Influence of age, gender, seasonal variation and geographic region on the occurrence of kidney stones and its composition: a retrospective study in a South African population

Abstract

Background: Kidney stone disease (KSD) remains a common problem that can create a burden on healthcare systems. Data on the frequency of KSD in South Africa are limited and not many peer-reviewed publications are available regarding epidemiological trends of this condition in most parts of Africa. This study aimed to provide detailed information about KSD and the influence of age, gender, season and geographical location on the occurrence of this condition in a South African population. This is a retrospective study which looked at kidney stone results and patient information retrieved from a laboratory information system.
Methods: Descriptive analysis was done for age, gender, season and geographical location, and the frequency of stone types as reported for different age groups and genders.
Results: Calcium oxalate (59.6%) and uric acid stones (11.3%) were the most common among adult males, while calcium phosphate (16.43%) and protein stones (1.2%) were prevalent among adult females. Struvite stones were slighty more common among males (1.4%), while ammonium urate stones were predominant among children (30%). All stone types were common in Gauteng province (66.1%) except for protein stones, which were predominant in the Eastern Cape province. Most stones were submitted to the laboratory during autumn (32.9%).
Conclusion: This study showed that specific factors favoured the development of kidney stones, such as advanced age, the male gender, moderate-to-lower temperatures and urbanised locations.