The ratio of glycated albumin to glycated haemoglobin correlates with insulin secretory function.

OBJECTIVE: Although glycated haemoglobin (A1c) levels are similar among patients with type 2 diabetes, the glycated albumin (GA)/A1c ratio varies considerably. On the basis of the hypothesis that endogenous insulin secretion might be correlated with the GA/A1c ratio, we investigated whether insulin secretory function or insulin resistance has different effects on the GA/A1c ratio in patients with type 2 diabetes using the standardized liquid meal test. DESIGN: A clinical, retrospective study. PATIENTS AND MEASUREMENTS: A total of 758 patients with type 2 diabetes ingested a standardized liquid meal (i.e. 500 kcal, 17·5 g fat, 68·5 g carbohydrate and 17·5 g protein). The subjects were divided into two groups: those with GA/A1c ratio <2·5 (n = 414) and those with GA/A1c ratio ≥2·5 (n = 344). We compared the A1c and GA levels, and the GA/A1c ratio and evaluated the relationships between the glycaemic indices and other parameters. Effects of ß-cell function [homeostasis model assessment (HOMA-ß), insulinogenic index (IGI)] and insulin resistance (HOMA-IR) on the GA/A1c ratio were also examined. RESULTS: The GA/A1c ratio was significantly correlated with HOMA-ß, IGI and body mass index (BMI) but not with HOMA-IR. Furthermore, after adjusting for age, gender, BMI, haemoglobin and albumin levels, the GA/A1c ratio was still inversely correlated with both HOMA-ß and IGI. CONCLUSIONS: The GA/A1c ratio is significantly correlated with insulin secretory function but not with insulin resistance.

Nonmonotonic behavior of resistance in a superconductor-Luttinger liquid junction.

Transport through a superconductor-Luttinger liquid junction is considered. When the interaction in the Luttinger liquid is repulsive, the resistance of the junction with a sufficiently clean interface shows nonmonotonic temperature or voltage dependence due to the competition between the superconductivity and the repulsive interaction. The result is discussed in connection with recent experiments on single-wall carbon nanotubes in contact with superconducting leads.