Biochemical factors in the lens opacities. Case-control study. The Lens Opacities Case-Control Study Group.

Objective: To evaluate associations with biochemical indicators of nutritional and other risk factors in the Lens Opacities Case-Control Study.

Design: Case-control study.

Setting And Participants: The Lens Opacities Case-Control Study determined risk factors for cortical, nuclear, and posterior subcapsular opacities among 1380 participants aged 40 to 79 years.

Data Collection: Vitamin E, selenium, and biochemistry profile determinations were performed on all patients; red blood cell enzymes and amino acids were measured in systematic samples of about 25% of the Lens Opacities Case-Control Study population.

Outcome: Laboratory test values in cases and controls were compared and expressed as odds ratios and 95% confidence intervals.

Results: In polychotomous logistic regression analyses controlling for age and sex, the risk of opacities was reduced to less than one half in persons with higher levels of vitamin E (odds ratio, 0.44 for nuclear opacities), albumin-globulin ratio (odds ratio, 0.41 for mixed opacities), or iron (odds ratio, 0.43 for cortical opacities); higher uric acid levels increased risk (odds ratio, 1.74 for mixed opacities). Persons with opacities were twice as likely to have high glutathione reductase activity (with flavin adenine dinucleotide), which suggests low riboflavin status (odds ratio, 2.13). Most odds ratios for amino acids were under unity and were significantly decreased for glycine (0.36) and aspartic acid (0.31).

Conclusions: Lens opacities were associated with lower levels of riboflavin, vitamin E, iron, and protein nutritional status. Higher levels of uric acid increased risk of mixed opacities. The findings for riboflavin, vitamin E, iron, and uric acid are compatible with the dietary intake and medical history results of the Lens Opacities Case-Control Study.