New Research on Care/Prevention of Chronic Diseases

Introduction Chronic disease prevention and management were hot topics receiving daily attention at the 2006 American Academy of Family Physicians (AAFP) Scientific Assembly. A comprehensive evidence-based lifestyle management plan for cardiovascular disease prevention was offered by Steven Masley, MD, FAAFP.[1] Alvin Lin, MD, FAAFP, and Kay M. Nelsen, MD, discussed how "good is not good enough" in our current approach to chronic disease care and offered new, more rigorous targets for physicians and patients alike.[2] Evidence-Based Lifestyle Changes for Cardiovascular Disease Guidelines for patients and physicians from the American Heart Association (AHA), the American Diabetic Association (ADA) and other organizations advocate lifestyle change including diet, exercise, smoking cessation, and other behaviors to improve cardiovascular (CV) risk. The number of research studies which pinpoint and specify the rationale for making changes, and the risk reduction associated with each lifestyle change, has grown significantly. This body of literature empowers physicians to better counsel patients on prevention of adverse CV events, particularly stroke and myocardial infarction. Dr. Masley reviewed the mechanism for plaque formation and rupture as the basis for a paradigm switch from coronary procedures such as angioplasty to diet change. Despite data supporting prevention, the United States spent $200 billion on CV therapies in 1998 with only 6% expended on preventive strategies for patients.[3] Yet interventional cardiology was associated with a failure rate of 40%, preventing only 1 of 30-40 deaths, and improving only 1 of 30-40 CV events.[3] The procedures also carried the risks for loss of cognitive function, death, and stroke.[4] Indications for revascularization procedures should only be angina and restoration exercise capacity. Among risk factors identified for CV disease, the top 5 are: Cholesterol; Diabetes mellitus (DM); Smoking; Hypertension; and Obesity. Ethnic differences exist for each risk factor[5]; for example, obesity and hypercholesterolemia have a higher prevalence among blacks and Hispanics compared with Asians. Dr. Masley suggested that exercise treadmill testing is useful for predicting CV risk because exercise capacity is a powerful predictor of mortality.[6,7] Class I evidence for stress testing indicated for evaluation of includes: Known CV disease; Suspected angina; Diabetics embarking on an exercise program; and An occupation that affects public health. Measures of cardiac fitness include the 1-minute heart rate recovery and the blood pressure (BP) response. Plaque assessment using carotid intimal media thickness is another tool that can help track responses to lifestyle change or medication.[8] The following 10 lifestyle steps were described by Dr. Masley to reduce adverse CV events: Step 1: Reduce low-density lipoprotein (LDL) cholesterol using a combination of dietary measures such as adding soy and garlic,[9] switching from saturated and hydrogenated fats to unsaturated fats, increasing plant sources of omega-3 fats,[10] and increasing monounsaturated nut intake of walnuts, almonds, and pecans[11,12] before medications are considered. Step 2: Improve total cholesterol/high-density lipoprotein cholesterol (TC/HDL) and triglyceride/HDL cholesterol (TG/HDL) ratios to reverse the metabolic syndrome epidemic. Increasing HDL levels may be achieved with prolonged regular aerobic exercise of no less than 30-45 minutes daily[13] and moderate alcohol intake of 1-2 drinks daily.[14,15] A modest increase may be seen with garlic,[16] onion (3% to 5% improvement), and soy (up to 5% improvement)[17] intake. The type of carbohydrate eaten affects insulin levels and TC/HDL ratios, and glycemic load is more important than glycemic index.[18] Hence, a high-fiber intake of grains, beans, vegetables, and fruits has a beneficial effect, while consumption of fluffy whole wheat breads and potatoes can raise postprandial blood sugar levels. Step 3: Increase intake of beneficial foods. Follow diets, such as the Mediterranean or Japanese diet, high in vegetables and fruits, fiber, olive oil, and soy[19,20]; the emphasis should be on adding healthy -- rather than eliminating unhealthy -- foods. More specifically, soy isoflavones (from, for example, edamame beans) are associated with possible reduction of clot formation[21,22] and improved endothelial function.[23,24] Dark cocoa reduces clotting and is a potent antioxidant, thereby suppressing LDL oxidation and, possibly, lowering plaque formation.[25] Step 4: Change type of fat intake to nuts and olive and canola oils, but remain mindful of calories associated with high nut consumption. One handful of walnuts has 280 calories, but if eaten before a meal can help to induce satiety and reduce overall caloric intake.[26] Saturated fats should be avoided because of: Increased clot formation; Weight gain; and Increased LDL cholesterol. Trans fats in margarines and processed foods should be avoided and lean proteins (chicken and turkey) should be selected over red meats. Step 5: Reduce LDL oxidation by: Eating at least 5 servings of fruits and vegetables daily, especially the most colorful produce (like blueberries, pomegranates, and red and black beans)[27]; and Adding garlic[28] and spices,[29] particularly capsaicin and curcumin from chili and turmeric, respectively. Step 6: Decrease clotting and CV events using: Omega-3 fats; Garlic; Moderate alcohol; and A baby aspirin for primary and/or secondary prevention of CV and cerebrovascular events, if there are no contraindications. Fish and seafood (which should be eaten 2-3 times weekly) are excellent sources of omega-3 fats; Dr. Masley's first-choice recommendations are: Salmon; Trout; Sardines; Mussels; and Oysters, followed by: Shellfish; Mahi mahi; and Halibut. His choices reflect lower mercury levels of less than 2 ppm; intake of big-mouthed fish, such as yellow-tail tuna, increases exposure to higher mercury content. Flax, soy products, nuts, green leafy vegetables, canola oil, and fish oil supplements also contain omega-3 fats. The dosing of omega-3 depends on its indication: 300 mg daily for health maintenance; 3-4 g daily for hypertriglyceridemia; 2-4 g for anti-inflammatory purposes or for disc herniation; and 1-2 g for arrhythmias. Fish oil supplements should be selected on the basis of independent testing for heavy metals, low levels of lipid peroxides (they should not taste fishy or rancid), and dosed to minimize risk for bleeding and drug interactions. Step 7: Enhanced arterial function and BP is best achieved by 30-60 minutes of moderate activity for 6 days a week burning at least 2000 kcal weekly, and strength training 2-3 times weekly working at least 8-12 body parts and targeting blood pressure (BP) at 110/70 mm Hg (below pre-hypertensive levels).[30] Salt intake should be limited to less than 2400 mg daily, while calcium and magnesium should be maintained at 100 mg and 500 mg daily respectively. Step 8: Judicious use of supplements is advised because of variability in evidence for efficacy and the lack of standardized manufacturing guidelines. Dr. Masley recommended adequate intake of: Folic acid 400 mcg daily (diet plus supplement); Vitamin B6 -- 10-25 mg daily; Vitamin B12 -- 10-1000 mcg; and Phytosterols from plant foods. Evidence for using coenzyme Q10, hawthorne, and acetyl-L-carnitine is inconclusive and these are not currently recommended for cardiac health. Step 9: Stress management should directly address adequate sleep (at least 7 hours daily) and restful and relaxing activities such as meditation, yoga, and deep prayer. Step 10: Success at making lifestyle changes is linked to: Physician attention to patient beliefs; Limitations and goals; and Venues for offering intensive and effective lifestyle change in practice, including the group medical visit model specifically focused on CV targets, regular chart review, and documentation of patient progress. Management of Chronic Disease: When Is Good Not Good Enough? Drs. Lin and Nelsen discussed how chronic diseases are a major cause of disability in the United States, reviewing the major causes of death and morbidity[2]: Childhood obesity; Arthritis; Adult DM; Hypertension; and Hypercholesterolemia. They presented data that provide physicians with specific and more rigorous goals and endpoints for the control of DM, cholesterol, and BP. As Dr. Nelsen explained, global focus of organizations such as the World Health Organization, United Nations, and the World Bank continues to be on infectious rather than chronic diseases. Despite the change in chronic disease management from acute hospital admission to ambulatory care delivery, the use of information systems and team-based healthcare, the goals of continuity of care, service integration, and patient education provided through patient-centered care are far from being reached worldwide. The burden of chronic diseases continues to rise with 29 million deaths worldwide in 2002 from[31]: CV disease; Cancer; Chronic respiratory disease; and DM. According to an important trial, "a combination of personal and non-personal health interventions could lower the global incidence of CV events by as much as 50%.[32]" Government action to reduce salt content of processed foods is an example of a non-personal health intervention. Case in Point: Diabetes Mellitus Twenty-one million Americans were diagnosed with DM in 2005 and 10 million over 60 years have DM currently. Only 1 out of 5 Healthy People 2000 goals were met for the US population namely, a small 3% reduction in amputations from DM.[33,34] The goals related to DM that have not been met are reduction of: Disease incidence; Renal disease; and Blindness. Only one half of diabetics are taking proper medications.[35] Health disparities in DM management persist, and although 90% of patients with DM see physicians, they are not well monitored for: Hemoglobin A1c (HbA1c) levels; Self glucose testing; Annual urinary albumin screening; and Foot care. Health education occurs for less than 50%.[36] Data from a meta-analysis propose HbA1c goals as low as possible, suggesting that there is no threshold that is too low.[37] In one study, for every 1% drop in HbA1c there was a 21% decrease in all-cause mortality and adverse endpoints. Another study demonstrated a 28% increased risk for death for every 1% increase in HbA1c value, regardless of BP, cholesterol level, body mass index, and smoking status.[38] The Lower the Better Even in those without DM, lower HbA1c is associated with reduced CV and all-cause mortality. LDL cholesterol goals for DM have been well articulated by the AHA and the American College of Cardiologists with atheromatous regression and reduced CV mortality demonstrated at lower levels when LDL is lowered to 60 mg/dL.[39] Like HbA1c and LDL cholesterol in DM, BP control is now guided by the "lower is better" principle. Regardless of comorbidities including DM, lower levels of BP are associated with better outcomes of mortality and CV events. The risk for CV morbidity and mortality begins at a BP of 115/75 mm Hg, and for every increase in blood pressure of 20 mm Hg systolic or 10 mm Hg diastolic, the risk for CV events increases 2-fold.[40] Conversely, every 2-mm Hg drop in systolic BP translates into a 10% drop in stroke incidence and a 7% drop in CV events. Some data are slightly more hopeful, including a study showing that diabetes processes of care (such as eye and foot exams, measurement of microalbuminuria, diabetic education, and vaccinations) and intermediate outcomes (for example, HbA1c and LDL cholesterol) have improved nationally in the United States in the past decade.[41] This same trial, however, showed that: 2 in 5 persons with diabetes still have poor LDL cholesterol control; 1 in 3 persons still has poor BP control; and 1 in 5 persons still has poor glycemic control. Summary Drs. Lin and Nelsen concluded that physicians need to be more aggressive with all lifestyle strategies that lead to reduced HbA1c, LDL cholesterol, and BP in both diabetic and nondiabetic patients. For diabetic patients, target HbA1c should be as low as possible. For LDL cholesterol, diabetics should aim for levels below 70 mg/dL. Patients with hypertension should be controlled to levels at or below 115/75 mm Hg.