Trends and Prevalence of Hypertension

1
The Health Effects of Sodium
Lawrence J Appel, MD, MPH Professor of Medicine,
Epidemiology and International Health (Human
Nutrition) Johns Hopkins University School of
Medicine and Bloomberg School of Public
Health Feb 19, 2009
2
Forms of Sodium

• 90 of sodium consumed as sodium chloride (salt)
• Other forms
• sodium bicarbonate
• sodium in processed foods, such as sodium
  glutamate, sodium benzoate, sodium phosphate

3
Useful Conversions
4
Adverse Effects ofExcess Salt Intake

• Established relationship
• Increased blood pressure
• Probable relationship
• Gastric cancer
• Suggestive relationship
• Increased risk of osteoporosis
• Increased left ventricular mass
• Hypothesized relationship
• Overweight/obesity

? CVD and Stroke
5
Salt and Stomach Cancer Ecological Analysis
190
KOR
170
r0.702
150
Plt0.001
130
Deaths from Stomach Cancer (per 100,000 Per year)
JAPAN
110
CHI
90
POL
POR
COL
70
HUN
GDR
ITA
50
SPA
FIN
N.I
FRG
NET
ICE
MAL
30
TOB
BEL
E.W
CAN
ARG
DEN
MEX
10
USA
0
6
7
8
9
10
11
12
13
14
Salt Intake (grams/day)
Adapted from Joossens, Int J Epi 199625494-504
6
Magnitude of BP ProblemPopulation Perspective

• Worldwide, cardiovascular disease (heart disease
  and stroke) is the leading cause of death
• 62 of strokes and 49 of CHD events attributed
  to elevated BP
• 26 of adults worldwide (972 million) have
  hypertension

WHO, World Health Report 2002 Reducing Risks,
Promoting Healthy Life, Kearney Lancet
2005305217
7
Magnitude of BP ProblemIndividual Perspective

• The lower your blood pressure, the lower your
  risk of cardiovascular disease (even if you do
  not have hypertension)
• Your lifetime risk of developing hypertension is
  90

Vasan, JAMA 20022871003
8
Leading Causes of Death, Worldwide in 2002
Cardiovascular diseases
Infectious and parasitic diseases
Cancer
Respiratory infections
Respiratory diseases
Unintentional injuries
Perinatal conditions
Digestive diseases
Intentional injuries
Neuropsychiatric conditions
Diabetes mellitus
Genitourinary diseases
Maternal conditions
Congenital anomalies
Nutritional deficiencies
Others
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
Number of deaths (x1000)
9
Major Underlying Factors causing Death - Worldwide
Raised Blood Pressure
7 million
Tobacco
High cholesterol
Underweight
Unsafe sex
Low fruit vegetables intake
High BMI
Developed region
Physical inactivity
Developing region
Alcohol
Unsafe water, sani hygiene
0
1
2
3
4
5
6
7
Millions of Deaths
Ezzati et al. Lancet 20023601347-60.
10
Blood Pressure Classification
11
Stroke Mortality by Level of Usual Systolic BP
Definition of Hypertension
Source Prospective Studies Collaboration,
Lancet, 2002 Meta-analysis of 61 prospective
studies with 2.7m person-yrs, 11.9k deaths
12
Distribution of BP Levels in US Adults, Ages 18
and Older (NHANESIII)
Prehypertension SBP 120-39 or DBP 80-89
Normal lt120/80
31
27
42
Hypertension SBP gt 140 or DBP gt 90
Source Wang, Hypertension, 2004
13
Mean SBP and DBP by Age and Race/Ethnicity for
Women, Age 18 Years and Older
150
140
130
Systolic
120
110
SBP Rise with Age 0.6 mmHg per year
mm Hg
100
90
Diastolic
80
70
18-29
30-39
40-49
50-59
60-69
70-79
80
Age
Source Burt V, et al. Hypertension, 1995
14
Prevalence of High Blood Pressure by Age and
Race/Ethnicity, Women, Age 18 and Older
100
Blacks
90
Whites
80
Mexican Americans
70
60
Percent
50
40
30
20
10
0
18-29
30-39
40-49
50-59
60-69
70-79
80
Age Group
Source Burt V, et al. Hypertension, 1995
15
Blood Pressure Trends in Children and
Adolescents, Ages 8-17 years
Source Comparison of NHANES III (1988-1994) and
NHANES 1999-2000, Muntner, JAMA 2004
16
Trends in Prevalence of Hypertension in Older US
Adults, by Age and Ethnicity
Source Comparison of NHANES III (1988-1994) and
NHANES 1999-2004 Ostchega , Am Ger Soc 2007
17
Types of Evidence Relating Salt Intake to Blood
Pressure
18
SBP Slope with Age (mmHg/yr) by Median Na
Excretion in 52 Communities Worldwide
0 1,150 2,300
3,450 4,600 5,750
INTERSALT BMJ 1988297319
19
Effect of Reduced Sodium Intake on Blood Pressure

• gt 50 trials of sodium reduction on blood pressure
• 10 dose response trials
• 3 trials of sodium reduction as a means to
  prevent hypertension

20
Sodium Dose Response Trials
Luft, 1979 (14 non-hypertensive)
21
Sodium Dose Response Trials
MacGregor, 1989 (20 hypertensive)
22
Sodium Dose Response Trials
Johnson, 2001 (n17 non-hypertensive elderly)
23
Sodium Dose Response Trials
Johnson, 2001 (n15 elderly with isolated
systolic hypertension)
24
Sodium Dose Response Trials
Johnson, 2001 (n8 elderly with
systolic-diastolic hypertension)
25
Sodium Dose Response Trials DASH-Sodium Trial
Control Diet
2.1
6.7 plt.0001
4.6
Systolic Blood Pressure
3.0 Plt.0001
1.3
DASH Diet
1.7
1.5 (65) 2.4 (106) 3.3 (143)
Sodium Level gm/d (mmol) per day
Sacks, 2001 (412 prehypertensive and
hypertensive adults)
26
Population-Based Strategy SBP Distributions
Before Intervention
Reduction in Mortality
Stroke CHD Total -6 -4 -3 -8 -5 -4 -14 -9 -7
Stamler R. Hypertension 199117I-16I-20.
27
Predicted Benefits of Reducing Sodium on Stroke
and Heart Attack Deaths

• Reducing sodium by 400 mg/day would reduce
• ? strokes by 5
• ? heart attacks by 3
• Reducing sodium by 2,400 mg/day would reduce
• ? strokes by 24
• ? heart attacks by 18

Hypertension 2003421093-99
28
Effects of Reduced Na on CVD Events Results
from 3 Randomized Trials
1Appel, Arch Int Med, 2001 2Chang, AJCN, 2006
3Cook, BMJ, 2007
29
Effects of Reduced Na Intake on CVD Longterm
Results from the TOHP Follow-Up Study (Cook et
al, BMJ, 2007)
30
Issues Related to Salt Intake

• How much salt do we need?
• How much salt do we consume?
• Where does it come from?
• Does salt intake vary by weight status?

31
Obligatory Losses of Sodium
32
Sodium Recommendations from IOM Report

• Upper Limit (UL)
• 2.3 g (100 mmol)/day for adults
• Adequate Intake (AI)
• 1.5 g (65 mmol)/day for adults

33
(No Transcript)
34
(No Transcript)
35
Sources of Dietary Sodium
(62 adults who completed 7 day dietary records)
Inherent 12
Food Processing 77
At the Table 6
During Cooking 5
Mattes and Donnelly, JACN, 1991 10 383
36
Sodium Intake (Na) by Body Mass Index (BMI)
as estimated from 24 Hour Urinary Sodium
Excretion, Unpublished Data, PREMIER
37
Other Issues

• Health Benefits of Reducing of Salt Intake in
  Children and Young Adults
• Opportunities to Reduce Racial Disparities in
  Blood Pressure
• Salt sensitivity
• Need for a population-based approach

38
Mean Systolic and Diastolic BP
Yanomami, ages 20-59 Men Women
U.S. Children, ages 1- 17
SBP Rise with Age boys 1.9 mmHg / yr girls
1.5 mmHg / yr
? (101)
? (91)
Systolic
? (65)
? (56)
Diastolic
20 - 59
Age (yrs)
Age (yrs)
Pediatrics, 2004114555-576 (for 50th
Percentile Height) J Human HTN, 1989, 3331-407
39
Effects of Sodium Reduction in Children Results
of a Meta-Analysis

• 10 Trials
• 966 Children
• Mean age14
• Median duration 20wk
• 42 Reduction in Na

He and MacGregor, HTN 2006
40
Blood Pressure Measured in Adolescence and Young
Adults is Associated with Subsequent
Cardiovascular Disease
1Pathologic Determinants of Atherosclerosis in
Youth (PDAY) 2Coronary Artery Risk Development in
Young Adults (CARDIA), Muscatine Study 3Harvard,
U.Penn, and U.Glasgow Alumni Studies
1Pathologic Determinants of Atherosclerosis in
Youth (PDAY) 2Coronary Artery Risk Development in
Young Adults (CARDIA), Muscatine Study 3Harvard,
U.Penn, and U.Glasgow Alumni Studies
41
Opportunity to Reduce Racial Disparities in BP
Greater Effects of Sodium Reduction in
African-Americans
African-Americans
Non-African-Americans
- 2.2 Plt.001
- 4.5 Plt.001
- 5.1 Plt.001
- 8.0 Plt.001
0 P-interaction lt 0.05
Vollmer, Ann Int Med 2001
42
Factors Associated with Increased Salt Sensitivity

• Fixed factors
• African-Americans
• Middle and older-aged persons
• Genetic Factors
• Individuals with
• Hypertension
• Diabetes
• Chronic Renal Insufficiency
• Modifiable
• Low potassium intake
• Poor quality diet

43
Salt Sensitivity

• Possible to identify groups that have greater
  response to sodium reduction, BUT
• Tremendous variability within group
• Impossible to identify salt sensitive
  individuals
• Irrelevant as a public health concept given the
  vast scope of the blood pressure and
  cardiovascular disease epidemics

44
Sodium Reduction Stands Apart As An Effective
Public Health Intervention

• Principal cause of elevated blood pressure
• Amenable to intervention without substantial
• Behavioral change
• Massive educational campaign
• Low cost to implement

45
Summary

• Worldwide, elevated blood pressure is the leading
  cause of mortality
• A reduced salt intake lowers blood pressure
• The estimated benefits of salt reduction are
  substantial and warrant major public health
  efforts to reduce salt intake

46
Sodium Reduction is Now Chic !

• Song Amazing
• Artist Kanye West
• Im amazing, yeah Im all that
• Victorious, yeah we warriors
• We make history, strive for victory
• Standing at my podium, Im trying to watch my
  sodium
• Die high blood pressure either let the feds catch
  ya