Note from the National Guideline Clearinghouse (NGC) and the American Dietetic Association (ADA): Several recommendations of this guideline were based on the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC 7). The purpose of JNC 7 is to provide an approach to the prevention and management of hypertension. The hypertension working group did not review topics that were already addressed in the review conducted by the JNC 7 group.
Ratings for the strength of the recommendations (Strong, Fair, Weak, Consensus, Insufficient Evidence), conclusion grades (I-V), and statement labels (Conditional versus Imperative) are defined at the end of "Major Recommendations."
Hypertension (HTN): Classification of Blood Pressure
HTN: Blood Pressure Measurement in Assessment
Blood pressure measurement should be used to classify blood pressure as Normal, Prehypertension, or Hypertension (Stage 1 or Stage 2), to estimate risk for disease, and to identify treatment options. Elevated blood pressure is associated with risk of damage to the heart (left ventricular hypertrophy [LVH], angina, myocardial infarction [MI], coronary artery disease, heart failure), brain (transient ischemic attack [TIA], stroke, dementia), kidney (chronic kidney disease [CKD]), peripheral arteries, and eyes (retinopathy).
Consensus, Imperative
HTN: Blood Pressure Measurement in Monitoring and Evaluation
Blood pressure measurement should be used to monitor and evaluate the effectiveness of therapy. Elevated blood pressure is associated with risk of damage to the heart (LVH, angina, MI, coronary artery disease, heart failure), brain (TIA, stroke, dementia), kidney (CKD), peripheral arteries, and eyes (retinopathy).
Consensus, Imperative
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding classification of blood pressure.
Hypertension (HTN): Food/Nutrient and Medication Interaction
HTN: Food/Nutrient and Medication Interaction Assessment
Dietitians should assess food/nutrient-medication interactions in patients that are on pharmacologic therapy for hypertension, as many antihypertensive medications interact with food and nutrients.
Consensus, Imperative
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding food/nutrient and medication interactions.
Hypertension (HTN): Dietary Approaches to Stop Hypertension (DASH) Dietary Pattern
HTN: DASH Diet
Individuals should adopt the DASH dietary pattern which is rich in fruits, vegetables, low-fat dairy, and nuts; low in sodium, total fat, and saturated fat; and adequate in calories for weight management. The DASH dietary pattern reduces systolic blood pressure by 8 to 14 mm Hg.
Consensus, Imperative
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding DASH dietary pattern.
Hypertension (HTN): Physical Activity
Physical Activity
Dietitians should encourage individuals to engage in aerobic physical activity for at least 30 minutes per day on most days of the week, as it reduces systolic blood pressure by approximately 4 to 9 mmHg.
Consensus, Imperative
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding physical activity
Hypertension (HTN): Dietary Sodium
HTN: Sodium Intake
Dietary sodium intake should be limited to no more than 2300 mg sodium (100 mmol) per day. Reduction of dietary sodium to recommended levels lowers systolic blood pressure by approximately 2 to 8 mm Hg.
Strong, Imperative
HTN: Sodium Intake Monitoring and Evaluation
If the patient demonstrates adherence to a 2300 mg sodium diet but has not achieved the treatment goal, then the dietitian should recommend the DASH dietary pattern and/or reduction in sodium to 1600 mg to further reduce blood pressure.
Strong, Conditional
Recommendation Strength Rationale
- Conclusion statement is Grade I
Hypertension (HTN): Weight Management
Weight Management
Optimal body weight should be achieved and maintained (body mass index [BMI] 18.5 to 24.9) to reduce blood pressure. Weight reduction lowers systolic blood pressure by 5 to 20 mm Hg per 22 lbs (10 kg) body weight loss.
Consensus, Imperative
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding weight management.
Hypertension (HTN): Omega-3 Fatty Acids
Omega-3 Fatty Acids
Advise that the consumption of omega-3 fatty acids may not be beneficial for the management of hypertension, since their consumption does not appear to lower blood pressure.
Fair, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade II
Hypertension (HTN): Dietary Protein
Dietary Protein
Advise that the consumption of protein may or may not be beneficial for the reduction of blood pressure, since the effect of increased protein intake on blood pressure is unclear.
Weak, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Soluble Fiber
Soluble Fiber
Advise that the consumption of soluble fiber may or may not be beneficial for the reduction of blood pressure, since the effect of increased soluble fiber intake on blood pressure is unclear.
Weak, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Potassium
Potassium
Dietitians should advise individuals to consume adequate food sources of potassium as part of Medical Nutrition Therapy to reduce blood pressure. Research suggests that potassium intake lower than recommended levels (Dietary Reference Intakes [DRI]) is associated with increased blood pressure.
Fair, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade II
Hypertension (HTN): Vitamins
Vitamin C
Advise that the consumption of vitamin C may or may not be beneficial for the reduction of blood pressure, since the effect of increased vitamin C intake on blood pressure is unclear.
Weak, Imperative
Vitamin E
Advise that the consumption of vitamin E may or may not be beneficial for the reduction of blood pressure, since the effect of increased vitamin E intake on blood pressure is unclear.
Weak, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Dietary Magnesium
Dietary Magnesium
If magnesium is proposed as a therapy to reduce blood pressure, advise that the effect of magnesium as a single nutrient on blood pressure in healthy or hypertensive adults is unknown. The effect of dietary patterns with magnesium intake above the DRI on blood pressure in healthy or hypertensive adults is minimal. However, some dietary patterns that contain magnesium lower than recommended levels (DRI) may be associated with elevated blood pressure.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statement is Grade II
Hypertension (HTN): Calcium
Calcium
If calcium is proposed as a therapy to reduce blood pressure, advise that the effect of calcium as a single nutrient on blood pressure in healthy or hypertensive adults is unclear. Epidemiological studies report that dietary patterns containing calcium lower than recommended levels (DRI) may be associated with elevated blood pressure. The effect of dietary patterns with calcium intake above the DRI on blood pressure in healthy or hypertensive adults is minimal.
Fair, Conditional
Recommendation Strength Rationale
- Conclusion statement is Grade II
Hypertension (HTN): Fruits and Vegetables
Fruits and Vegetables
Advise the consumption of at least five to ten servings of fruits and vegetables per day, based on research reporting significant reductions in blood pressure after consumption of either the DASH dietary pattern or a diet rich in fruits and vegetables.
Strong, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade I
Hypertension (HTN): Soy Foods
Soy Foods
Advise that the consumption of soy foods may or may not be beneficial for the reduction of blood pressure, since the effect of increased soy food intake on blood pressure is unclear.
Weak, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Garlic
Garlic
Consumption of garlic may or may not be beneficial for the reduction of blood pressure, since the current evidence is inconclusive regarding its effect on blood pressure.
Weak, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Cocoa and Chocolate
Cocoa and Chocolate
Consumption of cocoa or chocolate may or may not be beneficial for the reduction of blood pressure, since the current evidence is inconclusive regarding its effect on blood pressure.
Weak, Imperative
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Caffeine
Caffeine Intake
For those who consume caffeine, advise blood pressure monitoring; while acute intake of caffeine increases blood pressure, the effect of chronic caffeine intake is unclear.
Weak, Conditional
Recommendation Strength Rationale
- Conclusion statement is Grade III
Hypertension (HTN): Alcohol Consumption
Alcohol Consumption
For individuals who can safely consume alcohol, consumption should be limited to no more than 2 drinks (24 oz beer, 10 oz wine, or 3 oz of 80-proof liquor) per day in most men and to no more than 1 drink per day in women. A reduction in alcohol consumption may reduce systolic blood pressure by approximately 2 to 4 mmHg.
Consensus, Conditional
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding alcohol.
Hypertension (HTN): Management of Blood Pressure
HTN: Comprehensive Program for Blood Pressure Management
Management of elevated blood pressure should be based on a comprehensive program including lifestyle modification (weight reduction, medical nutrition therapy and physical activity) and pharmacologic therapy. Research indicates that a comprehensive program can prevent target organ damage and improve cardiovascular outcomes.
Consensus, Imperative
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding management of blood pressure.
Hypertension (HTN): Goals of Therapy
HTN: Blood Pressure Treatment Goal
A treatment goal of <140/90 mm Hg is recommended for individuals without comorbidities. This level is associated with preventing target organ damage and decreasing cardiovascular risk factors and complications.
Consensus, Imperative
HTN: Blood Pressure Treatment Goal for Individuals with Diabetes or Renal Disease
For individuals with hypertension and diabetes or renal disease, a treatment goal of <130/80 mm Hg is recommended. These individuals are at an increased risk for cardiovascular and renal morbidity and mortality.
Consensus, Conditional
Recommendation Strength Rationale
The ADA Hypertension Expert Work Group concurs with the recommendations from the JNC 7, regarding goals of therapy.
Definitions:
Conditional versus Imperative Recommendations
Recommendations can be worded as conditional or imperative statements. Conditional statements clearly define a specific situation, while imperative statements are broadly applicable to the target population without restraints on their pertinence. More specifically, a conditional recommendation can be stated in if/then terminology (e.g., If an individual does not eat food sources of omega-3 fatty acids, then 1g of EPA and DHA omega-3 fatty acid supplements may be recommended for secondary prevention).
In contrast, imperative recommendations "require," or "must," or "should achieve certain goals," but do not contain conditional text that would limit their applicability to specified circumstances. (e.g., Portion control should be included as part of a comprehensive weight management program. Portion control at meals and snacks results in reduced energy intake and weight loss).
Levels of Evidence
Strength of Evidence Elements |
Grade I
Good/Strong
|
Grade II
Fair
|
Grade III
Limited/Weak
|
Grade IV
Expert Opinion Only
|
Grade V
Grade Not Assignable
|
Quality
- Scientific rigor/validity
- Considers design and execution
|
Studies of strong design for question
Free from design flaws, bias and execution problems
|
Studies of strong design for question with minor methodological concerns
OR
Only studies of weaker study design for question
|
Studies of weak design for answering the question
OR
Inconclusive findings due to design flaws, bias or execution problems
|
No studies available
Conclusion based on usual practice, expert consensus, clinical experience, opinion, or extrapolation from basic research
|
No evidence that pertains to question being addressed |
Consistency
Of findings across studies
|
Findings generally consistent in direction and size of effect or degree of association, and statistical significance with minor exceptions at most |
Inconsistency among results of studies with strong design
OR
Consistency with minor exceptions across studies of weaker designs
|
Unexplained inconsistency among results from different studies
OR
Single study unconfirmed by other studies
|
Conclusion supported solely by statements of informed nutrition or medical commentators |
NA |
Quantity
- Number of studies
- Number of subjects in studies
|
One to several good quality studies
Large number of subjects studies
Studies with negative results having sufficiently large sample size for adequate statistical power
|
Several studies by independent investigators
Doubts about adequacy of sample size to avoid Type I and Type II error
|
Limited number of studies
Low number of subjects studies and/or inadequate sample size within studies
|
Unsubstantiated by published studies |
Relevant studies have not been done |
Clinical Impact
- Importance of studies outcomes
- Magnitude of effect
|
Studied outcome relates directly to the question
Size of effect is clinically meaningful
Significant (statistical) difference is large
|
Some doubt about the statistical or clinical significance of effect |
Studies outcome is an intermediate outcome or surrogate for the true outcome of interest
OR
Size of effect is small or lacks statistical and/or clinical significance
|
Objective data unavailable |
Indicates area for future research |
Generalizability
To population of interest
|
Studied population, intervention and outcomes are free from serious doubts about generalizability |
Minor doubts about generalizability |
Serious doubts about generalizability due to narrow or different study population, intervention or outcomes studied |
Generalizability limited to scope of experience |
NA |
This grading system was based on the grading system from: Greer N, Mosser G, Logan G, Wagstrom Halaas G. A practical approach to evidence grading. Jt Comm. J Qual Improv. 2000; 26:700-712. In September 2004, The ADA Research Committee modified the grading system to this current version.
Criteria for Recommendation Rating
Statement Rating |
Definition |
Implication for Practice |
Strong |
A Strong recommendation means that the workgroup believes that the benefits of the recommended approach clearly exceed the harms (or that the harms clearly exceed the benefits in the case of a strong negative recommendation), and that the quality of the supporting evidence is excellent/good (grade I or II)*. In some clearly identified circumstances, strong recommendations may be made based on lesser evidence when high-quality evidence is impossible to obtain and the anticipated benefits strongly outweigh the harms. |
Practitioners should follow a Strong recommendation unless a clear and compelling rationale for an alternative approach is present. |
Fair |
A Fair recommendation means that the workgroup believes that the benefits exceed the harms (or that the harms clearly exceed the benefits in the case of a negative recommendation), but the quality of evidence is not as strong (grade II or III)*. In some clearly identified circumstances, recommendations may be made based on lesser evidence when high-quality evidence is impossible to obtain and the anticipated benefits outweigh the harms. |
Practitioners should generally follow a Fair recommendation but remain alert to new information and be sensitive to patient preferences. |
Weak |
A Weak recommendation means that the quality of evidence that exists is suspect or that well-done studies (grade I, II, or III)* show little clear advantage to one approach versus another. |
Practitioners should be cautious in deciding whether to follow a recommendation classified as Weak, and should exercise judgment and be alert to emerging publications that report evidence. Patient preference should have a substantial influencing role. |
Consensus |
A Consensus recommendation means that Expert opinion (grade IV)* supports the guideline recommendation even though the available scientific evidence did not present consistent results, or controlled trials were lacking. |
Practitioners should be flexible in deciding whether to follow a recommendation classified Consensus, although they may set boundaries on alternatives. Patient preference should have a substantial influencing role. |
Insufficient Evidence |
An Insufficient Evidence recommendation means that there is both a lack of pertinent evidence (grade V)* and/or an unclear balance between benefits and harms. |
Practitioners should feel little constraint in deciding whether to follow a recommendation labeled as Insufficient Evidence and should exercise judgment and be alert to emerging publications that report evidence that clarifies the balance of benefit versus harm. Patient preference should have a substantial influencing role. |
*Conclusion statements are assigned a grade based on the strength of the evidence. Grade I is good; grade II, fair; grade III, limited; grade IV signifies expert opinion only and grade V indicates that a grade is not assignable because there is no evidence to support or refute the conclusion. The evidence and these grades are considered when assigning a rating (Strong, Fair, Weak, Consensus, Insufficient Evidence - see chart above) to a recommendation.
Adapted by the American Dietetic Association from the American Academy of Pediatrics, Classifying Recommendations for Clinical Practice Guideline, Pediatrics. 2004;114;874-877.