Serum Na + and K + as risk factors in age-related cataract: An Indian perspective

Abstract

Background: Recent reports suggest an association between deranged metabolism and age-related cataracts (ARC). Aim: This study was planned and carried out to evaluate some biochemical variables as possible risk factors for the different morphological types of ARC. Materials and Methods: We compared serum Na + and K + in 100 cases of ARC and 100 age- and gender-matched controls. The ARC patients were sub-grouped according to the WHO cataract grading system into posterior sub-capsular (PSC), nuclear (NC), cortical (CC) and mixed cataracts (MC). Statistical analysis was done using t-test, ANOVA, and post-hoc (Tukey) test. The 95% CI are reported; significance was set at P ≤ 0.05. Results: Although within normal range, the overall mean serum levels of Na + were significantly higher (P < 0.001; 95% CI for difference: 2.95 to 8.56) in the cases (145.39 (±3.04) mEq/L) as compared to controls (139.63 (±13.91) mEq/L). Except for the PSC group, sub-group analyses showed significantly higher Na + levels than controls (P < 0.05). There was no significant difference in serum K + levels. Importantly, serum Na + and K + levels were within the normal reference range in all the subjects. Conclusion: This study suggests that there is a tendency to have higher Na + levels in ARC as compared to non-ARC subjects, although within normal reference values.