Excess Dietary Sodium: Impact on Hypertension and Health Outcomes

1. Excess Dietary Sodium: Impact on Hypertension and Health Outcomes Presenters name Institution Updated April 2011

2. Overview • Hypertension : a leading risk factor for death and disability • High sodium intake is an important determinant of hypertension and hypertension-related complications • How much sodium do we need? • A reduction in dietary sodium intake reduces blood pressure and reduces hypertension-related complications

3. Hypertension is a significant risk factor for: cerebrovascular disease coronary artery disease congestive heart failure renal failure peripheral vascular disease dementia atrial fibrillation Hypertension as a Risk Factor

4. Leading causes of death, Canada, 2005, males and females combined 31% 30% 9% 5% http://www.phac-aspc.gc.ca/publicat/lcd-pcd97/index-eng.php

5. Organ damage related to hypertension Cerebrovascular disease - transient ischemic attacks - ischemic or hemorrhagic stroke - dementia Hypertensive retinopathy Left ventricular dysfunction and hypertrophy Coronary artery disease - myocardial infarction - angina pectoris - congestive heart failure Chronic kidney disease - hypertensive nephropathy GFR < 60 ml/min/1.73 m2) - albuminuria - ESRD/dialysis Peripheral artery disease - intermittent claudication -abdominal aortic aneurysm

6. Hypertension is prevalent and costly 25 * 20 15 Routine medical exams Depression Acute respiratory tract infection Million visits/year Diabetes Hypertension 10 5 0 Reasons for visits to physicians in Canada * Antihypertensives are one of the most expensive drug categories Source: IMS HEALTH Canada 2002. http://www.imshealthcanada.com/

7. Risk factors for hypertension • High dietary sodium intake • Obesity • High alcohol intake • Sedentarity • Smoking • Inadequate vegetable and fruit intake • Inadequate milk product intake

8. Systolic BP by deciles of 24hUVNa K. Stolarz-Skrzypek, European Project on Genes in Hypertension (EPOGH) Investigators – ESH 2010

9. 1.75 1.50 1.25 1.00 0.75 0.50 High sodium intake increases risk of complications in hypertensive patients CHD Death CVD Death All Death * High sodium intake * * Hazard Ratio Lower sodium intake * p  0.001 He FJ, MacGregor GA. a meta-analysis of randomized trials. Implications for public health. J Hum Hypertens 2002;16:761-770

10. In summary • High dietary sodium intake has significant effects on blood pressure and on blood pressure-related complications • Hypertension is a leading risk factor for death and disability • Hypertension is a major cardiovascular risk factor • Hypertension is very prevalent and has a large impact on health care resource use

11. Dietary sodium intake for adults In Canada and the USA, 1300-1500 mg/day (age dependant) is estimated to be adequate (Adequate Intake or AI) 2300 mg/day is above the upper limit recommended for health (upper limit; UL) Canadian Hypertension Education Program (CHEP) recommends: Reduce sodium intake to less than 1500 mg both for the prevention and the treatment of hypertension Dietary Reference Intakes, IM 2003

12. Recommendations for daily salt intake 2,300 mg sodium (Na) = 100 mmol sodium (Na) = 5.8 g of salt (NaCl) = 1 level teaspoon of table salt • 80% of average sodium intake is in processed foods • Only 10% is added at the table or in cooking Institute of Medicine, 2003

13. Av. Sodium Intake* (mg/day)of Canadian Adults 4000 3500 3000 2500 2000 1500 1000 500 0 20-39yr 40-59 60 yr + yr Men Women M&W *Does not include sodium added at the table or during home cooking Ref: Canadian Community Health Survey, Nutrition Survey

14. Most of the sodium in our diet comes from processed food! 12% 11% 77% • 12% natural content of foods • “Hidden“ sodium: 77% from processing of food -manufacturing and restaurants • “Conscious“ sodium: 11% added at the table (5%) and in cooking (6%) J Am College of Nutrition 1991;10:383-93

15. Sources of sodium from "processed food“in Canada % of all sodium intake Health Reports, Vol. 18, No 2, May 2007

16. 4 2 0 -2 Change in Systolic Blood Pressure (mmHg) -4 Normotensives -6 -8 Hypertensives -10 -12 -130 -50 -70 -90 -110 -30 Change in Urinary Sodium (mmol/24h) Lower sodium reduces SBP Meta-analysis Results: He FJ, MacGregor GA. a meta-analysis of randomized trials. Implications for public health. J Hum Hyptens 2002;16:761-770

17. Sodium: Meta-analyses The Cochrane Library 2006;3:1-41

18. Health care cost savings in Canadaby reducing dietary sodium Using the Cochrane review data: a reduction in average dietary sodium intake by 1800 mg/d (from 3500 mg to 1700 mg in Can.) would result in: • 1 million fewer hypertensive Canadians • Almost double the BP treatment and control rate • Hypertension care cost savings of $430 to 538 million /yr Can J Cardiol 2007;23:437-443

19. Impact of reducing BP through dietary sodium in Canada Modelling Results: Annual Reduction in incidence of Myocardial infarction (5%) Strokes (13%) Heart Failure (17%) Reduction in health care costs associated with the overall predicted 8.6% reduction CVD $1.7 billion per year (1998 costs) Can J Cardiol. 2008;24:497-501

20. Observed effect of lower sodium intake on cardiovascular events in Trials of Hypertension Prevention (TOHP trials) • 25-30% lower risk of cardiovascular events in those who had been in the low sodium groups (pre-hypertensive patients) • 759-1012 mg/day reduction in dietary sodium during intervention BMJ 2007;334:885-92

21. Success storiesfor reducing dietary sodium • Finland (1970) • UK (1996) • Food Standard Agency • CASH – Consensus action on salt and health • WASH (2005) –World Action on Salt and Health

22. Changes in DBP, sodium intake and stroke deaths in Finland 5600 mg 5600 mg 3360 mg 3360 mg DBP Stroke Sodium Karppanen H et al Progress, Cardiovascular Disease 2006;49:59-75

23. Global initiatives Success of World Action on Salt and Health (WASH) raising public, political and manufacturers’ awareness. WHO’s statement on “Reducing salt intake in populations”. Major global food and beverage manufacturers agreed to cut salt in their foods products. World Hypertension Day 2009. Theme: “Salt and Hypertension” – a massive global public health campaign to reduce dietary salt through a variety of initiatives including food sector and other stakeholders’ participation.

24. In summary • Lower sodium consumption decreases blood pressure • Lower sodium consumption decreases hypertension-related complication rates

25. Key messages • Sodium is an important contributor to high blood pressure • Reducing sodium reduces blood pressure and prevents cardiovascular disease • Canadian sodium intake is higher than the recommended levels for health • Policies to reduce population sodium intake can be effective

26. Where can I get resources? • www.sodium101.ca • Hypertension website • www.hypertension.ca • Dial a dietitian • www.dialadietitian.org • Dietitians of Canada • www.dietitians.ca • Consensus Action on Salt & Health (CASH) • www.actiononsalt.org.uk • World Action on Salt &Health (WASH) • www.worldactiononsalt.com/ • World Health Organization (WHO) • www.who.int/dietphysicalactivity/reducingsalt/en