Hi, My PCOS was diagnosed by my gyn. I have several blood filled cysts on my ovaries that I have to monitor. Funny though, they are not related to PCOS. People who have cysts on their ovaries from pcos tend to have what looks like a string of pearls in the ovary. Some do not. The symptoms vary greatly from individual to individual. She diagnosed me with a simple fasting insulin test. She also tested my estrogen. She then sent me to an endocrinogist. He specializes in the endocrine system - hormones, adrenals, etc. He ran more tests on other hormones,etc. He did not run the c-peptide test. He also wanted to rule out Cushing's disease so I had a 24 hour urine collection (fun, fun). The symptoms of PCOS, CUshings, and FMS are quite similar. Hope this helps. If you have more questions, ask. Here is some info on c-peptide that I found for you: C-peptide Also known as: Insulin C-peptide, Connecting peptide Related tests: Insulin, Glucose email this page print this article The Test ------------------------------------------------------------------------ How is it used? When is it ordered? What does the test result mean? Is there anything else I should know? How is it used? When a patient has newly diagnosed type 1 or type 2 diabetes, C-peptide can be used to help determine how much insulin the patient’s pancreas is still producing and whether or not that insulin is being used effectively. Type 1 diabetes is an autoimmune process that often starts in early childhood and involves the almost complete destruction of the beta cells over time. Eventually, little or no insulin (or C-peptide) is produced, leading to a complete dependence on exogenous insulin. In type 2 diabetes, often called “adult-onset diabetes,” a combination of factors leads to decreased insulin production and increased insulin resistance, along with some beta cell damage. Type 2 diabetics usually are treated with oral drugs to stimulate their body to make more insulin and/or to cause their cells to be more sensitive to the insulin that is already being made. Eventually, type 2 diabetics may make very little insulin and require injections. Any insulin that the body does make will be reflected in their C-peptide level; therefore, the C-peptide test can be used to monitor beta cell activity and capability over time and to help your doctor determine when to begin supplementing your insulin. C-peptide measurements also can be used in conjunction with insulin and glucose levels to help diagnose the cause of documented hypoglycemia and to monitor its treatment. Symptoms of hypoglycemia may be caused by excessive supplementation of insulin, alcohol consumption, inherited liver enzyme deficiencies, liver or kidney disease, or insulinomas (tumors of the islet cells in the pancreas that can produce uncontrolled amounts of insulin and C-peptide). When is it ordered? C-peptide levels may be ordered if you have newly diagnosed diabetes, as part of an evaluation of your “residual beta cell function” (how much insulin your beta cells are making). With type 2 diabetes, the test may be ordered if your doctor wants to monitor the status of your beta cells and insulin production over time and to determine if/when insulin injections may be required. C-peptide blood and urine levels also may be monitored to check your renal function and C-peptide clearance rate. C-peptide levels may be done when there is documented acute or recurring hypoglycemia. Symptoms include sweating, palpitations, hunger, confusion, visual problems, and seizures, although these symptoms also can occur with other conditions. The C-peptide test may be used to help separate excessive insulin production from excessive administration and to help diagnose insulinomas. If you have had your pancreas removed or are one of the few patients to have had pancreas islet cell transplants (in order to restore your ability to make insulin), your C-peptide levels may be monitored to verify the effectiveness of treatment and continued success of the procedure. What does the test result mean? High levels of C-peptide generally indicate high levels of insulin. This may be due to excessive insulin production, a response to high levels of blood glucose caused by glucose intake and/or insulin resistance. (With insulin resistance, the body’s cells do not use insulin normally to transport glucose inside the cell. The cells become “starved for glucose,” interpret that as a lack of insulin, and signal the body to make more.) High levels of C-peptide also are seen with insulinomas and may be seen with hypokalemia, pregnancy, Cushing’s syndrome, and renal failure. During a glucose tolerance test (GTT), there will often be a temporary 5 to 6 fold increase in C-peptide levels. Low levels of C-peptide are seen when insufficient insulin is being produced by the beta cells or when production is suppressed by exogenous insulin or with suppression tests that involve substances, such as epinephrine. Diuretics and alcohol intake also may cause low levels in some cases. In most cases, test results are reported as numerical values rather than as "high" or "low", "positive" or "negative", or "normal". In these instances, it is necessary to know the reference range for the particular test. However, reference ranges may vary by the patient's age, sex, as well as the instrumentation or kit used to perform the test. To learn more about reference ranges, please see the article, Reference Ranges and What They Mean. To learn the reference range for your test, consult your doctor or laboratorian. Is there anything else I should know? C-peptide testing is not widely used and may not be available in every laboratory. There are two main methods of doing the C-peptide test: RIA (radioimmunoassay) and ICMA (immunochemiluminometric assay). These two methods have different normal ranges, as well as sensitivities and specificities, and are not interchangeable. If you are going to have a series of C-peptide tests performed, they should be done at the same laboratory using the same method. Even though they are produced at the same rate, C-peptide and insulin leave the body by different routes. Insulin is processed and eliminated by the liver, while C-peptide degrades and is removed by the kidneys. Since the half-life of C-peptide is about 30 minutes to insulin’s 5 minutes, normally there will be about 5 times as much C-peptide in the bloodstream as insulin. Add to this the fact that a person’s kidneys and/or liver may not be clearing insulin and C-peptide out efficiently and you end up with an inherent imprecision in the C-peptide test. It can give your doctor important information about your beta cells and insulin production, but it is not perfect. You will need to fast for a C-peptide blood test if the results will be used to evaluate hypoglycemia.