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.

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We studied the case-controlled effect of diabetes type and the first calendar year visit to the Diabetes Center on the prevalence of microvascular complications in early-onset diabetic patients.Subjects had type 2 diabetes diagnosed before the age of 15 and visited the Center inthe 1980s (1980-1988, n=42) and 1990s (1989-1998, n=42). Age-and duration-matched type 1 diabetic patients visited in the 1980s (n=104) and 1990s (n=91). The prevalence of diabetic complications in the80s group was obtained in 1988 and that of the 90s group in 1998. The prevalence of proliferative retinopathy was higher and of simple retinopathy lower in type 2 than in type 1 in both groups.The prevalence of proliferative retinopathy and clinical nephropathy tended to be higher with increasing calender year in both types, although simple retinopathy was significantly lower in type 1 diabetics in the 90s than in the 80s (p<0.005). About half of 90s type 2 diabetics had undergone intermittent treatment in the past, and theyexperienced a significant deterioration in complications.

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[in Japanese]

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