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Hypertension: Medical Management and Nutritional Approaches Hypertension Persistently high arterial blood pressure Systolic blood pressure above 140 mm Hg and/or diastolic blood pressure above 90 mm Hg Normotensive = 120/80 mm Hg Prehypertensive = 120–139/80-89 mm Hg Stage 1 hypertension = 140–159/9099 mm Hg Stage 2 hypertension = >160/>100 mm Hg Prevalence and Incidence 29% of adult US population Related to body mass index High prevalence in African Americans 5% of pediatric population; prevalence increases with age Strong positive relationship between blood pressure and risk of CVD events Pathophysiology Blood pressure is a function of cardiac output multiplied by peripheral resistance Affected by diameter of blood vessel Atherosclerosis decreases diameter, increases blood pressure Drug therapy increases diameter, lowers blood pressure Circulatory Systems in the Body 1. Coronary—supplies blood to heart muscle (can form collateral circulation) 2. Cerebral—supplies blood to head 3. Splanchnic—supplies blood to abdomen (exercise removes blood and food attracts blood to this area) 4. Pulmonary—supplies blood to lungs (O2 and CO2 exchange) Measures of Heart Function 1. Beats or pulse 2. BP systolic and diastolic 3. ECG Determinants of Blood Pressure 1. Blood volume 2. Vascular resistance to pressure 3. Heart stroke volume Cardiac Output ■ Amount of blood pumped by heart (vol/min) ■ Stroke volume times heart rate Vascular Resistance ■ Viscosity of blood ■ Width of vessels—(constriction or dilation)—controlled by muscle tone in vessel walls Regulation of Blood Pressure Sympathetic nervous system (SNS)—responds immediately; baroreceptors monitor BP Vasomotor center in brain SNS innervated tissues contract or dilate vascular bed 2. Renin-angiotensin system—retains Na and H2O to increase blood volume; constricts blood vessels; increases aldosterone 3. Kidneys—respond to renin-angiotensin system; aldosterone and antidiuretic hormone (ADH) are sent out as needed 1. Homeostatic Control of Blood Pressure Short term —Sympathetic nervous system —Vasoconstriction —Vasodilation Long term —Fluid volume —Renin-angiotensin system Hypertension 1. 90% HTN is essential HTN (cause unknown; perhaps prenatal impacts?) 2. 10% HTN is secondary to other diseases 3. HTN is a risk factor for MI, CVA, renal failure Renin-Angiotensin Cascade Redrawn from Guyton AC: Textbook of medical physiology, ed 8, Philadelphia, 1991, WB Saunders. Causes of Hypertension Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000. Risk Factors for Developing Hypertension (Adapted from National High Blood Pressure Education Program Working Group report on primary prevention of hypertension. Arch Intern Med 153:186, 1993. Copyright 1993, American Medical Association. Reprinted with permission.) Risk Stratification in Patients with Hypertension (From The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. sixth report (JNC VI). Arch Intern Med 157:2413, 1997.) Uncontrolled Hypertension Leads to increased Workload on heart Damage to arteries Atherosclerosis Coronary heart disease esp. CHF Strokes Transient ischemic attacks (TIAs) Kidney damage Microvascular hemorrhages in brain and eye The DASH Diet Trials Randomized feeding trial comparing effects of 3 diet patterns: control, high fruits/vegetables, and high fruits/vegetables/whole grains/lowfat dairy (DASH diet) DASH diet high in potassium, magnesium, calcium, fiber and low in fat, saturated fat, and cholesterol DASH diet significantly lowered BP in all groups, but especially in African-Americans Effects of Diet on BP (DASH Trial) OMNI-Heart Feeding Study Subjects were 164 adults with prehypertension or stage 1 hypertension, 55% African American, mean BMI 30 Compared effect of 3 healthy diet patterns—all reduced in saturated fat and cholesterol, rich in fruits, vegetables, potassium, and other minerals at recommended levels Diets were high CHO (58% of calories), high in protein, high in unsaturated fat Researchers provided all the food for the study Each feeding period lasted 6 weeks and body weight was kept constant. http://www.medscape.com/viewarticle/523041 OMNI-Heart Diets CHO Diet PRO DIET UNSAT FAT DIET CHO % kcal 58 48 48 PRO % kcal 15 25 15 FAT % kcal 27 27 37 MFA % kcal 13 13 21 PUFA % kcal 8 8 10 SFA % kcal 6 6 6 OMNI-HEART Results Results: All 3 diets lowered systolic blood pressure Substitution of protein or mfa for CHO lowered blood pressure further; Compared with the carbohydrate diet, estimated 10-year coronary heart disease risk was lower and similar on the protein and unsaturated fat diets http://www.medscape.com/viewarticle/523041 OMNI-Heart Feeding Study National Heart, Lung, and Blood Institute National High Blood Pressure Education Program U.S. Department of Health and Human Services National Institutes of Health National Heart, Lung, and Blood Institute The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) Express—Succinct evidence-based recommendations. Published in JAMA May 21, 2003, and as a Government Printing Office publication. New Features and Key Messages For persons over age 50, SBP is a more important than DBP as CVD risk factor. Persons who are normotensive at age 55 have a 90% lifetime risk for developing HTN. Those with SBP 120–139 mmHg or DBP 80–89 mmHg should be considered prehypertensive who require health-promoting lifestyle modifications to prevent CVD. New Features and Key Messages (Continued) Thiazide-type diuretics should be initial drug therapy for most, either alone or combined with other drug classes. Certain high-risk conditions are compelling indications for other drug classes. Most patients will require two or more antihypertensive drugs to achieve goal BP. If BP is >20/10 mmHg above goal, initiate therapy with two agents, one usually should be a thiazide-type diuretic. Blood Pressure Classification BP Classification SBP mmHg DBP mmHg Normal <120 and <80 Prehypertension 120–139 or 80–89 Stage 1 Hypertension 140–159 or 90–99 Stage 2 Hypertension >160 or >100 CVD Risk HTN prevalence ~ 50 million people in the United States. The BP relationship to risk of CVD is continuous, consistent, and independent of other risk factors. Each increment of 20/10 mmHg doubles the risk of CVD across the entire BP range starting from 115/75 mmHg. Prehypertension signals the need for increased education to reduce BP in order to prevent hypertension. Benefits of Lowering BP Average Percent Reduction Stroke incidence 35–40% Myocardial infarction 20–25% Heart failure 50% BP Control Rates Trends in awareness, treatment, and control of high blood pressure in adults ages 18–74 National Health and Nutrition Examination Survey, Percent II 1976–80 II (Phase 1) 1988–91 II (Phase 2) 1991–94 1999–2000 Awareness 51 73 68 70 Treatment 31 55 54 59 Control 10 29 27 34 Sources: Unpublished data for 1999–2000 computed by M. Wolz, National Heart, Lung, and Blood Institute; JNC 6. BP Measurement Techniques Method Brief Description In-office Two readings, 5 minutes apart, sitting in chair. Confirm elevated reading in contralateral arm. Ambulatory BP monitoring Indicated for evaluation of “white-coat” HTN. Absence of 10–20% BP decrease during sleep may indicate increased CVD risk. Provides information on response to therapy. May help improve adherence to therapy and evaluate “white-coat” HTN. Self-measurement CVD Risk Factors Hypertension* Microalbuminuria or estimated GFR <60 Cigarette smoking ml/min 2 Obesity* (BMI >30 kg/m ) Age (older than 55 for Physical inactivity men, 65 for women) Dyslipidemia* Family history of premature CVD (men Diabetes mellitus* under age 55 or women under age 65) *Components of the metabolic syndrome. Target Organ Damage Heart • Left ventricular hypertrophy • Angina or prior myocardial infarction • Prior coronary revascularization • Heart failure Brain • Stroke or transient ischemic attack Chronic kidney disease Peripheral arterial disease Retinopathy Goals of Therapy Reduce CVD and renal morbidity and mortality. Treat to BP <140/90 mmHg or BP <130/80 mmHg in patients with diabetes or chronic kidney disease. Achieve SBP goal especially in persons >50 years of age. Lifestyle Modification Modification *Weight reduction Approximate SBP reduction (range) 5–20 mmHg/10 kg weight loss *Adopt DASH eating plan 8–14 mmHg *Dietary sodium reduction 2–8 mmHg Physical activity 4–9 mmHg *Moderation of alcohol consumption 2–4 mmHg *medical nutrition therapy interventions Classification of Antihypertensive Drugs Diuretics —Thiazides —Loop diuretics —Potassium-sparing diuretics Beta blockers (BB) Angiotensin II receptor blockers (ARBs) Alpha-beta blockers Alpha1 receptor blockers ACE inhibitors (angiotensin converting enzyme) Calcium antagonists Direct vasodilators Algorithm for Treatment of Hypertension Lifestyle Modifications Not at Goal Blood Pressure (<140/90 mmHg) (<130/80 mmHg for those with diabetes or chronic kidney disease) Initial Drug Choices Without Compelling Indications With Compelling Indications Stage 1 Hypertension Stage 2 Hypertension (SBP 140–159 or DBP 90–99 mmHg) Thiazide-type diuretics for most. May consider ACEI, ARB, BB, CCB, or combination. (SBP >160 or DBP >100 mmHg) 2-drug combination for most (usually thiazide-type diuretic and ACEI, or ARB, or BB, or CCB) Not at Goal Blood Pressure Optimize dosages or add additional drugs until goal blood pressure is achieved. Consider consultation with hypertension specialist. Drug(s) for the compelling indications Other antihypertensive drugs (diuretics, ACEI, ARB, BB, CCB) as needed. Compelling Indications These are reasons for using a particular class of medications For example, patients with diabetes, kidney damage, and high blood pressure should begin treatment with ACE inhibitors. Heart attack (in conjunction with hypertension) is a compelling indication for the prescription of betablockers and, in certain instances, ACE inhibitors Heart failure should first be treated with ACE inhibitors and diuretics. Classification and Management of BP for adults BP classification Normal SBP* mmHg DBP* mmHg Lifestyle modification <120 and <80 Encourage Initial drug therapy Without compelling indication Prehypertension 120–139 or 80–89 Yes No antihypertensive drug indicated. Stage 1 Hypertension Yes Thiazide-type diuretics for most. May consider ACEI, ARB, BB, CCB, or combination. Yes Two-drug combination for most† (usually thiazide-type diuretic and ACEI or ARB or BB or CCB). Stage 2 Hypertension 140–159 or 90–99 >160 or >100 *Treatment determined by highest BP category. †Initial combined therapy should be used cautiously in those at risk for orthostatic hypotension. ‡Treat patients with chronic kidney disease or diabetes to BP goal of <130/80 mmHg. With compelling indications Drug(s) for compelling indications. ‡ Drug(s) for the compelling indications.‡ Other antihypertensive drugs (diuretics, ACEI, ARB, BB, CCB) as needed. Minority Populations In general, treatment similar for all demographic groups. Socioeconomic factors and lifestyle important barriers to BP control. Prevalence, severity of HTN increased in African Americans. African Americans demonstrate somewhat reduced BP responses to monotherapy with BBs, ACEIs, or ARBs compared to diuretics or CCBs. These differences usually eliminated by adding adequate doses of a diuretic. Children and Adolescents HTN defined as BP—95th percentile or greater, adjusted for age, height, and gender. Use lifestyle interventions first, then drug therapy for higher levels of BP or if insufficient response to lifestyle modifications. Drug choices similar in children and adults, but effective doses are often smaller. Uncomplicated HTN not a reason to restrict physical activity. Web site www.nhlbi.nih.gov/ Your Guide to Lowering Blood Pressure Reference Card Lifestyle Modifications Sodium: not more than 2.4 grams sodium/day Activity: activity like brisk walking 30 minutes/day most days of the week Alcohol: not more than 1 drink a day for women; 2 drinks a day for men DASH diet: low in sodium, high in potassium, calcium, cholesterol, saturated fat Weight: weight loss of as little as 10 lb can prevent or treat high blood pressure Weight Management Risk of developing high blood pressure is 2-6 times higher in overweight than normal weight persons 20-30% of the hypertension in the US is attributable to excess weight In Framingham, weight increase of 10% predicted rise in blood pressure of 7 mm/hg Weight gain during adult life is responsible for much of the rise in blood pressure seen with aging Weight Management Excess body weight may increase blood pressure through increased insulin resistance and hyperinsulinemia, activation of the sympathetic nervous and renin-angiotensin systems, and changes in the kidney Weight loss lowers vascular resistance, total blood volume, cardiac output, and sympathetic nervous system activity; improves insulin resistance Weight loss in an overweight person is the single most effective lifestyle intervention to reduce blood pressure Weight Management In the Trial of Antihypertensive Intervention and Management, goal for energy intake to facilitate weight loss was 25 kcals/kg minus 500 to 1000 kcal daily to produce a .5 to 1 kg weight loss/week to achieve total weight loss of 4.5 kg. Wylie-Rosett et al, 1993 Sodium and Hypertension Relationship between sodium and hypertension is stronger in Older people Those with a family history of hypertension Those with higher blood pressures at baseline 30-50% of hypertensives and 15-25% of normotensives are salt sensitive Salt sensitivity more common in black race, obesity, advanced age, diabetes, renal dysfunction, use of cyclosporine Sodium and Hypertension Addition of a sodium restriction to a DASH diet lowers SBP 3 mmHg and DBP 2 mmHg This reduction is associated with a 17% reduction in prevalence of hypertension, 6% reduction in CHD, 15% reduction in stroke and TIA Salt Restriction Recommendation is for moderate salt restriction (6 grams salt, 100 mEq or 2400 mg Na daily) Salt is the issue, because chloride ion with sodium raises blood pressure May normalize blood pressure in Stage 1 hypertension Levels of Na Restriction g Na 4 2-3 mEq Na 174 87-130 1 0.5 43 22 Description No added salt Mild to moderate restriction Strict sodium restriction Severe sodium restriction Alcohol and Hypertension 5-7% of hypertension is due to alcohol consumption 3 drinks per day is the threshold for raising blood pressure; associated with a 3 mmHg increase Physical Activity and Hypertension Less active persons are 30-50% more likely to develop hypertension than active persons Medium to high levels of activity protective against stroke (Framingham) Walking reduces blood pressure in adults by an average of 2% In a meta-analysis of 54 randomized trials, walking reduced blood pressure an average of 4 mmHg, irrespective of weight change Potassium In population studies, potassium intake and blood pressure are inversely related Sodium/potassium ratio is important Sodium/potassium ratio of 1:1 a 3.4 mmHg decrease in systolic BP is predicted High potassium intake inversely related to stroke Other Factors Calcium, Magnesium, and Lipids: role still unclear DASH diet high in lowfat dairy products Response to Dietary Rx Salt sensitive respond well to sodium restriction Most respond to increased potassium in diet. • 1.1 to 3.3 g Na is safe • 1.9 to 5.6 g K is recommended to achieve ratio Na:K of 1, which is goal If taking a potassium-wasting diuretic drug, increased potassium in diet is essential. Most respond to increased calcium (at least the RDA)—use the DASH diet protocol DASH Diet Works within 14 days Lowers BP quite well Includes more potassium, calcium, other nutrients DASH Fact Sheet www.nhlbi.nih.gov/heal th/public/heart/hbp/dash/ new_dash.pdf DASH Diet —cont’d Pattern —7-8 whole grains —4-5 vegetables —4-5 fruits —2-3 low-fat or fat-free dairy products —6 oz or less meat/poultry/fish —4-5 servings nuts, beans, or legumes/week —2-3 servings fat (total kcal = 27% fat) DASH Diet Patterns for Different Calorie Levels Kcals Grain Veg Fruit Dairy Meat/ Nuts/ Fats/ Pro Legume oils 1600 6 4 4 2 1 .5 1 2000 8 5 5 3 2 1 2 2600 10 5 5 3 2 1 2 3100 13 6 6 4 2 1 3 Sodium Processed and restaurant foods provide 80% of sodium intake Read labels; sodium content of different brands varies 10% added in cooking at home and at table; 10% naturally occurring Americans consume ~4,000 mg/day; 2005 Dietary Guidelines for Americans recommend <2,300 mg/day; those with hypertension, African Americans and middle-aged and elderly should consume <1,500 mg/day Food Label Terms Sodium free, no sodium = <5 mg/serving Very low sodium = <35 mg/serving and per 100 g food Low sodium = <140 mg/serving and per 100 g food Reduced sodium = 50% less than comparison food Salt Substitutes Composition: KCl, CaCl, Al-Cl KCl can provide extra potassium for those taking diuretics KCl can be harmful if patient has renal insufficiency “Lite” salt contains sodium Some spices and herbs are low in sodium Others are high in sodium Classification of Antihypertensive Drugs Diuretics —Thiazides —Loop diuretics —Potassium-sparing diuretics Beta blockers (BB) Angiotensin II receptor blockers (ARBs) Alpha-beta blockers Alpha1 receptor blockers ACE inhibitors (angiotensin converting enzyme) Calcium antagonists Direct vasodilators http://www.nhlbi.nih.gov/hbp/treat/bpd_type.htm Lifestyle Modifications for Prevention of Hypertension Lose weight if overweight Limit alcohol Increase physical activity Decrease sodium intake Keep potassium intake at adequate levels Take in adequate amounts of calcium and magnesium Decrease intake of saturated fat and cholesterol Stop smoking Summary Lifestyle modifications for prevention of hypertension— quite effective! Management of hypertension—very important to reduce risk of heart attack or stroke