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.