Chapter 09 9 Hyperlipidemia and Dyslipidemia C H A P T E R Grandjean, Gordon, Davis, and Durstine

Definition Hyperlipidemia –General term used to refer to chronic elevations in the fasting blood concentrations of triglyceride, cholesterol, or specific subfractions of each Dyslipidemia –A combination of genetic, environmental, and pathological factors that can work together to abnormally alter blood lipid and lipoprotein concentrations (continued)

Definition (continued) Hypercholesterolemia – Implies elevated blood cholesterol concentration >240 mg/dl. 124 Hypertriglyceridemia –Denotes only elevated triglyceride concentration (continued)

Definition (continued) Postprandial lipemia –Characterized by exaggerated levels of triglycerides in the blood and failure to return to baseline levels within 8 to 10 h after consumption of dietary fat Hyperlipoproteinemia or dyslipoproteinemia –Elevated lipoprotein concentrations

Scope Important modifiable risk factor for coronary heart disease –Relative risks for coronary heart disease (CHD) mortality and a subsequent CHD-related event are reduced 24.5% and 29.5% with every 1 mmol/L (~39 mg/dl) decrease in total cholesterol. –For every 1 mmol/L reduction in LDL-C, the relative risks for CHD mortality and coronary-related events are decreased 28% and 26.6%, respectively. Prevalence –44.4% of American adults 20 yr of age or older, 41.8% of men, and 46.3% of women have total serum cholesterol >200 mg/dl (>5.18 mmol/L).

Figure 9.1

Pathophysiology Lipoprotein metabolic pathways –Blood lipoproteins move lipids between intestine, liver, and extrahepatic tissue. –Transport of cholesterol and triglyceride is generally described in terms of two general processes: LDL receptor pathway Reverse cholesterol transport (continued)

Pathophysiology (continued) Postprandial lipemia –Time needed after a meal for blood triglyceride levels to return to fasting levels is 6 to 8 h. –Exaggerated or prolonged lipemia is associated with increased CAD risk. (continued)

Pathophysiology (continued) Metabolic dyslipidemia –Elevation of bloodborne fatty acids observed with metabolic dyslipidemia affects the vascular endothelium and leads to: Reduced nitric oxide production Induced adhesion characteristics Facilitated oxidative damage Inflammation Diminished vascular compliance and reactivity

Signs and symptoms Silent diseases –Majority lack signs and symptoms Hypercholesterolemia exception: –Familial hypercholesterolemia Xanthomas Atheromas (continued) Clinical Considerations

Hypertriglyceridemia exception: –Familial lipoprotein lipase (LPL) deficiency Abdominal pain Recurrent acute pancreatitis Development of cutaneous xanthomata Milky plasma Clinical Considerations (continued)

Medical History and Physical Exam Clinical screening –Analysis of the blood lipid profile –Measured every 5 years –Can begin at age 20 Classification of dyslipidemias –NCEP ATP III guidelines (continued)

Medical History and Physical Exam (continued) Blood testing –Basic measurements include: Total LDL-C HDL-C Triglyceride estimates –Can include postprandial lipid testing

LDL Cholesterol Goals and Cut Points See table 9.3 for LDL cholesterol goals and cut points for therapeutic lifestyle changes (TLD) and drug therapy in different risk categories.

Diagnostic Testing Exercise testing –Individuals at risk for CAD –Consider possible comorbidities Cardiovascular testing –Goals: Diagnose CAD Functional capacity Exercise intensity range (continued)

Diagnostic Testing (continued) Musculoskeletal testing –Goals: Determine musculoskeletal strength Endurance Performance (continued)

Diagnostic Testing (continued) Flexibility testing –Goals Determine the range of motion in all joints Assist in the assessment of functional abilities related to exercise prescription and ADLs Contraindications –Exercise is not contraindicated for those with a dyslipidemic blood profile. –When diseases are suspected or present, protocols for testing a patient are likely to change.

Treatment Engage in regularly practiced physical activity. Consume a heart-healthy diet. Lose weight. Prevent weight regain after weight loss. Quit smoking. Improve stress management. Lipid-lowering medication.

Exercise Prescription Cardiovascular exercise –150 to 300 min of moderate-intensity or –75 to 150 min of vigorous-intensity physical activity per week –8 to 10 mi of running per week shown to be necessary to significantly change HDL-C concentration –3 to 5 or more days per week to help reach dose recommendations –Moderate- to vigorous-intensity physical activity may be accumulated throughout the day –10-min increments are acceptable (continued)

Table 9.6

Exercise Prescription (continued) Resistance exercise –Very limited effect on improving blood lipid and lipoprotein concentrations –Follow previous recommendations (chapter 5) –Cardiovascular exercise should be prioritized Range of motion exercise –No known benefit to lipid and lipoprotein profiles –Follow previous recommendations (chapter 5) –Important to overall fitness

Table 9.7

Conclusion Exercise is an essential element of management of patients with dyslipidemias, with proven benefits that likely extend to a reduction in mortality and morbidity. In addition to exercise programming, nutritional choices and body composition improvements are needed and, when necessary, use of appropriate medications.