233 is It Possible to Predict the Presence of Low Free Testosterone Levels Without Free Testosterone Measurement?

We evaluated the relationship between free testosterone (FT) and total testosterone (TT) levels and investigated the best method of diagnosing low FT levels in late-onset hypogonadism (LOH) patients. We hypothesized that multiple confounding factors would predict low FT, and as such factors we assessed age, TT, LH, FSH, E2, HCT, and testicular volume. A consecutive series of 210 patients attending our unit for LOH syndrome was studied. Initially, we evaluated the sensitivity, specificity, and positive and negative predictive values of TT levels in the diagnosis of low FT levels. We then selected the factors correlated with FT. For each factor, ROC analysis was used to find a cutoff value for the presence of low FT levels. We allocated 1 point to each value beyond the cutoff and then summed the points. We then used the summed point scores to predict which patients would have low FT levels.