Evaluation of the Patient before Exercise
Before beginning an exercise program, the individual with diabetes mellitus should undergo a detailed medical evaluation with appropriate diagnostic studies. This examination should carefully screen for the presence of macro- and microvascular complications which may be worsened by the exercise program. Identification of areas of concern will allow the design of an individualized exercise prescription which can minimize risk to the patient. Most of the following recommendations are excerpted from the Health Professional's Guide to Diabetes and Exercise.
A careful medical history and physical examination should focus on the symptoms and signs of disease affecting the heart and blood vessels, eyes, kidneys and nervous system.
A graded exercise test may be helpful if a patient, about to embark on a moderate- to high-intensity exercise program (see Table 1),[4,5,6] is at high risk for underlying cardiovascular disease, based on one of the following criteria:
age > 35 years
type 2 diabetes of > 10 years duration
type 1 diabetes of > 15 years duration
presence of any additional risk factor for coronary artery disease
presence of microvascular disease (retinopathy or nephropathy, including microalbuminuria)
In some patients who exhibit nonspecific electrocardiogram (ECG) changes in response to exercise, or who have nonspecific ST and T wave changes on the resting ECG, alternative tests such as radionuclide stress testing may be performed. In patients with diabetes planning to participate in low-intensity forms of exercise (< 60% of maximal heart rate) such as walking, the physician should use clinical judgment in deciding whether to recommend an exercise stress test. Patients with known coronary artery disease should undergo a supervised evaluation of the ischemic response to exercise, ischemic threshold, and the propensity to arrhythmia during exercise. In many cases, left ventricular systolic function at rest and during its response to exercise should be assessed.
Peripheral Arterial Disease (PAD)
Evaluation of PAD is based on signs and symptoms, including intermittent claudication, cold feet, decreased or absent pulses, atrophy of subcutaneous tissues and hair loss. The basic treatment for intermittent claudication is nonsmoking and a supervised exercise program. The presence of a dorsalis pedis and posterior tibial pulse does not rule out ischemic changes in the forefoot. If there is any question about blood flow to the forefoot and toes on physical examination, toe pressures as well as Doppler pressures at the ankle should be carried out.
The eye examination schedule should follow the American Diabetes Association's Clinical Practice Guidelines. For patients who have proliferative diabetic retinopathy (PDR) that is active, strenuous activity may precipitate vitreous hemorrhage or traction retinal detachment. These individuals should avoid anaerobic exercise and exercise that involves straining, jarring or Valsalva-like maneuvers.
On the basis of the Joslin Clinic experience, the degree of diabetic retinopathy has been used to stratify the risk of exercise, and to individually tailor the exercise prescription. Table 2 is reproduced, with minor modifications, from The Health Professional's Guide to Diabetes and Exercise.
Specific exercise recommendations have not been developed for patients with incipient (microalbuminuria > 20 albumin excretion) or overt nephropathy(> 200 mg/min). Patients with overt nephropathy often have a reduced capacity for exercise which leads to self-limitation in activity level. Although there is no clear reason to limit low-to-moderate intensity forms of activity, high-intensity or strenuous exercises should probably be discouraged in these individuals.
Neuropathy; Peripheral (PN)
Peripheral neuropathy may result in loss of protective sensation in the feet. Significant PN is an indication to limit weight-bearing exercise. Repetitive exercise on insensitive feet can ultimately lead to ulceration and fractures. Evaluation of PN can be made by checking the deep tendon reflexes, vibratory sense and position sense. Touch sensation can best be evaluated by using monofilaments. The inability to detect sensation using the 5.07 (10 g) monofilament is indicative of the loss of protective sensation.Table 3 lists contraindicated and recommended exercises for patients with loss of protective sensation in the feet.
The presence of autonomic neuropathy may limit an individual's exercise capacity and increase the risk of an adverse cardiovascular event during exercise. Cardiac autonomic neuropathy (CAN) may be indicated by resting tachycardia (> 100 beats per minute), orthostasis (a fall in systolic blood pressure > 20 mm Hg upon standing), or other disturbances in autonomic nervous system function involving the skin, pupils, gastrointestinal or genitourinary systems. Sudden death and silent myocardial ischemia have been attributed to CAN in diabetes. Resting or stress thallium myocardial scintigraphy is an appropriate noninvasive test for the presence and extent of macrovascular coronary artery disease in these individuals. Hypotension and hypertension after vigorous exercise are more likely to develop in patients with autonomic neuropathy, particularly when starting an exercise program. Because these individuals may have difficulty with thermoregulation, they should be advised to avoid exercise in hot or cold environments and to be vigilant about adequate hydration.
Cite this: Diabetes Mellitus and Exercise - Medscape - Dec 01, 1997.