Reversing the tide of metabolic syndrome (pcos mentioned)

[KatCarney]

Reversing the tide of metabolic syndrome

Mary Anne Staudt Dumas
2,646 words
1 June 2003
Nursing
1
ISSN: 0360-4039
English
Copyright (c) 2003 ProQuest Information and Learning. All rights reserved. Copyright Springhouse Corporation Jun 2003

One in three Americans has metabolic syndrome, making this constellation of disease processes a serious health threat. Find out what you can do to help patients conquer this syndrome.

A syndrome by any other name is still a syndrome. Known as Syndrome X, insulin resistance syndrome, and cardiovascular dysmetabolic syndrome, metabolic syndrome is characterized by insulin resistance; high triglycerides, low high-density lipoprotein (HDL) cholesterol, and possibly elevated low-density lipoprotein (LDL) cholesterol; central obesity; and hypertension. The most recent estimates indicate that one in three Americans has this syndrome.

Clearly, metabolic syndrome has become a major health crisis in this country. Recent statistics indicate that 50 million Americans are being treated for hypertension; 38 million adults have high cholesterol levels; and 17 million have diabetes (another 16 million have prediabetes). Significantly, 50% of individuals diagnosed with metabolic syndrome have a family history of this syndrome. Recently, metabolic syndrome has also been linked to polycystic ovarian syndrome.

Why is metabolic syndrome coming to the forefront now? In the past, each disease state-hypertension, insulin resistance, and high cholesterol-was treated separately, by subspecialists, with separate treatment goals. Additionally, many patients who were being treated for each of these disease states weren't treated to goal levels. Undertreatment is a problem that has contributed to the progression of metabolic syndrome.

Because care was fragmented, it failed to address the real issue: Metabolic syndrome is a constellation of diseases requiring a coordinated management approach to make a positive impact on improving patient outcomes. Furthermore, many patients weren't educated to understand that the clinical problems included in metabolic syndrome require an integrated effort among health care providers. Metabolic syndrome can lead to complications such as diabetes, coronary artery disease, and stroke.

The purpose of this article is to explore the mechanism by which metabolic syndrome develops, the presenting signs and symptoms, and the strategies for successful treatment.

Why metabolic syndrome occurs

Insulin resistance commonly occurs long before the patient is aware that a problem exists. Insulin is a powerful growth hormone that exerts a strong effect on various body systems. Normally, insulin receptors on the cells of the body recognize insulin and allow it to transport glucose into the cells, where the glucose is converted to energy. Insulin resistance occurs when these insulin receptors no longer recognize insulin. The amount of insulin rises as carbohydrate or sugar intake increases. The insulin receptors can't manage the increased insulin level and won't permit glucose to enter the cells. Additionally, the insulin receptors become resistant to the elevated levels of circulating insulin. This results in hyperglycemia and hyperinsulinemia, reducing the body's energy source at the cellular level.

In excessive amounts, insulin causes muscle hypertrophy and vascular remodeling. It also results in increased levels of triglycerides, small-particle LDL cholesterol, and serum uric acid; increased platelet adhesion; increased response to angiotensin II; and reduced amounts of nitric oxide, a vasodilator, produced in the vascular endothelium. These changes alter the lining of the vascular endothelium, resulting in vasoconstriction and vascular remodeling. Additionally, hyperinsulinism increases fat storage in the abdomen and stimulates the appetite, leading to increased obesity.

Recognizing metabolic syndrome

The hallmarks of metabolic syndrome are identified by clinical findings on examination and by appropriate lab tests. Metabolic syndrome should be suspected in patients with these key clinical indicators:

* waist/hip ratio (umbilicus/hip) greater than 0.8 in women and greater than 0.95 in men

* a body mass index (BMI) greater than 24.9

* abnormal lipid levels: triglycerides greater than 150 mg/dl, HDI, less than 40 mg/dl, and elevated LDL or total cholesterol

* blood pressure greater than 140/90

* two elevated fasting blood glucose levels (greater than 126 mg/dl) or an elevated random blood glucose level (greater than 200 mg/dl, accompanied by symptoms of polyuria, polydipsia, or polyphagia)

* symptoms of polycystic ovarian syndrome (irregular or absent menstrual periods, ovarian cysts, infertility, high blood pressure, acne, hirsutism, alopecia, central obesity, and elevated insulin levels, insulin resistance, or diabetes)

* hyperuricemia (greater than 5.8 mg/dl in women; greater than 7.4 mg/dl in men)

* acanthosis nigricans (darkening of the skin, usually seen on the neck or under the arms).

Treatment options

Once the diagnosis of metabolic syndrome has been made, a treatment plan-featuring an integrated problem management approach-will be developed with the patient. Treatment strategies should integrate standards of care and recommendations from the American Heart Association (AHA); American Diabetes Association (ADA); the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; and the National Kidney Foundation. For optimum results, health care providers need to: (1) recognize abnormal lab values that require treatment, (2) treat to goal, and (3) communicate with the patient through follow-up at regular intervals. The treatment/management objectives are as follows:

* Educate patients and help build their knowledge to increase their understanding of metabolic syndrome and their active engagement in achieving their treatment goals.

* Reduce modifiable risk factors.

* Normalize and maintain the blood pressure, lipid and blood glucose levels, the waist/hip ratio, and the BMI. * Prevent complications.

* Maintain or improve the quality of life.

The treatment strategies developed will assist the patient in achieving these objectives.

Lifestyle modifications

Lifestyle modifications are the most difficult to achieve and sustain. Overweight patients should strive to lose weight and maintain a BAI less than 24.9 or a reduced waist/hip ratio. Patients should bl on a calorie-restricted (1,200 calories for women, 1,600;calories for men) and saturated-fat-restricted diet and engage in aerobic exercise 30 minutes a day, five times i week, as recommended by the AHA and the ADA. Finally, enrolling in a smoking-cessation program is essential; nicotine is a potent vasoconstrictor and has been identified as the primary cause of heart disease.

Lipid levels

Diet is a cornerstone of therapy to reduce lipid levels. Patients should eat a low-fat, low-cholesterol, reduced-- carbohydrate diet. According to the NCEP-ATP III guidelines, total cholesterol intake should be less than 200 mg/day; fat intake, 25% to 35% of total calories peg day; saturated fats, less than 7% of total fat intake; and soluble fiber, 20 to 30 grams/day. Restricting carbohydrate intake to 45% to 50% of total daily caloric requirements can also help patients achieve the goal of lowering triglyceride levels.

Lipid levels can be managed pharmacologically as well. The drug class of choice to reduce LDL cholesterol and triglyceride levels is the statins (HMG-CoA reductase inhibitors, such as atorvastatin [Lipitor], pravastatin [Pravachol], and simvastatin [Zocor]). The statins are effective in decreasing LDL, slightly elevating HDL, and decreasing triglycerides. Cholesterol is metabolized by the liver at night. Evening dosing is recommended for many of the statins to maximize efficacy in reducing cholesterol. Statins can be administered concomitantly with fibric acid derivatives (gemfibrozil [Lopid]) in patients with low HDL and high triglyceride levels. The statin dosage should be reduced, however, to avoid the potential complication of myalgia.

Ezedmibe (Zetia) is the newest lipid-lowering drug on the market, and newest drug class. Its mechanism of action differs from other lipid-lowering agents: It's the first one to act at the brush border of the small intestine to inhibit the absorption of cholesterol. This reduces the amount of intestinal cholesterol delivered to the liver, which reduces the amount of cholesterol in the hepatic stores and reduces the serum cholesterol level. In clinical trials, ezetimibe decreased LDL, Apo B, and triglycerides levels and increased HDL levels. Ezetimibe is given once a day, and it can be used as complementary therapy to the statins. It's contraindicated in patients with hepatic insufficiency, and when ezetimibe is used with statins, liver function tests should be assessed according to the standard of care for statins. This drug holds promise for reducing cardiac morbidity and mortality, particularly when multiple lipid-lowering agents are needed.

Bile acid sequestrants (cholestyramine [Questran]) are sometimes prescribed for patients with low HDL levels, although these drugs wouldn't be considered first-line agents. This class of drugs may increase triglyceride levels. The multiple dosing schedule required by bile acid sequestrants may limit adherence. Cholestyramine is highly protein bound and, therefore, competes for protein-binding sites with other protein-bound drugs, such as warfarin (Coumadin) and digoxin.

The bile acid sequestrant colesevelam (WelChol) was recently approved by the Food and Drug Administration for use with the statins. This drug is not absorbed into the bloodstream, and through its mechanism of action, it prevents cholesterol from being absorbed by the blood. Its advantage over other bile acid sequestrants is its once-a-day dosage. Colesevelam is contraindicated in patients with intestinal blockage.

Nicotinic acid (niacin) is effective in reducing elevated levels of triglycerides and small-particle LDL and raising low HDL. A drawback to using nicotinic acid is its tendency to cause flushing. Administration of 325 mg of enteric-coated aspirin with nicotinic acid effectively reduces this reaction. A long-acting preparation of niacin (Niaspan) reportedly has fewer adverse effects than shorter-acting niacin.

Normalizing blood pressure

The goal of blood pressure management is to reduce the blood pressure to less than 140/90, with the optimum level being less than 130/80 (especially in patients with prediabetes or diabetes). Patients should be urged to purchase a home blood pressure monitoring device, measure and record their blood pressure, and bring the logbook to each office visit.

A low-salt diet (less than 2,400 mg/day) is important in reaching the treatment goal. Patients should be instructed not to add salt when cooking or to use a salt shaker at the table. Foods containing more than 400 mg/serving of sodium and preserved foods (such as canned or frozen foods or processed lunch meats) should be avoided because of their high sodium content.

Diet modifications may not bt sufficient to control blood pressure. A 10-pound (4.5-kg) weight loss can be effective in lowering blood pressure by 10 mm Hg. When blood pressure levels aren't successfully normalized and controlled by lifestyle modifications, pharmacotherapy should be added. Because endothelial dysfunction is one of the primary outcomes of metabolic syndrome, choosing a drug that prevents further endothelial damage should be the first-line therapy.

Angiotensin-converting enzyme inhibitors (ACEIs, such as enalapril [Vasotec] and lisinopril [Zestril, Prinivil]) and angiotensin-receptor blockers (ARBs, such as irbesartan [Avapro] and valsartan [Diovan]) are effective in preventing endothelial damage. Neiter ACEIs nor ARBs affect carbohydrate metabolism or aggravate lipid levels. They have been found to maintain renal function and are renal protective. All patients with prediabetes or diabetes should take these drugs to preserve renal function.

Patients whose renal status prohibits the use of ACEIs or ARBs may be candidates for other antihypertensive drug classes that can provide effective blood pressure management. Selection of an antihypertensive medication should be determined by patient comorbidities. Monotherapy is rarely effective for long-term blood pressure control. Most patients require at least two medications to control blood pressure; others may require three medications. Available classes of antihypertensive drugs include:

* beta-blockers. These drugs are effective in preventing further endothelial damage; however, they increase lipid levels and insulin resistance. Beta-blockers have been associated with adverse effects such as lethargy, impotence, decreased libido, and interference with carbohydrate metabolism. Although nonselective betablockers (propranolol [Inderal]) have been contraindicated for patients with restrictive airway disease or chronic obstructive pulmonary disease (COPD), cardioselective beta-blockers (such as atenolol [Tenormin] and metoprolol [Lopressor]) may be used in pulmonary patients with careful monitoring.

* thiazides. These diuretics are beneficial in preventing osteoporosis through the reabsorption of calcium. Thiazides are particularly effective in lowering blood pressure in the elderly and African-Americans. They'll increase LDL and triglyceride levels, decrease insulin sensitivity, and increase uric acid levels. Thiazides are inexpensive, excellent first-line agents and can be used concomitantly with other antihypertensives.

* alpha-blockers. Although useful in reducing blood pressure, these drugs have no effect on lipid levels, but they can increase insulin sensitivity. They aren't preferred first-line therapy for patients with metabolic syndrome but are frequently added as a second agent in men with benign prostatic hypertrophy.

* calcium channel blockers. These drugs are appropriate for patients who have a contraindication to or can't tolerate beta-blockers. They have minimal effects on lipid levels and insulin sensitivity. However, they shouldn't be used in patients with systolic heart failure or immediately after myocardial infarction.

Preventing and managing insulin resistance

As with other aspects of metabolic syndrome, diet is a cornerstone of therapy for insulin resistance. Reducing carbohydrate intake to 45% to 50% of total daily calorie intake will help to decrease insulin resistance.

Patients who are insulin-resistant may benefit from the administration of an insulin sensitizer such as rosiglitazone (Avandia) or pioglitazone (Actos). Drugs from this class of oral antidiabetic agents called thiazolidinediones work at the cellular level to increase insulin recognition by the receptors.

Metformin (Glucophage) is another drug that's been effective in normalizing the blood glucose level. Metformin decreases hepatic glucose production and intestinal absorption of glucose and improves insulin sensitivity (increased peripheral glucose uptake and utilization). This is particularly helpful for patients who have extreme elevations in their blood glucose levels at night and after meals. As a result of the drug's mechanism of action, patients taking metformin usually will initially lose weight. This may encourage them to follow dietary and exercise guidelines for weight loss.

An over-the-counter dietary supplement also may be helpful; chromium has been found to increase glucose utilization and decrease insulin resistance. Caution should be exercised in relation to herbal supplements.

The potency, purity, and quality may vary by lot because supplements aren't regulated by the Food and Drug Administration. Many herbal supplements also have a carbohydrate base to mix and stabilize the herbs, which can affect serum glucose levels in patients with diabetes.

Adjunctive therapies

Additional treatment options have been identified to help patients with metabolic syndrome:

* Low-dose aspirin (81 to 325 mg) is recommended for men over age 45 and postmenopausal women (due to decreased estrogenic protection) to help prevent myocardial infarction.

* Folic acid and vitamin B6 decrease homocysteine levels and are beneficial to cardiovascular health. An elevated level of homocysteine has been associated with heart disease.

* Vitamin E has been found to help maintain cardiovascular health in some studies by accelerating the breakdown of LDL while increasing HDL. Other studies, however, have found no positive effect. Vitamin E can decrease the risk of thrombus formation.

* Garlic may reduce total cholesterol by 5% to 10% in patients with tppderately elevated cholesterol (around 220 mg/dl). The recommendation is to eat 7 grams of garlic (a few cloves) per day.

* Large doses of omega-3 fatty acids (6 grams/day) may lower total cholesterol and triglyceride levels. Fish oil supplements are acceptable, but eating fish, such as cold water salmon, daily is preferred.

Improving quality of life

Because metabolic syndrome is a constellation of disease processes, treating it requires an integrated approach. The health care provider and patient are partners working to successfully treat metabolic syndrome, achieve the therapeutic goals, and reduce complications. Cornerstones of therapy include lifestyle modifications, judicious pharmacologic management, and a collaborative provider/patient partnership. Taking steps to prevent the devastating effects of diabetes, coronary artery disease, and stroke will help improve the patient's quality of life while providing cost-effective care that reduces the burden on America's health care system.

Mary Anne Staudt Dumas, RN, CFNP, PhD

Mary Anne Staudt Dumas, RN, CNP, PhD, is clinical associate professor at SUNY Stony Brook, Stony Brook, N.Y., and a family nurse practitioner in the Primary Care Clinic at the Northport Veterans Affairs Medical Center, Northport, N.Y.