The utility of urinary myo-inositol as a marker of glucose intolerance

ObjectiveThe most common screening tests for glucose intolerance are fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c). Because it reflects the current status of hyperglycemia, urinary myo-inositol (UMI) may be useful. We evaluated UMI as a screening tool for glucose intolerance.Design and methodsA cross-sectional, community-based population study of 1057 Japanese residents. 173 with an FPG level between 5.5 and 6.9 mmol/L and an HbA1c under 6.5% had an oral glucose tolerance test. We measured UMI level before (fasting UMI) and 2 h after (2 h-UMI) glucose ingestion. Δ-UMI was defined as the difference between fasting UMI and 2 h-UMI.ResultsΔ-UMI, 2 h-UMI and HbA1c levels significantly increased as glucose intolerance worsened. Δ-UMI level was significantly positively correlated with 2 h-UMI level (r = 0.896, p < 0.001). Using cutoff levels from receiver operating characteristic (ROC) analyses, the sensitivity of Δ-UMI (82.1%) and 2 h-UMI (79.3%) were higher than that of HbA1c (48.3%). The area under the ROC curve values for Δ-UMI (0.903) and 2 h-UMI (0.891) were higher than that for HbA1c (0.785).Conclusions2 h-UMI is useful as a non-invasive screening of glucose intolerance.