Diabetes in the Elderly 1, 2, 3

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1 Diabetes in the Elderly 1, 2, 3 WF Mollentze Feb 2010 Diabetes in the elderly differs from diabetes in younger people Prevalence: o Diabetes increases with age affecting approximately 10% of people over 65 years. o Half of these people are unaware that they have diabetes o Beta-cell dysfunction manifested by impaired glucose-induced insulin secretion and o Resistance to insulin-mediated glucose disposal contribute to this high prevalence (Fig 21.6, Davidson s) Glycosuria: o The renal threshold for glucose rises with age, so glycosuria may not develop until the blood glucose concentration is markedly raised o Screening and diagnosis: Patients with classic hyperglycemic symptoms or hyperglycemic crisis can continue to be diagnosed when a random (or casual) PG of 11.1 mmol/l is found. Pancreatic carcinoma: o May present in old age with the development of diabetes, in association with weight loss and diminished appetite 1 Principles and Practice of Medicine, 20 th Edition (International). Editors: NA Boon, NR Colledge, BR Walker. Churchill Livingstone. 2 UpToDate 17.1, Feb American Association of Diabetes. Standards of medical care in 2010.

2 Complications: o Life expectancy decrease with increasing age Mean life expectancy in the developed world (Table 7.1, Davidson s) Males Females At birth 76 years 81 years At 60 years 20 years 23 years At 70 years 13 years 15.5 years At 80 years 7.5 years 9 years o Renal function declines with increasing age: nephrons decline in number from the age of 30 years; creatinine clearance declines at a rate of about 10 ml/min per decade after the age of 50 years. o Older individuals with diabetes have higher rates of premature death, functional disability, and coexisting illnesses such as hypertension, CHD, and stroke than those without diabetes. o Older adults with diabetes are also at greater risk than other older adults for several common geriatric syndromes, such as polypharmacy, depression, cognitive impairment, urinary incontinence, falls with injury, and persistent pain. o Screening for complications: particular attention should be paid to complications that would lead to functional impairment. Management: (See Table in Davidson s: Checklist for follow-up of patients with diabetes mellitus) o Glycaemic control: The optimal degree of diabetes control in older people still has to be determined. Strict glycaemic control should be avoided in the very frail patient. o Cognitive and affective function: may benefit from improving glycaemic control. o Hypoglycaemia: older people have reduced symptomatic awareness in of hypoglycaemia and limited knowledge of symptoms, and are at greater risk of and from hypoglycaemia. o Mortality: the mortality rate of older people with diabetes is more than double that of age-matched non-diabetic people, largely because of increased deaths from cardiovascular disease. o Individualise management: Older adults with diabetes can be fit and healthy or frail with many comorbidities and functional disabilities. Clinical trials of hypertension in the elderly have consistently demonstrated benefit from antihypertensive therapy, including patients over the age of 80 (Goal BP: The systolic pressure goal is less than 140 mmhg if tolerated with the possible exception of selected patients with isolated systolic hypertension and the goal diastolic pressure is 85 to 90 mmhg) Lipid and aspirin therapy may benefit those with life expectancy at least equal to the time frame of primary or secondary prevention trials. o Special care is required in prescribing and monitoring pharmacologic therapy in older adults. Metformin is often contraindicated because of renal insufficiency or significant heart failure.

3 o TZDs can cause fluid retention, which may exacerbate or lead to heart failure. They are contraindicated in patients with CHF (New York Heart Association class III and IV), and if used at all should be used very cautiously in those with, or at risk for, milder degrees of CHF. Sulfonylureas, other insulin secretagogues, and insulin can cause hypoglycemia. Insulin use requires that patients or caregivers have good visual and motor skills and cognitive ability. Drugs should be started at the lowest dose and titrated up gradually until targets are reached or side effects develop. Diabetic retinopathy: Screen not only for diabetic retinopathy but also for cataracts and glaucoma, which are more common in elderly diabetic compared with non-diabetic subjects. o Diabetic nephropathy: the presence of microalbuminuria in elderly patients with type 2 diabetes may not be due to diabetic nephropathy, and therefore other conditions should be ruled out o Foot problems: The prevalence of diabetic neuropathy in patients with type 2 diabetes is > 50% in patients over age 60 years. More than 30% of older diabetic patients cannot see or reach their feet, and may therefore be unable to perform routine foot inspections. Elderly diabetic patients must have their feet examined at every visit Assess whether the patient can see and reach his or her feet Inquire about other family members or friends who could be trained to do routine foot inspections. Visits to a podiatrist on a regular basis should also be considered. A detailed neurologic examination and assessment for peripheral arterial disease should be performed at least yearly. Advice on foot care must be given to any patient whose feet are at high risk Case 1 A 75-year old patient on treatment for type 2 diabetes for the past 15 years presents to the emergency department in a confused state. He is currently taking the following medication: Enalapril 10 mg daily for hypertension, gliclazide 160 mg two times per day before meals, metformin 500 mg tabs three times per day with meals, simvastatin 20 mg at night, and aspirin 150 mg in the morning. His plasma glucose on arrival is 2.9 mmol/l. His pulse rate is 110 per minute and his blood pressure 145 / 90 mm Hg. His HbA1c concentration a week ago was 5.6 %. A urinary dipstick test shows 2+ proteinuria. His serum urea is 14.2 mmol/l and his serum creatinine concentration is 320 mol/l. Question 1 What is the most likely cause for this patient s mental state? a. Transient cerebral ischaemia b. A subdural haematoma c. Hyponatraemia d. Hypoglycaemia

4 Question 2 What is the most likely explanation for the patient s plasma glucose of 2.9 mmol/l? a. Skipped meal b. Unusual strenuous physical activity c. Overdose of metformin d. Renal impairment Question 3 How will you correct the patient s plasma glucose? a. Glucagon 1 mg IMI stat b. Commence IV infusion of 10% D/W c. Sweetened drink per os d. 50 ml of 50% D/W IV stat Question 4 What would your next step be after correction of the patient s blood sugar? a. Discharge patient with an instruction to decrease dose of OHA. b. Admit the patient with the intention to modify therapy under close observation.

5 Case 2 A 78 year-old lady visits you in your surgery complaining of tiredness and severe itching in the genital area. On examination she has candida vulvovaginitis. Her random plasma glucose at the time same time is 10.8 mmol/l. How will you proceed? Case 3 An 85-year old man presents to the emergency department with an acute Right-sided stroke. His vital signs are: GCS 12/15, pulse 108 per minute, regular, BP 168/95 in the R arm, respiratory rate 16 / min. Special investigations: serum urea 11.4 mmol/l, serum sodium 128 mmol/l, serum potassium 5.8 mmol/l and s-creatinine 198 µmol/l. He is incontinent and a Multistix dipstick test reveals blood 1+, proteien 1+ and glucose 2+. His random plasma glucose concentration is 14.8 mmol/l. Question 1 What are the possible explanation(s) for this patient s blood sugar level? Question 2 How will you manage this patient?

6 Case 4 A 79 year old gentleman with type 2 diabetes of 7 year s duration and well-controlled on oral hypoglycaemic agents now presents during a routine follow-up visit with a fasting PG of 11.9 mmol/l and a HbA1c of 9.8%. He is taking metformin 850 mg 3xday and gliclazide 160 mg 2x day. How will you proceed?