Salt and our health final

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Salt and Cardiovascular disease

Jafar Al-Said, M.B. CHb. MD. FASNNephrology and Internal Medicine Consultant

Bahrain Specialist Hospital

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Presentation scheme: Introduction. Historical points. Salt effect on health:

HTN.Stroke.Kidney disease.Kidney stones.Osteoporosis.Stomach Cancer.Obesity.Meniere’s disease. Alzheimer’s disease

Conclusion.

NaCl

Source: 1- Mining.2- Sea Water (brine)

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Boiling Brine into pure salt

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Relation of Salt and Na:

Table Salt had 40%-60% Na.

1 gm salt has 400mg-600mg Na.

One tea spoon of Salt has : -2300 mg Na. -3500-5500 mg Salt.

Introduction 1. Salt played an important part in Civilizations

for centuries.

2. Its use mentioned since 6050 BC.

3. Egyptian were using it for trade between Phoenicians an Mediterranean's.

4. It is a major preservative. It was used in preparing conserving the Mummies in Egypt.

5. It is mentioned in Assyrian, Babylonian, Chinese and Greek history.

Historic pointsSalary = Salarium Argentum= Salt rations for roman solders.

Salad = Salt.

One of the commodities in the past. Used as Currency and trade. Soldiers were paid by Salt. Taxies were put on salt trade.

Salt raotes in the Roman times.

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Roman Salt Roats

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Romans Salt Routes.

Salt in different countries Austria: Salzburg = City of Salt.

Tuzla: Bosina-Herzegovina. ( Tuz= Salt).

Jordan: As-Salt town. In Byzantine times.

Syracuse, New York = Salt City.

Salt in Wars and Revolutions: 16th Century; Spanish bankruptcy after blockade of Iberian

Salt works by Dutch.

1789-1791; French Revolution.

18th century Salt played a role in the American Revolutions when British strategies were to deny American rebels access to salt.

1812; Napoleon retreat from Moscow many soldiers died because of unhealed wound from lack of salt.

1864. American Civil war. Saltville battle in Virginia.

1930, Gandhi Revolution against British salt taxation in India. Walk to the sea to gather tax free salt for nations poor.

Salt Monopoly and taxation 2200 BC Chinese emperor taxed salt.

1259-1946; “Gabelle” French kings used salt tax.

1785 Salt Taxes support British colonies. 10000 peoples arrested in England for smuggling salt.

1825; Erie Canal in New York. The ditch that salt built. Salt tax revenues paid half cost.

Until 1975 Italy taxes the Salt by 70%.

World free trade had lead to abolishing of this Monopoly. As in Taiwan.

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Salt and religion. Egyptian Mummies.

Greek Worshippers.

Jewish Temple offering include salt.

Catholic Church use salt in Purifying rituals.

Buddhist salt repels evil spirit.

1933 Dalai Lama buried sitting up in a bed of Salt.

Last Supper; Leonardo da Vinci

1495-1498

Last Supper; Leonardo da Vinci

1495-1498

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Lets go back to our real medical world

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Recommended daily intake of Salt

Age Max. Salt intake/ day0-6 months <1gm6-12 months 1gm

1-3 years 2gm4-6 years 3gm7-10 years 5gm>11 years 6gm

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Average Daily Salt Intake in Male and Female Americans, as Ascertained from 24-Hour Dietary Recall, 2005–2006.

Appel LJ, Anderson CA. N Engl J Med 2010;362:650-652.

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Salt and HypertensionAnimal studies : BP in Chimpanzees with

modification of salt

Denton D, Weisinger R, Mundy N I, et al. The effect of increased salt intake on blood pressure of chimpanzees. Nat Med. 1995;1:1009-16.

10-15gm/day

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Epidemiology

Communities with high salt consumption showed higher BP.

Page L B, Damon A, Moellering R C, Jr. Antecedents of cardiovascular disease in six Solomon Islands societies. Circulation. 1974;49:1132-46.

Page L B, Vandevert D E, Nader K, Lubin N K, Page J R. Blood pressure of Qash'qai pastoral nomads in Iran in relation to culture, diet, and body form. Am J Clin Nutr. 1981;34:527-38.

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Epidemiologic studiesIntersalt study:

N = 10079.Adults 20-59 years.Global medical centers = 52 from 32

countries.

Aim: Investigate the relation of electrolyte excretion to BP. INTERSALT. Intersalt

: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group. Bmj. 1988;297:319-28.

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Intersalt results

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Dose response salt reduction

Dose-response relationship between the reduction in salt intake as judged by reduction in 24h urinary sodium and systolic blood pressure. INTERSALT. Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group. British Medical Journal. 1988; 297, 319-28

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Reducing Salt reduce BP

Interventional study. N = 3000. Randomized to salt reduction and control. In two cohort populations. Net salt reduction was 33-44mmol/day. Followed for 10-15years.

Results: Cardiovascular events were 25% less in the

interventional group.

Trial of Hypertension Prevention( TOHP I & II)Cumulative incidence of cardiovascular disease (CVD) by sodium intervention group in TOHP I and II, adjusted for age, sex, and clinic

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Trial of Hypertension Prevention (TOHP I & II)

Cumulative incidence of cardiovascular disease (CVD) by sodium intervention group in TOHP I and II, adjusted for age, sex, and clinic

Cook NR, Cutler JA, Obarzanek E, Buring JE, Rexrode KM, Kumanyika SK Appel LJ & Whelton PK. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOTP). BMJ, Apr 2007; 334: 885; doi: 10.1136/bmj.39147.604896.55

N=3000.TOHP I = 18 monthsTOHP II = 36-48 months.

Decreased salt by 25-30%

Results:TOHP I decreased BP -1.7/0.9mmHg.TOHP II decreased BP – 1.2/0.7mmHg

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Reducing salt reduce BP in South Asian population in UK

• Modest salt reduction 4gm/day for 6 wks.

• Decreased BP by -5.4/2.2 mmHg

He et al. Effect of Modest Salt reduction on Blood Pressure, Urinary Albumin and pulse Wave velocity in white, black and Asian mild hypertensives. Hypertension. 2009; 54, 482-488.

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Salt reduction in new born.

Aim: effect of low salt diet on new born BP.

N=500 new born. For 6months. Randomized study to moderate salt reduction.

Results : At 6 months the systolic BP was lower by

2.1mmHg. The reduction in BP was maintained after 15 years.

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Results:

Hofman A, Hazebroek A, Valkenburg H A. A randomized trial of sodium intake and blood pressure in newborn infants. Jama. 1983;250:370-3.

Geleijnse J M, Hofman A, Witteman J C, et al. Long-term effects of neonatal sodium restriction on blood pressure. Hypertension. 1997;29:913-7.

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Two Village controlled Low salt study

2 villages in Portugal. One village had been offered low salt

processed food. It was given information on how to reduce

the salt.

Results: After one year BP was less and in two years

both systolic and diastolic BP were lower. Forte J G, Miguel J M, Miguel M J, et al.. Salt and blood pressure: a community trial. J Hum Hypertens. 1989;3:179-84.

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Results:

Forte J G, Miguel J M, Miguel M J, et al.. Salt and blood pressure: a community trial. J Hum Hypertens. 1989;3:179-84.

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Population studiesJapan: Reducing salt from 18gm to 14 gm over one decade. Stroke mortality reduced by 80%.Iso H, Shimamoto T, Yokota K, et al. [Changes in 24-hour urinary excretion of sodium and potassium in a community-based heath education program on salt reduction]. Nippon Koshu Eisei Zasshi. 1999;46:894-903.

Finland:14000 population with instruction to reduce salt increase fruits and vegetables and stop smoking. Reduced stroke mortality by 66% Reduced CAD mortality by 55%.RR= 0.5 for salt reduction. Vartiainen E, Sarti C, Tuomilehto J, Kuulasmaa K. Do changes in cardiovascular risk factors explain changes in mortality from stroke in Finland ? Bmj. 1995;310:901-4.

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Mortality and salt intakeFinland: increased salt intake showed

increase Cardiovascular and total Mortality.

Tuomilehto J, Jousilahti P, Rastenyte D, Moltchanov V, Tanskanen A, Pietinen P, Nissinen A. Urinary sodium excretion and cardiovascular mortality in Finland: a prospective study. Lancet. 2001;357:848-51

Randomized controlled trial

Increased 6 gm of Salt/day

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Treatment trials

Reduced salt intake from 10-12gm/day to 5-6gm/day will:

1.Reduce BP as single AntiHTN.2.Additive to AntiHTN.3.More in low renin; blacks and elderly.

MacGregor G A, Markandu N D, Best F E, et al. Double-blind randomised crossover trial of moderate sodium restriction in essential hypertension. Lancet. 1982;1:351-5.

He F J, Markandu N D, Sagnella G A, MacGregor G A. Importance of the renin system in determining blood pressure fall with salt restriction in black and white hypertensives. Hypertension. 1998;32:820-4.

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Treatment trials

Salt reduction in three levels 12, 6, 3gm/day. In mild untreated essential HTN individuals:

Lower BP in lower salt intake.

Continued BP control for one year.

MacGregor G A, Markandu N D, Sagnella G A, et al. Double-blind study of three sodium intakes and long-term effects of sodium restriction in essential hypertension. Lancet. 1989;2:1244-7.

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Meta-analysis of salt reduction and BP changes

He F J, MacGregor G A. Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials. Implications for public health. J Hum Hypertens. 2002;16:761-70.

28 RCT trialsSalt reduce from 10 to 5gm.4wks.

Results:Reduce salt 6gm/day:24% decreased stroke death.20% decrease IHD death

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Salt intake and stroke death

Perry IJ, Beevers DG. Salt intake and stroke: a possible direct effect. Journal of Human Hypertension. 1992; 6, 23-25

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NIH report 2010Salt reduction is No.1 Cardiovascular preventive measure.

Aim to decrease daily salt to: 6gm in 2015. 3gm in 2025.

NICE. Prevention of Cardiovascular Disease. Public health guidance 25. Published June 2010

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As part of the implementation of the WHO Global Strategy on Diet, Physical Activity and Health and the 2008-2013 Action Plan for the Global Strategy for the Prevention and Control of Noncommunicable Diseases

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Current dietary guidelines for Americans recommend that adults in general should consume no more than 2,300 mg of sodium per day. At the same time, consume potassium-rich foods, such as fruits and vegetables. However, if you are in the following population groups, you should consume no more than 1,500 mg of sodium per day, and meet the potassium recommendation (4,700 mg/day) with food.

Most Americans Should Consume Less Sodium(1,500 mg/day or less

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Relation of Salt to LVH in individuals with systolic BP >121mmHg.

Schmeider RE et al. Dietary salt intake. A determinant of cardiac involvement in essential hypertension. Circulation. 1988; 78, 951-956

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Cochrane reviewAim: Salt reduction and Cardiovascular Mortality.Total studies were 7 RCTs.Population was 6489.(758 (11.6 %)were HTN).Follow up was variable 3-13 years.

Results:No strong evidence that reduce salt is beneficial.2.6 folds higher mortality in heart failure with decreased salt intake.

Taylor RS, Ashton KE, Moxham T, Hooper L, Ebrahim SPublished Online: October 5, 2011Advice to reduce the amount of salt eaten reduces blood pressure but there is insufficient evidence to confirm the predicted reductions in people dying prematurely or suffering cardiovascular disease

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Salt intake & Proteinuria Decreased Salt intake from 10gm to 5gm

decreased urine protein by 19.4%.Swift P A, Markandu N D, Sagnella G A, He F J, Macgregor G A. Modest Salt Reduction Reduces Blood Pressure and Urine Protein Excretion in Black Hypertensives. A Randomized Control Trial. Hypertension. 2005; 46:308-12

Decreased Salt from 9.7gm to 6.5gm decrease 24 hour albuminuria.

He FJ, Marciniak M, Visagie E, et al: Effect of modest salt reduction on blood pressure, urinary albumin, and pulse wave velocity in white, black, and Asian mild hypertensives. Hypertension 54: 482-488, 2009

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Water retention

Access Salt cause more water retention in: Heart failure. Renal failure. Cirrhosis patients. In women cyclical and idiopathic edema. Sitting for long time like long flights.

MacGregor G A, de Wardener H E, Idiopathic edema., in Diseases of the kidney., G.C. Schrier RW, Editor. 1997, Little Brown and Company.: Boston. p. 2343-2352.Perry I J, Beevers D G. Salt intake and stroke: a possible direct effect. J Hum Hypertens. 1992;6:23-5.

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Salt and vascular dementia

Salt

Stroke HTN

Vascular dementi

a• Passmore P. Preventing dementia following a stroke. The Journal of Quality

Research in Dementia. 2008;Issue 66. • Fratiglioni L et al. Prevention of Alzheimer’s disease and dementia. Major findings

from the Kungsholmen project. Physiology & Behaviour.2007; 92;, 98-104.• Stewart R et al. Change in blood pressure and incident dementia. A 32 year

prospective study. Hypertension. 2009; 54, 233-240.• Nagai M et al. Hypertension and Dementia. American Journal of Hypertension.

2010; 23(2), 116-124

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How to start decreasing the salt in a community?

Laws to start to enforce: Establishing and evaluating public-awareness campaigns.“

"Setting progressive salt targets for reformulating existing processed food and engaging with the food industry in setting standards for new foods."

"Surveying population salt intake, progress of reformulation, and effectiveness of communication."

"Engagement with industry, including regulation, to create a level playing field so as not to disadvantage more enlightened and progressive companies."

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Conclusion: Salt is strongly related to our lives.

It is one of the oldest compounds used.

It is strongly related with many diseases:HTN.Stroke.Kidney disease.Kidney stones.Osteoporosis.Stomach Cancer.Obesity.Meniere’s disease. Alzheimer’s disease.

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Take Home Message

Reducing salt in our diet is recommended.

Normotensive: 4-6 gm per day.

Hypertensive: 2-4 gm per day.

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