Transcript Lecture Two

I.
II.
OST 524
Diet and Hypertension
(www.msu.edu/course/hnf/470)
NHLBI Joint National Commission VI
Treatment Guidelines (www.nhlbi.nih.gov)
Non-pharmacologic therapies in HTN trt
III. Dietary approaches to the trt of HTN
IV.
DASH trial: results and implications
V.
Implications of National Dietary Guidance
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Summary points
(Ramsay LE et al. BMJ 1999: 319: 630-635)
Use non-pharmacological measures in all hypertensive and
borderline hypertensive people
Initiate antihypertensive drug treatment in people with sustained
systolic blood pressure 160 mm Hg or sustained diastolic blood
pressure 100 mm Hg
Decide on treatment in people with sustained systolic blood
pressure according to the presence or absence of:
target organ damage, cardiovascular disease, diabetes, or a
10 year coronary heart disease risk of 15% according to the
Joint British Societies coronary heart disease risk assessment
programme or risk chart
Good evidence from trials shows that several lifestyle
modifications lower blood pressure:
•
weight reduction to achieve an ideal body weight
via reduced fat and total calorie intake;
•
regular physical exercise designed to improve
fitness; this should be predominantly dynamic
(brisk walking, for example) rather than
isometric (weight training);
•
limiting alcohol consumption to <21 units per
week for men and <14 units per week for women;
• reduced use of salt when preparing food and
elimination of excessively salty foods from the diet;
• increased consumption of fruit and vegetables.
Lifestyle modifications that further reduce
cardiovascular disease risk are:
stopping smoking;
reducing total intake of saturated fat,
replacing it with PUFA or MUFA fats;
increased intake of oily fish;
regular physical exercise.
Non-pharmacological advice should be offered to all
hypertensive people and those with a strong family
history of hypertension.
Such measures may obviate the need for drug
treatment or reduce the dose or number of drugs
required to control blood pressure.
When drug treatment has to be introduced
more quickly, non-pharmacological measures
should be instituted in parallel with drug treatment.
A philosophical paradigm in which one attempts to explain
complex phenomena using relatively simple principles.
Dietary Patterns and Mortality Studies
•
Assess effect of specific dietary patterns in
longitudinal studies on subsequent mortality.
•
Patterns used include:
Mediterranean:
W.H.O.:
High vs. Low
High MUFA: SFA ratio
Moderate ethanol consumption
High consump. legumes/cereals/
Low consump. meat/dairy products
PUFA/SFA (g)
Fruit/vegetable
Pulses/nuts/seeds
Dietary Fiber
Protein
Results
Mediterranean Dietary Pattern and Survival in the Elderly
(Trichopoulou et al. (1995) BMJ 311: 1457-60)
•
In an elderly rural Greek cohort, total diet score was used
as a predictor of hazard of death.
•
No individual dietary component was independently
associated with decreased risk of death .
•
A one unit increase in diet score was associated with
a significant 17% reduction in overall mortality (95% CI
1-31%).
Results
W.H.O. Dietary Pattern and Mortality in Elderly Men
(Huifbregts et al. (1997) BMJ 315: 13-17)
•
In 3 elderly cohorts (Finland, Netherlands, and Italy),
healthy diet indicator score was used as a predictor
of hazard of death after 20 years of followup..
•
No individual dietary component was independently
associated with decreased risk of death .
•
Healthy diet indicator score was inversely associated
with mortality (p for trend <0.05). Relative risk in
healthiest vs. least healthy score= 0.87 (95% CI:
0.77-0.98)
Assessment of Obesity
Body Mass Index
Waist Circumference
Weight (kg) / Height (m)2
Weight (lbs) X 703
Height Squared (in 2)
Underweight
Normal
Overweight
Obese
Morbid Obesity
Good Estimate of
Central Adiposity
Men:
Women:
< 18
18-24
25-29
> 30
> 40
40”
35”
Weight Gain since age 18
Level of Fitness
Bjorntorp P. Obesity. Lancet 350: 423-426, 1997
The Obesity Epidemic
• U.S.: 20% of men & 25% of women are obese.
• 97 million Americans are overweight or obese.
(59.4% of men and 51% of women)
• >10% of 4-5 year old children are obese.
– ~2-fold increase over preceding decade
These increases have occurred despite successes in reducing
dietary fat as % of kcal.
Source: NCHS, National Health and Nutrition Examination Survey,1997
Kuczmarski et al. National Health and Nutrition Examination Surveys,
MMWR; 43: 818-821,1994.
Consequences of Modest Weight
Gain
10% increase in weight results in:
Fasting Blood Glucose of 2-3 mg/dL
Systolic Blood Pressure of 6-7 mm Hg
Conditions Associated With Obesity
(Relative Risk)
Diabetes Mellitus
(Type II)
(RR>>3)
Stroke
(RR= 2-3)
Gall Bladder Disease
(RR>>3)
Obesity
Coronary Heart Disease Gout
(RR= 2-3)
(RR=2-3)
Sleep Apnea
(RR>>3)
Hypertension
(RR>>3)
Osteoarthritis
(RR=2-3)
Upper Body Fat Distribution Increases
Metabolic Complications
Central or Visceral Adiposity vs.
Excess central or abdominal fat
is an independent predictor of
disease risk.
Visceral fat is more metabolically
active.
Highly susceptible to Syndrome X.
Subcutaneous Adiposity
Minimal risk associated
with lower body obesity.
Insulin Resistance
Hyperinsulinemia
HDL Cholesterol
SYNDROME X
VLDL
Cholesterol
Hypertriglyceridemia
Hypertension
Glucose
Intolerance
DEADLY QUARTET
Android Obesity
Zemel M. 1998. National Conference on Obesity and Co-morbidities,
Ft. Myers, FL.
Lipoprotein Lipase
Leptin
PAI-1
IL-6
Adipsin
(Complement D)
Lactate
Serum Free Fatty Acids
Angiotensinogen
Benefits of Modest Weight Loss
• Normalizes high blood pressure
• Blood levels
•
•
•
•
•
LDL cholesterol
Insulin
Glycated hemoglobin (HbA1C)
Blood glucose
Uric acid
•
HDL Cholesterol
• Improved Quality of Life
Controlling Blood Pressure: Approaches and Hypotheses
•
Since only 47% of Americans have optimal BP, the
demographics of aging and its effect of BP are of concern.
•
National guidelines suggest NaCl intakes, reduced alcohol
consumption, K consumption (?), and WEIGHT CONTROL.
•
What about non-pharmacologic approaches? Hints-*Replacing animal products with vegetable products
BP
*High mineral content (K, Mg), fiber and fat may contribute?
*Observational studies indicate inverse associations of BP with:
Mg, K, Ca, fiber, and protein in foods
Trial Participants:
459 adults of which 133 had stage I HTN
(B.P. 140-159/90-99)
49% women; 60% African-American
Acclimation Diet:
Low fruits (F), vegetables (V), dairy products
~40% fat for 3 weeks
The Diets:
Duration:
1.
2.
3.
Control Diet: average for fat, F&V consumption
8-10 servings of F&V, ~35+% fat
Low-fat (<30% kcal), 8-10 servings of F&V,
Rich in low-fat dairy foods.
8 weeks
New Engl J Med (1997) 336: 1117-1124
Nutrient
Control
K (mg)
1700
4700
Mg (mg)
185
500
Ca (mg)
450
450
Fiber (g)
9
Na (g)
Total Fat
(% of kcal)
3-3.5
V&F
31
3-3.5
36
Combo
4700
500
1240
31
3-3.5
36
26
Source: http://dash.bwh.harvard.edu/
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DASH Comments
B.P. reductions occurred quickly (2
weeks) and were maintained throughout the
study.
Investigators estimated that incidence of CHD
and strokes in U.S. could be reduced by 15%
and 27%, respectively, if DASH diet were
followed.
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Dietary Guidelines 2000 (Proposed)
Aim, Build, Choose--for Good Health
Aim for Fitness
Build a Healthy Base
Choose Sensibly
Dietary Guidelines 2000 (proposed)
Aim
1.
2.
Aim for a healthy weight.
Be physically active each day.
Build
3.
4.
Let the Pyramid guide your choices.
Choose a variety of grains daily,
especially whole grains.
Choose a variety of fruits and
vegetables daily.
Keep food safe to eat.
5.
6.
Choose Sensibly
7.
8.
9.
10.
Choose a diet that is low in saturated
fat and cholesterol and moderate
in total fat.
Choose beverages and foods that limit
your intake of sugars.
Choose and prepare foods with less
salt.
If you drink alcoholic beverages, do
so in moderation.