University of Castilla-La Mancha
Toledo, 45071, Spain
Location status: Recruiting
NCT Number: NCT07659444
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.
Interested in participating?
Request Info18 year and older
All sexes
Interventional
Not applicable
Toledo, 45071, Spain
Location status: Recruiting
Healthy volunteers accepted: No
Only the study team can determine whether someone qualifies for participation.
Inclusion criteria
Exclusion criteria
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.
Time frame: From enrolment to the end of the intervention, 14 days.
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.
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.
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.
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.
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.
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.
Plasma triglyceride concentration will be measured in blood before each OGTT.
Time frame: From enrolment to the end of the intervention, 14 days.
Total cholesterol concentration will be measured in blood before each OGTT.
Time frame: From enrolment to the end of the intervention, 14 days.
HDL-cholesterol concentration will be measured in blood before each OGTT.
Time frame: From enrolment to the end of the intervention, 14 days.
LDL-cholesterol concentration will be measured in blood before each OGTT.
Time frame: From enrolment to the end of the intervention, 14 days.
The estimated glomerular filtration rate will be calculated from serum creatinine and reported in mL/min/1.73 m².
Time frame: From enrolment to the end of the intervention, 14 days.
Serum creatinine concentration will be measured in blood before each OGTT.
Time frame: From enrolment to the end of the intervention, 14 days.
The urinary albumin-to-creatinine ratio will be measured in urine before each OGTT.
Contact information is provided by the study sponsor or research team.
University of Castilla-La Mancha
Other
Effects of 14-Day Metformin Withdrawal on OGTT-Derived Insulin Sensitivity in Adults With Metabolic Syndrome: A Randomized Controlled Trial
Acronym: METMS
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View the official ClinicalTrials.gov record (opens in a new tab)This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.
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