Chapter Metabolic Syndrome Peterson and Gordon C H A P T E R

Disease Definition Metabolic syndrome –Collection of interrelated cardiometabolic risk factors that are present in a given individual more frequently than may be expected with a chance combination Usually presence of overweight or obesity Greater risk for developing atherosclerotic cardiovascular disease

Clinical Criteria See table 10.1 for harmonized clinical criteria for the metabolic syndrome.

Scope Prevalence of the metabolic syndrome is 34.1% based on NHANES data and ATP III criteria (adults ≥20 yr). Current statistics do not indicate a tapering of metabolic syndrome prevalence in the United States. Evidence from NHANES III has indicated that approximately two-thirds of adolescents aged 12 to 19 yr present with one or more metabolic abnormalities. Cumulative annual costs of medical care for CVD (~$286 billion) and diabetes (~$116 billion) may be attributable to the prevalence of and cost incurred by obesity (~$147 billion per year) and the metabolic syndrome.

Pathology Etiology of metabolic syndrome widely debated Components may occur due to: –Obesity and ectopic adiposity –Insulin resistance –Mitochondrial dysfunction

Figure 10.2

Clinical Considerations Signs and symptoms Patients often present with: Elevated glucose Hypertension Elevated triglyceride levels Low high-density lipoprotein cholesterol level Abdominal obesity Microalbuminuria Hyperuricemia Fatty liver disease (continued)

Clinical Considerations (continued) High levels of PAI-1 and fibrinogen (i.e., prothrombotic state) Elevated high-sensitivity C-reactive protein (hsCRP) (i.e., proinflammatory state) Cholesterol gallstones Polycystic ovary syndrome Disordered sleeping (e.g., sleep apnea)

Medical Exam and Physical History Identify the core risk components of metabolic syndrome. Monitor abdominal obesity. Obtain clinical measure of waist circumference.

Diagnostic Testing Identify the five risk components of the metabolic syndrome Include laboratory screening for: –Impaired fasting glucose –Impaired glucose tolerance (continued)

Diagnostic Testing (continued) Additional testing may be warranted to screen for: –Clinical inflammation –Thrombosis –Hyperandrogenemia –Microalbuminuria –Hyperuricemia –Cholesterol gallstones –Sleep apnea (continued)

Diagnostic Testing (continued) Exercise testing –Appropriate risk stratification for patients diagnosed with metabolic syndrome should be based on the presence of dyslipidemia, hypertension, and hyperglycemia. –Standardized treadmill protocols that use relatively small workload increases are recommended and are often well tolerated by those with obesity and metabolic syndrome.

Treatment Interventions to promote weight loss (e.g., caloric restriction, increased physical activity, pharmacological agents, and even surgical procedures when necessary) Behavioral modifications –Improvements in diet quality –Participation in physical activity –Smoking cessation

Exercise Prescription Cardiovascular exercise Individuals are encouraged to accumulate 150 to 250 min of moderate-intensity PA per week, an energy equivalent of 1,200 to 2,000 kcal –Continuous or intermittent low intensity (40-60% VO 2 or HRR) to moderate intensity (50% to 75% VO 2 or HRR) –Sessions should be 30 to 60 min in duration (minimum of 10 min for intermittent cardiovascular exercise) –Gradual progression in duration and intensity may be effective for chronic weight maintenance (continued)..

Exercise Prescription (continued) Resistance exercise –Recommendations pertaining to resistance exercise for the metabolic syndrome are at present nonexistent. Current minimum recommendations call for “resistance exercise training” to supplement cardiovascular exercise. –Performed two (preferably three) nonconsecutive days per week –Single set of 5 to 10 resistance exercises for the whole body –Moderate level of intensity that allows 10 to 15 repetitions (continued)

Exercise Prescription (continued) Range of motion exercise –Adjunct modality to supplement cardiovascular and resistance exercise –Should be performed at least 2 or 3 d/wk following a warm- up or workout, when muscles are “warm” –Static, dynamic, or proprioceptive neuromuscular facilitation (PNF) activities suggested for all major muscles and joints of the body –Static stretching—recommendations are that each stretch be completed for at least four repetitions and held for 15 to 60 s (continued)

Exercise Prescription (continued) See table 10.4 for exercise testing review.

Conclusion Patients with the metabolic syndrome are usually overweight or obese and have significantly greater risk for developing CVD, insulin resistance, and type 2 diabetes, as well as early mortality. Diagnosis of the metabolic syndrome requires presence of three or more of the following risk factors: (1) elevated waist circumference, (2) elevated triglycerides, (3) reduced HDL cholesterol, (4) elevated blood pressure, and (5) elevated fasting glucose. (continued)

Conclusion (continued) When combined with dietary interventions, cardiovascular exercise has been widely regarded as the most acceptable means to induce weight loss and reduce cardiometabolic health risk. Mounting evidence indicates that resistance training may also be a viable treatment option, comparable to aerobic exercise.