Lifestyle Modification as a Prescription for Hypertension : Dietary counselling, weight reduction

Transcription

1 Lifestyle Modification as a Prescription for Hypertension : Dietary counselling, weight reduction Luc Trudeau, md Cardiovascular Prevention Centre Jewish General Hospital Assistant-Professor of Medicine McGill University Montreal, Quebec 1

2 Disclosures No conflict of interest for this talk

3 Renal mechanisms for sodium-dependent hypertension Acute high sodium intake - Renal retention of fluid BP Chronic high sodium intake - Resets renal threshold for sodium excretion less sodium excretion - Peripheral resistance - Subnormal vasodilation to sodium load Nat. Med :64 3

4 Factors that lead to sodium- sensitivity of blood pressure Intrauterine growth retardation (IUGR) Low nephron mass Renal disease Inflammation, injury, etc Genetic abnormalities Exogenous agents Ageing sodium excretion 4

5 High sodium intake increases risk of hypertension-related complications Hazard Ratio CHD Death * CVD Death * All Death * High sodium intake Lower sodium intake 0.75 * p He FJ, MacGregor GA. a meta-analysis of randomized trials. Implications for public health. J Hum Hypertens 2002;16:

6 Sodium Reduction for the Treatment of Hypertension Sodium substitution: a low-cost strategy for blood pressure control among rural Chinese: A randomized, controlled trial RCT of 12 months; n = 608 Sodium Substitute (65% NaCl, 25% KCl, 10% MgSO4) compared to normal salt (100% NaCl) Mean age = 60; 56% ; Mean BP = 159/93 Mean SBP drop = 3.7 mm Hg (p 0.001) No difference in DBP J Hypertension 2007, 25 (10) 6

7 Sodium Reduction for the Treatment of Hypertension No difference in groups for food taste (saltiness) J Hypertension 2007, 25 (10) 7

8 Salt Reduction for the Treatment of Hypertension Effect of no added salt on BP control and 24-hr urinary sodium excretion in mild to moderate HTN RCT of 6 weeks; n = 80 (60 cases; 20 controls) Na intake < 2.4 grams / 24 hours < urinary sodium 100 meq / 24 hours 24-hour ABPM done before and after Mean daytime = 12.1 / 6.8 mm Hg (p = 0.001) Mean nightime = 11.1 / 5.9 mm Hg (p = 0.01) Only 36 % reached < urinary sodium 100 meq / 24 hours BMC Cardiov Dis, Nov 2007

9 Effects of Dietary Sodium Reduction on Blood Pressure in Subjects with Resistant Hypertension. Results from a Randomized Trial One week of 50 mmol/d Outcome Mean office SBP Mean office DBP Daytime SBP Daytime DBP BP mmhg mmhg mmhg mmhg Pimenta, Hypertension 2009

10 Can Salt Reduction in Hypertension Prevent CV Events? Salt reduction in a Veteran Retirement Home Randomised control trial; 1981 subjects 768 experimental and 1213 control Salt alternative (49% NaCl and 49% KCl) compared to regular sodium chloride Average F/U 31 months CVD-related deaths: 13.1 / 1000 in salt substitute Am J Clin Nutr, 2006; / 1000 in control

11 Relative risk of cardiovascular disease overall in TOHP I and TOHP II Group Salt intervention (%) Control (%) Hazard ratio (95% CI) CVD*, overall CVD, TOHP I CVD, TOHP II ( ) ( ) ( ) *Cardiovascular disease is a composite of MI, stroke, revascularization, or death due to cardiovascular causes Cook NR et al. BMJ 2007; available at:

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

13 "Hidden" sodium intake of Canadian adults Adults 20 to to 59 >60 Men 20 to to 59 >60 Women 20 to to 59 Age Group (years) Average daily sodium intake (mg) 3,370 3,128 2,688 3,906 3,544 3,039 2,845 2,700 >60 2,398 Underestimate of 10-20% as based on questionnaire and does not include sodium added in cooking or at the table Health Reports, Vol. 18, No 2, May

14 Dietary Reference Intakes-Sodium (DRIs) Published in the 2004 electrolyte report (water, potassium, sodium, chloride and sulfate) DRIs were set based on the effects of sodium on raising BP Adequate Intake (AI) = recommended daily intake. There are no health benefits above the AI Tolerable Upper Intake Level (UL) = highest average daily intake level likely to pose no risk of adverse effects, for nearly everyone. This is not a target. Individuals should not routinely exceed the UL 14

15 Recommended Dietary Reference Intakes of Sodium by Age Group Age group (years) Adequate Intake (AI) (mg/day) Upper Level (UL) (mg/day) > AI: Adequate Intake UL: Upper Level 15

16 The sodium intake of most Canadians adults exceeds the UL 100 % above UL Male Female to to to or older Upper Limit Health Reports, Vol. 18, No 2, May

17 Most of the sodium in our diet comes from processed food! 77% 12% 11% Natural content of foods "Conscious" sodium "Hidden" sodium 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:

18 Sources of sodium from "processed food in Canada Sauces Beef Cereals Cheese Potatoes Poultry and pultry disches Liquid milk and milk-based beverages Pasta Soups Pizzas, sandw iches, submarines, Hamburgers and hot dogs % of all sodium intake Health Reports, Vol. 18, No 2, May

19 Example of typical meals eaten outside of the home vs. Dietary Reference Intakes Type of eating establishment Fast Foodburger-type Donut shop Submarine Description of meal Hamburger, medium fries (without added salt), small chocolate milkshake Hot chocolate and muffin variety of muffins Variety of fillings 6 inch sandwich Approximate Sodium content (mg) % Adequate Intake year olds (1300 mg/day) % Adequate Intake 9-50 year olds (1500 mg/day) 1210 mg 93 % 81 % 890 mg mg 1010 mg 1660 mg 68% - 90% 59 % - 78 % 78% - 128% 67 % - 111% 19 19

20 Sodium: Meta-analyses Average Reduction of sodium in mg/day 1800 mg/day Hypertensives Reduction of BP 5.1 / 2.7 mmhg 2300 mg/day 7.2/3.8 mmhg Average Reduction of sodium in mg/day 1700 mg/day Normotensives Reduction of BP 2.0 / 1.0 mmhg 2300 mg/day 3.6/1.7 mmhg The Cochrane Library 2006;3: Canadian Hypertension Education Program Recommendations 20

21 Potential Benefits of a Wide Spread Reduction in Dietary Sodium in Canada REDUCTION IN AVERAGE DIETARY SODIUM FROM ABOUT 3500 MG TO 1700 MG 1 million fewer hypertensives 5 million fewer physicians visits a year for hypertension Health care cost savings of $430 to 540 million per year related to fewer office visits, drugs and laboratory costs for hypertension Improvement of the hypertension treatment and control rate 13% reduction in CVD Total health care cost savings of over $1.3 billion/year Penz ED, Cdn J Cardiol Canadian Hypertension Education Program Recommendations Joffres MR_CJC_ 23(6)

22 Recommendations for daily salt intake Age 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 2010 Canadian Hypertension Education Program Recommendations Recommended Intake and over 1200 Institute of Medicine,

23 NEJM, 2001 DASH diet

24 2010 Processing Adds Sodium To Food Natural Food Sodium (mg) Processed Food Sodium (mg) Plain pasta 5 Pasta & sauce 800 Cucumber 2 Dill Pickle 385 Fresh salmon 56 Canned salmon 272 Cheddar cheese 176 Processed cheese 407 Coffee milk & sugar 15 Cappuccino from mix 250 Hypertension Canada 24

25 2010 Breakfast Menu Makeover Menu 1, Higher Sodium Sodium (mg) CFG Menu+ Lower Sodium Sodium (mg) Commercial raisin bran muffin large Butter 2 pats Multigrain bread 2 slices Peanut butter 1 Tbsp Flavoured coffee 16 oz. 300 Banana Coffee with 2oz 1% milk Total Hypertension Canada 25

26 2010 Dinner Menu Makeover MENU 1 + Higher Sodium Sodium (mg) CFG MENU + Lower Sodium Sodium (mg) Fast food chicken burger Medium french fries Grilled chicken breast 75g Baked potato Plain Yogourt 1 Tbsp Ketchup 1 Tbsp. Milkshake 16 oz Tomato slices 6 Steamed broccoli 1 cup Canned peaches- 1/2 cup Milk 1% 8 oz Total Hypertension Canada 26

27 Obesity Increases Blood Pressure Mechanisms: - circulating volume - insulin level - SNS activity

28 Meta-analysis (25 randomised studies) : effects of weight reduction on blood pressure n = 4874 SBP = 4.44 mm Hg 1 kg = 1.05 SBP 0.92 DBP DBP = 3.57 mm Hg Neter, J. E. et al. Hypertension 2003;42: Copyright 2003 American Heart Association

29 Meta-analysis (8 studies): mean differences on weight and DBP + SBP with a follow-up of at least 2 years n =? Aucott, L. et al. Hypertension 2009;54: Copyright 2009 American Heart Association

30 How to Obtain a Weight Reduction: Effect of the DASH Diet Alone and in Combination with Exercise and Weight Loss on Blood Pressure HTN obese/overweight subjects; 4 month duration - 3 groups: usual diet, DASH alone, DASH + weight reduction + physical activity - WR: 500 cal/d deficit; predicted loss = 0.5 kg/week - PA: 30 min. 3/week at 70-85% HR reserve Results : kg (usual); 0.3 kg (DASH alone) kg (DASH + WR + PA) - SBP: 3.4, 11.2, 16.1 mmhg - DBP: 3.8, 7.5, 9.9 mmhg Arch Ann Med, 170 (2), 2010

31 Sodium Reduction and Weight Loss in the Treatment of Hypertension in Older Persons: A Randomized Controlled Trial of Nonpharmacologic Interventions in the Elderly (TONE) JAMA. 1998;279:

32 Conclusion - Decreasing salt intake lowers blood pressure in both normotensives and hypertensives - Less salt can prevent hypertension and is part of the treatment in established hypertension - RCT s and population action have shown an impact on the incidence of CV events - Losing weight in high BMI patients can reduce blood pressure; better with physical activity - Adherence to both strategies is a concern - A multi-disciplinary approach (nutritionist, kinesiologist, nurse) is needed