Hyperlipidemia Chapter 22

VIDEO There are four principal lipoprotein classes:lipoprotein 1. Chylomicrons are derived from intestinal absorption of exogenous (dietary) triglyceride. 2. Very low density lipoprotein (VLDL) is synthesized in the liver and is the primary transport mechanism for endogenous triglyceride.

Low-density lipoprotein (LDL) represents the final stage in the catabolism of VLDL and is the principal carrier of cholesterol. High-density lipoprotein (HDL) is involved in the reverse transport of cholesterol and is typically studied as two separate subfractions: HDL 2 and the more dense HDL 3.

Hyperlipidemias Hyperlipidemia indicates elevated blood triglyceride and cholesterol. Hypertriglyceridemia denotes only elevated triglyceride concentration. Hypercholesterolermia implies only elevated blood cholesterol concentration.

Hyperlipidemias Hyperlipoproteinemia or dyslipoproteinemia denotes elevated lipoprotein concentrations. Hyperlipoproteinemia is associated with genetic abnormalities or may be secondarily related to an underlying disease such as diabetes mellitus.

Principle Concerns with CAD: (see NCEP standards, p.168) Hypertriglyceridemia > 200 mg/dl Hypercholesterolemia >240 mg/dl HDL-C – recommended > 40 mg/dl men; 50 mg/dl women LDL-C – recommended 160 is high.

Effects on the Exercise Response Generally, dyslipidemia does not alter the exercise response to a single session of exercise unless the dyslipidemia is longstanding and has led to CAD or secondary illness. Medical management of dyslipidemia is needed before beginning an exercise program. Because dyslipidemic clients may have prescribed medications for other conditions, the type and dose of these medications should be noted before the person undergoes exercise testing or exercise training

Effects of Exercise Training Benefits include: Triglyceride concentrations are generally lower. Reduced blood lipids following a meal (postprandial lipemia) Reduced numbers of LDL-C that poses the higher CVD risk (small molecules) HDL cholesterol (HDL-C) concentrations are typically higher (but not always). Enzyme activity in the metabolism of lipoproteins is increased. ** These exercise training changes will enhance reverse cholesterol transport and can be augmented further by a low- fat diet, weight loss, and reduction in adiposity.**

Management and Medications Therapies with diet, weight loss, and exercise are adjunctive to pharmacological therapy and are extremely important for the following reasons: Low-fat and high-carbohydrate diets lower HDL-C and increase triglyceride concentrations; however, exercise diminishes these effects of diet on HDL-C and triglyceride concentrations. Low-calorie diets that cause weight loss decrease total cholesterol and LDL-C, and increase HDL-C (variant changes in different patients). Drug use and interactions are very complicated. You should review medications and interactions when considering an exercise program. (see p.171)

Recommendations for Exercise Testing If the dyslipidemia condition is congenital, but the patient does not have any signs or symptoms of some other primary condition, exercise testing can follow normal protocols used for populations at risk for CAD. The Primary Objectives of Exercise Testing are: 1) Diagnose CAD 2) Determine Functional Capacity 3) Determine appropriate intensity range for aerobic training.

Recommendations For Exercise Programming Presently available information suggests that there may be different energy expenditure thresholds for different lipids and lipoproteins. 1) Triglyceride concentrations are lower in hypertriglyceridemic men after two weeks of aerobic exercise (45 min/day) on consecutive days 2) HDL-C concentrations are frequently increased by exercise regimens requiring 1000 to 1200 kcal of energy expenditure/wk (minimal training period of 12 wk).

Recommendations For Exercise Programming (see Table 22.2, p.172) The primary goal for exercise training is to expend calories by exercise training with exercise that is: performed at moderate intensities (40-80% of maximal functional capacity), performed often (preferably > 5 days/wk), performed once a day, although exercising twice a day may be necessary to increase total energy expenditure and may be useful in persons with time constraints or severe exercise intolerance from chronic disease or morbid obesity. May also incorporate resistance training as an adjunct fitness exercise

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