Pharmacy Times

A Q&A on Outpatient Treatment of Elderly Patients with Diabetes

Author: Justin Sherman, PharmD

At least 20% of patients older than 65 years currently have diabetes. They make up a growing segment of the health care population--a segment that is expected to grow even more rapidly over the next few decades.1,2

Treatment approaches should be highly individualized and dynamic. Therefore, considering the following questions will optimize the management of this special group of patients.

Should the Same Treatment Goals Be Used for the Elderly?

The American Diabetes Association (ADA) guidelines dictate that a goal level of hemoglobin A1C should be <7%.2 For an ideal patient, clinicians should aggressively treat to reduce A1C to <6%. Yet, elderly patients (>65 years), the young (<13 years), and those with limited life expectancies, comorbid conditions, or frequent or severe hypoglycemia may need less stringent goals.

Thus, the level of control depends on individually weighing risk versus benefit. In contrast with their nondiabetic counterparts, the diabetic elderly are at risk for increased comorbidity, cognitive and physical impairment, depression, falls, and polypharmacy.2 Not all elderly persons with diabetes, however, have the same risk. Some are active, with little comorbidity and reasonable life expectancies. The age of onset of the diabetes--middle age versus elderly--also may influence disease burden and in the future may dictate different treatment goals.3 In addition, the duration of the diabetes and other factors influence disease burden.

A general goal, however, is this: manage diabetes intensively for all who benefit, regardless of age. Those who will likely benefit from long-term management (those with a life span of =10 years) and are cognitively aware, active, and compliant with intense self-management should maintain the same goals as younger patients.2

What Treatment Will Lower the Risk of Cardiovascular Complications?

No long-term studies have been conducted to demonstrate the benefits of tight glycemic, blood pressure, and lipid control in the diabetic elderly, and large-scale trials have been criticized for excluding the elderly.2,4 Yet, strong evidence exists to aggressively treat hypertension--and possibly lipids--rather than treating hyperglycemia alone.

For example, the blood pressure goal for the diabetic elderly is still <130/80 mm Hg. The elderly benefit equally, and perhaps even more so, than their younger counterparts. In the Heart Outcomes Prevention Evaluation study, aggressively treating hypertension with ramipril lowered the risk for major cardiovascular events. It showed a 25% greater benefit for the diabetic elderly.5 In the Systolic Hypertension in the Elderly Program trial, chlorthalidone reduced the risk of coronary events.6

In the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, chlorthalidone was compared with amlodipine, lisinopril, and doxazosin. 7 The thiazide-like diuretic (doxazosin) reduced cardiovascular disease risk and heart failure in the diabetic elderly. This finding is consistent with using hydrochlorothiazide for isolated systolic hypertension, which is common in the elderly.

However, the Seventh Report of the Joint National Committee on hypertension recognizes that angiotensin-converting enzyme (ACE) inhibitors have renoprotective effects, and that often 2 or more medications are needed for diabetic patients to achieve target blood pressure. 8

Often, comorbidities dictate using ACE inhibitors or angiotensin receptor blockers and ?-blockers. Yet, ?-blockers can mask hypoglycemia, a-blockers can cause orthostasis, and multiple medications can cause hypotension. Although standard doses often help the elderly reach the goal, initial doses may need to be lower than those for younger patients.8

Finally, subanalyses of major studies give indirect evidence that antihyperlipidemia treatment can reduce myocardial infarction, coronary death, and stroke.9 Although many older patients deal with muscle pain, specific muscular adverse effects with statins--including rhabdomyolysis--are not age-related. Again, treatment of hyperlipidemia depends on risk versus benefit. Because the diabetic elderly have an increased risk for cardiovascular disease, ADA guidelines advocate aggressively managing lipids and using aspirin unless otherwise indicated.2

What Recommendations Will Avoid Hypoglycemia?

Of the potential complications from intensive glycemic control, hypoglycemia is in the forefront of the clinician's mind. Common symptoms include fatigue, headache, difficulty concentrating, and excessive hunger, but they can manifest differently in the elderly (eg, blurred vision and dizziness often are experienced).10 Sometimes, symptoms are blunted due to impaired cognition or autonomic neuropathy. Along with advanced age, factors increasing hypoglycemia risk include comorbidities, poor behavioral compliance, the use of certain medications, and polypharmacy.

Many elderly patients have not adapted to their diabetes in terms of diet. The elderly are satiated more quickly and food loses its taste, and as a result the elderly consume fewer meals. Because patients with diabetes should eat smaller meals more often, patients eating 1 or 2 meals daily may have more postprandial hyperglycemia.

Maladaptive eating behaviors are compounded when patients take medications incongruently with meals- especially sulfonylureas and insulin. Dietary errors account for 53% of hypoglycemic episodes when the patient has skipped a particular meal.10 Also, patients may take sulfonylureas and rapid-acting insulin after meals, and the result may be postprandial hypoglycemia. For example, the Diabetes Outcomes in Veterans Study showed an increased hypoglycemic risk, depending on the number of insulin injections per day and whether rapid-acting insulin was used.11 In fact, hypoglycemia is 3 times more frequent with insulin versus oral medications.10

Whereas sulfonylureas and fast-acting insulin can cause hypoglycemia, thiazolidinediones and metformin generally do not. Second-generation sulfonylureas are less problematic than first-generation agents. These agents usually are prescribed twice daily, and doses should be split appropriately (for example, 10 mg glyburide twice daily rather than 20 mg once daily). Also, nonsulfonylurea secretagogues lower postprandial glucose levels with relatively less hypoglycemic incidents. Therefore, the clinician might consider switching a patient with significant hypoglycemia (once per week or significant symptoms) to one of these latter agents. Still, sulfonylureas reduce A1C by 1% to 2% and are effective agents, so any decision to change medications should be judicious and individualized.

Finally, the need for tight control of glycemia and comorbidities often leads to polypharmacy.12 Both diabetes and hypertension frequently require multiple medications. Thus, polypharmacy can increase adverse effects and the potential for medication interactions. Consequences result when medications do not achieve goal levels, however, so stopping medications should receive careful consideration.

Polypharmacy is compounded when patients use multiple physicians and obtain prescriptions from several pharmacies. Simple measures can prevent polypharmacy, such as instructing patients to maintain an active list of their medications, including OTC drugs and nutritional supplements. Single medications that can treat multiple conditions should be used when feasible. Patients with multiple providers should coordinate medications at 1 pharmacy. Education of patients also is key: they should understand the indications and possible adverse effects of each medication, as well as their treatment goals.

Conclusion

Treatment goals for elderly patients with diabetes should be individualized, but in many cases they are no less aggressive than those for younger patients. This population is highly susceptible to cardiovascular complications and thus should be treated accordingly, in terms of optimizing medications and treatment goals. Plans may need to be changed, however, due to challenges that are relatively unique to elderly patients, including severe hypoglycemia and polypharmacy.

References

1. Chau D, Edelman SV. Clinical management of diabetes in the elderly. Clin Diabetes. 2001;19(4):172-175.

2. American Diabetes Association. Standards of medical care in diabetes-2007. Diabetes Care. 2007;30(supp1):S4-S41.

3. Selvin E, Coresh J, Brancati FL. The burden and treatment of diabetes in elderly individuals in the U.S. Diabetes Care. 2006;29(11):2415-2419.

4. McMurdo ME, Witham MD, Gillespie ND. Including older people in clinical research [editorial]. BMJ. 2005;331:1036-1037.

5. Heart Outcomes Prevention Evaluation Study Investigators. Effects of ramipril on cardiovascular and microvascular outcomes in people with diabetes mellitus: results of the HOPE study and MICRO-HOPE substudy. Lancet. 2000;355:253-259.

6. Curb JD, Pressel SL, Cutler JA, et al. Systolic Hypertension in the Elderly Program Cooperative Research Group. Effect of diuretic-based antihypertensive treatment on cardiovascular disease risk in older diabetic patients with isolated systolic hypertension. JAMA. 1996;276:1886-1892.

7. The ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic. The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA. 2002;288:2981-2997.

8. Chobanian AR, Bakris GL, Black HR, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. JAMA. 2003;289:2560-2572.

9. Verny C. Management of dyslipidemia in elderly diabetic patients. Diabetes Metab. 2005;31:5S74-5S81.

10. Lecomte P. Diabetes in the elderly: considerations for clinical practice. Diabetes Metab. 2005;31:5S105-5S111.

11. Murata GH, Hoffman RM, Shah JH. A probabilistic model for predicting hypoglycemia in type 2 diabetes mellitus: the Diabetes Outcomes in Veterans Study (DOVS). Arch Intern Med. 2004;164:1445-1450.

12. Good CB. Polypharmacy in elderly patients with diabetes. Diabetes Spec. 2002;15:240-248.