Transcript Sodium and your health

Sodium and Your Health
Rebecca Burson, M.D., M.P.H.
Assistant Clinical Faculty at Texas A&M FM Residency
Sodium and health
 Discuss briefly how sodium is utilized in the body
 Discuss how sodium affects hypertension
 Discuss how sodium affects congestive heart failure
 Discuss how sodium affects chronic kidney disease
Dietary Sodium, hypertension, and the
scope of problem
 Salt is common in the American
diet
 average daily intake > 3.0 grams
 Ingesting too much salt can
contribute to worsening of many
common health problems
 hypertension, congestive heart
failure, and chronic kidney disease.
 Associated morbidity and mortality
 Modifiable factors, including
adjustments in sodium intake.
Article 1
Sodium’s Role in the Human Body
 Sodium draws water to itself and is therefor a way to maintain blood volumes
and blood pressure at appropriate levels
 Sodium is an element essential for nerve and muscle function
 Muscle contractions and nerve signals utilize sodium to communicate with
electrical currents
 Hyponatremia
 Too little sodium
 Muscle cramps, headaches, irritability, fatigue, nausea, confusion, hallucinations,
coma, death
 Hypernatremia
 Too much sodium
 Lethargy, spasticity, seizures
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Sodium’s Adverse Affects
 Excess consumption of sodium is a major contributor to the disease processes
related to elevated blood pressures
 Sodium chloride (table salt)
 Increased sodium intake leads to elevated blood pressures
 Increased sodium can cause renal injury and increase the rate of injury already
caused by diabetes or glomerulonephritis
 It can cause an increase in filtration rate, increased albumin excretion,
increased oxidative stress, and increased fibrosis
 All further damaging and scarring to the kidneys
 Increased amounts of sodium can decrease the effects of some blood pressure
medications
 Which help lower blood pressures and stop protein excretion from the kidneys
Article 1
Hypertension
Definitions of elevated blood pressure
 Normal blood pressure: 120/80 mmHg (systolic/diastolic)
 Pre hypertension: 121-139/81-89 mmHg
 Hypertension: > 140/90 mmHg
Hypertension and Related Diseases
 Blood pressure has a direct effect on many diseases
 Blood pressure can be modifiable
 Examples of diseases related to blood pressure
 coronary artery disease
 stroke
 congestive heart failure
 chronic kidney disease
 Coronary artery disease and stroke are among the top causes of morbidity
 Chronic hypertension
 fibrosis of heart, kidneys, and arteries
 Left ventricular hypertrophy
Article 1
Hypertension
 Essential Hypertension
 No clear identifiable cause, such as kidney or adrenal disease
 Seen mostly in societies where dietary intake is greater than 100 meq/day (2.3 g
sodium)
 1 teaspoon of salt is 2.3 g of sodium
 Certain societies can be as low as 50 meq/day (1.2 g Sodium)
 Observations show there may be a threshold level of sodium intake as it relates
to elevated blood pressure
 Chloride ion important
 Elevated blood pressure not seen in other ion combinations such as sodium citrate or
ammonium chloride
 Age related hypertension is associated with increased stiffness of major blood
vessels in the body
Article 1
Essential Hypertension and Sodium
Excretion
 In essential hypertension, hypertension which is not related to kidney
disease or adrenal disease
 sodium excretion is impaired
 It is theorized that essential hypertension has a genetic component and
that certain genes may be responsible for the bodies inability to process
sodium properly
Article 4
Sodium as it Relates to Hypertension
 Mechanism of sodium sensitivity aren’t well understood
 May be related to the way the body processes sodium and chloride
 A increased intake of sodium typically leads to increased blood volume
which causes an increased pressure to be noted at the kidneys
 This pressure leads to the excretion of salt and water in the kidneys known as
“pressure natriuresis” which is the body’s regulatory mechanism for decreasing
blood pressure
 Sodium and water are urinated and normal blood pressure restored
 This blood pressure regulatory system is accomplished through hormone signals
involving the liver, kidneys, adrenal glands, and posterior pituitary gland
 Renin-Angiotensin-Aldosterone System
Article 2
http://en.wikipedia.org/wiki/Renin%E2%80%93angiotensin_system
Salt Sensitivity
 Salt sensitivity
 Blood pressure that changes in relation to amount of sodium in the body
 Increases with age
 African Americans
 Obese patient
 Metabolic syndrome
 Chronic kidney disease
 May play a role in development of hypertension in these patient groups
 These groups don’t appear to utilize the renin-angiotensin-aldosterone
system as much to regulate sodium levels and blood pressure
Article 2
Salt Sensitivity
 Those without salt sensitivity can process a sodium load without an increase
in blood pressure by suppressing the renin release and increasing atrial
natriuretic peptide
 ANP is a natural dilator of arteries and stimulates sodium excretion which
decreases blood pressure
 Those who are not salt sensitive also tend to have a baseline lower blood
pressure
Article 2
Effects of Increased Sodium Intake
 Hyperfiltration
 Leads to kidney damage – overworking of the kidneys
 Reduced effectiveness of calcium channel blockers and ACE Inhibitors in
patients with proteinuria
 Increased calcium excretion
 Left ventricular hypertrophy
 Elevated heart rate
 Insulin resistance
 Stomach cancer incidence increased
 Asthma
Article 1
Sodium Restriction and Hypertension
 Restricting dietary sodium
 Lower extracellular volume which decreases blood volume and blood pressure
 This decrease in blood pressure has been seen in both hypertensive and normotensive patients
 Appears to improve response to blood pressure medications
 except calcium channel blockers
 Sodium restriction may also decrease the degree of potassium depletion that occurs
when taking diuretics
 Potassium is a key element in cellular function
 Increase in renin production
 Lead to blood pressure more dependent on Angiotensin II
 Leads to blood pressure more responsive to ACE Inhibitors (ex. Lisinopril) and Angiotensin II
receptor blockers (ex. Losartan)
Article 2
Benefits of Decreased Sodium Intake
 Sodium reduction is related to less stiffness in blood vessels
 Sodium reduction is related to arterial vasodilation
 Decrease cardiac output due to less blood volume
 Decrease work load on the heart
 Weight loss decreases the sympathetic nervous system
 Less activation of the RAAS
 Decreased blood pressure
 Weight loss is thought to lessen sodium retention
 Decreased blood pressure
Article 4
Effects of Decreased Sodium Intake
 Lower urinary calcium excretion (decreased kidney stones)
 Potential reduced risk of osteoporosis
 Less calcium excreted from body
 Increased anti-protein effects on patients with chronic kidney disease who are
taking ACE Inhibitors
 Help slow progression of CKD
 Improvement of left ventricular hypertrophy
 Chronic high blood pressure causes the muscle wall to thicken and stiffen and therefor
has a decreased ability to pump as well as a normal heart
 LVH and chronic hypertension are cofactors in the development of certain types of
congestive heart failure
Article 2
Sodium and Comorbid Diseases
 Sodium intake also related to other conditions that can aggravate
hypertension
 Insulin resistance
 Affects propensity for DMII and hypertriglyceridemia
 Cofactors in chronic kidney disease and atherosclerosis
 Hyperlipidemia
 Renal injury
 Can lead to increased renal vasoconstriction and decreases sodium excretion
 Can lead to worsening of hypertension
Article 2
Article 4
Article 4
145
Control diet
140
135
Higher to lower sodium
Control: −8
DASH: −7
−2.1 (−0.1 to −4.0)
−8.0 (−4.9 to
−11.1)
−6.0 (−4.0 to −7.9)
−7.5 (−4.2 to
−10.8)
DASH diet
−1.6 (0.6 to −3.8)
130
125
0
−6.7 (−3.5 to
−9.8)
−5.1 (−3.0 to −7.3)
Lower-sodium DASH vs. higher-sodium control: −15
High (3.5 g)
Intermediate (2.3 g)
Low (1.2 g)
Dietary Sodium
Figure 2. Sodium Reduction, the DASH Diet, and Changes in Systolic Blood
Pressure.
Article 4
The figure shows the additive beneficial effects of the DASH diet and reduced
intake of sodium on systolic blood pressure in patients with mild hypertension who were older than 45 years of age. The participants were a subgroup
of those in the study of the effects of the DASH diet and reductions in dietary
sodium,53 who were randomly assigned to follow a DASH diet (33 participants) or a typical U.S. diet (37 participants) for 90 days. During that period,
each group consumed three versions of the diet adjusted for daily sodium
content. The participants in each group consumed each of the sodiumadjusted diets for 30 days in a crossover design; body weight was held constant. The two downward-sloping arrows on the left depict the effect of intermediate sodium intake as compared with higher sodium intake, and the
two downward-sloping arrows on the right depict the effect of lower sodium
intake as compared with intermediate sodium intake. The dotted lines show
the effect of the DASH diet as compared with the typical U.S. diet at each
level of dietary sodium. Numbers shown represent the mean changes with
95% confidence intervals. Adapted from Bray et al.54
DASH Diet vs. Control
Diet
3.5, 2.3, and 1.5 grams
sodium per day
(high/intermediate/low)
NEJM, 2011
“Systolic blood pressure was 12 mm Hg higher among
participants between 55 and 76 years of age than among
those between 21 and 41 years of age when they were given
a typical U.S. diet that was high in sodium.
This difference in systolic blood pressure is similar to that
in the U.S. population when the same age groups are
compared.55 In marked contrast, systolic blood pressure was
the same among older and younger participants when they
were given the DASH diet with low sodium content. This
finding suggests that the typical rise in blood pressure that
occurs with age during adult life may be prevented or
reversed if the low- sodium DASH diet is followed.”
“Women, blacks, and those with the
metabolic syndrome have a mildly
enhanced reduction in blood pressure in
response to a low-sodium diet".
53,54,56,5
Article 4
Congestive Heart Failure
Congestive Heart Failure
 Heart failure is one of the most common causes of hospitalization,
readmission, and death
 Its prevalence and morbidity/mortality makes the importance of early
intervention and patient care at home critical
 Approximately 5.8 million Americans have heart failure
 Leading cause of hospitalization in patients over 64
 Over ¼ of those patients will be readmitted within 30 days
Article 5
Congestive Heart Failure
 Heart failure is when the pumping mechanism of the heart does not work
properly
 Increased blood pressures and failed pumping mechanism of the heart
 fluid leaks back into the tissues (lungs, legs)
 Shortness of breath and fatigue
 The physiology of heart failure is related to decreased cardiac output,
increased blood pressures, and decreased blood flow to the kidneys
 This perpetuates a cycle of the kidneys attempting to hold onto sodium
and water to keep blood pressures elevated despite the fact that the
body’s blood pressure is elevated
Article 6
Article 6
Figure.
Effects of sodium intake in heart failure: low-sodium
intake may have varied effect on heart failure.
Intravascular volume contraction improves
hemodynamics and reduces diuretic requirement,
congestion, and myocardial wall stress, leading to
compensated heart failure.
Intravascular volume contraction, however, may also
lead to a vicious cycle of increased sodium and
water retention through neurohormonal activation
predisposing to decompensated heart failure. AVP
indicates arginine vasopressin; Na, sodium; K,
potassium; MR, mitral regurgitation; PWCP,
pulmonary wedge capillary pressure; red plus,
diuretic action enhances contraction of intravascular
volume; red minus, low diuretic doses reduce
hormonal activation and contraction of intravascular
volume.
Article 6
Congestive Heart Failure
 At least 1/5 of the patients with acute episodes of heart failure are due to
ingestion of too much sodium
 Decreased sodium and decreased blood pressure enhances the effects of
blood pressure medications and helps prevent excess loss of potassium by
antihypertensive medications
 The American Heart Association and the American College of Cardiology
 recommend less than 3 grams per day of sodium ingestion for those with heart
failure
 recommends less than 2 grams per day in those with severe heart failure
Article 5
Monitoring Sodium intake
 Monitor salt intake
 Daily weights
 Identify concerning symptoms
 Shortness of breath
 Increased swelling in legs
 Adjust medications
 Good patient self care has been shown to reduce readmission to the
hospital for acute exacerbation of congestive heart failure by 40%
Article 5
Chronic Kidney Disease
Chronic Kidney Disease
 Diabetes and high blood pressure are the top 2 causes of chronic kidney
disease
 The number of people who are on Medicare disability due to end stage
kidney disease
 increased from approximately 10,000 in 1973 to approximately 615,000 as of
December 2011
Article 7
Chronic Kidney Disease
 High sodium intake decreases the anti-protein effects of antihypertension
medications such as ACE inhibitors or Angiotensin Receptor Blockers
 Decreased blood pressure = less damage to the kidneys
 Proteinuria associated with worsening kidney function
 High sodium intake also related to a higher incidence of end stage renal
disease
 Maintaining lower blood pressures is the mainstay of CKD treatment
 Prevent further damage to the kidneys from elevated blood pressures
 Goal blood pressure of less than 130 mmHg systolic
Article 7
Recommendations for Sodium Intake
 Because 90% of people will eventually develop high blood pressure the
2013 guidelines at U.S. Department of Health and Human Services suggests
that all people consume less than 2300 mg/day
 A decreased intake of sodium by 75 meq/day for 4 or more weeks has
shown a decrease in blood pressure by 5/3 mmHg in hypertensives and 2/1
mm Hg for those without hypertension
 More of a reduction in blood pressure seen with salt restriction in older
adults versus younger adults
 It seems that sodium restriction can reduce the blood pressure rise seen with age
Article 2
Recommendations Around the World

World Health Organization

Centers for Disease Control

The United Nations

The U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture
(USDA)
 http://health.gov/dietaryguidelines/default.asp
 Dietary guideline for Americans (every 5 years)
 Advises sodium intake of 2300mg/day or less

National Institute of Health
 DASH diet (Dietary approach to stop hypertension)
 Fruits, vegetables, whole grains, low fat dairy, low in saturated and trans fats, low sugar, low sodium
 Advises 2300mg/day of sodium, and 1500mg/day or less to further lower sodium in certain populations
Recommendations for Sodium Intake
 American Heart Association
 1.5 grams sodium/day or less
 JNC 7 in 2003
 2.3 grams sodium/day
 2007 European Society of Hypertension
 2 grams/day
 Department of Agriculture and of Health and Human Services and National
Institute of Health
 2.3 grams/day or less of sodium
 If over 50 years old, African American, HTN, DMII, CKD
 then less 1.5 grams/day
Table 1. Re com m e nde d We e k ly and Occas ional Food Purchas e s for One Pe rs on Follow ing a He althful Die t Containing 2100 k cal and 1500 m g of Sodium pe r
Day.*
Type of Food We e k ly purchas e s
Se rvings pe r Wk Se rving Size
Total Am ount
Re com m e ndations
Purchas e d pe r Wk
Market periphery
Vegetables†
Leafy greens
Salad greens
Other greens
Cruciferous
Colorful‡
Do most weekly shopping in this section
4
4
3
15
1 cup
1/2 cup
1/2 cup
1/2 cup
Other
Fruits
Fresh
3
1/2 cup
20
Dried
Juice
Herbs, alliums, and other seasonings
Meat, poultry, and fish
Fish and shellfish
8
4
Use freely
1 medium or
1/2 cup
chopped
1/4 cup
1 glass (8 oz)
2
6–8 oz
1 lb
Poultry
Red meats
Dairy products
Milk
Yogurt
Cheese
Processed-food aisles§
Nuts (whole or butter)
Legumes
Olives
Spices
Baked goods
2
1
6–8 oz
2–4 oz
1 lb
1/4 lb
10
3
4
1 glass (8 oz)
1 cup
1 slice
10
3
2
Use freely
20
Tomato products
Chips and other snacks
Chocolate or sweets
Other food aisles (sweetened beverages, candy, cookies)
Le s s frequent purchases‖
Breakfast cereals
Pasta, rice, and grains
Cooking oils
Table fats
12
16
Salad dressings and mayonnaise
Sugars
Desserts
Eggs
21
24
Salt
1 oz
1 cup
1/2 cup
1 slice
1–2 bags or heads
1–2 bunches
1–2 heads
8–12 individual items
1/2 lb
15–20 individual items
1 bag
1 qt
1/2 gallon
1 container
1/4 lb
1 bag or jar
1 can or bag
1 jar
1 bag
4
3
1
2/3 cup
1/2 cup
1 oz
2 jars or cans
3 bags
1 bar or similar amount
2
3
1/2 cup
1 cup
(cooked)
1 tbs
1 tsp
1 1/2 cups
1/2 cup
Lettuce, mixed spring greens, spinach bunch (about 1 lb)
Kale, collard greens, mustard greens (about 1 lb)
Broccoli, cabbage, cauliflower (about 1 lb)
Tomatoes, carrots, squash, peppers, sweet potatoes, corn, eggplant, avocados (about 3 lb)
Celery, green beans, peas, lima beans, sprouts
Apples, pears, grapes, bananas, peaches, plums, oranges, tangerines, berries, cantaloupe, pineapple
Raisins, apricots, prunes, cherries (about 1/2 lb)
Orange, grapefruit, unsweetened carrot
Thyme, ginger, garlic, onion, bay leaf, lemon juice
Cod, sea bass, halibut; fresh or canned salmon, tuna, or sardines; mollusks, shrimp, crabmeat
Turkey, chicken, low-sodium cold cuts
Beef, pork, lamb, low-sodium cold cuts
Choose low-fat or nonfat products
Choose low-fat or nonfat products (about 32 oz)
Soft or hard
Choose only low-sodium products¶
Walnuts, almonds, peanuts (about 1/2 lb)
Chickpeas, lentils, black beans (about 1 lb)
Black, green, stuffed (about 1/4 lb)
Black pepper, cayenne, cinnamon, paprika
Bread, rolls, pancakes, waffles (about 1 1/2 lb); choose wholegrain products
Sauce, juice, whole or diced (about 12 oz per jar or can)
Tortilla chips, popcorn, pretzels (about 1 1/2 oz per bag)
Granola bars, chocolate bars (about 1 oz)
Skip these aisles
Oats, bran, whole wheat flakes, other whole grains
Pasta, brown rice, bulgur, quinoa, wheat berries
3/4 cup
1/3 cup
Canola, corn, sunflower, olive, soybean
Soft, oil-based spreads free of trans fat
1
3
1 tsp
1 tsp
1/2 cup
1
1/2 cup
1/2 cup
1/2 cup
3
Choose low-sodium items
Table sugar, jelly, honey, maple syrup
Ice cream, sorbet, frozen yogurt, other (4 oz)
Large eggs
7
1/3 tsp
2 1/3 tsp
Salt for cooking or added at the table
References
 1. Circulation. 2011;123:1138-1143, Appel et al.
 2. https://uptodate.com/contents/salt-intake-salt-restriction-and-primaryessential-hypertension
 3. https://uptodate.com/contents-antihypertension-therapy-andprogression-of-non-diabetic-chronic-kidney-disease-in-adults
 4. N Engl J Med 2010:362:2102-12. Sacks M.D., Frank M. and Campos PhD.,
Hannia
 5. https://uptodate.com/contents-overview-of-the-therapy-of-heart-failuredue-to-diastolic-dysfunction
 6. http://circ.ahajournals.org/content/126/4/479.full#T1
 7. https://uptodate.com/contents-epidemiology-of-chronic-kidney-disease