Chapter 24Chapter 24

Exercise ManagementExercise Management

Exercise ManagementExercise Management

Diabetes is a chronic metabolic disease Diabetes is a chronic metabolic disease characterized by an absolute or relative characterized by an absolute or relative deficiency of insulin that results in deficiency of insulin that results in hyperglycemia. hyperglycemia. Clinical Overview Clinical Overview ((hyperlink))

Clinical CriterionClinical Criterion Fasting blood glucose > 125 mg/dlFasting blood glucose > 125 mg/dl Random blood glucose > 200 mg/dl with Random blood glucose > 200 mg/dl with hyperglycemic symptoms Two hour glucose > 200 mg/dl during an oral glucose tolerance test (Two hour glucose > 200 mg/dl during an oral glucose tolerance test (

OGTT) )

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Blood glucose measurements that are bound Blood glucose measurements that are bound to hemoglobin (HbA1c) provides an average to hemoglobin (HbA1c) provides an average blood glucose level over a prolonged period – blood glucose level over a prolonged period – 60 -90 days60 -90 daysIndividuals with diabetes are at risk for Individuals with diabetes are at risk for developing microvascular complications, developing microvascular complications, including retinopathy and nephropathy; including retinopathy and nephropathy; macrovascular disease; and various macrovascular disease; and various neuropathies (both autonomic and peripheral). neuropathies (both autonomic and peripheral). Neuropathy can also enable silent ischemia.Neuropathy can also enable silent ischemia.

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Type 1 DiabetesType 1 Diabetes - In type 1 diabetes mellitus, there is - In type 1 diabetes mellitus, there is an absolute deficiency of insulin caused by a marked an absolute deficiency of insulin caused by a marked reduction in insulin secreting beta cells of the reduction in insulin secreting beta cells of the pancreas. pancreas. Type 1 diabetics are prone to develop ketoacidosis Type 1 diabetics are prone to develop ketoacidosis when hypoinsulinemia results in hyperglycemia.when hypoinsulinemia results in hyperglycemia.The cause of type 1 diabetes is thought to involve The cause of type 1 diabetes is thought to involve an autoimmune response directed at the beta cells an autoimmune response directed at the beta cells which are eventually destroyed.which are eventually destroyed. The factors that trigger the autoimmune response The factors that trigger the autoimmune response have not been specifically identified but may include have not been specifically identified but may include viruses or toxins.viruses or toxins.

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Type 2 DiabetesType 2 Diabetes - Individuals with Type 2 - Individuals with Type 2 diabetes are considered to have a relative diabetes are considered to have a relative insulin deficiency because they may haveinsulin deficiency because they may have

elevated, reduced, or normal insulin levels but elevated, reduced, or normal insulin levels but still present with hyperglycemia.still present with hyperglycemia. Thus, Type 2 diabetics present with Thus, Type 2 diabetics present with hyperglycemia regardless of blood insulin hyperglycemia regardless of blood insulin statusstatus

Exercise ManagementExercise Management In type 2 diabetes, peripheral tissue insulin In type 2 diabetes, peripheral tissue insulin resistance and defective insulin secretion resistance and defective insulin secretion occur. occur. With insulin resistance, glucose does notWith insulin resistance, glucose does not

readily enter the insulin-sensitive tissues readily enter the insulin-sensitive tissues (primarily(primarily

muscle and adipose tissue),muscle and adipose tissue), and hyperglycemia occurs. and hyperglycemia occurs. The hyperglycemia causes the beta cells of The hyperglycemia causes the beta cells of the pancreas to secrete more insulin in an the pancreas to secrete more insulin in an attempt to maintain a normal blood glucose attempt to maintain a normal blood glucose concentration.concentration.

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The additional endogenous insulin is usually The additional endogenous insulin is usually ineffective in lowering blood glucose and may further ineffective in lowering blood glucose and may further contribute to insulin resistance.contribute to insulin resistance. Eventually the beta cells may become exhausted Eventually the beta cells may become exhausted and fail to produce adequate amounts of insulin.and fail to produce adequate amounts of insulin. The mechanisms underlying insulin resistance The mechanisms underlying insulin resistance remain unclear but probably involve defects in the remain unclear but probably involve defects in the binding of insulin to its receptor and in post-receptor binding of insulin to its receptor and in post-receptor events such as glucose transport.events such as glucose transport.Obesity significantly increases insulin resistance, Obesity significantly increases insulin resistance, thus the majority of patients with type 2 diabetes are thus the majority of patients with type 2 diabetes are obese.obese.

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Those with type 2 diabetes do not develop Those with type 2 diabetes do not develop ketoacidosis except under conditions of ketoacidosis except under conditions of unusual stress unusual stress (e.g., trauma).(e.g., trauma).

Family history is a risk factor for type 2 Family history is a risk factor for type 2 diabetes, and type 2 diabetes typically occurs diabetes, and type 2 diabetes typically occurs after age 40.after age 40.

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Gestational Diabetes - Gestational diabetes Gestational Diabetes - Gestational diabetes occurs during pregnancy because of the occurs during pregnancy because of the contra-insulin effects of pregnancy contra-insulin effects of pregnancy (pregnancy (pregnancy hormones effect insulin uptake and production).hormones effect insulin uptake and production).

Risk factors for the development of Risk factors for the development of gestational diabetes include family history of gestational diabetes include family history of gestational diabetes, previous delivery of a gestational diabetes, previous delivery of a large birth weight baby, and obesitylarge birth weight baby, and obesity Approximately 50% of the women who Approximately 50% of the women who develop gestational diabetes develop type 2 develop gestational diabetes develop type 2 diabetes later in life.diabetes later in life.

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Impaired Glucose ToleranceImpaired Glucose Tolerance

and Impaired Fasting Glucoseand Impaired Fasting Glucose

Impaired glucose tolerance (IGT) and impaired Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are intermediate fasting glucose (IFG) are intermediate metabolic conditions between normoglycemia metabolic conditions between normoglycemia clinical diabetes. clinical diabetes. (see link above)(see link above)

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Effects on the Exercise ResponseEffects on the Exercise ResponseThe effect of diabetes on a single exercise session is The effect of diabetes on a single exercise session is dependent on several factors, including:dependent on several factors, including: use and type of medication to lower blood glucoseuse and type of medication to lower blood glucose(insulin or oral hypoglycemic agents)(insulin or oral hypoglycemic agents) timing of medication administrationtiming of medication administration blood glucose level prior to exercise timing, blood glucose level prior to exercise timing, amount, and type of previous food intakeamount, and type of previous food intake presence and severity of diabetic complications;presence and severity of diabetic complications; use of other medication secondary to diabetic use of other medication secondary to diabetic complications, complications, the intensity, duration, and type of exercise.the intensity, duration, and type of exercise.

Exercise ManagementExercise ManagementEffects of Exercise TrainingEffects of Exercise Training Possible improvement in blood glucose control with Possible improvement in blood glucose control with type 2 diabetes, but is not considered a component of type 2 diabetes, but is not considered a component of treatment in type 1 diabetes to lower blood glucose treatment in type 1 diabetes to lower blood glucose ((must < 250 mg/dl for type 1 patient to exercise, no ketonesmust < 250 mg/dl for type 1 patient to exercise, no ketones), but may ), but may improve CV healthimprove CV health Improved insulin sensitivity / lower medication Improved insulin sensitivity / lower medication requirement.requirement. Reduction in body fat.Reduction in body fat.CV benefitsCV benefitsPrevention of Type 2 diabetes, especially those with Prevention of Type 2 diabetes, especially those with IGT, hx of Gestational Diabetes , or family hx.IGT, hx of Gestational Diabetes , or family hx.

Exercise ManagementExercise ManagementDiabetes Management and MedsDiabetes Management and Meds Insulin allows glucose to enter the cells of Insulin allows glucose to enter the cells of insulin sensitive tissue. There are several insulin sensitive tissue. There are several different types of insulin available different types of insulin available pharmaceutically pharmaceutically (injected or via insulin pump)(injected or via insulin pump) that vary in that vary in onset, peak, duration, and source onset, peak, duration, and source (see table 24.1 on (see table 24.1 on page 185).page 185).

Oral agents for type 2 diabetes are Oral agents for type 2 diabetes are medications that help the pancreas secrete medications that help the pancreas secrete more insulin, alter carbohydrate absorption, more insulin, alter carbohydrate absorption, reduce liver glycogenolysis, and/or increase reduce liver glycogenolysis, and/or increase insulin sensitivity insulin sensitivity (see table 24.2 and 24.3 on pages 186-87).(see table 24.2 and 24.3 on pages 186-87).

Exercise ManagementExercise Management The most significant effect of both insulin and The most significant effect of both insulin and oral hypoglycemic agents on exercise testing oral hypoglycemic agents on exercise testing and exercise training is their ability and exercise training is their ability to cause to cause hypoglycemiahypoglycemia. Attention to timing of . Attention to timing of medication, food intake, and blood glucose medication, food intake, and blood glucose level before and after exercise is necessary. level before and after exercise is necessary. If exercise is of long duration If exercise is of long duration (i.e., > 60 min),(i.e., > 60 min), blood glucose should be periodically tested blood glucose should be periodically tested duringduring exercise. exercise.

Exercise ManagementExercise ManagementRecommendations for Exercise TestingRecommendations for Exercise TestingExercise testing using protocols for populations at risk Exercise testing using protocols for populations at risk for coronary artery disease (CAD) is recommended in for coronary artery disease (CAD) is recommended in people who:people who:

have type 1 diabetes and are over the age of 30have type 1 diabetes and are over the age of 30 have had type 1 diabetes longer than 15 yearshave had type 1 diabetes longer than 15 years have type 2 diabetes and are over age 35have type 2 diabetes and are over age 35 have either type 1 or type 2 diabetes and one or have either type 1 or type 2 diabetes and one or more more of the other CAD risk factors;of the other CAD risk factors; have suspected or known CADhave suspected or known CAD have any microvascular or neurological diabetic have any microvascular or neurological diabetic complications.complications. See Table 24.4, p.187 (posted below)See Table 24.4, p.187 (posted below)

Exercise ManagementExercise ManagementRecommendations for Exercise TestingRecommendations for Exercise TestingDiabetic patients who do not meet any of the Diabetic patients who do not meet any of the

pervious criteria may be tested with pervious criteria may be tested with protocols for the general healthy protocols for the general healthy population. In these individuals, the primary population. In these individuals, the primary objective is to:objective is to:

1)1) Identify the presence and extent of CADIdentify the presence and extent of CAD2)2) Determine the appropriate intensity range for Determine the appropriate intensity range for

aerobic exercise testing.aerobic exercise testing.Diabetic patients who present chronotropic impairment during Diabetic patients who present chronotropic impairment during

exercise are at a increased risk of MI and all cause exercise are at a increased risk of MI and all cause mortality.mortality.

Exercise ManagementExercise Management

Exercise ManagementExercise ManagementRecommendations for Exercise ProgrammingRecommendations for Exercise Programming(see Table 24.5, pp.188-189, next slide)

The exercise prescription for people with diabetes The exercise prescription for people with diabetes must be individualized according to medication must be individualized according to medication schedule, presence and severity of diabetic schedule, presence and severity of diabetic complications, and goals and expected benefits of the complications, and goals and expected benefits of the exercise program.exercise program. Food intake with exercise Food intake with exercise mustmust be considered for be considered for type 1 individuals. These patients must have food type 1 individuals. These patients must have food supplies on hand during the exercise session. The supplies on hand during the exercise session. The amount of carbohydrate ingestion is dependent on amount of carbohydrate ingestion is dependent on the length of the exercise session.the length of the exercise session.

Exercise ManagementExercise Management

Exercise ManagementExercise ManagementRecommendations for Exercise ProgrammingRecommendations for Exercise Programming Exercise is contraindicated if:Exercise is contraindicated if: there is active retinal hemorrhage or there has there is active retinal hemorrhage or there has been recent therapy for retinopathy been recent therapy for retinopathy (e.g., laser treatment)(e.g., laser treatment)

illness or infection is presentillness or infection is present blood glucose is above 250 mg/dl and ketones areblood glucose is above 250 mg/dl and ketones arepresent present (blood glucose should be lowered before(blood glucose should be lowered before

initiation of exercise)initiation of exercise) ororblood glucose is < 70 mg/dl because the risk ofblood glucose is < 70 mg/dl because the risk ofhypoglycemia is great hypoglycemia is great (if postexercise blood glucose is < 100 (if postexercise blood glucose is < 100 mg/dl, carbohydrate should be eaten and blood glucose allowed to mg/dl, carbohydrate should be eaten and blood glucose allowed to increase before the initiation of exercise) increase before the initiation of exercise)

Exercise ManagementExercise ManagementRecommendations for Exercise ProgrammingRecommendations for Exercise Programming Exercise precautions include the following:Exercise precautions include the following: keeping a source of rapidly acting carbohydratekeeping a source of rapidly acting carbohydrate

available during exerciseavailable during exercise consuming adequate fluids before, during, andconsuming adequate fluids before, during, and

after exerciseafter exercise practicing good foot care by wearing proper shoespracticing good foot care by wearing proper shoes

and cotton socks, and inspecting feet after exercise;and cotton socks, and inspecting feet after exercise;carrying medical identification.carrying medical identification.

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