Is there a role for metformin in Gestational Diabetes?
The standard of care for gestational diabetes has been lifestyle (diet changes (carbohydrate restriction) and activity) and if not at goal (fasting < 90-95 mg/dl, 1 hour after meal < 140, 2 hour < < 120) then insulin is used. However, there is a literature on the use of metformin and sulfonylureas (glyburide) in pregnancy. I do NOT recommend the use of sulfonylureas during pregnancy as insulin is safer and more effective. Its use may be justified in certain circumstances such as patient populations if insulin will not be available or used safely and effectively (and metformin is not tolerated) as improved glucose control may trump the potential side effects. A meta-analysis (BMJ January 21st 2015, 350:h102) found glibenclamide clearly inferior to both insulin and metformin. Metformin (plus insulin when needed) performed slightly better than insulin.
Metformin is widely used in pregnancy but this remains a controversial area. Firstly and of interest, metformin is used in women with polycystic ovarian syndrome (PCOS) during the first trimester of pregnancy (when organ development is occurring) and there is clinical evidence this is safe and potentially cuts the risk of early miscarriage.
The medical literature also supports the use of metformin. There are randomized clinical trials using metformin in the treatment of women with GDM. In the Metformin in Gestational Diabetes (MiG) trial (NEJM 2008;358:2003-2015, 751 women were randomized to receive either metformin or insulin. There was no significant difference in the composite fetal outcome between the two groups although preterm birth was found to be increased in the metformin group. Women in the metformin group had less weight gain compared with women in the insulin group. The results provide further evidence regarding the safety of metformin in pregnancy. A comparable, but much smaller, randomized trial of 63 patients found similar results. (J. Reprod. Med 2007;52, 1011-1015). A metanalysis of metformin vs insulin (PLOS one 2013; 8(5):e645985 ) found comparable glucose control and neonatal outcomes. They comment that metformin may be more suitable for women with mild GDM. Obviously insulin can be added or substituted if glucose control is not achieved with metformin.
Recent studies also support the safety of metformin (it does cross the placenta while insulin does not). An Austalasian study of neurodevelopmental outcomes at 2 years of 211 offspring treated with metformin versus insulin (Arch Dis Child Fetal neonatal Ed, 2016 Feb 24 Arch Dis Child Fetal Neonatal Ed. 2016 Feb 24. pii: fetalneonatal-2015-309602. doi: 10.1136/archdischild-2015-309602. [Epub ahead of print)) showed no significant differences in outcomes. A recent meta-analysis (Ir J Med Sci 2016 Feb 9) suggest that metformin may be beneficial in GDM but called for more studies.
Also of interest there was a recent trial on the use of metformin in 202 obese pregnant women without diabetes (N Engl J Med. 2016 Feb 4;374(5):434-43. doi: 10.1056/NEJMoa1509819.) This showed that women with BMI > 35, maternal weight gain was reduced but not neonatal birth weight.
The standard of care for gestational diabetes has been lifestyle (diet changes (carbohydrate restriction) and activity) and if not at goal (fasting < 90-95 mg/dl, 1 hour after meal < 140, 2 hour < < 120) then insulin is used. However, there is a literature on the use of metformin and sulfonylureas (glyburide) in pregnancy. I do NOT recommend the use of sulfonylureas during pregnancy as insulin is safer and more effective. Its use may be justified in certain circumstances such as patient populations if insulin will not be available or used safely and effectively (and metformin is not tolerated) as improved glucose control may trump the potential side effects. A meta-analysis (BMJ January 21st 2015, 350:h102) found glibenclamide clearly inferior to both insulin and metformin. Metformin (plus insulin when needed) performed slightly better than insulin.
Metformin is widely used in pregnancy but this remains a controversial area. Firstly and of interest, metformin is used in women with polycystic ovarian syndrome (PCOS) during the first trimester of pregnancy (when organ development is occurring) and there is clinical evidence this is safe and potentially cuts the risk of early miscarriage.
The medical literature also supports the use of metformin. There are randomized clinical trials using metformin in the treatment of women with GDM. In the Metformin in Gestational Diabetes (MiG) trial (NEJM 2008;358:2003-2015, 751 women were randomized to receive either metformin or insulin. There was no significant difference in the composite fetal outcome between the two groups although preterm birth was found to be increased in the metformin group. Women in the metformin group had less weight gain compared with women in the insulin group. The results provide further evidence regarding the safety of metformin in pregnancy. A comparable, but much smaller, randomized trial of 63 patients found similar results. (J. Reprod. Med 2007;52, 1011-1015). A metanalysis of metformin vs insulin (PLOS one 2013; 8(5):e645985 ) found comparable glucose control and neonatal outcomes. They comment that metformin may be more suitable for women with mild GDM. Obviously insulin can be added or substituted if glucose control is not achieved with metformin.
Recent studies also support the safety of metformin (it does cross the placenta while insulin does not). An Austalasian study of neurodevelopmental outcomes at 2 years of 211 offspring treated with metformin versus insulin (Arch Dis Child Fetal neonatal Ed, 2016 Feb 24 Arch Dis Child Fetal Neonatal Ed. 2016 Feb 24. pii: fetalneonatal-2015-309602. doi: 10.1136/archdischild-2015-309602. [Epub ahead of print)) showed no significant differences in outcomes. A recent meta-analysis (Ir J Med Sci 2016 Feb 9) suggest that metformin may be beneficial in GDM but called for more studies.
Also of interest there was a recent trial on the use of metformin in 202 obese pregnant women without diabetes (N Engl J Med. 2016 Feb 4;374(5):434-43. doi: 10.1056/NEJMoa1509819.) This showed that women with BMI > 35, maternal weight gain was reduced but not neonatal birth weight.
www.healthjourneysupport.com
Links to useful gestational diabetes resources:
American Diabetes Association
Mayo Clinic
National Institute of Diabetes and Digestive and Kidney diseases NIH: NIDDK
American Diabetes Association
Mayo Clinic
National Institute of Diabetes and Digestive and Kidney diseases NIH: NIDDK
Gestational Diabetes
Why does this develop?
Pregnancy is an insulin resistant state. The body compensates by producing extra insulin. If there is still not enough insulin then the blood glucose levels will rise. There may be underlying susceptibility factors such as genetic factors (can be reflected by family history of diabetes and/or ethnic background) and underlying conditions such as polycystic ovarian syndrome or obesity.
Why is screening for and detecting GDM important?
Elevated blood glucose levels can lead to fetal macrosomia (abnormally large baby) and this an lead to mechanical obstetrics complications at delivery. There are other potential negative consequences to gestational diabetes (and excess body fat) that treatment can help limit or avoid.
Why does this develop?
Pregnancy is an insulin resistant state. The body compensates by producing extra insulin. If there is still not enough insulin then the blood glucose levels will rise. There may be underlying susceptibility factors such as genetic factors (can be reflected by family history of diabetes and/or ethnic background) and underlying conditions such as polycystic ovarian syndrome or obesity.
Why is screening for and detecting GDM important?
Elevated blood glucose levels can lead to fetal macrosomia (abnormally large baby) and this an lead to mechanical obstetrics complications at delivery. There are other potential negative consequences to gestational diabetes (and excess body fat) that treatment can help limit or avoid.
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Type 1 Diabetes: The Latest TechnologyInsulin pumps
Insulin pumps are small devices that can be worn and are programmed to deliver insulin through a catheter directly under the skin. Here is the 2015 American Diabetes Association Consumer Guide to Insulin Pumps: http://main.diabetes.org/dforg/pdfs/2015/2015-cg-insulin-pumps.pdf Tubeless: Omnipod Tubed: Minimed Medtronic T-Slim Animus Vibe CGMS: Continuous glucose monitor systems (CGMS) have sensors that track blood sugar levels automatically every few minutes 24 hours a day. A transmitter on the sensor reports the data to a wireless monitor, and sounds an alarm if sugars reach a preset dangerous level. This alarm transmits to all designated cell phones immediately. We can help link your CGMS to your insulin pump so it will adjust insulin administration accordingly. Here is the 2014 American Diabetes Association Consumer Guide to CGM's: http://main.diabetes.org/dforg/pdfs/2014/2014-cg-continuous-glucose-monitors.pdf Blinded diagnostic: Minimed iPro Dexcom Abbott Libre (available in Europe) Closed loop systems (pending approval in USA or in development:) |
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