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Salt intake, stroke, and cardiovascular disease : meta-analysis of prospective studies

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Strazzullo, Pasquale, Elia, Lanfranco d', Kandala, Ngianga-Bakwin and Cappuccio, Francesco. (2009) Salt intake, stroke, and cardiovascular disease : meta-analysis of prospective studies. BMJ, Vol.339 . b4567. ISSN 0959-535X

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Official URL: http://dx.doi.org/10.1136/bmj.b4567

Abstract

Objective: To assess the relation between the level of habitual salt intake and stroke or total cardiovascular disease outcome.

Design: Systematic review and meta-analysis of prospective studies published 1966-2008.

Data sources: Medline (1966-2008), Embase (from 1988), AMED (from 1985), CINAHL (from 1982), Psychinfo (from 1985), and the Cochrane Library.

Review methods: For each study, relative risks and 95% confidence intervals were extracted and pooled with a random effect model, weighting for the inverse of the variance. Heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Criteria for inclusion were prospective adult population study, assessment of salt intake as baseline exposure, assessment of either stroke or total cardiovascular disease as outcome, follow-up of at least three years, indication of number of participants exposed and number of events across different salt intake categories.

Results: There were 19 independent cohort samples from 13 studies, with 177 025 participants (follow-up 3.5-19 years) and over 11 000 vascular events. Higher salt intake was associated with greater risk of stroke (pooled relative risk 1.23, 95% confidence interval 1.06 to 1.43; P=0.007) and cardiovascular disease (1.14, 0.99 to 1.32; P=0.07), with no significant evidence of publication bias. For cardiovascular disease, sensitivity analysis showed that the exclusion of a single study led to a pooled estimate of 1.17 (1.02 to 1.34; P=0.02). The associations observed were greater the larger the difference in sodium intake and the longer the follow-up.

Conclusions: High salt intake is associated with significantly increased risk of stroke and total cardiovascular disease. Because of imprecision in measurement of salt intake, these effect sizes are likely to be underestimated. These results support the role of a substantial population reduction in salt intake for the prevention of cardiovascular disease.

Item Type:

Journal Article

Subjects:

R Medicine > RC Internal medicine

Divisions:

Faculty of Medicine > Warwick Medical School > Health Sciences > Population, Evidence & Technologies (PET) > Warwick Evidence
Faculty of Medicine > Warwick Medical School > Health Sciences
Faculty of Medicine > Warwick Medical School > Translational & Systems Medicine > Metabolic and Vascular Health
Faculty of Medicine > Warwick Medical School

Library of Congress Subject Headings (LCSH):

Salt -- Physiological effect -- Research, Cardiovascular system -- Diseases, Cerebrovascular disease -- Nutritional aspects

Journal or Publication Title:

BMJ

Publisher:

BMJ Group

ISSN:

0959-535X

Official Date:

24 November 2009

Dates:

Date	Event
24 November 2009	Published

Volume:

Vol.339

Number of Pages:

Page Range:

b4567

Identification Number:

10.1136/bmj.b4567

Status:

Peer Reviewed

Publication Status:

Published

Access rights to Published version:

Open Access

Funder:

Seventh Framework Programme (European Commission) (FP7)

Grant number:

FP7-HEALTH- 2007-201550 (FP7)

References:

1 He FJ, MacGregor GA. A comprehensive review on salt and health and
current experience of worldwide salt reduction programmes. J Hum
Hypertens 2009;23:363-84.
2 World Health Organization. Reducing salt intake in populations:
report of a WHO forum and technical meeting. WHO, 2007:1-60.
3 He FJ, MacGregor GA. 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.
4 He FJ, MacGregor GA. How far should salt intake be reduced?
Hypertension 2003;42:1093-9.
5 Moher D, Cook DJ, Eastwood S, Olkin I, Rennie D, Stroup DF.
Improving the quality of reports of meta-analyses of randomised
controlled trials: the QUOROM statement. Quality of reporting of
meta-analyses. Lancet 1999;354:1896-900.
6 Alderman MH, Madhavan S, Cohen H, Sealey JE, Laragh JH. Low
urinary sodium is associated with greater risk of myocardial
infarction among treated hypertensive men. Hypertension
1995;25:1144-52.
7 Alderman MH, Sealey JE, Cohen H, Madhavan S and Laragh JH.
Urinary sodium excretion and myocardial infarction in hypertensive
patients: a prospective cohort study. Am J Clin Nutr
1997;65(suppl):682-6S.
8 AldermanMH, Cohen H, Madhavan S. Dietary sodiumintake and
mortality: the national health and nutrition examination survey
(NHANES I). Lancet 1998;351:781-5.
9 He J,Ogden LG, Vupputuri S,Bazzano LA, Loria C, Whelton PK. Dietary
sodium intake and subsequent risk of cardiovascular disease in
overweight adults. JAMA 1999;282:2027-34.
10 Kagan A, Popper JS, Rhoads GG, Yano K. Dietary and other risk factors
for stroke in Hawaiian Japanese men. Stroke 1985;16:390-6.
11 Hu HH, Sheng WY, Chu FL, Lan CF, Chiang BN. Incidence of stroke in
Taiwan. Stroke 1992;23:1237-41.
12 Tunstall-Pedoe H, Woodward M, Tavendale R, A’Brook R,
McCluskey MK. Comparison of the prediction by 27 different factors
of coronary heart disease and death in men and women of the
Scottish heart health study: cohort study. BMJ 1997;315:722-9.
13 Tuomilehto J, Jousilahti P, Rastenyte D, Moltchanov V, Tanskanen A,
Pietinen, P, et al. Urinary sodium excretion and cardiovascular
mortality in Finland: a prospective study. Lancet 2001;357:848-51.
14 Nagata C, Takatsuka N, Shimizu N, Shimizu H. Sodium intake and
risk of death from stroke in Japanese men and women. Stroke
2004;35:1543-7.
15 Cohen HW, Hailpern SM, Fang J, Alderman MH. Sodium intake and
mortality in the NHANES II follow-up study. Am J Med
2006;119:275 e7-14.
16 Geleijnse JM, Witteman JC, Stijnen T, Kloos MW, Hofman A,
Grobbee DE. Sodium and potassium intake and risk of
cardiovascular events and all-cause mortality: the Rotterdam study.
Eur J Epidemiol 2007;22:763-70.
17 Cook NR, Cutler JA, Obarzanek E, Buring JE, Rexrode KM,
Kumanyika SK, et al. Long term effects of dietary sodium reduction
on cardiovascular disease outcomes: observational follow-up of the
trials of hypertension prevention (TOHP). BMJ 2007;33:885-8.
18 LarssonSC, VirtanenMJ, MarsM,MannistoS, Pietinen P, AlbanesD,
et al. Magnesium, calcium, potassium, and sodium intakes and risk
of stroke in male smokers. Arch Intern Med 2008;168:459-65.
19 UmesawaM, Iso H, Date C, Yamamoto A, Toyoshima H,Watanabe Y,
et al. Relations between dietary sodium and potassium intakes and
mortality from cardiovascular disease: the Japan collaborative cohort
study for evaluation of cancer risks. Am J Clin Nutr 2008;88:195-202.
20 Cohen HW, Hailpern SM, AldermanMH. Sodium intake andmortality
follow-up in the third national health and nutrition examination
survey (NHANES III). J Gen InternMed 2008;23:1297-302.
21 Downs SH, Black N. The feasibility of creating a checklist for the
assessment of the methodological quality both of randomised and
non-randomised studies of health care interventions. J Epidemiol
Community Health 1998;52:377-84.
22 Dersimonian R, Laird N. Meta-analysis in clinical trials. Control Clin
Trials 1986;7:177-88.
23 Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring
inconsistency in meta-analyses. BMJ 2003;327:557-60.
24 Egger M, Davey SG, Schneider M, Minder C. Bias in meta-analysis
detected by a simple, graphical test. BMJ 1997;315:629-34.
25 Sutton AJ, Duval SJ, Tweedie RL, Abrams KR, Jones DR. Empirical
assessment of effect of publication bias on meta-analyses. BMJ
2000;320:1574-7.
26 Bax L, Yu LM, Ikeda N, Tsuruta H, Moons KG. Development and
validation of MIX: comprehensive free software for meta-analysis of
causal research data. BMC Med Res Methodol 2006;6:50.
27 World Health Organization. The world health report 2002—reducing
risks promoting healthy life. WHO, 2002.
28 Scientific Advisory Committee on Nutrition. Salt and health.
Stationery Office, 2003:1-134.
29 World Health Organization. Reducing salt intake in populations.
Report of a WHO forum and technical meeting. WHO, 2007:1-60.
30 Lewington S, Clarke R, Qizilbash N, Peto R, Collins R. Age-specific
relevance of usual blood pressure to vascular mortality: a metaanalysis
of individual data for one million adults in 61 prospective
studies. Lancet 2002;360:1903-13.
31 Karppanen H, Mervaala E. Sodium intake and mortality. Lancet
1998;351:1509.
32 KupariM, Koskinen P, Virolainen J. Correlates of left ventricularmass
in a population sample aged 36 to 37 years. Focus on lifestyle and
salt intake. Circulation 1994;89:1041-50.
33 Schmieder RE, Messerli FH, Garavaglia GE, Nunez BD. Dietary salt
intake. A determinant of cardiac involvement in essential
hypertension. Circulation 1988;78:951-6.
34 Du Calair G, Ribstein J, Daures JP, Mimran A. Sodium and left
ventricular mass in untreated hypertensive and normotensive
subjects. Am J Physiol 1992;263:H177-81.
35 Avolio AP, Clyde KM, Beard TC, CookeHM, Ho KK,O’RourkeMF.
Improved arterial distensibility in normotensive subjects on a low
salt diet. Arteriosclerosis 1986;6:166-9.
36 Du Calair G, Ribstein J, Mimran A. Dietary sodium and target organ
damage in essential hypertension. Am J Hypertens 2002;15:222-9.
37 Verhave JC, Hillege HL, Burgerhof JG, Janssen WM, Gansevoort RT,
Navis GJ, et al. Sodium intake affects urinary albumin excretion
especially in overweight subjects. J InternMed 2004;256:324-30.
38 National Institutes of Health. Clinical guidelines on the identification,
evaluation, and treatment of overweight and obesity in adults—the
evidence report. Obes Res 1998;(suppl 2):51-209S.
39 Strazzullo P, Barba G, Cappuccio FP, Siani A, Trevisan M, Farinaro E,
et al. Altered renal sodiumhandling inmen with abdominal adiposity
and insulin resistance: a link to hypertension. J Hypertens
2001;19:2157-64.
40 World Health Organization. The world health report 2004—changing
history. WHO, 2004.
41 Selmer RM, Kristiansen IS, Haglerod A, Graff-Iversen S, Larson HK,
Meyer HE, et al. Cost and health consequences of reducing the
population intake of salt. J Epidemiol Community Health
2000;54:697-702.
42 MurrayCJ, Lauer JA, HutubessyRC,NiessenL, TomijimaN,RodgersA,
et al. Effectiveness and costs of interventions to lower systolic blood
pressure and cholesterol: a global and regional analysis on reduction
of cardiovascular-disease risk. Lancet 2003;361:717-25.
43 Asaria P, Chisholm D, Mathers C, Ezzati M, Beaglehole R. Chronic
disease prevention: health effects and financial costs of strategies to
reduce salt intake and control tobacco use. Lancet
2007;370:2044-53.
44 Godlee F. The food industry fights for salt. BMJ 1996;312:1239-40.
45 Cappuccio FP. Salt and cardiovascular disease. BMJ
2007;334:859-60.