Life expectancy is largely determined by functional status of an individual and presence of different co-morbidities. There is some evidence that diabetes treatment is not pursued as vigorously in older groups, with inadequate treatment offered to individuals aged 85 years and over.[9
] There are other conflicting data about the severity of the diabetes in older persons. Many associated co-morbidities like cerebral aging, atherosclerotic changes, compromised cardiorespiratory reserve, blunting of hormone profile, poor hepatic glycogen reserve, cataract, neuropathy, cerebrovascular disease, hyperosmolar nonketotic coma (HONK), hyponatremia, etc. are to be taken into consideration while treating the elderly patients with diabetes.[10
With increasing age, the pattern of presentation in diabetes changes, with most patients having a fasting plasma glucose (FPG) of 125 mg/dL or less, while their postprandial values mostly remaining above 200 mg/dL,[10
] exposing this group of patients to the risk of developing cardiovascular morbidities.[11
The cognitive function of geriatric patients weakens along with declining levels of glycemic control.[12
] Notwithstanding the fact that almost 60% of diabetic patients aged 75 years and above have hypertension, it is very important to treat the same along with other risk factors, i.e. high lipid levels.[13
] This emphasizes the significance of nonglycemic interventions in this group, and there is apprehension that these treatments may not be that effective in older patients with diabetes. Older individuals with diabetes, however, may be at greater risk of experiencing treatment-related complications than younger persons. For example, metformin treatment, particularly when administered in combination with sulfonylureas (SUs), has been associated with higher mortality,[15
] although one cannot be certain if this was due to the presence of more severe underlying illness in patients whose physicians selected this treatment approach. Health economic models have suggested that the benefits of treating glycemia may be somewhat less in older than in younger patients.[16
] A reasonable compromise to treating older patients may be to provide all individuals with diabetes, who in the judgment of the treating physician have a reasonable life expectancy, with conventional standard of care to achieve glycemic control even as the complexity of such an endeavor is constantly appreciated.
The American Geriatric Society strongly recommends individualizing the target setting of diabetes care in the elderly and has included in their Guidelines six geriatric syndromes such as polypharmacy, depression, cognitive impairment, urinary incontinence, injurious falls, and pain which should get priority over endeavors to achieve a tight glycemic goal. This Consensus group fully appreciates the view that it takes 8 years for aggressive glycemic control to reduce the risk of diabetic microvascular complication, but only 2 years of treating hypertension and dyslipidemia to reduce the risk of cardiovascular disease; hence, both morbidity and mortality can be reduced more by targeting cardiovascular risk factors than by intensively managing hyperglycemia.[17
In a recent joint position Statement, the American Diabetes Association (ADA), American Heart Association and American College of Cardiology, based on the findings of Veterans Affairs Diabetes Trial (VADT), Action to Control Cardiovascular Risk in Diabetes (ACCORD), and the Action in Diabetes and Vascular Disease: Preterax and Diamicron-Modified Release Controlled Evaluation (ADVANCE) trials, suggested that the potential risk of intensive glycemic control may outweigh its benefits in patients with a very long duration of diabetes, a known history of severe hypoglycemia, advanced atherosclerosis and advanced age/frailty.[18
The South Asian Consensus Guidelines reiterate this viewpoint, and emphasize cautious glycemic control strategies, coupled with management of other cardiovascular risk factors, in the geriatric diabetic population. The Guidelines also emphasize tailoring glycemic goals for patients based on age, comorbid conditions, risk of hypoglycemia, and life expectancy.
Patient-centered management design
Approach to management of diabetes in elderly is largely influenced the constraints (please see above). The management issues which are of paramount importance are described in .
Guidelines and some important tips for designing a patient-specific treatment plan for an elderly patient with diabetes
ADA uses FPG as the criteria of diagnosis, while WHO uses Oral Glucose Tolerance test (OGTT) as the diagnostic parameter.[7
] FPG increases by 1–2 mg/dL/decade and the postprandial plasma glucose (PPG) increases by 15 mg/dL/decade after 30 years of age. Such physiological changes lead to the overestimation of diabetes in the elderly if WHO parameter is used, while the ADA criteria tend to underdiagnose the same in this population.
The South Asian Consensus Statement endorses WHO Guidelines.
Screening geriatric population
Screening for diabetes complications should be individualized in older adults, but particular attention should be paid to complications that may lead to functional impairment.
The South Asian Consensus Guidelines do not recommend universal screening for all geriatric individuals, but do encourage opportunistic screening. This means that a geriatric person should get blood glucose estimation done whenever the opportunity presents, i.e. during a routine examination or while getting blood test done for fever or any other inter-current illness.
Glycemic control goals
Target glycated hemoglobin (HbA1c) should always be individualized in elderly patients based on their functional status, life expectancy, and cognitive function. While a goal of 7% or lower may be appropriate for most older adults who are healthy, such a target value for other older adults may be more challenging given the issues of hypoglycemia. Most recent information with regard to the HbA1c target set by different agencies is available in .
Targets of glycemic control in geriatric population as suggested by various premier agencies
For patients with advanced diabetes complications, life-limiting comorbid illness, or substantial cognitive or functional impairment, it is reasonable to set less-intensive glycemic target goals. These patients are less likely to benefit from reducing the risk of microvascular complications and more likely to suffer serious adverse effects from hypoglycemia. However, patients with poorly controlled diabetes may be subject to acute complications of diabetes, including dehydration, poor wound healing, and hyperglycemic hyperosmolar coma. Glycemic goals at a minimum should avoid these consequences.
The South Asian Consensus Guidelines recommend setting tighter glycemic targets for patients with non-healing wounds or inter-current infection such as tuberculosis. The group also endorses the view that older adults who are functional, cognitively intact, and have significant life expectancy should receive diabetes care using goals developed for younger adults. Glycemic goals for older adults not meeting the above criteria may be relaxed using individual criteria, but hyperglycemia leading to symptoms or risk of acute hyperglycemic complications should be avoided in all patients. Other cardiovascular risk factors should be treated in older adults with consideration of the time frame of benefit and the individual patient. Treatment of hypertension is indicated in virtually all older adults, and lipid and anti-platelet therapy may benefit those with life expectancy at least equal to the time frame of primary or secondary prevention trials.
Safety issues and monitoring of therapy for better glycemic control
Elderly people are at higher risk for hypoglycemia due to age-associated decreases in hepatic oxidative enzyme activity and concomitant decline in renal function, polypharmacy, inadequate and/or erratic nutritional intake, hypoglycemic unawareness secondary to loss of counter-regulatory response to hypoglycemia, and cognitive impairment.[21
Hypoglycemic episodes are associated with a higher rate of injurious falls in older persons, which is a very common geriatric syndrome and affects the quality of life of the elderly.[17
] It is also one of the major limiting factors in glycemic control by pharmacological means. In major interventional studies, intensively treated patients experienced twofold to threefold higher incidence of hypoglycemia. The incidence per person year varies from 1.23 to 2.78 depending on the type of pharmacological modality used. The most dangerous form is silent nocturnal hypoglycemia which may present in an atypical manner simulating cerebrovascular accidents.[22
The risk factors for hypoglycemia among elderly patients are tabulated in . Managing diabetes effectively involves patient and family education regarding signs and symptoms of hypoglycemia, regular home blood glucose monitoring, carrying replacement glucose in pocket, and practicing safe driving. It is important to know that annual self-management training has to be conducted. The clinician must weigh many factors as the risks and benefits of tight glycemic control in elderly patients are evaluated in the context of treatment strategies and priorities.
Risk factors for hypoglycemia in elderly patients
The care of older adults with diabetes is complicated by their clinical and functional heterogeneity. Some older individuals would have developed diabetes years earlier and may have significant complications; others who are newly diagnosed may have had years of undiagnosed diabetes with resultant complications; and yet another subset may have even fewer complications. Some older adults with diabetes are frail and have other underlying chronic conditions, substantial diabetes-related co-morbidity, or limited physical or cognitive functioning. Other older individuals with diabetes have little co-morbidity and are active. Life expectancies are highly variable for this population, but often longer than clinicians realize, or in other words, try to believe.
The South Asian Consensus Guidelines recommend that the aforesaid heterogeneity must be taken into consideration by providers caring for older adults with diabetes while setting and prioritizing treatment goals.