GDM: Pharmacologic Therapy (2008)
- Women with GDM diagnosed between 24 and 28 weeks gestation
- Singleton pregnancies
- Without medical complications other than GDM
- Multiple fetuses
- Women with medical complications in addition to GDM
Recruitment
Women were recruited from 3 hospitals in Italy
Design
Upon enrollment into the study, patients were randomized into 1 of 2 protocols: C (conventional) or M (modified). Each protocol group was stratified by pre-pregnancy BMI (<20, 20-26, >26).
Blinding used (if applicable)
None used.
Intervention (if applicable)
Regular insulin before meals or Isophane insulin at bedtime was added (starting at 0.1 U/kg/injection) or the dose was modified (2-3 u/injection) when BG was highter than predetermined target - fasting, post-breakfast, post-lunch or post-dinner. Dietary prescriptions were adjusted to maintain BG below target.
C group's glycemic target was 90 fasting/120 post-prandial mg/dl regardless of fetal biometry.
M group's glycemic targets differed according to fetal abdominal circumference centile (AC): 80/100 mg/dl if > 75th, 100/140 if < 75th.
Statistical Analysis
Student's t test was used to assess differences in means among groups. Categorical data were evaluated by Pearson chi-squared test with Yates correction. Statistical signficance was set at p <0.05.
Timing of Measurements
- Both groups were taught to monitor capillary glucose levels using memory reflectance meters at least 4 times/day.
- Ultrasound exams for fetal biometry were scheduled every 2 weeks for Group M and at 34 and 38 weeks for group C.
- Metabolic controls were scheduled every two weeks for both groups.
- Hypoglycemic monitoring of the neonates was done immediately after birth, then every 30 minutes x the first 3 hours, then hourly x the next 6 hours.
Dependent Variables
- For abdominal circumference > 75th %ile, requiring insulin
- For AC <75th %ile, requiring insulin
- Neonates with macrosomia
- Neonates classified as LGA
Independent Variables
- Conventional therapy (C)
- Modified therapy (M)
Control Variables
Initial N: 240 women (80 in group C and 160 in group M)
Attrition (final N): 229 women (78 in group C and 151 in group M)
Age: Group C: 33.5 + 4.2 years, Group M: 33.8 + 4.6 years
Ethnicity: not mentioned
Other relevant demographics:
Anthropometrics:
No signficant differences between groups C and M in age, BMI, parity, abdominal circumference, plasma glucose, HbA1c or fructosamine levels at entry
Location:
Women were followed in one of 3 hospitals in Italy
Variables |
Group C % |
Group M % |
Statistical Significance of Group Difference |
AC > 75th% ile,insulin treatment required | 15.4 | 59.7 | p < 0.01 |
AC < 75th %ile, insulin treatment required |
17.9 |
10.1 |
p< 0.01 |
Neonates classified as LGA |
17.9 |
7.9 |
p< 0.05 |
Neonates classifed as macrosomic |
11.5 |
3.3 | p< 0.05 |
Neonates classifed as SGA | 10.3 | 6 | NS |
AC > 75th %ile with neonates LGA |
30.8 | 7.9 | p< 0.001 |
AC > 75th %ile with neonates classifed as macrosomic | 17.8 | 4.5 | p <0.001 |
AC <75th %ile, neonates SGA | 30.3 |
14.5
|
p <0.001 |
Other Findings
Our data show the value of a flexible ultrasound based approach to the the treatment of GDM. This model does not necessarily involve a generalized aggressive treatment, allowing to concentrate therapeutic effects on a small subgroup of women showing indirect ultrasound evidence of fetal hyperinsulinzation. Such a selective approach allowed to obtain near-normalization of fetal growth, with clear advantages on global pregnancy outcome.
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.) | 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? | 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? | ??? | |
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? | 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? | ??? | |
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)? | ??? | |
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 | |