A DIURNAL RHYTHM IN THE EXCRETION OF NEUTRAL REDUCING LIPIDS BY MAN AND ITS RELATION TO THE 17-KETOSTEROID RHYTHM*

Abstract

The urinary output of 17-ketosteroid and neutral reducing lipid was measured simultaneously on aliquots of "sleep," "morning" and "day" samples from 24 normal, healthy d* [male][male] aged 24 to 72 yrs. The great majority of these subjects showed minimal excretion of both types of substance during the sleep period, maximal output in the morning and less than morning values in the day specimens, when the output is expressed on either a/hr. or a/g. of creatinine basis. The mean output increases for both the morning and day excretions are statistically significant. There is a significant correlation between absolute levels of 17-ketosteroid and neutral reducing lipid. Although a similar diur-1 nal pattern of excretion occurs for both types of urinary substance the changes in excretion (on either a % or absolute change basis) of each are not significantly correlated. This is taken to indicate the factors evoking urinary 17-ketosteroid increase (or decrease) are not the same as those evoking neutral reducing lipid change.