1. Medical Nutrition Therapy in Hypertension
Chapter 36
Medical Nutrition Therapy in Hypertension

2. Hypertension
Persistently high arterial blood pressure, defined as systolic blood pressure above 140 mm Hg and/or diastolic blood pressure above 90 mm Hg

3. Circulatory Diseases/Problems
1. Hypertension (HTN)
2. Hyperlipidemias
3. Atherosclerosis
4. Coronary heart disease
5. Congestive heart failure
6. Cerebrovascular disease
7. Peripheral vascular atherosclerotic occlusive disease

4. 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)

5. Measures of Heart Function
1. Beats or pulse
2. BP systolic and diastolic
3. ECG

6. Determinants of Blood Pressure
1. Blood volume
2. Vascular resistance to pressure
3. Heart stroke volume

7. Cardiac Output ■ Amount of blood pumped by heart (vol/min)
■ Stroke volume times heart rate

8. Vascular Resistance ■ Viscosity of blood
■ Width of vessels—(constriction or dilation)—controlled by muscle tone in vessel walls

9. Regulation of Blood Pressure
1. 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

10. Homeostatic Control of Blood Pressure
Short term
—Sympathetic nervous system
—Vasoconstriction
—Vasodilation
Long term
—Fluid volume
—Renin-angiotensin system

11. 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

12. Renin-Angiotensin Cascade
Redrawn from Guyton AC: Textbook of medical physiology, ed 8, Philadelphia, 1991, WB Saunders.

13. Classification of Blood Pressure for Adults Ages 18 Years and Older
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.
*Not taking antihypertensive drugs and not acutely ill. When systolic and diastolic blood pressures fall into different categories, the higher category should be selected to classify the individual’s blood pressure status. For example, 160/92 mm Hg should be classified as stage 2 hypertension, and 174/120 mm Hg should be classified as stage 3 hypertension. Isolated systolic hypertension is defined as systolic blood pressure 140 mm Hg or greater and diastolic blood pressure less than 90 mm Hg and staged appropriately (e.g., 170/82 mm Hg is defined as stage 2 isolated systolic hypertension). In addition to classifying stages of hypertension on the basis of average blood pressure levels, clinicians should specify presence or absence of target organ disease and additional risk factors. This specificity is important for risk classification and treatment.
†Optimal blood pressure with respect to cardiovascular risk is less than 120/80 mm Hg. However, unusually low readings should be evaluated for clinical significance.
‡Based on the average of two orr more readings taken at each of two or more visits after an initial screening.

14. Treatment of Hypertension—Cause
Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000.

15. Treatment of Hypertension— Pathophysiology
Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000.

16. Treatment of Hypertension— Medical and Nutritional Therapy
Algorithm content developed by John Anderson, PhD, and Sanford C. Garner, PhD, 2000.

17. 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, Copyright 1993, American Medical Association. Reprinted with permission.)

18. Components of Cardiovascular 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.)

19. Untreated or 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

20. Medical Management of Hypertension Based on Risk
High-normal BP and Stage 1 hypertension in low- or medium-risk group
—Begin with trial of lifestyle modification for 6 to 12 months
High-normal BP and Stage 1 hypertension in high-risk group
—Begin with drug therapy in addition to lifestyle modification
Stages 2 and 3 all risk groups

21. Steps to Manage High Blood Pressure
Weight management
—If over 115% of ideal body weight, exercise and hypocaloric diet estimate 25 kcal/kg minus 500 to 1000kcal/day
Salt restriction
—6 g NaCl or 2400 mg Na/day

22. Levels of Na Restriction
g Na mEq Na Description
No added salt
Mild to moderate restriction
Strict sodium restriction
Severe sodium restriction

23. 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

24. DASH Diet Works within 14 days Lowers BP quite well
Includes more potassium, calcium, other nutrients

25. 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)

26. DASH Diet Website
p/dash/new_dash.pdf

27. 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 1

28. 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 2

29. Classification of Antihypertensive Drugs
Diuretics
—Thiazides
—Loop diuretics
—Potassium-sparing diuretics
Beta blockers
Alpha-beta blockers
Alpha1 receptor blockers
ACE inhibitors
Calcium antagonists
Direct vasodilators

30. Antihypertensive Drugs
Volume Depletors Sympathetic Blockers
Diuretics Peripheral
Thiazides Reserpine
Chlorthalidone Guanethidine
Metolazone
Loop diuretics Central: methyldopa
Furosemide Clonidine
K+ sparing ß-receptor: propranolol
Spironolactone Atenolol
Triamterene Metoprolol
Amiloride Nadolol
Timolol
α-receptor: phentolamine
Phenoxybenzamine
Prazosin 4

31. 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

32. Summary
Lifestyle modifications for prevention of hypertension—quite effective!
Management of hypertension—very important to reduce risk of heart attack or stroke!