Abstract
We evaluated fasting C-peptide immunoreactivity (FCPR) applicable to insulin users as an indicator of insulin resistance.
We simultaneously measured FCPR and fasting immunoreactive insulin (FIRI) in 127 noninsulin-using type 2 diabetic inpatients before discharge (FCPR=FIRI×0.194+1.32), and proposed the formula CPR-IR (1) =FPG×FCPR÷217.3 and CPR-IR (2) =FPG×(FCPR-1.32) +78.6as an indicator of insulin resistance. CPR-IR (2) correlated better with HOMA-IR than with CPR-IR (1). On this basis, we simultaneously measured FPG and FCPR in 91 type 2 diabetic inpatients on insulin therapy before discharge, and compared CPR-IR (1) with CPR-IR (2) to determine the relationship to insulin-resistance-related markers.CPR-IR (2) correlated better with maximal BMI, BMI when diabetes mellitus was diagnosed, BMI at discharge, urinary CPR, FCPR, and uric acid than with CPR-IR (1).
Our results showed that FPG×(FCPR-1.32)÷78.6 can serve as a feasible standard of insulin resistance under the conditions of decreased glucose toxicity in type 2 diabetic patients undergoing insulin therapy.
