Sodium and Your Health - PowerPoint Presentation

Slide1

Sodium and Your Health

Rebecca Burson, M.D., M.P.H.

Assistant Clinical Faculty at Texas A&M FM ResidencySlide2

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 diseaseSlide3

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 mortalityModifiable factors, including adjustments in sodium intake.

Article 1Slide4

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 sodiumMuscle cramps, headaches, irritability, fatigue, nausea, confusion, hallucinations, coma, deathHypernatremiaToo much sodiumLethargy, spasticity, seizureswww.uptodate.comSlide5

Sodium’s Adverse Affects

Excess consumption of

sodium

is a major contributor to the disease

processes related to elevated

blood pressuresSodium chloride (table salt)Increased sodium intake leads to elevated blood pressuresIncreased sodium can cause renal injury and increase the rate of injury already caused by diabetes or glomerulonephritisIt can cause an increase in filtration rate, increased albumin excretion, increased oxidative stress, and increased fibrosisAll further damaging and scarring to the kidneysIncreased 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 1Slide6
Slide7

Hypertension Slide8

Definitions of elevated blood pressure

Normal blood pressure: 120/80 mmHg (systolic/diastolic)

Pre hypertension: 121-139/81-89 mmHg

Hypertension: > 140/90 mmHgSlide9

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

c

oronary artery diseasestrokecongestive heart failurechronic kidney diseaseCoronary artery disease and stroke are among the top causes of morbidityChronic hypertensionfibrosis of heart, kidneys, and arteriesLeft ventricular hypertrophy

Article 1Slide10

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 sodiumCertain 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 pressureChloride ion importantElevated blood pressure not seen in other ion combinations such as sodium citrate or ammonium chlorideAge related hypertension is associated with increased stiffness of major blood vessels in the body

Article 1Slide11

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 4Slide12

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 restoredThis blood pressure regulatory system is accomplished through hormone signals involving the liver, kidneys, adrenal glands, and posterior pituitary glandRenin-Angiotensin-Aldosterone System

Article 2Slide13

http://en.wikipedia.org/wiki/Renin%E2%80%93angiotensin_systemSlide14

Salt Sensitivity

Salt sensitivity

Blood pressure that changes in relation to amount of sodium in the body

Increases with age

African Americans

Obese patientMetabolic syndrome Chronic kidney diseaseMay play a role in development of hypertension in these patient groupsThese groups don’t appear to utilize the renin-angiotensin-aldosterone system as much to regulate sodium levels and blood pressureArticle 2Slide15

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 2Slide16

Effects of Increased Sodium I

ntake

Hyperfiltration

Leads to kidney damage – overworking of the kidneys

Reduced effectiveness of calcium channel blockers and ACE Inhibitors in patients with proteinuria

Increased calcium excretionLeft ventricular hypertrophyElevated heart rateInsulin resistanceStomach cancer incidence increasedAsthmaArticle 1Slide17

Sodium R

estriction 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 patientsAppears to improve response to blood pressure medications except calcium channel blockersSodium restriction may also decrease the degree of potassium depletion that occurs when taking diuretics

Potassium is a key element in cellular functionIncrease 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 2Slide18

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 systemLess activation of the RAASDecreased blood pressureWeight loss is thought to lessen sodium retentionDecreased blood pressure

Article 4Slide19

Effects of Decreased S

odium

I

ntake

Lower urinary calcium excretion (decreased kidney stones)

Potential reduced risk of osteoporosis Less calcium excreted from bodyIncreased anti-protein effects on patients with chronic kidney disease who are taking ACE InhibitorsHelp slow progression of CKDImprovement of left ventricular hypertrophyChronic high blood pressure causes the muscle wall to thicken and stiffen and therefor has a decreased ability to pump as well as a normal heartLVH and chronic hypertension are cofactors in the development of certain types of congestive heart failure

Article 2Slide20

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

HyperlipidemiaRenal injury Can lead to increased renal vasoconstriction and decreases sodium excretionCan lead to worsening of hypertensionArticle 2Slide21

Article 4Slide22

Article 4Slide23

Article 4

DASH Diet vs. Control Diet

3.5, 2.3, and 1.5 grams sodium per day (high/intermediate/low)

NEJM, 2011Slide24

“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

simi

lar

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 4Slide25

Congestive Heart FailureSlide26

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

failureLeading cause of hospitalization in patients over 64Over ¼ of those patients will be readmitted within 30 daysArticle 5Slide27

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 kidneysThis 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 elevatedArticle 6Slide28

Article 6Slide29

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 6Slide30

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 Cardiologyrecommend less than 3 grams per day of sodium ingestion for those with heart failurerecommends less than 2 grams per day in those with severe heart failureArticle 5Slide31

Monitoring Sodium intake

Monitor salt intake

Daily weights

Identify concerning symptoms

Shortness of breath

Increased swelling in legsAdjust medicationsGood patient self care has been shown to reduce readmission to the hospital for acute exacerbation of congestive heart failure by 40%Article 5Slide32

Chronic Kidney DiseaseSlide33

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 7Slide34

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 diseaseMaintaining lower blood pressures is the mainstay of CKD treatment Prevent further damage to the kidneys from elevated blood pressuresGoal blood pressure of less than 130 mmHg systolic

Article 7Slide35

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 hypertensionMore of a reduction in blood pressure seen with salt restriction in older adults versus younger adultsIt seems that sodium restriction can reduce the blood pressure rise seen with ageArticle 2Slide36

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.aspDietary guideline for Americans (every 5 years)Advises sodium intake of 2300mg/day or lessNational Institute of HealthDASH 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 populationsSlide37

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 Hypertension2 grams/dayDepartment of Agriculture and of Health and Human Services and National Institute of Health2.3 grams/day or less of sodium If over 50 years old, African American, HTN, DMII, CKDthen less 1.5 grams/daySlide38
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References

1. Circulation. 2011;123:1138-1143, Appel et al.

2.

https://uptodate.com/contents/salt-intake-salt-restriction-and-primary-essential-hypertension

3.

https://uptodate.com/contents-antihypertension-therapy-and-progression-of-non-diabetic-chronic-kidney-disease-in-adults4. N Engl J Med 2010:362:2102-12. Sacks M.D., Frank M. and Campos PhD., Hannia5. https://uptodate.com/contents-overview-of-the-therapy-of-heart-failure-due-to-diastolic-dysfunction

6. http://

circ.ahajournals.org/content/126/4/479.full#T17. https

://uptodate.com/contents-epidemiology-of-chronic-kidney-disease