Comparison of Insulin Alone to Insulin With Metformin to Treat Gestational Diabetes Mellitus

NCT ID: NCT03651531

Last Updated: 2020-07-24

Basic Information

• Recruitment Status: TERMINATED
• Clinical Phase: PHASE3
• Total Enrollment: 1 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-01-03
• Study Completion Date: 2019-07-30

Brief Summary

This study is a prospective, unmasked randomized clinical trial comparing the use of insulin vs combination insulin and metformin for treatment in women diagnosed with gestational diabetes mellitus (GDM). The investigator's hypothesis is that the combination of metformin and insulin will be superior to insulin alone to achieve tight glucose control during pregnancy.

Detailed Description

The objective of this study is to compare the effectiveness of insulin alone vs the combination of insulin and metformin in treating patients with gestational diabetes (GDM). Currently, outside of pregnancy, the treatment of type 2 diabetes mellitus (T2DM) with both metformin and insulin is superior to using insulin alone. In pregnancy, insulin alone has traditionally been used, though some advocate the use of metformin alone as primary therapy. There have been no trials published to date specifically comparing combination therapy to insulin alone. Our hypothesis is that the combination of metformin and insulin will improve overall control of blood glucose, the improvement of which has been demonstrated to improve maternal and neonatal outcomes. Control of blood glucose will be determined by hemoglobin A1c at the time of delivery.

Conditions

Gestational Diabetes

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

insulin

Group Type: ACTIVE_COMPARATOR

Insulin

Intervention Type: DRUG

Weight based insulin will be calculated using 0.7 units/kg/day in the first trimester, 0.8 units/kg/day in the second trimester and 1 units/kg/day in the third trimester. This total insulin will then be divided into short acting insulin and intermediate acting insulin per provider discretion.

insulin and metformin

Group Type: ACTIVE_COMPARATOR

Insulin

Intervention Type: DRUG

Weight based insulin will be calculated using 0.7 units/kg/day in the first trimester, 0.8 units/kg/day in the second trimester and 1 units/kg/day in the third trimester. This total insulin will then be divided into short acting insulin and intermediate acting insulin per provider discretion.

Metformin

Intervention Type: DRUG

Will be initiated at dose of 500 mg twice daily. If glycemic control is suboptimal, the dose of metformin will be increased to 1000 mg twice a day. Metformin will be titrated prior to increases in insulin.

Interventions

Insulin

Weight based insulin will be calculated using 0.7 units/kg/day in the first trimester, 0.8 units/kg/day in the second trimester and 1 units/kg/day in the third trimester. This total insulin will then be divided into short acting insulin and intermediate acting insulin per provider discretion.

Intervention Type: DRUG

Metformin

Will be initiated at dose of 500 mg twice daily. If glycemic control is suboptimal, the dose of metformin will be increased to 1000 mg twice a day. Metformin will be titrated prior to increases in insulin.

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• Able to read and write English and/or Spanish and give written consent
• Diagnosis of GDM, defined as an abnormal glucose tolerance test performed after 12 weeks gestation using 1 of the 2 criteria below:
• 50 gram 1 hour oral diabetes screening testing yielding a result of > 200 mg/dL
• A 100 gram 3 hour oral glucose tolerance testing yielding >2 abnormal values (normal values defined as fasting blood glucose < 95, 1 hour < 180, 2 hour < 155 and 3 hour < 140)
• Singleton gestation
• Gestational age between 12 and 34 weeks and 6 days determined by last menstrual period (LMP) confirmed by ultrasound using criteria set forth by the ACOG (Committee on Obstetric Practice). If LMP is unknown then gestational age must be set by ultrasound prior to 20 weeks gestation.

Exclusion Criteria

• Pre-existing DM either by diagnosis preceding pregnancy or hemoglobin A1c >6.5 collected during the current pregnancy
• Uncontrolled chronic hypertension, as this may alter maternal and perinatal outcomes measured.
• Multiple gestations
• Major fetal anomalies anticipated to require NICU admission
• Contraindication to metformin (allergy, history of lactic acidosis, pre-existing renal disease (Cr >1.5 mg/dL), active liver disease, current alcohol abuse).
• Vitamin B12 deficiency, as metformin reduces intestinal absorption of vitamin B12
• Medications known to effect glucose metabolism other than insulin and metformin as this may mask any effect between the two treatments.
• Known inability to tolerate metformin.

• Minimum Eligible Age: 18 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

Women and Infants Hospital of Rhode Island

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Christopher Nau, MD

Role: PRINCIPAL_INVESTIGATOR

Women & Infants Hospital

Erika Werner

Role: PRINCIPAL_INVESTIGATOR

Women & Infants Hospital

Locations

Women & Infants Hospital

Providence, Rhode Island, United States

Countries

United States

References

Committee Opinion No 700: Methods for Estimating the Due Date. Obstet Gynecol. 2017 May;129(5):e150-e154. doi: 10.1097/AOG.0000000000002046.

Reference Type: BACKGROUND

PMID: 28426621 (View on PubMed)

Other Identifiers

1099865-3

Identifier Type: -

Identifier Source: org_study_id