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

Objective: The 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 methods: A 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. Results: δ-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). Conclusions: 2. h-UMI is useful as a non-invasive screening of glucose intolerance.