OBJECTIVE—The high–molecular weight (HMW) form of adiponectin, an adipocyte-derived insulin-sensitizing hormone, has been reported to be the most active form of this hormone. We investigated whether measurement of plasma HMW adiponectin levels, using our newly developed enzyme-linked immunosorbent assay system for selective measurement of human HMW adiponectin level, may be useful for the prediction of insulin resistance and metabolic syndrome.

RESEARCH DESIGN AND METHODS—A total of 298 patients admitted for diabetes treatment or coronary angiography served as study subjects. Receiver operator characteristic (ROC) curves for the HMW ratio (HMWR; ratio of plasma level of HMW adiponectin to that of total adiponectin) and plasma total adiponectin levels were plotted to predict the presence of insulin resistance and metabolic syndrome.

RESULTS—The area under the ROC curve (AUC) of the HMWR values to predict the presence of insulin resistance was significantly larger than that of plasma total adiponectin level in total subjects (0.713 [95% CI 0.620–0.805] vs. 0.615 [0.522–0.708], P = 0.0160). The AUC for the HMWR values to predict the presence of metabolic syndrome was significantly larger than that for plasma total adiponectin levels in men (0.806 [0.747–0.865] vs. 0.730 [0.660–0.800], P = 0.0025) and in women (0.743 [0.659–0.828] vs. 0.637 [0.532–0.742], P = 0.0458).

CONCLUSIONS—The HMWR value has better predictive power for the prediction of insulin resistance and metabolic syndrome than plasma total adiponectin level.