A post-trial survey to assess the impact of dissemination of results and unmasking on participants in a 13-year randomised controlled trial on age-related cataract.

BACKGROUND: The Italian-American Clinical Trial of Nutritional Supplements and Age-Related Cataract was designed to assess the impact of a multivitamin-mineral supplement on age-related cataract. Trial results showed evidence of a beneficial effect of the supplement on all types of cataract combined, opposite effects on two of the three types of cataract (beneficial for nuclear opacities and harmful for posterior sub-capsular opacities) and no statistically significant effect on cortical opacities. No treatment recommendations were made. A post-trial survey was conducted on 817 surviving elderly participants to assess their satisfaction, their understanding of treatment assignment to supplement or placebo and the success of masking. METHODS: Trial results were communicated by letter and the level of satisfaction and of understanding of the results was assessed by a questionnaire. Participants were offered the option of being unmasked: a second questionnaire was administered to this subset to assess their understanding of the randomisation process and the success of masking. RESULTS: 610 participants (74.7%) responded to the survey:94.6% thought the description of the results was "very clear" or "quite clear", 5.4% "not clear" or "do not know"; 89.8% considered the results "very interesting" or "quite interesting", 10.2% "not interesting" or "do not know"; 60.3% expressed "satisfaction", 17.2% "both satisfaction and concern", 2.6% "concern", 19.9% "indifference" or "do not know".480 participants (78.7%) accepted the offer to be unmasked to their treatment assignment: 395 (82.3%) recalled/understood the possibility of assignment to vitamins or placebo, 85 (17.7%) did not. 68 participants (17.2%) thought they had taken vitamins (79.4% were correct; p = 0.0006), 47 (11.9%) thought they had taken placebo (59.6% were correct; p = 0.46) and 280 (70.9%) declared they did not know. CONCLUSIONS: The results were made difficult to explain to study participants by the qualitatively different effect of treatment on the two most visually significant types of cataract. Although the study did not lead to a recommendation to use the dietary supplement, the vast majority of participants reported satisfaction after they received the results but almost 20% of the participants expressed some concern. Masking to treatment assignment was successful in the majority of participants.

Effects of multivitamin/mineral supplementation on plasma levels of nutrients. Report No. 4 of the Italian-American clinical trial of nutritional supplements and age-related cataract.

The use of multivitamin-mineral supplements has become increasingly common, but whether the use of such supplements improves micronutrient status remains still unclear. The objective of this report is to investigate how a long-term vitamin-mineral supplementation following the US Recommended Daily Intake (RDI) affected the plasma levels of selected nutrients in a subset (No. = 407) of participants in the Italian-American Clinical Trial of Nutritional Supplements and Age-related Cataract (CTNS). The CTNS was a double-blind, single centre, controlled clinical trial of 1020 participants aged 55-75 years randomized to a daily tablet of Centrum(R) or placebo. A representative sample of 40% of the 1020 subjects, whom plasma level of selected vitamins was determined at the baseline, was retested throughout the treatment period that averaged 9.0 +/- 2.4 years. Participants assigned to Centrum(R) showed a significant increase (p < 0.005) in mean/median plasma levels of vitamin E, beta-carotene, folate, and vitamin B12, and an improved riboflavin status when compared with participants assigned to placebo. Differences concerning vitamin C were statistically less relevant and those concerning vitamin A were at a borderline level. In the treated group the effect of supplementation on plasma levels of vitamins A, E, and C, and on the glutathione reductase activation coefficient was significantly higher in participants with lower nutritional status at baseline.

A randomized, double-masked, placebo-controlled clinical trial of multivitamin supplementation for age-related lens opacities. Clinical trial of nutritional supplements and age-related cataract report no. 3.

OBJECTIVE: To evaluate the effect of a multivitamin/mineral supplement on development or progression of age-related lens opacities. DESIGN: Randomized, double-masked, single center, placebo-controlled clinical trial. PARTICIPANTS: One thousand twenty participants, 55 to 75 years old and with early or no cataract, were randomly assigned to a daily tablet of a multivitamin/mineral formulation or a placebo. METHODS: Baseline and annual lens photographs were graded for severity of lens opacities according to a modification of the Age-Related Eye Disease Study system for classifying cataracts. MAIN OUTCOME MEASURES: The primary outcome was a prespecified increase from baseline in nuclear, cortical, or posterior subcapsular cataract (PSC) opacity grades or cataract surgery. Secondary outcomes included an increase in type-specific opacity grades, cataract surgery, and visual acuity (VA) loss from baseline > or =15 letters. RESULTS: Participants were observed for an average of 9.0+/-2.4 years. There was a decrease in total lens events in participants assigned to the multivitamin/mineral formulation compared with those assigned to the placebo (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.68-0.98; P = 0.03). Nuclear events were significantly less common (HR, 0.66; 95% CI, 0.50-0.88; P = 0.004) and PSC events significantly more common (HR, 2.00; 95% CI, 1.35-2.98; P<0.001) in participants taking the multivitamin/mineral formulation than in those assigned to the placebo. No statistically significant treatment effects were seen for cortical opacities, moderate VA loss, or cataract surgery. CONCLUSIONS: Lens events were less common in participants who took the multivitamin/mineral formulation, but treatment had opposite effects on the development or progression of nuclear and PSC opacities, the 2 most visually important opacity subtypes.

Galactokinase gene mutations and age-related cataract. Lack of association in an Italian population.

PURPOSE: To investigate possible associations between sequence changes in the galactokinase gene (GALK1) and age-related cataract in a European population. METHODS: Persons without lens opacities and persons with clinically significant age-related cataract were selected from those participating in the Collaborative Italian-American Clinical Trial of Nutritional Supplements and Age-Related Cataract or from those attending the Section of Ophthalmology of the University of Parma for cataract surgery. Type and severity of the opacities were assessed by slit-lamp and retro-illumination lens photographs. Mutations in GALK1 were identified by PCR amplification of individual exons and flanking sequences and sequencing using fluorescent terminator technology in an ABI 377 Prism or 3100 automated DNA sequencer. RESULTS: DNA samples were obtained from 115 individuals with clear lenses and from 185 individuals with cataract (106 with any nuclear, 88 with any cortical, and 25 with any posterior sub capsular cataract). 157 of the 185 patients with cataract (85%) were age-matched with a control within an age range of plus or minus 1 year. SNPs causing amino acid changes in the galactokinase protein were identified in exon 4; I184M, 1/115 control versus 0/185 cataractous individuals, p=0.38, exon 6; G274D, 0/115 control versus 1/185 cataractous individuals, p>0.99, and exon 7; V338A, 0/115 control versus 1/185 cataractous individuals, p>0.99. Thus, there were no significant differences in the distribution of sequence alterations resulting in amino acid changes between control and cataractous individuals. Eighty samples showed a C to T transition 43 bases into intron 7 (46 cataracts and 34 controls). Testing the distribution of the intron 7 findings showed Hardy-Weinberg equilibrium for both cases (p=0.73) and controls (p=0.51). There was no difference in C/T distribution between cases and controls (p=0.27). CONCLUSIONS: In this northern Italian population age-related cataract does not appear to be associated with GALK1 alleles. Since this is due to a lack of sequence changes in both affected and control individuals, this study cannot rule out the possibility of an association in other populations.

Baseline cataract type and 10-year mortality in the Italian-American Case-Control Study of age-related cataract.

Age-related cataract is reported to be associated with increased risk of death. The authors investigated the association of presence and type of cataract with mortality in the participants of the Italian-American Case-Control Cataract Study (Parma, Italy, 1987-1989), which included 1,008 persons aged 45-79 years who had age-related cataract and 469 who had clear lenses. Slit-lamp and retroillumination lens photographs were taken at baseline and graded with the Lens Opacities Classification System II. During 10 years of follow-up (range, 8.9-11.8 years; 11,318 person-years), the authors collected information on 1,429 participants and documented 339 deaths. After adjustment for age, sex, and other mortality risk factors, mixed cataracts with a nuclear/posterior subcapsular component were significantly associated with higher risk of death by Cox proportional hazards regression analyses. Hazard ratios were 2.26 (95% confidence interval (CI): 1.07, 4.76) for nuclear/posterior subcapsular and 1.62 (95% CI: 1.01, 2.61) for cortical/nuclear/posterior subcapsular opacities. In multivariate analysis, mixed types of opacity (any) were associated with increased mortality for malignancy (hazard ratio = 1.81, 95% CI: 1.04, 3.15) and "other" causes (hazard ratio = 2.29, 95% CI: 1.07, 4.92). These findings are compatible with the hypothesis that mixed types of cataract with a nuclear/posterior subcapsular component are indicators of accelerated aging.