglycemia; the risk of hypoglycemic episodes requiring assistance was three times as great in the ACCORD Trial,4 the number of severe hypoglycemic episodes was almost double in the ADVANCE Trial,5 and the number of instances of glucose levels documented to be less than 50 mg/dL was almost four times as great in the Veterans Affairs diabetes mellitus trial.6 Greater risk of hypoglycemia was seen with intensive treatment in the UKPDS study as well.1 Older age is a risk factor for hypoglycemia,7, 8 and hypoglycemia may present with serious symptoms, such as stroke, myocardial infarction, or death.7 Hypoglycemic episodes are possibly associated with greater dementia risk.8 Patients taking insulin7, 8 or sulfonylureas7 seem to have an especially high risk of hypoglycemia. Previous guidelines published in the Journal of the American Geriatrics Society state that, for frail older adults, persons with life expectancy of less than 5 years and others in whom the risks of intensive glycemic control appear to outweigh the benefits, a less-stringent target, such as HbA1c of 8% is appropriate.9 The Quality Indicators for the Care of Diabetes Mellitus in Vulnerable Elders state that, if HbA1c is 9% or higher, a therapeutic intervention should occur.10 I would suggest that a quality indicator be added, whereby the dangers of overtreatment, especially with insulin or sulfonylureas, are explicitly stated as signs of poor care. If a vulnerable older person, with a life expectancy of less than 10 years, is taking insulin or a sulfonylurea and has a HbA1c level under 7%, then the doses of these medications must be reduced. Although this quality indicator will not prevent all cases of hypoglycemia, it will reduce its occurrence. I hope that the Assessing Care of Vulnerable Elders investigators can adopt this as the 393rd quality indicator. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the author and has determined that the author has no financial or any other kind of personal conflicts with this paper. Author Contributions: David Sutin is solely responsible for the content. Sponsor's Role: No sponsor.
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Open Access
Mar 2, 2011
Shoichi Yamagishi 
