From arid south to temperate north: an FTIR-based analysis of the association between region, ethnicity, and renal stone composition in Iraq

To assess the effect of regional, environmental, and ethnic factors on stone formation. This retrospective, cross-sectional, comparative study was done at a national tertiary referral stone center in Sulaymaniyah, Iraq. Clinical data and stone composition profiles were studied for 170 patients (128 Kurdish and 42 Arab) between July 2025 and May 2026. Stone composition was analyzed using Fourier-transform infrared (FTIR) spectroscopy. Calcium oxalate monohydrate was the predominant primary component in both Kurdish (53.1%) and Arab (38.1%) cohorts. Overall primary stone distribution demonstrated no statistically significant difference between groups ( p = 0.089), though Arab patients exhibited a higher numerical proportion of primary uric acid calculi (26.2% vs. 18.0%). However, evaluation of secondary mineral components in mixed stones ( n = 82) revealed a statistically significant association with ethnic cohort ( p = 0.032). Secondary uric acid deposition was predominant in Arab patients (50.0% vs. 15.6%), whereas secondary carbonate-apatite was most common in Kurdish patients (39.1% vs. 16.7%). Size was recorded for only 57 of 170 patients (33.5%), and the median stone diameter was 14.0 mm (IQR: 8.0–22.0 mm). Ethnicity and regional environment may influence stone mineralogy in Iraq. The higher amount of uric acid stones in the Arab population may be associated with the arid climate and dietary habits of central and southern Iraq. These findings show the importance of region-specific preventative actions and adapted management to improve patient outcomes.