Metformin Effect on Brain Function in Insulin Resistant People aged 60+

Overview

About this study

The purpose of this study is to better understand the link between insulin resistance and dementia. Earlier studies have shown that people with insulin resistance are two to four times more likely to develop Alzheimer’s disease and other dementias. Other studies have shown a link between the drug Metformin (the most widely used medication to treat prediabetes and type 2 diabetes) and a reduction in the development of dementia.

The aim of this study is to investigate if 40 weeks of Metformin treatment (in people 60+ years) enhances brain function and how brain function interacts with the body’s metabolism in people with insulin resistance and in people without insulin resistance.

Insulin is a hormone produced by the pancreas that deals with sugar (glucose) in the blood. When we eat food, blood sugar levels increase, and the pancreas produces more insulin to keep blood sugar levels stable. If blood sugar decreases, then insulin levels decrease. If the body becomes resistant to insulin, then the body requires more insulin to balance out blood sugar levels. If this continues, eventually the pancreas is not able to produce the amount of insulin needed to balance out blood sugar leading to an elevated fasting blood sugar (fasting blood glucose value greater than 100 mg/dL). Insulin resistance is a primary risk factor for developing type 2 diabetes, heart disease, and dementia.

This study is recruiting two groups of people: people with insulin resistance and people without insulin resistance. To qualify for the insulin resistance group, a person would need to have an elevated fasting blood sugar test between 100mg/dL and 140mg/dL. To qualify for the non-insulin resistant group a person would need a blood sugar under 95mg/dL.

In people with insulin resistance the study will be measuring changes in brain functions, cognitive ability, and body’s metabolism. These series of tests are performed twice, once before and once after 40 weeks of taking Metformin. Brain functions are measured through a series of brain scans. Cognitive ability is measured using computerized tests. To measure the body’s metabolism, we measure insulin resistance during an overnight stay, blood tests to measure biomarkers, capacity for exercise, body composition scans, and muscle will be assessed from needle muscle biopsies.

In people without insulin resistance, the study will be collecting baseline measurements on brain function, cognitive ability, and body’s metabolism. These tests are performed once. Brain functions are measured through a series of brain scans. Cognitive ability is measured using computerized tests. To measure the body’s metabolism, we measure insulin resistance during an overnight stay, blood tests to measure biomarkers, and a body composition scan.

Remuneration and a travel reimbursement are provided.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria: 

To be eligible for the study, a subject must be willing to be randomized and be retained in the study for its duration and meet the following criteria:

  • Age ≥ 60 years.
  • BMI ≥ 25 kg/m^2.
  • Fasting glucose ≥ 100-140 mg/dL.
  • Non-smoker.
  • English language proficiency.

Exclusion Criteria:

The presence of any of the following is an exclusion for the study:

  • Active coronary artery disease or heart failure.
  • A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol such as the following examples:
    • Inpatient psychiatric treatment in the past 6 months;
    • Use of insulins
    • Type 1 diabetes
    • Presence of a known and active adrenal disorder;
    • Abnormal liver function test results (Transaminase > 2 times the upper limit of normal); testing required for subjects taking medications known to affect liver function or with diseases known to affect liver function;
    • Abnormal renal function test results (calculated GFR < 60 mL/min/1.73m^2); testing required for subjects with diabetes duration of greater than 5 years post onset of puberty;
    • Active gastroparesis;
    • If on antihypertensive, thyroid, anti-depressant or lipid lowering medication, lack of stability on the medication for the past 2 months prior to enrollment in the study;
    • Uncontrolled thyroid disease (TSH undetectable or > 10 mlU/L); testing required within three months prior to admission for subjects with a goiter, positive antibodies, or who are on thyroid hormone replacement, and within one year otherwise;
    • Abuse of alcohol or recreational drugs;
    • Infectious process not anticipated to resolve prior to study procedures (e.g., meningitis, pneumonia, osteomyelitis);
    • Uncontrolled arterial hypertension (resting diastolic blood pressure > 90 mmHg and/or systolic blood pressure >160 mmHg) at the time of screening;
    • Oral steroids;
    • A recent injury to body or limb, muscular disorder, use of any medication, any carcinogenic disease, or other significant medical disorder if that injury, medication or disease in the judgment of the investigator will affect the completion of the protocol;
    • Any metal in the body that could interfere with magnetic resonance imaging (MRI) including pacemaker or implanted defibrillator, neurostimulators, ear implants, metal fragments within the body, metal joints, rods, pins, plates or screws.
  • Subjects without English proficiency.

Recruitment for Non-Insulin Resistant Participants

To be eligible for the study, a subject must be willing to be randomized and be retained in the study for its duration and meet the following criteria:

  • Age ≥ 60 years.
  • 27kg/m^2 ≥ BMI 
  • 95 mg/dL ≥ Fasting glucose
  • Non-smoker.
  • English language proficiency.

Exclusion Criteria:

The presence of any of the following is an exclusion for the study:

  • Active coronary artery disease or heart failure.
  • A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol such as the following examples:
    • Inpatient psychiatric treatment in the past 6 months;
    • Presence of a known and active adrenal disorder.
    • Type 1 diabetes
    • Abnormal liver function test results (Transaminase > 2 times the upper limit of normal); testing required for subjects taking medications known to affect liver function or with diseases known to affect liver function;
    • Abnormal renal function test results (calculated GFR < 60 mL/min/1.73m^2); testing required for subjects with diabetes duration of greater than 5 years post onset of puberty;
    • Active gastroparesis;
    • If on antihypertensive, thyroid, anti-depressant or lipid lowering medication, lack of stability on the medication for the past 2 months prior to enrollment in the study;
    • Uncontrolled thyroid disease (TSH undetectable or > 10 mlU/L); testing required within three months prior to admission for subjects with a goiter, positive antibodies, or who are on thyroid hormone replacement, and within one year otherwise;
    • Abuse of alcohol or recreational drugs;
    • Infectious process not anticipated to resolve prior to study procedures (e.g., meningitis, pneumonia, osteomyelitis);
    • Uncontrolled arterial hypertension (resting diastolic blood pressure > 90 mmHg and/or systolic blood pressure >160 mmHg) at the time of screening;
    • Oral steroids;
    • A recent injury to body or limb, muscular disorder, use of any medication, any carcinogenic disease, or other significant medical disorder if that injury, medication or disease in the judgment of the investigator will affect the completion of the protocol;
    • Any metal in the body that could interfere with magnetic resonance imaging (MRI) including pacemaker or implanted defibrillator, neurostimulators, ear implants, metal fragments within the body, metal joints, rods, pins, plates or screws.
  • Subjects without English proficiency.

Eligibility last updated 8/26/21. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

K Nair, M.D., Ph.D.

Open for enrollment

Contact information:

Frederick de Ruiter B.S.

(507) 255-8932

DeRuiter.Frederick@mayo.edu

More information

Publications

Publications are currently not available

Study Results Summary

Not yet available

Supplemental Study Information

Not yet available

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CLS-20441970

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