DM: Blood Glucose Self-Monitoring (2007)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To describe breakfast and lunch postprandial glucose changes in subjects with type 1 diabetes using subcutaneous glucose-monitoring.
Inclusion Criteria:
  • Type 1 diabetes
  • Intensive insulin treatment
Exclusion Criteria:
  • Age <18 years or >69 years
  • BMI > 30 kg/m2
  • Detectable C-peptide
  • Glycosylated hemoglobin > 9%
  • Pregnancy
  • Alcohol/drug abuse
  • Abdominal/hepatic disease, anemia, low platelet count, clotting disorders
  • History of myocardial infarction, pre-proliferative retinopathy, neuropathy, and/or microalbuminuria > 200 µg/min

 

Description of Study Protocol:

Recruitment

Not provided

Design

Comparison of glycemic values every three minutes over a 24-hr period in 23 subjects with type 1 diabetes with good control

Blinding used (if applicable):Not applicable 

Intervention (if applicable): Not applicable

Statistical Analysis

  • Between-group comparisons: t-test or Mann-Whitney test (for non-Gaussian variables)
  • Comparison between parameters of glucose changes: paired t-tests or Wilcoxon tests.
Data Collection Summary:

Timing of Measurements

Every 3 minutes for 24 hours 

Dependent Variables

  • Intravenous blood glucose: glucose oxidase method (Vitros autoanalyzser, Ortho, Johnson & Johnson)
  • Capillary blood glucose: by patient, using his/her habitual glucometer
  • Subcutaneous glucose: GlucoDay (A. Menarini Diagnostics)

Independent Variables

  • Type 1 diabetes

Control Variables

  • Serum total cholesterol, HDL-cholesterol and triglycerides: no method provided
  • LDL-cholesterol: Friedewald method
  • HbA1c : HPLC cation exchange column (Modular Diabetic Monitoring System
  • Insulin doses: insulin was increased by 1 unit per carbohydrate portion and per 50 mg/dl increase in pre-prandial capillary glucose above the level of 100 mg/dl.

 

Description of Actual Data Sample:

Initial N: 23 subjects: 11 female, 12 male

Attrition (final N): none reported

Age:

  • Females: 42 years (23-50)
  • Males: 43 years (24-58)

Ethnicity: not provided

Other relevant demographics:

  • duration of diabetes: Females - 13 yrs (7-27); males - 20 (3-30)
  • Smoker: 3 of 11 females; 2 of 11 males
  • Alcohol: 7 of 11 females; 12 of 12 males

Anthropometrics : BMI: females - 22.9 kg/m2 ±1.9; males - 24.6±2.2

Location: Metabolic research unit, University of Antwerp, Belgium

 

Summary of Results:

 

Variables (based on subcutaneous glucose measurements)

Breakfast Lunch

Statistical Significance of Group Difference

2 hr glucose (mg/dl) 243±69 180±79 p<0.0001
Maximum glycemia (mg/dl)

313±105, at 78 min

 

304±119 at 57 min

p<0.0001

 

Other Findings

  • Duration of hyperglycemic periods was not different after breakfast or lunch, but time spent at glucose < 100 mg/dl was longer after lunch (p < 0.0001)
  •  HbA1c: females - 7.73%±0.83; males - 7.67±0.79
  • Fasting total cholesterol:L females - 4.81 mmol/L±0.7; males - 5.03±0.84
  • Fasting HDL cholesterol: females - 1.7±0.68mmol/L; males 1.69±0.34
  • Fasting triglycerides: females - 1.06±0.41; males - 1.01±0.4
  • Systolic blood pressure: females - 117 mmHg (98=135); males - 122 (105-146)
  • Diastolic blood pressure: females - 65 mmHg (55-78); males - 67 (55-92)

 

Author Conclusion:

Analysis of the one-day GlucoDay data demonstrated

  • a high inter-individual variability and a less than optimal postprandial glycemic control.
  • differences between post-breakfast and post-lunch periods that might be relevant in the adjustment of insulin regimens
  • a weak or absent association with parameters of diabetes control
Funding Source:
Reviewer Comments:
  • To use the GlucoDay device, subjects were required to be sitting or lying down during the whole time (like the old Biostater).  This does not reflect a normal day, especially in terms of physical activity
  • Breakfast and lunch were standardized meals:
    • Breakfast (883 kcal, 58.5% energy as fat and 30.5% of energy as carbohydrate
    • Lunch (698 kcal, 50.2% of energy as fat and 27.8% as carbohydrate.
    • NOTE: usually the % are the reverse.  Either the authors made an error in the report, or subjects received over half of their energy as fat, which would have some influence over the results of the subcutaneous blood glucose monitoring. 
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) No
 
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? ???
  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? No
3. Were study groups comparable? N/A
  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? N/A
  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? Yes
  4.1. Were follow-up methods described and the same for all groups? N/A
  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%.) N/A
  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? 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? ???
  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? No
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? N/A
  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? N/A
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? ???
  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? N/A
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)? No
  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