Transcript Dr Khanna HT(2)

DIETARY MODIFICATIONS IN
MANAGEMENT
OF HYPERTENSION
Dr Kumud Khanna
Head, Dept of Home Science,
University of Delhi
Director, Institute of Home Economics
HYPERTENSION
• Hypertension is a clinical syndrome
associated with significant metabolic
abnormalities, e.g. dysglycemia,
dyslipidemia, neurohormonal
abnormalities, sodium sensitivity and
endothelial dysfunction
• Epidemiologic data have
demonstrated that only 25%
hypertensive patients have their
blood pressure controlled adequately
• Aggressive blood pressure reduction
to prevent target organ damage and
reduce risk of cardiovascular events
is important
JNC VII, 2003 classification for adults aged 18 years
or older
Systolic BP(mmHg)
Normal
Prehypertension
Stage 1
Hypertension
Stage 2
Hypertension
<120
and
Diastolic
BP(mmHg)
<80
120-139 or
80-89
140-159 or
90-99
>160
or
> 100
Reduction in systolic blood pressure maybe even more important than reducing
diastolic pressure, at least for cardiovascular and renal protection
PREVALENCE OF HYPERTENSION IN
INDIA
•
•
•
•
2001 - 118 million
2025 - 214 million
Till early 1980s – prevalence 3 - 4%
Mid 1990s: urban areas 25 – 29%, rural areas 10 -13%
(ICMR, 1994)
Sentinel Surveillance Project, documented 28%
prevalence of hypertension (criteria: =JNC VI) from 10
regions of the country in the age group 20-69 years
Gupta (1994, 2001, 2003) through 3 serial
epidemiological studies (Criteria>=140/90 mm of Hg)
demonstrated rising prevalence of hypertension (30%,
36%, and 51% respectively among males and 34%, 38%
and 51% among females)
BENEFITS OF LOWERING BLOOD
PRESSURE
• Higher the BP, greater the
chance of myocardial
infarction, heart failure,
stroke and kidney disease
• For individuals 40-70 years,
20mm Hg increase in SBP
and 10mm Hg increase in
DBP doubles risk of CVD
• Antihypertensive therapy
associated with 35-40%
reduction in stroke, 20-25%
MI and more than 50%
heart failure incidence
Stamler, 1991
Goal of therapy 130/80 mm Hg
MANAGEMENT OF HYPERTENSION
Non pharmacologic interventions
• weight reduction
•regular aerobic exercise
• stress reduction
•diminishing alcohol consumption
•smoking cessation
•dietary modification -- specifically salt restriction
Lifestyle modification should be started as soon as possible
because with proper intervention, it may be possible to retard
the development of hypertension
LIFESTYLE MODIFICATION IS EFFECTIVE IN
REDUCING BLOOD PRESSURE
Elevated BP results from environmental factors, genetic factors, and
interactions among these factors
• Dietary factors have a prominent role in BP homeostasis
• Regular exercise 30 minutes, 4 times/ week, can result in a 5-10mm Hg
reduction in BP in hypertensive patients and up to 3mm Hg reduction in
BP of normal people. Additional benefits include weight reduction and
improvement in insulin sensitivity
• A small reduction in weight of 5 -10 kg can result in reduction of BP,
especially in patients with borderline hypertension
• There can be a 1-mm Hg reduction in blood pressure for each 1drink/day
reduction in alcohol consumption
•
The importance of smoking cessation is well established
Recommended Lifestyle Modifications and Their Individual
Effects on Blood Pressure
Modifications*
Reduce weight
Adopt DASH diet
Recommendation
Maintain normal body weight
(BMI of 18.524.9 kg/m2)
Rich in fruit, vegetables, and lowfat dairy; reduced saturated and
total fat content
Reduce dietary sodium
<100 mmol (2.4 g Na)/day
Increase physical
activity
Moderate alcohol
consumption
Aerobic activity >30 min/day most
days of the week
Men: ≤ 2 drinks/day
Women: ≤ 1 drink/day
Approximate
SBP Reduction
320 mm Hg
814 mm Hg
28 mm Hg
49 mm Hg
24 mm Hg
*Combining 2 or more of these modifications may or may not have an additive
effect on blood pressure reduction.
SBP = systolic blood pressure; BMI = body mass index; DASH = Dietary Approaches to Stop Hypertension
Chobanian AV, et al. JAMA. 2003;289:2560-2572;
Blumenthal JA, et al. Arch Intern Med. 2000;160:1947-1958.
Vegetarian Diets
Vegetarian diets have been associated with
low BP
• Individuals who consume a vegetarian diet
have markedly lower BP than nonvegetarians
• Vegetarians also experience a lower agerelated rise in BP
Decreasing Dietary Salt Intake Reduces Systolic Blood Pressure
Dietary Approaches to Stop Hypertension Trial
136
*
Systolic Blood
Pressure (mm Hg)
134
132
*
130
*
*
128
*
126
124
High-Salt
Diet†
1
2
3
Weeks on Low-Salt Diet‡
*Error bars represent standard deviation; †140 mmol/day; ‡62 mmol/day.
Reprinted from Obarzanek E, et al. Hypertension. 2003;42:
459-467, with permission from Lippincott Williams & Wilkins.
4
DASH study design tested three diets
-effects on BP
• Control diet - typical American diet
• Fruit and vegetable (F&V) diet - 8.5 servings
• Combination Diet -10serving of F & V, 2.7 serving low fat dairy
products/day
• Combination diet (5.5/3.0) reduced BP more than F&V
(2.8/1.1) or control diet
• DASH Advise – 8 servings of fruit and vegetables, 3 servings
low-fat dairy products and low fat diet
Gave evidence that possible to prevent and control
hypertension by diet
Effects of Diet on Blood Pressure
Dietary Approaches to Stop Hypertension Sodium Trial
Fruits-and- Vegetables
Diet
Control Diet
Diastolic Blood Pressure (mm Hg)
Systolic Blood Pressure (mm Hg)
132
130
128
126
124
122
88
86
84
82
80
78
0
1
2
3
4
5
6
7 8
Combination
Diet*
0
Week of Intervention
1
2
3
4
5
6
Week of Intervention
*Rich in fruits and vegetables, and rich in low-fat dairy products and low in saturated
and total fat. 0 = baseline.
Appel LJ, et al. N Engl J Med. 1997;336:1117-1124. Copyright © 1997, Massachusetts Medical
Society. All rights reserved.
7
8
Greater Restriction of Sodium Intake Lowers Diet-Reduced Blood
Pressure
Dietary Approaches to Stop Hypertension Sodium Trial
Systolic Blood Pressure (mm
Hg)
135
Control Diet
130
–5.9
(–8.0 to –3.7)†
–2.1
(–3.4 to –0.8)*
–4.6
(–5.9 to –3.2)†
–5.0
(–7.6 to –2.5)†
–2.2
(–4.4 to –0.1)†
DASH Diet
125
–1.3
(–2.6 to –0.0)†
–1.7
(–3.0 to –0.4)‡
120
150 mmol/day
100 mmol/day
50 mmol/day
Daily Dietary Sodium Content
*P < 0.05; †P < 0.011; ‡P < 0.01; ( ) denote 95% confidence interval.
DASH = Dietary Approaches to Stop Hypertension
Sacks FM, et al. N Engl J Med. 2001;344:3-10. Copyright © 2001, Massachusetts Medical
Society. All rights reserved.
Dietary Sodium Reduction Results in Greater Blood Pressure Reduction
in Older Than in Younger Adults*
Dietary Approaches to Stop Hypertension Sodium Trial
Patient Age Groups
Mean SBP
Reduction with
DASH Diet†
(mm Hg)
Mean SBP
Reduction with
American Diet†
(mm Hg)
23–41 years
1.0
4.8§
42–47 years
1.8‡
5.9§
48–54 years
4.3§
7.5§
55–76 years
6.0§
8.1§
*Patients were fed a 2,100 kcal diet containing either 150, 100 or 50 mmol sodium daily for 30 days while consuming either
the DASH diet or a typical American diet.
†These data reflect a reduction from the highest (150 mmol) to the lowest (50 mmol)
level of sodium.
‡p < 0.10; §p < 0.01.
DASH = Dietary Approaches to Stop Hypertension; SBP = systolic blood pressure
Bray GA, et al. Am J Cardiol. 2004;94:222-227.
Potassium
High potassium intake is associated with reduced BP
• Data from individual trials have been inconsistent
• 3 meta-analyses of trials - a significant inverse relationship between
potassium intake and BP in nonhypertensive and hypertensive
individuals
• Average SBP and DBP reductions associated with a net increase in
urinary potassium excretion of 2 g/d (50 mmol/d) were 4.4 and 2.5
mm Hg in hypertensive and 1.8 and 1.0 mm Hg in nonhypertensive
individuals ( Whelton et al, 1997 )
Limited evidence
Fish Oil Supplementation
• High-dose omega-3 PUFA supplements (3g/day) lower BP in hypertensive
individuals. (SBP -4.0mmHg; DBP -2.5mmHg)Hg
• In nonhypertensive individuals, BP reductions tend to be nonsignificant
• The effect is dose dependent
• Side effects include belching and a fishy taste
In view of the high dose required to lower BP and the side-effect profile, fish
oil supplements cannot be routinely recommended as a means to lower
BP
Protein Intake
• Significant inverse relationship between protein intake and BP
• In these studies, protein from plant sources (mainly soya) was
associated with lower BP, whereas protein from animal
sources had no effect
• In the recently completed OmniHeart study, partial
substitution of carbohydrate with protein (about half from
plant sources) lowered BP
Substitution of carbohydrate with increased intake of
protein, particularly from plants, can lower BP. However, it
remains uncertain whether the effects result from increased
protein or reduced carbohydrate
Effects of 3 healthy
dietary patterns
tested in the
OmniHeart feeding
study on systolic
BP
CARB [similar to the DASH diet],
PROT [rich in protein, about half from
plant sources]
UNSAT [rich in monounsaturated fat])
Appel, 2006
FATS
Saturated Fat
In majority of studies, saturated fat intake was not associated with hypertension
• Diet interventions that focused only on reducing saturated fat had no significant
effect on BP
• Because most trials tested diets that were both reduced in saturated fat and
increased in polyunsaturated fat, the absence of an effect on BP also suggests no
benefit from polyunsaturated fat
Omega-6 Polyunsaturated Fat Intake
Dietary intake of omega-6 polyunsaturated fat (mainly linoleic acid ) has little effect
on BP
• Monounsaturated Fat Intake
Overall, although increased monounsaturated fat appears to lower BP, this
relationship often is confounded by a concomitant reduction in carbohydrate intake.
• Hence, the effect of monounsaturated fat intake per se on BP is uncertain
• Cholesterol
Paucity of evidence precludes any conclusion about a relationship between dietary
cholesterol intake and BP
Calcium and Magnesium
• Modest reductions in systolic and diastolic BPs of 0.9 to
1.4 mm Hg and 0.2 to 0.8 mm Hg, respectively, with
calcium supplementation (400 to 2000 mg/d)
• Calcium supplementation attenuated the effect of a
high sodium intake on BP
• Evidence implicating magnesium as a major
determinant of BP is inconsistent
Overall, data are insufficient to recommend either
supplemental calcium or magnesium as a means to
lower BP
Vitamin C
It remains unclear whether an increased intake
of vitamin C reduces BP
Fibre
Increased fibre intake may reduce BP
• Overall, data are insufficient to recommend an
increased intake of fibre alone as a means to
lower BP
INDIAN STUDY
• Modified DASH Diet with 500g of fruit & Vegetable was
designed to suit Indians
• Adults (both males & females) aged 25-65yrs, who were
freshly diagnosed hypertensives(SBP<=160,DBP 90-100
mm Hg) participated in the study
• Subjects divided into 3 groups:
Control, Experimental 1, Experimental 2 with 75 subjects
in each group
INDIAN STUDY
• Control group: Subjects continued on their usual diet
pattern with advise on life style modifications of low
salt intake, daily 30 minutes walk and cessation of
smoking and alcohol intake
• Experimental group 1(E1) : Subjects given similar
advise on life style modifications as in control group
along with counseling to include a total of 500g of fruit
and vegetable in their daily diet
• Experimental group 2 (E2): Subjects followed the
modified DASH diet prescribed with 500g of fruit and
vegetable along with the life style modifications
Blood Pressure (Males)
Male BP
Control
Expt1
Expt2
SBP (W0)
152.09±7.1
150.06±7.1
152.59±5.9*
SBP (W12)
151.98±7.6a
149.63±9.1ab
146.65±10.4*b
DBP (W0)
95.94±5.07
95.5 ±3.13
96.67 ±2.51*
DBP (W12)
96.26 ±5.46a
96.33 ±4.26a
92.57 ±5.5b*
C:No sig. diff. in SBP &DBP.
E1:No sig. Diff. in SBP &DBP.
E2:Sig. diff. in SBP &DBP at
W12 compared to W0.
Significant at p<.05;
Significant change : SBP and
DBP - E2 group.
Significant difference : SBP&DBP
at wk 12-E2 had lowest
Blood Pressure (Females )
Female BP
SBP (W0)
SBP (W12)
Control
152.0±7.6
152.24±8.2a
Expt1
152.14±5.5*
149.9±8.2ab*
Expt2
149.67±6.9*
145.0±7.7*b
DBP (W0)
DBP (W12)
95.67±4.8*
95.24 ±4.6*
97.0 ±2.3*
93.67 ±4.1*
95.57 ±3.2*
92.14 ±3.8*
C:No sig. diff. in SBP
&DBP.
E1:Sig. Diff. in SBP
&DBP.
E2:Sig. diff. in SBP &DBP
at W12 compared to W0.
Significant at p<.05
Significant change :SBP & DBP - E1, E2;DBP -C
group.
SBP:wk12-E2 -lowest ; DBP fell wk12 all grps,
No significant diff. seen (Wk
12 lowest in E2 group)
Effect on Blood Pressure
• No significant difference for SBP & DBP among the three
groups at baseline, thus well matched
• Males: Significant difference for SBP & DBP at wk 12 - E2 had
lowest as compared to other groups.
• Females: Significant difference for SBP at wk 12 - E2 had
lowest as compared to other groups.
• As DBP in all groups fell at wk 12, thus no significant
difference in DBP seen ( DBP at Wk 12 lowest in E2 group).
• Could be attributed to
-slightly better compliance by females for PA,LS &MD diet
-Significant fall in Wt., BMI &WHR of E1 & E2 females
• Conformity with the DASH results
Biweekly Blood Pressure(Males)
Control
SBP
Expt1
DBP
SBP
DBP
Expt2
SBP
DBP
0Wk
152.1
95.9
150.0
95.5
152.6a
96.7a
2Wk
151.7
96.1
150.0
95.9
151.4a
96.0a
4Wk
151.9
96.2
150.0
95.8
149.6b
94.8b
6Wk
151.9
96.2
150.0
95.8
147.2c
93.2c
8Wk
151.9
96.3
150.0
95.8
147.6bc
93.4c
10Wk
151.9
96.3
150.0
95.2
147.6bc
92.6c
12Wk
152.0
96.3
149.6
96.3
146.7c
92.6c
Biweekly Blood Pressure (Females)
Control
Expt1
Expt2
SBP
DBP
SBP
DBP
SBP
DBP
0 Wk
152.0a
95.7
152.1a
97.0a
149.7a
95.6a
2 Wk
151.6a
95.4
152.0a
96.1a
148.5a
94.2a
4 Wk
151.6a
95.4
151.0a
96.0a
146.3b
93.8b
6 Wk
151.6a
95.4
150.0b
94.8b
146.3b
92.8b
8 Wk
151.4b
95.4
150.0b
94.8b
146.3b
92.8b
10 Wk
151.2b
95.2
149.0b
93.7b
145.0b
92.1c
12 Wk
151.2b
95.2
148.9b
93.7b
145.0b
92.1c
Biweekly Blood Pressures
• Fall in BP started within 2 week and lasted throughout the
study.
• Control Group: Male- mean SBP & DBP - no significant
decrease. Female - SBP - significant fall from the 8th week
onwards, DBP - no change.
• E 1 group : Male - mean SBP & DBP - no significant decrease .
Female - SBP & DBP - significant 6th week onward.
• E 2 group : Male- mean SBP & DBP –fall significant at W4.
Further significant fall observed at W6 and W12 (for SBP
only). Female-SBP-significant fall 4th week onwards, mean
DBP - again significant fall at W10.
Advantages of MD-Diet
• The importance of modified DASH diet is seen to be twofold, it caused maximum fall in BP and secondly an early
fall in the BP was observed as compared to other
interventions
• The fall in BP increased with duration of intervention
Thus indicating benefit of continuing on such a regime
for a longer period on BP
• Significant fall in BMI & WHR of both M&F in E2 gp after
12 wks. on M-DASH diet
• Significant fall in serum CH of both M&F in E2 gp after 12
wks.
Coefficients of Correlation
ACS
C-M
C-F
E1-M
E1-F
E2-M
E2-F
SBP
0.048
0.33
0.131
0.136
-0.048
0.480*
DBP
0.071
-0.31
-0.21
-0.209
-0.087
0.610*
BMI
-0.1
0.425
-0.173
-0.025
-0.043
0.147
WHR
-0.11
0.216
-0.058
-0.05
0.243
0.007
Wt
-0.11
0.417
-0.17
-0.05
-0.051
0.101
BS(F)
0.162
0.486
-0.163
-0.068
-0.123
0.115
S.Chol
-0.019
0.105
0.044
0.197
-0.070
0.051
Significant +ve correlation between % Av. compliance and fall in SBP & DBP in E2
group-F; indicates that compliance to modified DASH diet component may be
responsible for sig.reduction
Coefficients of correlation
Diff.
PA
Low salt
F&V
MD Diet
SBP
.057
.038
-.012
.29*
DBP
-.061
-.028
.021
.364*
BMI
-.031
.014
-.006
-.040
WHR
.021
.093
.087
-.019
Wt
-.037
.005
.004
-.067
BS(F)
-.004
.129
-.115
.342
S.Chol
-.119
-.088
.204
.243
Correlations between specific activity compliances& diff. –
Sig +ve correlation for ideal DASH diet and fall in SBP, DBP reemphasizing
that interventions with MD diet most effective in bringing significant
reduction in both SBP, DBP.
Conclusion
• Study sample had a high intake of total calories, fat,
sodium and a low fiber intake at baseline
• In an Indian Dietary pattern, though the inclusion of 500g
F&V daily resulted in significant lowering of BP in female
subjects only, but only after 6 weeks intervention;
whereas modified DASH diet resulted in a significant fall
in SBP and DBP, in all the subjects, within 4 weeks of
intervention
• Emphasis on Nutrition/diet Counseling required for
better compliance
Conclusions
Study also shows that fall in BP continues with
longer period of intervention. Therefore possible
to achieve normal BP by continuing on this nonpharmacological intervention.
Thus non-pharmacological approach of diet &
life style modifications effective in lowering the
BP of hypertensive patients