Randomized Controlled Trial

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POSITIVE: See Quality Criteria Checklist below.

To investigate the effectiveness of practice guideline nutritional care compared with usual nutrition care on medical and clinical outcomes for patients with type 2 diabetes in Oman.

• Age between 30 years and 70 years
• Diagnosed with having type 2 diabetes
• Free of diabetic complications (such as gastroparesis and renal disease)
• Consented to participate in the study.

• A recent heart attack or stroke (within the previous six months)
• A serious illness (such as cancer or surgery within the previous four weeks)
• Illnesses requiring corticosteroid therapy
• Became pregnant.

 

 

Recruitment

Two hundred subjects were invited to participate.

• This number was estimated based on the power calculation to detect a 1.0 percentage point difference in the amount of change in HbA1c levels between the groups
• A total of 77 subjects were required in each group. To account for sample dropout during the period of the study, 23 subjects (approximately 25%) were added to each group.

Design

Randomized controlled trial.

Blinding Used

Implied with measurements.

Intervention

• A total of 200 subjects were assigned randomly to the usual nutrition care group or the group receiving practice guidelines nutritional care
  • Each patient was given a number, which was put in a box
  • By random selection, the first 100 numbers were assigned to the usual nutrition care group.
• Usual Nutrition Care Group (UNC):
  • Before the first visit (after the referral is made) the dietitian obtains the referral data
  • First visit was approximately one hour:
    • A dietitian discusses the general principles of nutrition management of diabetes, nutrition education and nutrition prescription
    • Summary to referral physical
    • A physical will decide if the patient requires a follow-up visit six months after the first visit.
• Practice Guidelines Nutritional Care Group (PGC):
  • Initial visit was a minimum of one to 1.5 hours:
    • Assessment: Medical, lifestyle and psychological issues
    • Intervention: Nutrition prescription, education and goal setting.
  • First follow-up visit was a minimum of 30 minutes to 45 minutes (within two weeks of initial visit):
    • Assessment: Progress to stated short-term goals and intervention
    • Intervention: Change in medical nutritional treatment if the goals sited at the initial visit were not achieved; ongoing skills and education.
  • Second follow-up visit was a minimum of 30 minutes to 45 minutes (within two weeks to four weeks of the initial visit):
    • Assessment: Progress to target blood glucose goals
    • Intervention: Make medical nutritional treatment changes; recommend medical therapy changes as needed.
  • Ongoing follow-up visit was at minimum once every six to 12 months:
    • Communication: Long-term goals and plans for ongoing care, such as controlling blood glucose, having a healthy lifestyle and controlling risk factors of long-term complications.
  • Summary to referral source.

Statistical Analysis

• Continuous variables between the two groups were analyzed by ANOVA
• The changes in variables between at entry, at three months and at six months in each group were analyzed by paired T-test
• The level for significance for all tests was P<0.05
• All of the analyses were carried out using the Statistical Package for Social Sciences, version 15.0 (SPSS Inc, Chicago, IL, USA).

Timing of Measurements

• The study was conducted during the period from April 2009 to September 2009. The Muslim fasting month of Ramadan was not included in the study period.
• All subjects were assessed at the time of enrollment and three and six months later.

Dependent Variables

• Anthropometric measurements:
  • Weight: Measured with patients wearing light clothing and without shoes, by dietitians using an electric scale or beam-balance scale
  • Height: Measured using a wall measure
  • BMI: Calculated as weight in kilograms divided by height in square meters (kg/m²)
  • Waist circumference: Measured by dietitians using a cloth tape measure with subjects standing in a relaxed position. Subjects were measured at the horizontal level that yielded the minimum measurement.
• Glucose levels:
  • Were measured after a 12-hour fast at baseline, three months and six months
  • With the patient in a seated position, 30ml of venous blood was drawn from the antecubital vein
  • Assessment was made for:
    • Fasting plasma glucose: By the hexokinase method using Baxter Paramax
    • HbA1c levels: By ion exchange high-performance liquid chromatography on a Bio-Rad Diamat analyzer
• Lipid profile:
  • Assessment of:
    • Serum total cholesterol
    • LDL-cholesterol
    • HDL-cholesterol
    • Serum triglyceride values.
  • Lipid values were determined by enzymatic methods on the Baxter Paramax
• Outcomes were considered successful if:
  • Weight loss of 1.5kg to 3.0kg at four weeks to six weeks and a weight loss of 4.5kg to 9kg at six months
  • BMI 25 or less
  • Fasting plasma glucose level of 4.4mmol to 7.8mmol per L or a minimum 20% decrease from entry to six months
  • A HbA1c value of 58 mmol per mol [7.5% or less, with a normal measurement less than 42mmol per mol (6%)]
  • Minimum 20% decrease from initial appointment to six-month appointment
  • Total cholesterol of 5.2mmol per L or less
  • LDL-cholesterol of 3.38mmol per L or less
  • Triglyceride levels of less than 2.26mmol per L.

Independent Variables

• Practice guidelines for medical nutrition treatment
• Usual nutrition care.

• Initial N: N=200 subjects
• Attrition (final N): N=170 subjects (85% of the original enrollees).

Age

	UNC Group (N=85) Mean±SD	PGC Group (N=85) Mean±SD	All (N=170) Mean±SD	P
Age (years)	52.0±9.2	49.5±11.3	50.7±10.4	0.122

Ethnicity

Described as Arab patients.

Other Relevant Demographics

	UNC Group (N=85)	PGC Group (N=85)	All (N=170)
Gender
Male	N=33 (38.8%)	N=38 (44.7%)	N=71 (41.8%)
Female	N=52 (61.2%)	N=47 (55.3%)	N=99 (58.2%)
Diabetes duration
Less than four years	N=10 (11.8%)	N=22 (25.9%)	N=32 (37.6%)
More than four years	N=75 (88.2%)	N=63 (74.1%)	N=53 (62.4%)
Medical nutrition therapy (MNT)
MNT alone	N=11 (13%)	N=10 (11.8%)	N=21 (12.4%)
MNT and oral agents	N=37 (43.5%)	N=45 (52.9%)	N=82 (48.2%)
MNT and combination therapy (oral agents and insulin)	N=37 (43.5%)	N=30 (35.3%)	N=67 (39.4%)
Education
Less than high school	N=50 (58.8%)	N=48 (56.5%)	N=98 (57.6%)
High school	N=15 (17.6%)	N=17 (20%)	N=32 (18.8%)
College	N=20 (23.5%)	N=20 (23.5)	N=40 (23.5%)

Anthropometrics

There was no significant difference between groups at baseline.

	UNC group (n=85) Mean±SD	PGC group (n=85) Mean±SD	All (n=170) Mean±SD	p
Weight (kg)	72.2±12.9	73.3±13.6	72.7±13.0	0.586
Body mass index (kg/m2)	28.4±5.2	27.6±5.3	28.0±5.2	0.313
Waist circumference (cm)	97.9±8.3	97.2±7.5	97.5±7.9	0.554
Fasting plasma glucose (mmol per L)	12.1±3.3	12.4±3.1	12.3±3.2	0.466
HbA1c
(mmol per L)	88	89	89	0.632
(Percentage)	10.2±2.4	10.3±1.8	10.3±2.1
Cholesterol (mmol per L)	5.4±0.9	5.3±1.0	5.4±1.0	0.825
LDL-cholesterol (mmol per L)	3.46±0.88	3.57±0.93	3.52±0.90	0.437
HDL-cholesterol (mmol per L)	1.08±0.22	1.05±0.23	1.07±0.23	0.345
Triglycerides (mmol per L)	1.80±0.87	1.64±0.70	1.72±0.79	0.187
Urea (mmol per L)	5.3±1.4	5.6±1.2	5.5±1.3	0.084
Creatinine (mcgmol per L)	62.8±17.0	62.4±12.8	62.6±15.0	0.839
White blood cells (109 per L)	6.2±2.1	6.0±1.5	6.1±1.8	0.459
Hemoglobin (g per dL)	12.5±0.86	12.3±1.4	12.4±1.1	0.224
Platelets (109 per L)	280±68	291±61	286±65	0.309

Location

Muscat, Oman.

Key Findings

 

	PGC (N=85)			UNC (N=85)
Variables	Entry Mean±SD	Three Months Mean±SD	Six Months Mean±SD	Entry Mean±SD	Three Months Mean±SD	Six Months Mean±SD
Weight (kg)	73.3±13.6	68.7±13.9 Zero vs. three months*	68.2±13.4 Zero vs. six months*	72.2±12.9	69.7±12.2	69.6±12.1
BMI (kg/m2)	27.6±5.3	26.3±5.7 Zero vs. three months*	26.2±5.3	28.4±5.2	27.4±4.9	27.4±5.0
Waist circumference (cm)	97.2±7.5	96.9±7.6	96.9±7.9 ¥	97.9±8.3	99.0±8.7	100.0±8.7
Fasting plasma glucose (mmol per L)	12.4±3.2	10.4±2.5§ Zero vs. three months***	11.1±2.8 Zero vs. six months**	12.1±3.3	11.2±3.0	11.9±3.2
HbA1c
mmol per mol	89	75	80	88	79	84
Percentage	10.3±1.8	9.0±1.8 Zero vs. three months***	9.5±1.4 Zero vs. six months** Three vs. six months*	10.2±2.4	9.4±2.0	9.8±1.8
Cholesterol (mmol per L)	5.3±1.0	5.1±1.0	5.1±0.97	5.4±0.9	5.1±0.8 Zero vs. three months*	5.5±0.9 Three vs. six months**
LDL-cholesterol (mmol per L)	3.57±0.93	3.74±1.01	3.58±0.98	3.37±0.88	3.63±0.75	3.66±0.87
HDL-cholesterol (mmol per L)	1.05±0.23	1.01±0.33	1.09±0.32	1.08±0.22	1.05±0.25	1.01±0.22 Zero vs. six months*
Triglycerides (mmol per L)	1.64±0.70	1.39±0.62 Zero vs. three months*	1.42±0.58¥ Zero vs. six months*	1.80±0.87	1.70±0.75	1.98±0.96 Three vs. six months*

•  *P<0.05
• **P<0.01
• ***P<0.001
• § P=Significant difference between two groups at three-month point
• ¥ P=Significant difference between two groups at six-month point

PGC Group Findings

• Compared with entry time, the mean weight values of the PGC group decreased significantly at the three-month point of the study and these levels were sustained at six months
• At six months, 55.3% (N=47) of the group receiving PGC had achieved the target outcome of 4.5kg or more weight loss
• At three months, participants of PGC had reduced their entry fasting plasma glucose mean levels by 16.7% and their HbA1c mean levels by 13.1%
• At six months, those in the PGC group had reduced their mean fasting plasma glucose level by 11.2% and their HbA1c level by 8.2% compared with levels at entry to the study
• The waist circumference measurements of the group of patients receiving PGC show a significant decrease compared with patients in the UNC group at the six-month point.

UNC Group

• At 6 months, 14% (N=12) of the UNC group had achieved a successful weight loss of 4.5kg or more
• The UNC group showed an insignificant decrease at three months and then an upward trend at six months for both HbA1c and fasting plasma glucose
• The UNC group demonstrated a mean 7.3% reduction in fasting plasma glucose level and an 8% reduction of HbA1c level at the three-month point.

Both Groups

Approximately 57% (N=97) of all participants (N=170) achieved their target goal of a fasting plasma glucose level of 7.8mmol or less per L and a HbA1c values of 58mmol or less per mol (7.5%) or a 20% decrease after six months. 

Other Findings

•  By the end of the six-month point:
  • A total of 18.2% (N=31) of the total study group were treated by medical nutritional treatment alone [compared to 12.4% (N=21) at baseline]
  • A total of 47.1% (N=80) were treated by medical nutritional treatment and oral agent [compared to 48.2% (N=82) at baseline]
  • A total of 34.7% (N=59) by medical nutritional treatment with a combination therapy of insulin and oral agents [compared to 39.4% (N=67) at baseline].
• The group treated with medical nutritional treatment alone and the group treated with medical nutritional treatment and oral hypoglycemic agents experienced a greater weight loss than the other therapy groups (from baseline weight of 73.4±13.8kg to 68.2±13.2kg at six months)
• The group receiving medical nutritional treatment and a combination therapy of insulin and oral agents also experienced a weight loss from baseline (73.1±13.5kg to 68.4±14.5kg) at six months
• In the total group (N=170), 20 changes in therapy (12% subjects) were reported:
  • N=6 (7%) in the UNC group
  • N=14 (16.5%) in the PCG group (all recommended by the dietitian to the treating physician for implementation).

 

 

 

 

• Medical nutrition therapy provided by dietitians to Arab patients with type 2 diabetes in Oman resulted in significant improvements in anthropometric and biochemical outcomes in both the UNC group and the PCG group
• Subjects with type 2 diabetes tended to do better with PGC than UNC
• Ongoing medical counseling in nutrition by a trained dietitian is important for better long-term metabolic control.

Other:

not described