Sodium Intake and Socioeconomic Status as Risk Factors for Development of Age-Related Cataracts: The Korea National Health and Nutrition Examination Survey.
OBJECTIVE
Cataract is a very prevalent ocular disorder, and environmental risk factors for age-related cataracts have been widely investigated. We aimed to evaluate an association of dietary sodium intake and socioeconomic factors with the development of age-related cataracts.


METHODS
A cross-sectional case-control study based on the 2008-2011 Korea National Health and Nutrition Examination Survey. Dietary sodium intake was estimated using urinary sodium to creatinine ratio (U[Na+]/Cr).


RESULTS
Among a total 12,693 participants, 2,687 (21.1%) had cataracts and 10,006 patients without cataracts served as controls. The prevalence of cataracts increased with age and quartiles of U[Na+]/Cr (p for trend < 0.001). Multivariate logistic regression analyses revealed that factors related to the development of cataracts were age ≥ 50 years (adjusted odds ratio [aOR] 15.34, 95% confidence interval [CI] 13.31‒17.69), low income (aOR 1.85, 95% CI 1.64-2.09), low educational attainment (aOR 1.76, 95% CI 1.57-1.96), and high sodium intake (U[Na+]/Cr > 16.4 mmol/mmol; aOR 1.29, 95% CI 1.16-1.44). In a subgroup analysis, a robust effect on cataracts across U[Na+]/Cr quartiles was observed in patients ≥ 50 years of age (aOR 1.11, 95% CI 1.04-1.18), though not in younger patients (aOR 1.06, 95% CI 0.96-1.17).


CONCLUSIONS
Our results suggest that high sodium intake and low socioeconomic status may affect the development of cataracts, and that a low-salt diet could be helpful for the prevention of cataracts in an older population. Furthermore, efforts to close gaps in health services due to socioeconomic factors may contribute to a reduction in the prevalence of cataracts.
Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea.
Jeong Hun
JH
Bae
Department of Education and Research, Seoul National University Hospital, Seoul, Republic of Korea.
Doo Sup
DS
Shin
Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea.
Sung Chul
SC
Lee
Department of Family Medicine, Gachon University Gil Medical Center, Incheon, Republic of Korea.
In Cheol
IC
Hwang
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002386:Cataract / Q000453:epidemiology* / Q000209:etiology / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D016017:Odds Ratio; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012959:Socioeconomic Factors; D012964:Sodium / Q000652:urine; D012982:Sodium, Dietary / Q000008:administration & dosage; D055815:Young Adult
D012982:Sodium, Dietary; D012964:Sodium