EAL

GDM: Pharmacologic Therapy (2008)

Citation:

Study Design:

Class:

- Click here for explanation of classification scheme.

Quality Rating:

Research Purpose:

The purpose of this study was to determine the effects of short-acting insulin (SAI) compared to long-acting insulin (LAI) on glycemic control and fetal outcomes.

Inclusion Criteria:

Women with insulin-requiring GDM

Exclusion Criteria:

None stated

Description of Study Protocol:

Recruitment

Women were recruited from the Helsinki University Central Hospital Department of Obestetrics and Gynecology

Design

Women at risk for GDM (BMI > 25 kg/m2, age > 40 years, previous GDM, previous child with birth weight >4500 grams, glucosuria, macrosomia in current pregnancy) were given an oral glucose tolerance test at weeks 24-28 gestation. If the women had 2 or more abnormalities in OGTT, a 24 hour glucose profile was performed (measuring glucose every 4 hours). Insulin therapy was started when blood glucose was 5.5 mmol/L repeatedly or when with one abnormal preprandial level, one postprandial value was 7.8 mmol/L.

Diet was planned by a dietitian and daily energy intake was 1800 kcal, carbohydrates represented 50% of daily intake.

Women were randomized to either SAI or LAI groups.

Blinding used (if applicable): none

Intervention (if applicable)

SAI was given in 3 daily doses of 4 + 6+ 4 IU before breakfast, lunch and dinner respectively.

LAI was given initially as 14 IU every morning.

Insulin dose was adjusted individually after a second 24 hour blood glucose profile the day following initiation of insulin therapy.

Home blood glucose monitoring was done fasting, before breakfast, and before and after lunch and dinner at least twice weekly.

SAI group had an increase in dosage when one of the postprandial glucose values > 7.8 mmol/L.

LAI group had an increase in dosage if 2 of the daily preprandial blood glucose values > 5.5 mmol/L.

Statistical Analysis

The statistical significance of the differences between the means was assessed by the Student's t-test. P value <0.05 and a Chi Squared test in the case of categorical variables was considered statistically signficant.

Data Collection Summary:

Timing of Measurements

Fetal outcome measurements were done immediately after birth.

Dependent Variables

Maternal insulin dose and duration of therapy
Neonatal birth weight

Independent Variables

Short acting versus long acting insulin therapy

Control Variables

Maternal age
BMI
Parity

Description of Actual Data Sample:

Initial N: 23 women (11 short acting insulin, 12 long acting insulin)

Attrition (final N): 23

Age: Not available

Ethnicity: Not available

Other relevant demographics: Not available

Anthropometrics: Paper states that the groups were similar in terms of age, BMI and parity (data not shown)

Location: Helsinki, Finland

Summary of Results:

Neonatal outcome	Short acting insulin (SAI)	Long acting insulin (LAI)	P value
Birth weight (g + SD)	3079 (722)	3943 (492)	0.005
Relative birth weight (+ SD)	- 0.28 (1.11)	1.33 (1.29)	0.007
Macrosomia (>2 SD) (n)	0	4	0.05

Other Findings:

There were no signficant differences between groups in maximal insulin dose/day, the number of subjects whose insulin dose was increased, duration of insulin therapy or weeks of labor. There were no signficant differences between groups in maternal HbgA1c at delivery (data not shown).

Author Conclusion:

In our small prospective study, the overall diabetic control was similar, and the daily insulin doses did not differ between the groups. Our results suggest that GDM should be treated with short-acting insulin.

Funding Source:

University/Hospital:

Helsinki Direct University Central Hospital

Reviewer Comments:

Small sample size, compliance not measured, maternal glucose values not reported

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?		???
	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?	???
	2.4.	Were the subjects/patients a representative sample of the relevant population?	???
3.	Were study groups comparable?		???
	3.1.	Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT)	???
	3.2.	Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline?	???
	3.3.	Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.)	???
	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?	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?	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?	???
	6.5.	Were co-interventions (e.g., ancillary treatments, other therapies) described?	???
	6.6.	Were extra or unplanned treatments described?	???
	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?	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)?	Yes
	8.5.	Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)?	N/A
	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