MNT: Disorders of Lipid Metabolism (2015)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:

The objective of the Lipid Management Nutrition Outcomes Project was to document behavioral and clinical outcomes associated with use of the 1998 MNT Hyperlipidemia Protocol by a national network of RDs.

Inclusion Criteria:
  • Site criteria: Sites were required to have adequate patient volume (20 to 30 patients fitting the criteria within a six-month period)
  • Patient criteria: 25 to 70 years of age with at-risk lipid profiles based on National Cholesterol Education Program Adult Treatment Panel II criteria or triglycerides higher than 200mg per dL.
Exclusion Criteria:

Exclusion criteria:

  • No available lipid profile information within three months of initial RD consult
  • Most recent lipid profile within four weeks of a myocardial infarction
  • Lipid-lowering medication changes since the most recent lipid profile
  • Triglycerides higher than 1,000mg per dL
  • Body mass index higher than 40
  • Untreated, elevated thyroid-stimulating hormone
  • Diabetes diagnosed since the most recent lipid profile
  • Pregnant or lactating women
  • Steroid or weight-loss medication use
  • Residing in a controlled-living center
  • Liver or renal disease
  • Participating in other studies.
Description of Study Protocol:

Recruitment

One co-investigator from Clinical Nutrition Management and one from the Michigan Dietetic Association recruited State Coordinators at the Clinical Nutrition Management annual meeting and from within the American Dietetic Association state associations. State coordinators were asked to recruit and train five site RDs within their state, collect data, double-enter data into an ACCESS data base and participate in quality assurance. 

Design

Multicenter, prospective, non-controlled, non-randomized, observational outcomes study.

Intervention

To provide medical nutrition therapy for lipid management in an ambulatory setting. The RDs used the 1998 MNT Hyperlipidemia Protocol. 

Statistical Analysis

All data were analyzed using SPSS for Windows software. Student's T-test and Chi-square analysis were performed on the data. Paired T-test were used to compare pre- and post-intervention data for anthropometrics, food habit questionnaire (FHQ), and lipid parameters.

 

Data Collection Summary:

Timing of Measurements 

  • MNT visits: March 2000 to August 2001
  • Food habit questionnaire (given at first visit and during the follow-up RD visits). The actual protocol varied among the clinics.
  • Blood lipids (baseline within three months of initial RD visit); RDs obtained all lipid tests within one year after MNT)
  • Body weight was measured to the nearest 0.25 pounds (at screening and again during the follow-up visits). The actual protocol varied among the clinics.

Dependent Variables

  • Eating patterns (measured by food habit questionnaire)
  • Blood lipid levels (LDL-cholesterol, triglycerides, HDL-cholesterol, and total cholesterol)
  • Exercise frequency
  • Body weight.

Independent Variable

Medical nutrition therapy was provided following the recommendations of the 1998 MNT Hyperlipidemia Protocol.

 

 

Description of Actual Data Sample:

Initial N

377 adults (74.4% male) met inclusion criteria:

  • 162 of 377 received MNT (three to four RD visits)
  • 131 patients had only one visit with RD (not MNT)
  • Data were available for 280 adults including those with partial data; 239 patients with follow-up data and finally 219 patients without lipid-lowering medication. This article was based on the data from the 219 patients.

Age

Mean age was 52.3±10 years.

Ethnicity

84.3% Caucasian.

Other Relevant Demographics

  • 67.5% married or living with someone
  • 38.6% college graduates
  • 60.4% employed.

Anthropometrics

Mean BMI 30.5±4.5.

Location

11 states (CA, CO, FL, MA, MI, MN, MO, NE, NY, OH and OR). 24 sites and 52 RD counselors. 

Summary of Results:

 

Key Findings for 219 patients (167 Received MNT for Three or Four Visits)

 

  N=175 Patients with Baseline TG Less Than 400mg per dL N=44 Patients with Baseline TG More Than 400mg per dL

Variables

Mean±SD

P-Value

Mean±SD

P-Value

Change in Food Habit Questionnaire score* pre- to post-MNT

2.61±0.56 to 2.11±0.5

P<0.0001

2.65±0.57 to 2.22±0.62

P<0.0001

Change in total cholesterol (mg per dL, pre- to post-MNT and percent change)

246.5±45.6 to 229±41

(-6.3±13.0)

P<0.0001

245.6±6.7 to 211.5±52

(12.2 to 17.8)

P<0.0001

Change in triglycerides (mg per dL pre- to post-MNT and percent change)

 209.8±92.1 to 188.1±104.5  

(-3.8±44.1)

P=0.0026

540.1±156.3 to 362.2± 178.4

(-29.3±35.9)

P<0.0001

 * A score of less than 2.5 represents a diet less than 30% kcal from fat.

Other Findings

  • HDL-cholesterol: Increased (P<0.028) for the group that had baseline triglycerides about 400mg per dL
  • LDL-cholesterol: Decreased (P<0.0001) for the group that had baseline triglycerides below 400mg per dL
  • Exercise days: Exercise days (frequency per week) increased significantly in both groups (P<0.01)
  • Body weight: Body weight decreased significantly in both groups (P<0.01).
Author Conclusion:

The Lipid Management Nutrition Outcomes Project demonstrated the successful implementation of an MNT Hyperlipidemia Protocol in a a variety of settings across the United States. Patients reported food choices consistent with dietary fat reduction, lost weight, increased exercise and 44.6% had either a 15% drop in LDL-cholesterol or reached their LDL-cholesterol target. These positive outcomes support the use of the ADA evidenced-based MNT practice guidelines. 

Funding Source:
Not-for-profit
ADA Dietetic Practice Group Grant and the Clinical Nutrition Management DPG
Other:
Reviewer Comments:

Investigators did not separately report data for patients who received MNT per the protocol (three to four visits).

Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) Yes
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) Yes
 
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) N/A
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) N/A
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? N/A
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? ???
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) No
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? N/A
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? Yes
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) Yes
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? N/A
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? Yes
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? ???
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? N/A
  6.6. Were extra or unplanned treatments described? N/A
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? N/A
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? Yes
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? N/A
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes