Metformin × HbA1c

Study 1 · Limited

Early use of effective therapies may improve diabetes outcomes

Comparison

Metformin as first line therapy, followed by empagliflozin 10 mg as second line therapy, and tirzepatide 10 mg as third line therapy. · Metformin as first line therapy, followed by empagliflozin 10 mg as second line therapy, and liraglutide 1.8 mg as third line therapy. · Metformin as first line therapy, followed by empagliflozin 10 mg as second line therapy, and semaglutide 1.0 mg as third line therapy. · Metformin as first line therapy, followed by empagliflozin 10 mg as second line therapy, and dulaglutide 3.0 mg as third line therapy.

Duration / follow-up

156 weeks

Study 2 · Limited

GLP-1 agonists reduce heart fat thickness in diabetes.

Comparison

Patients received semaglutide as part of their treatment regimen. · Patients received dulaglutide as part of their treatment regimen. · Patients received metformin as the control treatment.

Duration / follow-up

12 weeks

Study 3 · Limited

Insulin glargine plus metformin and glimepiride improves glycemic control in type 2 diabetes.

Rct

Comparison

Patients received insulin glargine in the morning with fixed doses of metformin. · Patients received insulin glargine in the morning with fixed doses of glimepiride. · Patients received insulin glargine in the morning with fixed doses of both glimepiride and metformin.

Duration / follow-up

24 weeks

Study 4 · Included

Intermittent Fasting Diet Improves Glycemic Control in Type 2 Diabetes

Rct

Comparison

Participants received a 16 week intermittent fasting plan consisting of 2 nonconsecutive fasting days and 5 days of habitual intake. · Participants received metformin for 16 weeks. · Participants received empagliflozin for 16 weeks.

Duration / follow-up

16 weeks

Study 5 · Included

Metformin DR enhances glycemic control in T2D patients.

Rct

Comparison

Participants received placebo once daily at the beginning of the morning meal. · Participants received 600 mg of metformin delayed release once daily. · Participants received 900 mg of metformin delayed release once daily. · Participants received 1200 mg of metformin delayed release once daily. · Participants received 1500 mg of metformin delayed release once daily. · Participants received 2000 mg of metformin immediate release twice daily.

Duration / follow-up

16 weeks

Study 6 · Included

Metformin improves glycemic control in heart failure patients

Rct

Comparison

Participants received metformin for 3 months followed by a washout period and then switched to placebo for another 3 months. · Participants received placebo for 3 months followed by a washout period and then switched to metformin for another 3 months.

Duration / follow-up

13 weeks

Study 7 · Included

Metformin may improve glycemic control in youth with type 1 diabetes

Rct

Comparison

Participants received adjunctive metformin at a dose of 1000 mg daily for 9 months. · Participants received similar appearing placebo capsules daily for 9 months.

Duration / follow-up

1040 weeks

Study 8 · Included

Metformin may reduce prandial insulin needs in pregnant women with type 1 diabetes

Rct

Comparison

Pregnant women with type 1 diabetes receiving metformin. · Pregnant women with type 1 diabetes receiving placebo.

Duration / follow-up

4 weeks

Study 9 · Limited

Ranolazine improves glycaemic control when added to metformin in T2DM patients

Comparison

Patients receiving metformin as monotherapy. · Patients receiving metformin plus ranolazine.

Duration / follow-up

4 weeks

Study 10 · Included

Tofogliflozin may improve insulin secretory capacity in some type 2 diabetes patients

Rct

Comparison

Participants received 20 mg tofogliflozin per day for 4 weeks. · Participants received 500 mg metformin per day for 4 weeks.

Duration / follow-up

4 weeks

Study 11 · Included

Vildagliptin and Metformin Improve Glycemic Control in Type 2 Diabetes

Rct

Comparison

Patients received 50 mg of vildagliptin orally twice daily. · Patients received 500 mg of metformin orally twice daily with meals, with dosage adjustable.

Duration / follow-up

26 weeks