Circadian Periodicity of Circulating Plasma Lipid Peroxides, Uric Acid and Ascorbic Acid in Renal Stone Formers

Circadian periodicity of plasma lipid peroxides and serum ascorbic acid and uric acid levels were studied in one hundred renal stone formers (55 women and 45 men; age 20–60 years) and 50 clinically healthy volunteers (21 women and 29 men; age 21–45 years) with diurnal activity from 06:00 to 22:00 and nocturnal rest. A marked circadian variation was demonstrated by population-mean-cosinor for all studied variables in stone formers and healthy subjects. By comparison to the healthy controls, parameter tests indicate that the stone formers had a higher MESOR (±SE) of MDA (2.90 ± 0.03 vs. 2.28 ± 0.06; F = 94.929, p < 0.001), a lower MESOR of serum ascorbic acid (0.722 ± 0.010 vs. 0.839 ± 0.10; F = 32.083, p < 0.001), and a similar MESOR of serum uric acid. Furthermore, the patients also differed from the healthy subjects in terms of their circadian amplitude and acrophase (tested jointly) of all three variables (p < 0.001). The demonstration herein of a circadian rhythm in MDA, serum ascorbic and uric acid suggests that these variables could also serve as markers to optimize the timing of treatment and to assess the patient’s response to treatment for further management.