W.L. Strohmaier, J. Bonkovic-Oszi 2, B. Bruckner

Are there seasonal variations of renal colic in calcium oxalate stone formers in Germany?

Seasonal variations of renal colic have been described by many authors throughout the world for different countries. No such evaluation has yet been made for Germany. We have collected data to analyse whether such seasonal variations of renal colic are relevant in Germany as well.

Prospectively, we have studied n=1049 calcium oxalate stone formers with symptoms of renal colic treated in our department. We have divided them into four groups according to the quarters of the year. For stone analysis, x-ray diffraction / polarizing microscopy was used. Furthermore, the following general parameters have been examined in all patients: age, BMI, blood pressure, stone frequency, diabetes mellitus; blood: creatinine, glucose, uric acid, calcium, sodium and potassium; urine: pH, volume, calcium, uric acid, citrate, ammonia and urea. Using the statistic programme Prism 5 (GraphPad), significant differences between the four groups were calculated by the Kruskal-Wallis-test.

In Germany no seasonal variations of renal colic in calcium oxalate stone formers have been found. We have also not found seasonal variations in metabolic parameters or urine composition.

Low temperature fluctuations could be a potential explanation. However, there are countries with similar climate conditions showing seasonal variations of acute stone episodes. Another possible explanation for the missing variation in colic is the constant urine composition throughout the year. This was shown for other regions with a constant frequency of acute stone episodes. Further investigations are required to support this hypothesis.