Transcript Dietary salt, water, diuretics, hypotensive drugs

Hypertension, Diet and Dietary Sodium in
Canada.
Why is sodium reduction Controversial?
Norm Campbell
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Financial interests in sodium
• Salary support from HSF-CIHR to lead efforts to prevent and
control hypertension
• Only recent salt based grant was a $25,000 one year grant
(2012-2013) from the NCE Canadian Stroke Network to
develop and implement a weekly med-line search and review
on dietary salt
• I have received $750 to talk on unhealthy eating from a
Internal Medicine meeting in 2013
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Academic interests
Professor of Medicine, Community Health Sciences and
Physiology and Pharmacology, Libin Cardiovascular Institute,
O’Brien Institute of Public Health at the University of Calgary
-HSFC CIHR Chair in Hypertension Prevention and Control
-Chair of the Canadian Hypertension Advisory Committee (of
national health and scientific organizations) to lead the
nongovernmental effort to prevent and control hypertension
-President of the World Hypertension League
-Co-Chair of the PAHO/WHO Technical Advisory Group on
Cardiovascular Disease Prevention through Dietary Salt
Reduction
-Member of the WHO Nutrition Advisory Group
Focus on salt was based on assessment of evidence of benefit.
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HSFC CIHR Chair in Hypertension
Prevention and control
Mandate 2011-2016 to align government and non
governmental organizations on a Pan Canadian
Hypertension Framework vision and objectives.
– Develop a systematic approach and committee
structure for the health care sector to successfully
advocate for policy changes to reduce blood
pressure in the Canadian population.
– Aligning Canadian public health food policy with
global best practices.
Systolic blood pressure
greater than 115 mmHg
Figure obtained by cropping a downloaded figure from http://www.healthdata.org July 8 2014,
Burden of hypertension in Canada
• 7.4 million adult Canadians with hypertension
• In 2007/8 1100 Canadians a day were diagnosed with hypertension
• > 90% of us are estimated to develop hypertension in a average
lifespan
• Antihypertensive drug costs of 3 billion dollars/year
• Almost half of all people in Canada over age 60 are taking drugs to control
blood pressure
• 20-25 million physicians visits for hypertension/year
• Direct health care costs approximately 10% of overall health costs
• Societal burden (including indirect costs) are estimated to be 4.5
to 15% of GDP in high income countries
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Attributable Risk of Lifestyle to Hypertension
Risk factor
Increased salt in diet
Approximate attributable
risk for hypertension
32%
Decreased potassium in diet
17%
Overweight
32%
Sedentary lifestyle
17%
Excess alcohol
3%
Dietary fats
?%
The past and current situation
for hypertension in Canada
2007 / 2008
16%
CHHS 1985-1992
4%
14%
No 13%
impact on prevalence
No
impact
of
lifestyle
21%
43%
66%
Treated and BP controlled
22%
Treated and BP not controlled
Aware and BP not treated
Not Aware
CHMS: Canadian Heart Health Survey
CHMS: Canadian Health Measures Survey
Wilkins et al. Health Reports Feb 2010
Pan Canadian Hypertension Framework
An opportunity to discuss
how to improve the
prevention and control of
hypertension in Canada
2011-2020
Canadian Hypertension Advisory Committee
 Committee structure formed
to support HSF/CIHR Chair
mandate
 Comprised of 15 national
organizations to
advance/operationalize
Hypertension Framework
Canadian Hypertension Advisory
Committee Membership
Canadian Association of Cardiovascular Prevention
and Rehabilitation
Canadian Cardiovascular Society
Canadian Council of Cardiovascular Nurses
Canadian Diabetes Association
Canadian Medical Association
Canadian Nurses Association
Canadian Pharmacists Association
Canadian Society of Internal Medicine
Canadian Society of Nephrology
Canadian Stroke Network
College of Family Physicians of Canada
Heart and Stroke Foundation of Canada
Hypertension Canada
Public Health Physicians of Canada
Recommendation Priorities
Recommendation
1. Build Healthy Public Policy (1)
2.
Re-orient/redesign the health
services delivery system
Provincial Priority, Hypertension
Canada, C-CHANGE, Hypertension
experts
3. Build partnerships to create
supportive environments and evolve
the healthcare system (2)
4. Strengthen community action (3)
CHAMP Initiative
5. Develop personal skills for better
self-management
Hypertension Canada/HSF
6. Improve decision support (4)
7. Optimize information systems (5)
PHAC, Hypertension Canada and new
Chair priority
Priority Areas of Focus
Important &
Urgent
Policy Statement on
Marketing to Kids
Sodium Policy
& Advocacy
Healthy Food
in Canada
Healthy food
procurement
Standardized front of
package food labels that
contain health
connotations
Fiscal Policies
(Taxation/Subsidies)
Defining Healthy Food
Important but
less urgent
Reduce the impact of
financial interests on
healthy public food policies
Policy Positions
Highlights of recent national health and scientific
organizations actions on dietary sodium
2006: Blood Pressure Canada (BPC), a coalition of 27 organizations and the
Canadian Stroke Network prioritize actions to reduce dietary sodium
2006-8: BPC strategic planning committee formed
CSPI
2006-7: BPC policy
statement on dietary sodium endorsed by 17 national
health and scientific
organizations Canada
PHAC/Health
2007: Health and scientific organizations collaborate in Health Canada Sodium
PT’s
Working Group
Food
Processing
Industry
2007: Health and
scientific
organizations conduct
work on the impact of
dietary sodium on the health of Canadians
2007-: Extensive education programs for health care professionals and the
public- BPC, Hypertension Canada and Canadian Stroke Network
2011: Health and scientific organizations write public letter of concern to the
Prime Minister and all elected FPT officials regarding the Harper governments
lack of support for the Sodium Reduction Strategy for Canada created by SWG
2013: Strong national health and scientific organizations support for L Davies
parliamentary bill for sodium reduction
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WHO supports sodium reduction
• Internationally, in 2012, the World Health Organization
following an exhaustive and comprehensive review of the
clinical interventions and cohort studies of populations
• United Nations (independent national reviews, political and
based on advice of the WHO).
• All but 1 comprehensive scientific organization review.
• 31 of 31 surveyed national hypertension societies.
• Numerous scientific and health NGOs
• Global Burden of Disease Study estimated 1.65 million deaths
in 2010 from high dietary sodium/year.
- 486 authors from 302 institutions in 50 countries, indicated to be the
strongest evidence-based assessment of people’s health problems around
the world. WHO supported GATES funded.
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• There is no credible national or international
health or scientific organization, I am aware of
that has stated opposition to sodium
reduction to < 2400mg/day and most support
<2000mg/day. Canada’s upper limit of <2300
mg sodium/day is broadly supported within
the Canadian health and scientific community.
Hypertension Canada supports 2000 mg
sodium/day
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Who does not support sodium reduction
• The Salt Institute.
• Some of the food processing industry especially in the
United States.
• Several scientists and clinicians who have long
histories of close relationships with the salt or food
industries.
• A few dissident scientists most of whom have
personally performed research (usually with major
methodological weaknesses) that do not support
sodium reduction.
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Generating controversy
The studies that have created controversy are based on weak research
design
– Unreliable assessment of sodium intake (e.g. spot urine)
– Using extreme variation in dietary sodium over a duration of a few
days
– Do not address known confounding factors (explanations) for the
outcomes being tested,
– Control for blood pressure (the main mechanism of sodium induced
harm),
– Conducted in populations with diseases where reverse causality is
likely (i.e. sick people eat less and die more)
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Generating controversy
• Several controversial studies have been
conducted by consultants of the Salt Institute
(an umbrella organization of the salt industry)
• The results of the weak studies have been
highly leveraged into public attention by the
food and salt industries
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Sodium science
1) The use of weak methods indicate the need
for research standards to be set.
2) There is a need for a high quality RCT.
3) To me the enthusiastic claims to media that
sodium is not important for health based on
frail methods is endangering programs
designed to save millions of lives/year.
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Science of Salt Weekly
• Science of Salt Weekly is an initiative of the
(CIHR/HSFC) Chair in Hypertension
Prevention and Control.
• Funding for this 2-year initiative has been
provided by the Canadian Stroke
Network and the George Institute for
Global Health.
• This weekly newsletter features short
summaries of relevant Medline-retrieved
articles related to dietary sodium.
• To download issues or to sign-up for
automated email updates, visit:
http://www.hypertensiontalk.com
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Setting Research standards
• An international coalition of organizations
lead by the World Hypertension League is
forming to set research standards and
maintain regular systematic reviews of the
literature
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Some Best Global Practices to achieve the WHO
target (<5 g salt/day) and United Nations target
(30% decrease in dietary salt by 2025).
• Regulatory approaches that set targets and
timelines on sodium content of processed
foods (South Africa and Argentina)
• Voluntary approaches that set targets and
timelines on sodium content of processed
foods with close government oversight and
monitoring (Finland, England, Ireland, Brazil,
Chile (expected soon to be regulatory)
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Changes in DBP, salt intake and stroke
deaths in Finland
5600 mg
3360 mg
DBP
Salt
Stroke
Karppanen H et al Progress, Cardiovascular Disease 2006;49:59-75
Changes in CVD, blood pressure and salt
consumption in the England 2003-2011
Japan not well evaluated but reduced salt intake,
reduced population BP and reduced stroke
Sodium science:
• A substantive but incomplete evidence base
indicates the widespread addition of large amounts
of sodium to food is one of the largest public health
disasters of industrialization killing 1.65 million/yr. in
2010
• Current controversy is largely fueled by weak
research methods, and financial interests.
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