Metformin Withdrawal In Metabolic Syndrome

Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18+
SponsorUniversity of Castilla-La Mancha

About this trial

The goal of this clinical trial is to investigate how a short-term interruption of metformin treatment affects insulin sensitivity, glucose control, and metabolic flexibility in adults with metabolic syndrome who are taking metformin as part of their usual medical treatment. Temporary interruptions in metformin treatment may occur in real-life situations, such as missed doses, medication access problems, travel, or planned short-term discontinuation for clinical reasons. This study aims to understand whether stopping metformin for 14 days leads to rapid changes in glucose metabolism or whether the effects of previous metformin treatment may persist during a short period without the medication.

The main questions it aims to answer are:

Does stopping metformin for 14 days worsen glucose control or insulin sensitivity measured by oral glucose tolerance tests, HbA1c, and continuous glucose monitoring?

Does stopping metformin for 14 days affect metabolic flexibility, measured by indirect calorimetry during the oral glucose tolerance test?

Does stopping metformin for 14 days affect blood lipids, liver and inflammatory markers, red blood cell parameters, kidney function markers, fasting lactate levels, blood pressure, or heart rate?

Researchers will compare participants who stop metformin for 14 days with participants who continue their usual metformin treatment to see whether temporary metformin discontinuation affects insulin sensitivity, glucose control, metabolic flexibility, and other cardiometabolic markers.

Participants in the metformin discontinuation group will stop taking metformin for 14 days. They will attend study visits on day 0, day 4, day 7, and day 14. At each visit, they will complete an oral glucose tolerance test, have blood samples taken, and undergo indirect calorimetry measurements before and after the glucose drink. Blood pressure and heart rate will also be measured during the test. Participants will wear a continuous glucose monitor throughout the 14-day period to track glucose levels and help detect any potentially unsafe increase in blood glucose.

Participants in the usual-treatment group will continue taking metformin as prescribed. They will attend study visits on day 0 and day 14. At each visit, they will complete an oral glucose tolerance test, have blood samples taken, and undergo indirect calorimetry, blood pressure, and heart rate measurements during the test.

At the study visits, researchers will assess glucose and insulin responses, HbA1c, continuous glucose monitoring data, metabolic flexibility, blood lipid profile, liver and inflammatory markers, red blood cell parameters, kidney function markers, fasting lactate levels, blood pressure, and heart rate.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Currently treated with metformin as part of their usual medical care for at least 12 months before enrolment.

Diagnosis of metabolic syndrome according to established clinical criteria, based on the presence of at least three of the following components: increased waist circumference, elevated triglycerides, reduced HDL cholesterol, elevated blood pressure or antihypertensive treatment, and elevated fasting glucose or treatment for dysglycemia.

Stable metformin dose for at least 3 months before enrolment.

Willing and medically able to temporarily discontinue metformin for 14 days if assigned to the metformin discontinuation group.

Disqualifiers

Diagnosis of type 1 diabetes.

Current treatment with insulin or other glucose-lowering medications.

Previous history of severe hypoglycemia, diabetic ketoacidosis, hyperosmolar hyperglycemic state, or other acute diabetes-related metabolic complications.

Uncontrolled diabetes or clinically unsafe glycemic status at screening, defined as HbA1c above 8.0 %, fasting plasma glucose above 160 mg/dl, or any other glycemic value considered unsafe by the study physician.

Trial design

Design model

Parallel

Treatments tested in this trial

  • Temporary Metformin Withdrawal

    Behavioral

    Participants assigned to this intervention will temporarily stop taking their usual metformin treatment for 14 days. During this period, participants will undergo oral glucose tolerance tests and blood sampling on day 0, day 4, day 7, and day 14. They will also wear a continuous glucose monitoring device throughout the 14-day period to monitor glucose levels during metformin discontinuation.

Treatment groups

28 Participants
are divided into 2 treatment groups
Group A: METFOR WITHDRAWExperimental treatment 1 intervention
Group B: CONTROLActive comparator 1 intervention

Trial outcomes

Primary outcomes

1

Change in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)

HOMA-IR will be calculated from fasting plasma glucose and fasting insulin concentrations. Higher values indicate greater insulin resistance.

Time frame
From enrolment to the end of the intervention, 14 days.
2

Change in Matsuda Insulin Sensitivity Index

The Matsuda Insulin Sensitivity Index will be calculated from glucose and insulin concentrations obtained during the oral glucose tolerance test. Higher values indicate greater whole-body insulin sensitivity.

Time frame
From enrolment to the end of the intervention, 14 days.
3

Mean sensor glucose during the intervention period

Mean glucose concentration will be assessed using continuous glucose monitoring (CGM) during the 14-day intervention period.

Time frame
From enrolment to the end of the intervention, 14 days.

Secondary outcomes

1

Change in glycated hemoglobin

HbA1c will be measured in blood and reported as percentage of total hemoglobin.

Time frame
From enrolment to the end of the intervention, 14 days.
2

Percentage of time in range assessed by continuous glucose monitoring

Time in range will be defined as the percentage of time with sensor glucose between 70 and 180 mg/dL during the 14-day intervention period.

Time frame
From enrolment to the end of the intervention, 14 days.
3

Change in respiratory exchange ratio response during the oral glucose tolerance test

Respiratory exchange ratio (RER) will be assessed by indirect calorimetry during the oral glucose tolerance test. The response will be calculated using the pre-specified respiratory exchange ratio values obtained during the test.

Time frame
From enrolment to the end of the intervention, 14 days.
4

Change in plasma triglycerides

Plasma triglyceride concentration will be measured in blood before each OGTT.

Time frame
From enrolment to the end of the intervention, 14 days.

Other outcomes

Sponsors and contacts

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