EAL

HTN: Medical Nutrition Therapy (2015)

Citation:

Torres MRSG, Ferreira TS, Nogueira LP, Nascimento DCS, Sanjuliani AF. Dietary counseling on long-term weight loss in overweight hypertensive patients. Clinics. 2011; 66(10): 1,779-1,785.

PubMed ID: 22012051

Study Design:

Prospective Cohort Study

Class:

B - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To evaluate long-term weight loss in overweight, hypertensive patients receiving dietary counseling and to investigate if dietary counseling is related to modifications in:

Metabolic profile
Blood pressure
Use of medications for hypertension, diabetes or hyperlipidemia.

Inclusion Criteria:

Subjects were included if they were overweight or obese hypertensive outpatients of the Hypertension Clinic (CLINEX) of the Rio de Janeiro State University and the following:

Had their first individual nutritional consult between January 2002 and December 2005
Were followed for four years at the clinic
Ages 30 years to 80 years old
BMI of at least 25kg/m² (adult) or 27kg/m² (elderly).

Exclusion Criteria:

Current use of weight-loss medications
High level of physical activity
Recent (six months) changes in dietary intake, body weight (3kg or more) or intensity and frequency of exercise
Diagnosis or medical history (within three months prior to study) of eating disorders, major depression, drug addiction, hypothyroidism, insulin-dependent diabetes, severe gastrointestinal or renal diseases, coronary event or stroke
Pregnant or lactating.

Description of Study Protocol:

Recruitment

All subjects were selected from a specific healthcare facility that provided nutrition counseling to hypertensive patients.

Design

This is a longitudinal (retrospective) cohort study.

Blinding Used

All subjects were provided the same opportunities; however, those that chose to come to counseling more frequently were retrospectively assessed as the treatment group.

Intervention

Nutritional counseling for weight loss and maintenance in overweight, hypertensive adults was offered as part of usual facility protocol. Subjects who attended more than three sessions received instruction on Dietary Approaches to Stop Hypertension (DASH) in addition to generalized weight-reduction plans. All subjects were afforded similar treatment but the number of individualized counseling session they sought is what divided the study analysis.

Statistical Analysis

Used Stata 10 (Stata Corp., College Station, TX, USA).

Continuous variables expressed as means ± standard error
Comparisons of continuous variables using Student's T-test
Multiple linear regression analysis to adjust for age, gender, baseline BMI and use of anti-hypertensive and anti-diabetic drugs
Repeated measures ANOVA to evaluate differences at zero, six, 12, 24, 36 and 48 months
Chi-square test to compare by gender distribution, prevalence of diabetes and dyslipidemia, and use of drugs
Multiple logistic regression analysis to assess associations between dietary counseling and changes in the use of different drugs
Power analysis
P<0.05 significance.

Data Collection Summary:

Timing of Measurements

Dietary counseling was offered once per month for the first three months and every three months thereafter for each subject. Measurements were taken at individual appointments and reported in six month increments from baseline to four years.

Dependent Variables

Body weight (kg),body mass (kg/m²)
Glucose (mg per dL)
Urea (mg per dL),creatinine (mg per dL), uric acid (mg per dL)
Total cholesterol (mg per dL), HDL-cholesterol (mg per dL), LDL-cholesterol (mg per dL), triglycerides (mg per dL)
Systolic, diastolic and mean blood pressure (mm Hg)
Heart rate (bpm)
Medications.

Independent Variables

Dietary counseling: Patients who had at least four consultations during the four years of the study
Control: Those who scheduled a consultation and missed the appointment.

Control Variables

Age
Gender
Baseline BMI
Use of anti-hypertensive and anti-diabetic drugs
Weight loss.

Description of Actual Data Sample:

Initial N: N=148 (36 years to 78 years old; gender was not specified)
Attrition (final N): N=102 (44 males, 58 females)
Age: Mean 55.1+0.9 years
Ethnicity: Not specified except no noted differences in groups for comparison
Anthropometrics: Authors report as similar
Location: Rio de Janeiro, Brazil.

Summary of Results:

Key Findings

Subjects receiving more counseling showed significantly greater reduction in body weight (P<0.001)
Subjects receiving more counseling lost more weight and were more likely to keep it off long term than those that received less counseling [Dietary Counseling Group (DCG) -3.64±0.79kg vs. Control Group (CG) 0.81±0.66kg; P=0.001]
Weight losses of at least 10% were seen only in the DCG group.

Other Findings

Subjects receiving more counseling were less likely to need increase or initiation of medication dosage; however, this may relate to weight loss primarily.

Author Conclusion:

Overweight, hypertensive subjects who received more individualized nutrition counseling achieved greater long-term weight loss. These subjects required less increase or initiation of anti-hypertensive medications. This study looked at longer-term weight loss and weight maintenance than other previous studies.

Funding Source:

University/Hospital:

Rio de Janeiro State University, Rio de Janeiro, Brazil

Reviewer Comments:

Authors note significant limitations of this study are that it is a single center study and that the patients were allocated in both groups according to their willpower (i.e., patients chose how often to participate in counseling; therefore, those that participated more may have been more motivated by other reasons).

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)	Yes
	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.)	Yes
	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?	Yes
	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.)	Yes
	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?		Yes
	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%.)	Yes
	4.3.	Were all enrolled subjects/patients (in the original sample) accounted for?	Yes
	4.4.	Were reasons for withdrawals similar across groups?	Yes
	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?		No
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	No
	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?	No
	5.4.	In case control study, was case definition explicit and case ascertainment not influenced by exposure status?	No
	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?	N/A
	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?	Yes
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	Yes
	6.6.	Were extra or unplanned treatments described?	No
	6.7.	Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups?	Yes
	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?	No
	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)?	Yes
	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?	N/A
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