BIOCHEMICAL FACTORS IN THE LENS OPACITIES CASE-CONTROL STUDY

Objective: To evaluate associations with biochemical indicators of nut ritional and other risk factors in the Lens Opacities Case-Control Stu dy. Design: Case-control study. Setting and Participants: The Lens Opa cities Case-Control Study determined risk factors for cortical, nuclea r, and posterior subcapsular opacities among 1380 participants aged 40 to 79 years. Delta 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 2 5% of the Lens Opacities Case-Control Study population. Outcome: Labor atory test values in cases and controls were compared and expressed as odds ratios and 95% confidence intervals. Results: In polychotomous l ogistic regression analyses controlling for age and sex, the risk of o pacities was reduced to less than one half in persons with higher leve ls of vitamin E (odds ratio, 0.44 for nuclear opacities), albumin-glob ulin 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 t wice as likely to have high glutathione reductase activity (with flavi n adenine dinucleotide), which suggests low riboflavin status (odds ra tio, 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 ribof lavin, vitamin E, iron, and protein nutritional status. Higher levels of uric acid increased risk of mixed opacities. The findings for ribof lavin, vitamin E, iron, and uric acid are compatible with the dietary intake and medical history results of the Lens Opacities Case-Control Study.