EAL

DM: Effectiveness of MNT Provided by RD/RDN (2015)

Citation:

Barratt R, Frost G, Millward DJ, Truby H. A randomised controlled trial investigating the effect of an intensive lifestyle intervention v. standard care in adults with type 2 diabetes immediately after initiating insulin therapy. Br J Nutr 2008; 99(5): 1,025-1,031.

PubMed ID: 18197995

Study Design:

Randomized Controlled Trial

Class:

A - Click here for explanation of classification scheme.

Quality Rating:

POSITIVE: See Quality Criteria Checklist below.

Research Purpose:

To determine whether an intensive lifestyle intervention could be effective in reducing weight gain associated with insulin treatment in adults with type 2 diabetes.

Inclusion Criteria:

Type 2 diabetes
Within four weeks of starting insulin therapy
BMI higher than 27kg/m² and lower than 50kg/m²
Aged between 18 years and 75 years
Able to read and understand written English
Able to give informed consent.

Exclusion Criteria:

Presence of co-morbidities,such as inflammatory bowel disease, cancer or renal or liver disease, that may affect nutritional intake
Receiving medication such as Reductil or Orlistat to assist with weight loss
Females who were pregnant, lactating or planning a pregnancy.

Description of Study Protocol:

Recruitment

Recruitment took place at two tertiary hospitals over a two-year period. Potential participants were identified by clinic staff. They were then approached by the first author to ascertain their willingness to participate in the study.

Design

The trial was a randomized parallel intervention study. Subjects were randomly assigned to either the control or intervention groups following a computer-generated randomization table according to the order in which they were recruited. There were two levels of stratification for sex (male and female) and three levels of stratification for ethnicity (white, black and Asian).

Blinding Used

The trial was unblinded. Blinding was not possible due to the nature of the intervention. However, blinding was implied through measurements.

Intervention

The intervention consisted of a six-month intensive weight and lifestyle intervention. It followed the "Lifestyle Clinic," which aims to achieve a 500kcal per day energy deficit through motivation interviewing, initiation of patient empowerment and provision of support and advice. Subjects were seen by a registered dietitian six times over six months. The first appointment was approximately 90 minutes in duration and subsequent appointments were approximately 30 minutes in duration. Specific topics were discussed at each session and individualized targets were agreed upon and documented.
Subjects in the control group received standard care following general procedures that would occur regardless of study participation. This included an annual review in the endocrinology clinic, appointments and phone contact with diabetes specialist nurses and, if required, referral to other health professionals.

Statistical Analysis

Power calculations indicated that 21 subjects in each group were required for a statistical strength of 80% and a significance of 0.05. The total target number to recruit was 48 subjects, allowing for an estimated dropout rate of 20%.
The Kolmogorov-Smirnov statistic was used to test all data for normality
Primary analysis was carried out using an intention-to-treat analysis with baseline values carried forward to account for missing values
Parametric tests were used for the data found to be normally distributed
Intra-group analysis was conducted using paired T-tests, analyzing the difference between the start and end measurements
Paired T-tests were carried out on all patients collectively and the control and intervention groups separately
Independent T-tests were used for inter-group analysis, comparing the start and end measurements, in addition to the absolute change and percentage change in each parameter
Pearson X² tests were used to explore the relationship between categorical data
ANOVA showed that site of recruitment did not affect weight change or attrition rate, so all data were analyzed together.

Data Collection Summary:

Timing of Measurements

All measurements were taken at baseline and repeated after six months (except height).

Height
Weight
Waist circumference
Percentage body fat
BMI
Blood pressure
HbA1c
Glucose
Total cholesterol
HDL-cholesterol
LDL-cholesterol
Triglycerides.

Dependent Variables

Weight (using 0.1kg electronic scales)
Waist circumference (measured at naval level and correct to 0.2cm)
Percentage body fat (estimated using bioelectrical impedance analysis)
BMI (calculated by dividing the weight in kg by the height in meters squared)
Blood pressure (measured using an electronic sphygmomanometer)
HbA1c (analyzed from a fasting venous blood sample)
Glucose (analyzed from a fasting venous blood sample)
Total cholesterol (analyzed from a fasting venous blood sample)
HDL-cholesterol (analyzed from a fasting venous blood sample)
LDL-cholesterol (analyzed from a fasting venous blood sample)
Triglycerides (analyzed from a fasting venous blood sample).

Independent Variables

The intervention consisted of a six-month intensive weight and lifestyle intervention. It followed the "Lifestyle Clinic" which aims to achieve a 500kcal per day energy deficit through motivation interviewing, initiation of patient empowerment and provision of support and advice. Subjects were seen by a registered dietitian six times over six months. The first appointment was approximately 90 minutes in duration and subsequent appointments were approximately 30 minutes in duration. Specific topics were discussed at each session and individualized targets were agreed upon and documented.
Subjects in the control group received standard care following general procedures that would occur regardless of study participation. This included an annual review in the endocrinology clinic, appointments and phone contact with diabetes specialist nurses and, if required, referral to other health professionals.

Summary of Topics and Details Covered in the Lifestyle Intervention

Session	Target or Topic	Details
One	Access food intake	Encourage patient to keep a detailed food diary, recording type of food with details, amount, where eaten and feelings, to be kept continuously for at least six months.
One	Increase physical activity	Discuss appropriate activities, specific targets made with regards to amount and intensity. Aiming for at least five times of 30 minutes of moderate-intensity bouts per week.
Two	Personalized energy prescription	Energy requirements with 500kcal per day deficit calculated. Designated number of portions per food group with portion sizes to match energy requirements.
Two	Emotional eating	Discussion and identification of trigger foods and situations. Ascertain coping methods and strategies.
Three	Discussion on fat	Discussion of types of fat, high-fat foods, identification of fat sources in diet from food diary, education and advice aiming to reduce fat intake and improve fat quality by reduction of saturated fat.
Three	Food labels	Explanation of information provided on food labels, limited provided for fats, sugars and salts per 100g.
Four	Carbohydrates	Description of carbohydrate types including GI and the effects of GI on blood glucose.
	Purchasing foods	Ideals and information regarding eating out, shipping and preparation of food aiming to reduce energy intake and maximize nutritional composition.
	Chain of events	Discussion of the whole process of eating, from buying food, thoughts before eating, preparation, consumption and post-prandial feelings. Emotional implications and coping strategies to prevent negative chains.
Five	Hunger scale	Discussion of feelings of hunger and use of placing hunger on an analog scale. Evaluation of reasons for eating, aiming to reduce unnecessary eating habits.
Five	Review of previous topics	Clarification of all previous topics. Assessment of patient's understanding, elucidation of uncertainties.
Six	Review of achievements and results	Repeat of initial measurements, analysis of positive changes achieved over the past six months. Discuss of future targets and incentives.
Six	Details of supportive organizations	Details of support groups, weight-loss classes, websites and organizations available for ongoing long-term support.

Control Variables

Hospital protocols state that patients should be referred to a dietitian when insulin therapy is started; however, only 18% of the whole cohort was seen by another dietitian. Normal referrals or appointments with allied health professionals such as dietitians were unaffected for those in the control group but were documented for purposes of the study.

Description of Actual Data Sample:

Initial N: N=53 (specific numbers of male and female subjects were not defined)
Attrition (final N): N=50 (6% attrition rate)
Age: Mean age was 55.8 years (SD 11.3 years)
Ethnicity: White, black and Asian (specific numbers were not defined)
Anthropometrics: There were no significant differences in sex, ethnicity, age, BMI, percentage of body fat or HbA1c between the control and intervention groups
Location: South East England.

Summary of Results:

Key Findings

Summary of Baseline Anthropometric and Biochemical Data and the Changes Observed in the Intervention Group and Control Groups After Six Months of Insulin Therapy

	Baseline				Change Over Six Months
	Control Group (N=25)		Intervention Group (N=25)		Control Group (N=25)		Intervention Group (N=25
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	P*
Weight (kg)	90.2	16.9	96.6	15.6	4.6	3.7	-0.6	5.0	<0.001
BMI (kg/m²)	32.1	4.3	33.8	5.3	1.6	1.3	-0.3	1.9	<0.001
Waist circumference (cm)	109.7	11.0	112.8	13.0	4.9	5.0	-0.4	5.0	<0.001
Body fat (percent)	35.4	7.4	37.5	10.2	4.5	6.3	-0.1	7.1	0.027
Systolic BP (mm Hg)	143.9	27.1	142.2	19.9	3.8	14.7	-1.9	14.0	0.16
Diastolic BP (mm Hg)	79.5	14.1	80.9	8.4	0.5	8.5	-2.0	8.5	0.30
HbA1c	9.7	1.2	9.6	1.7	-1.2	1.8	-0.9	2.0	0.60
Total cholesterol (mmol per L)	4.6	1.0	4.1	0.8	-0.05	1.0	0.2†	1.0	0.47
HDL-cholesterol (mmol per L)	1.2	0.3	1.1	0.3	-0.07	0.2	-0.02†	0.2	0.35
LDL-cholesterol (mmol per L)	2.6	0.8	2.3	0.8	-0.1‡	0.8	-0.1	0.6	0.40
Total cholesterol:HDL ratio	3.8	1.0	3.7	1.1	0.2‡	0.8	0.1†	0.9	0.81
TAG (mmol per L)	1.8	0.9	1.9	1.1	0.1‡	0.9	0.1	1.0	0.84

*Difference between control and intervention groups (T-test).

† N=20

‡ N=24

The control group gained a significant amount of weight (4.6kg, SD 3.7kg, P<0.001). The intervention group maintained their original weight (mean weight change -0.6kg, SD 5.0kg).The difference in weight change between the intervention and control groups equated to 5.2kg, which was highly significant (P<0.001).
The control group gained an additional 5.1% of body weight in the six months commencing insulin. The intervention group lost 0.5% of body weight (P<0.001).

Other Findings

Both groups experienced a significant reduction in HbA1c. There were no differences in the initial, final or change in HbA1c or fasting glucose between the control and intervention groups.
There were only minor alterations in blood lipids throughout the study
There were no statistical differences in any of the lipid fractions between the groups either at the start or at the end of the study
There were small but non-significant alterations in blood pressure, but the change in blood pressure differed. The control group had a mean increase in both systolic and diastolic blood pressure, while the intervention group had a mean decrease in both readings.
Regardless of study group, overall, there was a positive correlation between percentage weight loss and fall in systolic blood pressure
There was an increase in all CVD risk scores in both groups, except for a very slight decrease in risk of a fatal CHD event in the intervention group. The changes that occurred and the difference between the groups was not significant.

Author Conclusion:

It is possible to prevent weight gain following insulin therapy through an intensive diet and lifestyle program. The present study demonstrates that weight gain is not an inevitable consequence of starting insulin therapy, but attenuation of the weight gain requires a high level of intervention. The first six months to one year after initiating insulin therapy provides the ideal window of opportunity.

Funding Source:

Government:

UK Medical Research Council

Reviewer Comments:

Despite hospital protocol, only 18% of the cohort was seen by another dietitian after starting insulin therapy. This may have affected outcomes of control group. It is possible that one session with a dietitian could attenuate weight gain.

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?	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?		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?		Yes
	5.1.	In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate?	N/A
	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?	N/A
	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?	Yes
	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?	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)?	N/A
	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