Role of KATP Channel Loss in Type 2 Diabetes
Hyperglycemia Induced Hyperexcitability: A Novel Role for KATP in the Progression of Type 2 Diabetes
Who can join
As published by the study on ClinicalTrials.gov. "Not stated" means the study hasn't said — ask the study team.
- Age
- 18 Years to 65 Years
- Sex
- All sexes
- Healthy volunteers
- Accepted
- Compensation
- Not stated
Other requirements are listed under Eligibility below. Only the study team can confirm whether you can join.
What to expect
No one can promise a trial will help you personally — that is what the research is trying to find out.
What participation involves
Not stated in the study description — ask the study team about visits and procedures.
- Compensation
- Not stated
- Study-related exams and procedures are typically provided at no cost. This is how many trials work in general — confirm the details for this study with the study team.
- Participants are monitored closely by the research team throughout the study.
- Some participants may receive access to an investigational treatment, which is still being studied.
- Your participation helps researchers learn whether this approach could help future patients.
About this study
In plain language
This study tests how insulin responds to one dose of glipizide, a drug that blocks KATP channels in cells that make insulin. These channels help control insulin release and blood sugar. The study includes people with and without type 2 diabetes to learn whether these channels become less active as diabetes develops.
Insulin is a hormone that is made by β-cells in the pancreas and when released into the bloodstream helps control blood sugar levels. Insulin release is regulated by electrical activity in the β-cell which is generated by the ATP-sensitive potassium (KATP) channel. While reduced KATP activity is associated with increased insulin secretion, animals lacking KATP exhibit reduced secretion. This crossover from hypersecretion to undersecretion with KATP loss mirrors insulin secretion during type 2 diabetes. Intriguingly, evidence from cell and animal models suggest that chronically stimulated β-cells can lose KATP revealing a possible role for KATP loss in the failure of insulin secretion and poor control of blood sugar observed in type 2 diabetes. This study will therefore examine insulin responses following ingestion of a single dose of a sulfonylurea called glipizide that inhibits KATP channels in people with and without type 2 diabetes. The goal is to determine whether KATP channel activity is reduced during type 2 diabetes progression.
Compensation is read from the study's own description and may be missing — always confirm with the study team.
Eligibility
Who can join
- You must fit one of four groups below. BMI is a measure of weight compared with height. A1C measures average blood sugar over time. The 2-hour test measures blood sugar after a glucose drink.
- Lean with normal blood sugar: BMI 18.5 to under 25; fasting blood sugar under 95 mg/dL; 2-hour blood sugar 140 mg/dL or less; and A1C 5.6% or less.
- Obesity with normal blood sugar: BMI 30 to under 50; fasting blood sugar under 95 mg/dL; 2-hour blood sugar 140 mg/dL or less; and A1C 5.6% or less.
- Obesity with raised fasting blood sugar: BMI 30 to under 50; fasting blood sugar 100–125 mg/dL; and 2-hour blood sugar under 200 mg/dL.
- Obesity with type 2 diabetes: BMI 30 to under 50; A1C 6.5–9.5%, fasting blood sugar at least 126 mg/dL, and 2-hour blood sugar at least 200 mg/dL; and/or a history of type 2 diabetes with current use of diabetes medicine.
Who can't join
- Using more than 0.5 units of insulin per kilogram of body weight each day, or changing diabetes medicine in the past 3 months.
- Weight changed by more than 2% in the past 2 months.
- A serious organ problem or disease other than obesity or type 2 diabetes.
- Regular tobacco use, or drinking at least 3 alcoholic drinks a day for men or 2 for women.
- Taking medicines that affect study results or make study procedures less safe and cannot be stopped for a short time. Examples include steroids, cholesterol medicines other than statins, and blood thinners.
- Anemia, meaning low levels of the blood protein that carries oxygen: hemoglobin below 10.0 g/dL.
- Pregnant or breastfeeding.
- Unable or unwilling to follow study rules, or the study team feels you are not a suitable candidate. This includes missed screening appointments or past medical visits.
Simplified for readability. The official criteria below are what the study team uses.
Official eligibility criteria
Inclusion Criteria: * Lean-normoglycemic group (n=10): BMI ≥18.5 and \<25.0 kg/m², fasting plasma glucose concentration \<95 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≤140-mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%. * Obesity-normoglycemic group (n=10): BMI ≥30 and \<50 kg/m², fasting plasma glucose concentration \<95 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≤140 mg/dl, and hemoglobin A1C (HbA1C) ≤5.6%. * Obesity-impaired fasting glucose group (n=10): BMI ≥30 and \<50 kg/m², fasting plasma glucose concentration 100-125 mg/dl, and 2-hr oral glucose tolerance test plasma glucose concentration \<200 mg/dl. * Obesity-type 2 diabetes group (n=10): BMI ≥30 and \<50 kg/m²; HbA1C 6.5-9.5%, fasting plasma glucose ≥126 mg/dl, 2-hr oral glucose tolerance test plasma glucose concentration ≥200 mg/dl and/or medical history of T2DM and currently using anti-diabetic medications. Exclusion Criteria: * Diabetes therapy with insulin at \>0.5 units/kg/day. * Any change in diabetes medication in previous 3 months. * Unstable weight (\>2% change during the last 2 months before entering the study). * Evidence of significant organ system dysfunction or disease other than obesity and T2D. * Regular use of tobacco products. * Excessive consumption of alcohol (≥3 drinks/day for men and ≥2 drinks/day for women). * Use of medications that are known to affect the study outcome measures (e.g., steroids, non-statin lipid-lowering medications) or increase the risk of study procedures (e.g., anticoagulants) and that cannot be temporarily discontinued for this study. * Anemia (Hemoglobin \<10.0 g/dL). * Pregnant or breastfeeding. * Unable or unwilling to follow the study protocol or for any reason the research team believes the volunteer is not an appropriate candidate for this study, including non-compliance with screening appointments or previous medical visits.
Study sites (1)
MO
- Washington University in St. Louis · St Louis, MO 63110Kyle Timmons · Study contact · 314-362-8699 · timmons@wustl.eduNathaniel York, PhD · Principal investigatorMore trials in St Louis