[Stress-related alteration of urine compositions: idiopathic CaOx stone formers, patients with chronic inflammatory bowel disease (CIBD) and healthy controls].

BACKGROUND

Increased emotional stress in everyday life influences the way of living and metabolism of people living in developed countries. Contemporaneously, the incidence and prevalence of urolithiasis rises. Does a pathogenetically relevant relationship exist between chronic stress burden and permanently altered urinary composition?

PATIENTS AND METHODS

The influence of chronic stress burden on urine composition and risk of urinary calcium oxalate (CaOx) stone formation was, for the first time, comprehensively investigated in 29 healthy controls (CG), 29 idiopathic CaOx stone formers (SF) and 28 patients suffering from chronic inflammatory bowel disease (CIBD). After 4 days with standardized nutrition, 24-h urine was collected. Extensive urinalysis was performed and APCaOx index calculated. Evaluation of subjective stress level was carried out by using the standardized and well-established questionnaire Trierer Inventar zur Beurteilung von chronischem Stress (TICS). The concentration values of the urinary parameters as well as the APCaOx values were linearly correlated with the stress scores obtained from the different items of the TICS. A significance level p≤0.05 was considered to indicate statistical significance.

RESULTS

The mean APCaOx indices amounted to 0.8±0.3 in CG, 1.2±0.7 in SF and 1.9±1.2 in CIBD. The increased APCaOx in SF mainly results from relatively increased Ca and oxalate excretions, whereas in CIBD this also results from reduced urinary excretions of citrate and Mg as well as reduced 24-h urinary volumes. The calculation of linear correlation coefficients between a TICS stress dimension and a concentration value of a urinary parameter or APCaOx results in r values not exceeding 0.600. However, some of these correlations are statistically highly significant. In SF only one combination with Ca was observed, while in CIBD in contrast a number of combinations, in particular including Na, was obtained. In CG direct statistical relationships between stress burden and citrate as well as Mg exist. In this group, increased stress burden is associated with increased inhibitory potential to prevent CaOx stone formation.

CONCLUSION

In the investigated study groups, differently complex relationships between amount of stress burden and risk of CaOx stone formation were observed, however, without obvious physicochemical principle(s). In some individuals, stress can be associated with a significantly stress-related alteration of urinary composition towards increased CaOx stone formation risk. The results obtained from the CIBD group allow for the first time a conclusive link between emotional stress and inflammatory activity on the one hand and inflammatory activity and metabolic risk constellation of CaOx stone formation on the other hand.