Chapter 37: Exercise Prescription in Patients with Diabetes

Transcription

1 Chapter 37: Exercise Prescription in Patients with Diabetes American College of Sports Medicine. (2010). ACSM's resource manual for guidelines for exercise testing and prescription (6th ed.). New York: Lippincott, Williams and Wilkins

2 Epidemiology and Pathophysiology of Diabetes Definition: abnormal glucose metabolism resulting from defects in insulin release, action, or both Higher prevalence in nonwhites in the U.S. Many related complications increase morbidity and mortality Complications related to extended hyperglycemia and blood glucose (BG) fluctuations and affect macrovascular, microvascular, and neural processes Types of Diabetes Type 1 Diabetes Mellitus (T1DM) Young onset Type 2 Diabetes Mellitus (T2DM) Typically older onset, but becoming more common in younger individuals Gestational Diabetes Mellitus (GDM) Onset during or soon after pregnancy

3 Clinical Features of Diabetes Diagnosis: based on established criteria Glucose regulation (aka, glycemic control): the maintenance of blood glucose in a normal range with a goal of reducing the risk of secondary complications BG regulation is primary focus after diagnosis Performed with medications, diet, and exercise Glycemic control assessed by glycosylated hemoglobin (aka, HbA1c) values Nondiabetic range = 4%-6% Goal is 7%

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5 Clinical Features of Diabetes Glucose regulation: normally controlled by hepatic release and dietary intake and by peripheral uptake of glucose Diabetes often requires artificial glucose regulation Insulin injections or continuous subcutaneous insulin infusion (i.e., insulin pump) Oral hypoglycemic agents β-cell stimulants for insulin release Drugs to improve insulin sensitivity Drugs that abate intestinal absorption of carbohydrates

6 Treatment Best initiated by a multidisciplinary team of specialists: Physician Diabetes educator Registered dietician Exercise physiologist Keys to adequate treatment: treatment should focus on controlling blood glucose and risk factors for diabetes-related complications Control and treat blood glucose: intensive self blood glucose monitoring and oral drugs or exogenous insulin (or both) Lose weight and improve blood lipid profile: balanced diet and regular physical activity/exercise Enhance fitness: regular physical activity/exercise Smoking cessation Self-manage: diabetes self-management education

7 Acute and Chronic Exercise-Related Physiologic Responses in Diabetes Acute exercise: Improves insulin sensitivity Facilitates glucose uptake Aids in glucose homeostasis Chronic Exercise: Improves cardiovascular function Improves blood lipids and lipoproteins Lowers BP Decreases body mass, fat mass, and body fat distribution Affects fat-free mass (maintain or increase) Improves insulin sensitivity Improves glucose control (T2DM only) Increases metabolism Enhances postprandial thermogenesis

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9 Screening Exercise Prescription in Diabetes Pre-exercise glucose levels If below 100 mg/dl, then no exercise until rises above 100 mg/dl If hyperglycemic, need to ensure no symptoms or ketones (typically produced with values > mg/dl) before allowing exercise Screening for vascular and neurologic complications, including silent ischemia and retinopathy Assessment for cardiovascular risk factors and metabolic syndrome Determine if pre-exercise training stress test is indicated

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12 Exercise Prescription in Diabetes Aerobic Training Exercise Prescription Precautions of Aerobic Training Consider supervision in all patients for initial training Supervision strongly suggested for those early post diabetes-related event or surgery Warm-up and cool-down very important in this population Consider modality based on individual patient, focusing on body weight, mobility, balance, peripheral neuropathy, and condition of feet with respect to sores and ulcers Monitor pre- and postexercise blood glucose, especially for the first several exercise sessions, to avoid hypoglycemia Require stress test if performing vigorous exercise

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14 Exercise Prescription in Diabetes Resistance Training Exercise Prescription Precautions of resistance training May need to consider not performing due to uncontrolled high blood pressure Avoid Valsalva maneuver Often contraindicated if retinopathy Seek physician confirmation

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16 Exercise Prescription in Diabetes Flexibility Exercise Prescription Precautions of flexibility training Appropriate modification(s) of stretches due to joint limitations, obesity, or pregnancy restrictions in the case of GDM should be made. Avoid ballistic stretching due to increased risk of musculoskeletal injury.

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18 Exercise Prescription in Diabetes Exercise prescription for cardiac clientele Encourage participation in cardiac rehabilitation. Hypoglycemic symptoms may be reduced in those with neuropathies or taking a β-blocker. Stress test is often needed to detect ischemia (reduced ability to feel angina) and for accurate heart rate based prescription (autonomic neuropathy). Aerobic, resistance, and flexibility training are similar to the patient without cardiac disease.

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20 Exercise Recommendations for Specific Diabetes-Related Complications Autonomic Neuropathy Affects the involuntary functions of the body, including the cardiac, vascular, GI, and genitourinary systems Cardiac effects can lead to: Elevated resting heart rate Reduced heart rate reserve Inability to sense angina Postexercise hypotension Thermoregulatory dysfunction Prone to dehydration Hypoglycemia unawareness

21 Exercise Recommendations for Specific Diabetes-Related Complications Peripheral Neuropathy Affects the extremities, especially the lower legs and feet Loss of sensation in or desensitized feet Prone to ulcers and wounds Poor wound healing Increased incidence of lower limb amputation Need to check feet daily Watch injuries from overstretching and loss of balance/falls Non weight-bearing exercise modes indicated when severe

22 Exercise Recommendations for Specific Diabetes-Related Complications Nephropathy When excessive urinary protein is present (microalbuminuria >30 and <300 mg dl 1 ) Hypertension increases risk Goal is to delay onset of end-stage renal disease (ESRD) Focus: Low- to moderate-intensity aerobic and resistance exercise Proper hydration strategies Avoidance of activities that cause excessive elevation in BP

23 Exercise Recommendations for Specific Diabetes-Related Complications Retinopathy Nonproliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR) Requires tight glucose and blood pressure control Can get a 15% improvement in aerobic capacity with low- to moderate-intensity exercise training

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