Association between OPN genetic variations and nephrolithiasis risk

Osteopontin (OPN) has an important role in urolithiasis. However, few studies have explored the association between OPN genetic variants and urolithiasis risk. In the present study, three single-nucleotide polymorphisms (SNPs) (rs28357094, rs11439060 and rs11730582) located on the promoter of OPN were genotyped in a total of 480 individuals, including 230 nephrolithiasis patients and 250 matched healthy controls, and the associations between these SNPs and nephrolithiasis risk in different genetic models was assessed. No significant differences were identified in the genotype and allele frequencies of OPN rs28357094 or rs11730582 (P=0.805 for rs28357094; P=0.577 for rs11730582, respectively). However, carriers with the OPN rs11439060 insertion (ins) types (ins/deletion and ins/ins) were overrepresented in urolithiasis patients compared with the controls [odds ratio (OR), 1.55; 95% confidence interval (CI), 1.08-2.22]. In the stratified analysis, the increased risk was more evident among younger subjects (adjusted OR, 1.68; 95% CI, 1.01-2.81), females (2.15; 1.14-4.08), overweight subjects (1.80; 1.07-3.05), normotensive subjects (2.48; 1.02-6.00), abnormal blood sugar subjects (1.58; 1.08-2.30), smokers (1.63; 1.02-2.60), and ever-drinkers (1.98; 1.10-3.60).. These findings revealed that the OPN rs11439060 polymorphism may act as genetic biomarker for the detection of high-risk nephrolithiasis patients.