Repeated determinations of serum uric acid, cholesterol, and cortisol levels were done three times a week on 20 healthy young Navy men during a 16-week underwater demolition team (UDT) training course, a period of considerable physical and psychological stress. The intraindividual correlations between uric acid and cholesterol levels, uric acid and cortisol levels, and cholesterol and cortisol levels all showed a considerable range of values, both positive and negative, and several of the correlations were statistically significant. However, across-subjects correlations of the mean values of these measures were of low order, which indicated that a cross-sectional sampling design can mask the considerable variability in intraindividual values. This variability indicates that there can be a considerable individuality in patterns of biochemical response and adaptation to stress.Many clinical studies have in¬ dicated a relationship between increased levels of blood uric acid and blood lipids. Subjects studied have included patients with gout,1·2 essential hypercholesterolemia and xanthomatosis,2·3 myocardial and peripheral vascular disease,48 and normals, both stressed and nonstressed.7·912 There are, however, conflicting data on the correlation between blood levels of uric acid and, specifically, cholesterol. This correlation has been reported as positive,''"7·10"12 negative,810 or non¬ existent.1·2'4·9·11·13"15 Major méthod¬ ologie problems contributing to the disparate findings in these studies in¬ clude the use of subjects with differ¬ ing ages, sexes, illnesses, and life situations.Furthermore, most of these studies were cross-sectional, with only a few including two or more blood uric acid and cholesterol level determina-tions on the same patients. Schoenfeld and Goldberger5 examined 14 patients with heart conditions week¬ ly for six to ten weeks and con¬ cluded that increases in uric acid were associated with increases in cholesterol. Dreyfuss and Czaczkes n studied 21 medical students on the morning of an examination and again two days later. Mean cholesterol level was higher on the examination day compared to the control day; mean uric acid level did not change.There was a small negative correla¬ tion (-0.20) between these variables on the examination day but no cor¬ relation on the control day. Kasl et al15 studied approximately 150 men, stably employed in three companies, who lost their jobs because of per¬ manent plant shutdowns. Blood uric acid and cholesterol levels were de¬ termined while the job loss was im¬ pending, at approximately fourmonth intervals thereafter for a year, and once again at the end of two years. There were no correlations between the mean uric acid and cholesterol levels of the men in any of the three companies, nor among men in a control group.Even in these three studies, in which repeated measurements were done, the correlations were made across subjects, thereby masking any intraindividual differences in the relationship between uric acid and cholesterol levels. The study of a g...