Chapter 37: Diabetes in the Elderly
Canadian Diabetes Association 2013 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada
- It is generally accepted that being “elderly” is a concept that reflects an age continuum starting after age 65 and is characterized by a slow, progressive impairment in function that continues until the end of life.
- Normal aging is associated with a progressive increase in A1C, and there is a significant discordance between fasting plasma glucose–based and A1C-based diagnosis of diabetes in the elderly, a difference that is accentuated by race and gender.
- Pending further studies to define the role of A1C in the diagnosis of diabetes in the elderly, other screening tests may need to be considered in some patients.
Reducing the Risk of Developing Diabetes
- Lifestyle interventions are effective in reducing the risk of developing diabetes in elderly people at high risk for the development of the disease.
- Acarbose, rosiglitazone and pioglitazone also are effective in preventing diabetes in elderly people at high risk. Metformin may not be effective.
- Elderly individuals with diabetes should be referred to a diabetes healthcare team. Interdisciplinary interventions tailored for this age group have been shown to improve glycemic control.
- A pharmaceutical care program can significantly improve medication compliance, as well as the control of diabetes and its associated risk factors.
- Healthy elderly people with diabetes should be treated to achieve the same glycemic, blood pressure and lipid targets as younger people with diabetes [Grade D, Consensus].
- Aging is a risk factor for severe hypoglycemia with efforts to intensify therapy. The increased risk of hypoglycemia appears to be due to an age-related reduction in glucagon secretion, impaired awareness of hypoglycemic warning symptoms and altered psychomotor performance, which prevents the patient from taking steps to treat hypoglycemia.
- In elderly people with cognitive impairment, strategies should be used to strictly prevent hypoglycemia, which include the choice of antihyperglycemic therapy and less stringent A1C target [Grade D, Consensus].
- In the frail elderly, while avoiding symptomatic hyperglycemia, glycemic targets should be A1C ≤8.5% and fasting plasma glucose or preprandial PG 5.0–12.0 mmol/L, depending on the level of frailty. Prevention of hypoglycemia should take priority over attainment of glycemic targets because the risks of hypoglycemia are magnified in this patient population [Grade D, Consensus].
- The most commonly applied definition of “frailty” (Fried's Frailty Phenotype) suggests that a patient is frail when 3 or more of the following criteria are present: unintentional weight loss (>10 pounds in the past year), self-reported exhaustion, weakness (grip strength), slow walking speed and low physical activity.
- Progressive frailty has been associated with reduced function and increased mortality, and older patients with diabetes are more likely to be frail.
- When frailty occurs, it is a better predictor of complications and death in elderly patients with diabetes than is chronological age or burden of comorbidity.
- The Clinical Frailty Scale, developed by Rockwood et al, has demonstrated validity as a 7-point frailty scale that has since been modified to a 9-point frailty scale from 1 (very fit) to 9 (terminally ill), which can help to determine which subjects are frail.
Nutrition and physical activity
- Nutrition education programs can improve metabolic control in ambulatory older people with diabetes.
- Elderly people with type 2 diabetes should perform aerobic exercise and/or resistance training, if not contraindicated, to improve glycemic control [Grade B, Level 2].
- Prior to instituting an exercise program, elderly subjects should be carefully evaluated for underlying CV or musculoskeletal problems that may preclude such programs.
- Aerobic exercise improves arterial stiffness and baroreflex sensitivity, both surrogate markers of increased CV morbidity and mortality.
- Resistance training has been shown to result in modest improvements in glycemic control, as well as improvements in strength, body composition, and mobility.
- Exercise programs may reduce the risk of falls and improve balance in patients with neuropathy. However, it appears difficult to maintain these lifestyle changes outside of a supervised setting.
Oral antihyperglycemic agents
- In lean elderly people with type 2 diabetes, the principal metabolic defect is impairment in glucose-induced insulin secretion. Thus, initial therapy should involve agents that stimulate insulin secretion.
- In obese elderly people with type 2 diabetes, the principal metabolic defect is resistance to insulin-mediated glucose disposal, with insulin secretion being relatively preserved. Initial therapy in this case should involve agents that improve insulin resistance.
- There have been no randomized trials of metformin in the elderly, although clinical experience suggests it is an effective agent. Metformin may reduce the risk of cancer in elderly patients with diabetes.
- Alpha-glucosidase inhibitors are modestly effective in older people with diabetes, but a substantial percentage of individuals cannot tolerate them because of gastrointestinal side effects.
In elderly people, thiazolidinediones should be used with caution due to the increased risk of edema and heart failure [Grade D Consensus], though they are effective agents. Rosiglitazone, but not pioglitazone, may increase the risk of CV events and deathThese agents also increase the risk of fractures in women. When used as monotherapy, they are less likely to fail than metformin or glyburide.
- In elderly people with type 2 diabetes, sulphonylureas should be used with caution because the risk of hypoglycemia increases exponentially with age [Grade D, Level 4].
- In general, initial doses of sulphonylureas in the elderly should be half of those used for younger people, and doses should be increased more slowly [Grade D, Consensus].
- Gliclazide and gliclazide MR [Grade B, Level 2] and glimepiride [Grade C, Level 3] should be used instead of glyburide, as they are associated with a reduced frequency of hypoglycemic events.
- Meglitinides may be used instead of glyburide to reduce the risk of hypoglycemia [Grade C, Level 2 for repaglinide; Grade C, Level 3 for nateglinide], particularly in patients with irregular eating habits [Grade D Consensus].
- Dipeptidyl peptidase (DPP)-4 inhibitors (linagliptin, saxagliptin and sitagliptin) are similarly effective in young and old patients, cause minimal hypoglycemia when used alone and do not result in weight gain.
- The efficacy of liraglutide with respect to A1C and weight is independent of age and is well tolerated in the elderly with a low risk of hypoglycemia.
- Insulin regimens in the elderly should be individualized and selected to promote patient safety.
- The clock drawing test may be used to predict which elderly subjects will have difficulty learning to inject insulin [Grade D, Level 4].
- In elderly people, if insulin mixture is required, premixed insulins and prefilled insulin pens should be used instead of mixing insulins to reduce dosing errors and to potentially improve glycemic control [Grade B, Level 2].
- Premixed insulin analogues can be administered after meals and may be associated with better control than basal insulins, but at the expense of more hypoglycemia and greater weight gain.
- Premixed insulin analogues can result in equivalent glycemic control to basal-bolus regimens.
- In older people with poorly controlled type 2 diabetes requiring insulin, both continuous subcutaneous insulin infusion and basal-bolus regimens can result in excellent glycemic control with reduced glycemic variability, as well as good safety and patient satisfaction.
- Detemir and glargine may be used instead of NPH or human 30/70 insulin to lower the frequency of hypoglycemic events [Grade B, Level 2].
- Insulin therapy may increase the risk for falls and fractures, although the mechanism is unclear.
Prevention and Treatment of Complications
- Treatment of hypertension in elderly people with diabetes is associated with a significant reduction in CV morbidity and mortality and microvascular events, and may also preserve renal function.
- Several different classes of antihypertensive agents have been shown to be effective in reducing the risk of CV events and end stage renal disease, including thiazide-like diuretics, long-acting calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin II receptor blockers. Any of these agents is a reasonable first choice.
- Although the calcium channel blocker amlodipine may be associated with an increased risk of CHF, the combination of ACE inhibitor and amlodipine appears to reduce CV events more than the combination of an ACE inhibitor and hydrochlorothiazide.
- Cardioselective beta blockers and alpha-adrenergic blockers are less likely to reduce CV risk than the above agents.
- ACE inhibitors may be particularly valuable for people with diabetes and ≥1 other CV risk factor.
- The Canadian Hypertension Education Panel (CHEP), in collaboration with the Canadian Diabetes Association, have maintained the target BP of <130/80 mm Hg in elderly patients with diabetes.
- The treatment of dyslipidemia with statins for both primary and secondary prevention of CV events has been shown in most studies to significantly reduce CV morbidity and mortality in older people with diabetes.
- The data on the use of fibrates in this patient population are equivocal, although they may reduce albuminuria and slow glomerular filtration rate loss.
- Type 5 phosphodiesterase inhibitors appear to be effective for the treatment of erectile dysfunction in carefully selected elderly people with diabetes.
- Depression is common in elderly patients with diabetes. A systematic approach to the treatment of depression not only improves quality of life but reduces mortality.
Diabetes in nursing homes
- The prevalence of diabetes is high in institutions and is often under diagnosed.
- Individuals frequently have established macro- and microvascular complications, as well as substantial comorbidity.
- Antipsychotic drug use is a risk factor for the development of diabetes in patients in institutions.
- In elderly nursing home residents, regular diets may be used instead of “diabetic diets” or nutritional formulas [Grade D, Level 4], as diabetic diets have not been shown to effectively modify the level of glycemic control.
- For selected nursing home residents with type 2 diabetes, substitution of regular insulin by lispro insulin (bolus analogue) may improve glycemic control and A1C levels with a reduced number of hypoglycemic episodes.
For definitions of the levels of evidence cited in this chapter, please refer to the Guideline Recommendations: Levels of Evidence.
If you would like more details on this topic, please visit the Canadian Diabetes Association Clinical Practice Guidelines: Chapter 37.