Diabetes Mellitus Specific Clinical Patterns with Aging
A variety of metabolic, sensory, and cardiovascular conditions accompany the widespread prevalence of diabetes in the elderly and contribute to the reduced life expectancy that occurs with diabetes. Life expectancy reductions in diabetic individuals at ages 50 to 59 are 6 to 7 years, at ages 60 to 69 are 4 to 5 years, and at age 70 and above life expectancies are reduced by 3 years. In addition, the longer diabetes has been present, the greater the life expectancy reduction.
Hypertension occurs in 30% to 50% of those with diabetes in 45-to 64-year-olds but is present in 70% of diabetic patients aged 65 to 74. Diabetic ketoacidosis mortality is greater in individuals over age 75 (50 per 100,000 diabetic patients) than age 65 to 74 (20 per 100,000 diabetic patients).
Hyperosmolar nonketotic coma is essentially a disorder of the elderly diabetic. Twenty-four percent of all cases of legal blindness occur in diabetic individuals over age 65 years. Peripheral neuropathy, the most common diabetic neuropathy, has a prevalence of 25% to 35%in diabetic patients between 65 and 74 years of age. Absent pulses are twice as frequent in diabetic versus nondiabetic individuals (20% versus 13%) in the age group 55 to 74 years. The risk of leg amputations is 15 to 40 times greater for a person with diabetes. Renal failure requiring dialysis occurs most often from the pool of patients with diabetes mellitus, and recent evidence suggests progression to renal failure is more rapid in older patients.
The incidence of stroke is almost twice as great in diabetic individuals at all ages. Stroke incidence increases with advancing age to incidence rates four times greater: the rate at age 45 to 49 is 30 per 1000 and at age 65 to 69 is 133 per 1000. Between the ages of 45 and 64, 8.4% of diabetic individuals have had a stroke, a prevalence that increases to 12.7% in individuals more than 65 years of age. The incrementally greater impact of the number of risk factors for stroke in the elderly diabetic population has been studied in the Framingham Heart Study. With increasing numbers of risk factors, including hypertension, hypertension treatment, diabetes mellitus, cigarette smoking, preexisting heart disease, atrial fibrillation, and ECG changes compatible with left ventricular hypertrophy, 10-year stroke probability increases geometrically.
Advancing age in diabetic individuals is associated with increasing prevalence of a host of gastrointestinal diseases including hiatus hernia, ulcers, and gallstones, trends that are more apparent in females than males with diabetes mellitus (NHANES II).
Infection rates, particularly urinary tract infections and viral pneumonia, are twice as frequent in diabetic individuals than nondiabetic individuals. Current evidence suggests no age-related increase in infection rates. Periodontal disease shows a linear increase with age in diabetic individuals.
The overall impact of comorbid disease, being more prevalent in older diabetic individuals, is substantial. Although hospital discharges primarily for diabetes mellitus decrease with advancing age, those for associated diseases increase dramatically. Hospitalization rates are 40% to 80% higher in diabetic patients than nondiabetic patients depending on age.
Advancing age is also associated with a progressive increase in length of hospital stay with diabetes mellitus.