OBJECTIVE: Nerve sorbitol levels have been measured in sural nerve biopsy samples from patients with diabetic sensorimotor polyneuropathy in several studies using different methods and measurement units. In this study, we compared the results of sorbitol assays to determine the required sensitivity of analytical methods for nerve sorbitol measurements. RESEARCH DESIGN AND METHODS: We performed a literature search using PaperChase for reports of nerve sorbitol in diabetic patients and selected those with nerve conduction studies to delineate the severity of nerve damage. RESULTS: In patients who had undergone a nerve conduction study, the standardized nerve sorbitol levels were 0.034-0.300 nmol/mg wet nerve. CONCLUSIONS: Our results showed the level of sensitivity required in laboratory methodology to perform this assay in the target population and aid in the planning of clinical research trials of aldose reductase inhibitor agents.