Fasting urine pH is independent of insulin sensitivity

Background: It has recently been suggested that a low urine pH be added to the abnormalities linked to insulin resistance. This conclusion is based on the finding of a low urine pH in individuals with clinical syndromes associated with insulin resistance and not on studies in which a direct measure of insulin sensitivity was shown to be significantly related to differences in urine pH. Objective: To address this issue, we quantified insulin-mediated glucose uptake (IMGU) by using the insulin suppression test in 96 apparently healthy, nondiabetic individuals and defined its relation to fasting urine pH. Design: Urine samples were collected and analyzed from a cohort of healthy subjects within a narrow body mass index range who were recruited to determine insulin sensitivity. Results: There was an approximate 6-fold variation in values for IMGU in this population, with no relation to urine pH (r = 0.02). Furthermore, there was no relation between body mass index, as a surrogate estimate of insulin resistance, and urine pH (r = 0.06). Conclusion: On the basis of these findings, we question the view that a low urine pH be added to the abnormalities linked to insulin resistance in low-risk populations.