Effect of Fasting on Hypoglycemic Counterregulation in Type 1 Diabetes

This study is investigating how fasting (not eating for a period of time) affects the body's ability to respond to low blood sugar (hypoglycemia) in people with type 1 diabetes. When blood sugar drops too low, the body normally releases hormones like adrenaline and glucagon to raise it. In type 1 diabetes, this protective response can become blunted over time. Researchers want to know whether fasting changes how this protective response works. **You may be eligible if...** - You have a confirmed diagnosis of type 1 diabetes - You are C-peptide negative (your pancreas makes no insulin at all) - You are of any race, ethnicity, or gender - You are non-obese (BMI of 30 or less) **You may NOT be eligible if...** - You are pregnant - You smoke cigarettes - You take steroids that target inflammation (such as prednisone) - You take medications that affect adrenaline signaling (such as beta-blockers or bronchodilators) - Your blood count (hematocrit) is below 33% - You have HIV or hepatitis - You have cardiovascular or peripheral vascular disease - You have diabetic nerve damage (neuropathy), eye damage (retinopathy), or kidney damage (nephropathy) - You have another condition that your study doctor believes could interfere with the results or make participation unsafe Talk to your doctor to see if this trial is right for you.