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Objectives To examine the association between multiple measures of visual impairment ( VI) and incident mobility limitations in older adults. Design Prospective observational cohort study. Setting Memphis, Tennessee, and Pittsburgh, Pennsylvania. Participants Health, Aging and Body Composition study participants aged 70 to 79 without mobility limitations at the Year 3 visit (N = 1,862). Measurements Vision was measured at the Year 3 visit, and VI was defined as distance visual acuity ( VA) worse than 20/40, contrast sensitivity ( CS) less than 1.55 log Contrast, and stereoacuity ( SA) greater than 85 arcsec. Incident persistent walking and stair climbing limitation was defined as two consecutive 6-month reports of any difficulty walking one-quarter of a mile or walking up 10 steps after 1, 3, and 5 years of follow-up. Results At Year 3 (baseline for these analyses), 7.4% had impaired VA, 27.2% had impaired CS, and 29.2% had impaired SA. At all follow-up times, the incidence of walking and stair climbing limitations was higher in participants with VA, CS, or SA impairment. After 5 years, impaired CS and SA were independently associated with greater risk of walking limitation (hazard ratio ( HR) CS = 1.3, 95% confidence interval ( CI) = 1.1-1.7; HRSA = 1.3, 95% CI = 1.1-1.6) and stair climbing limitation ( HRCS = 1.4, 95% CI = 1.1-1.8; HRSA = 1.3, 95% CI=1.1-1.7). Having impaired CS and SA was associated with greater risk of mobility limitations ( HRwalking limitations = 2.0, 95% CI = 1.6-2.5; HRstair limitation = 2.1, 95% CI = 1.6-2.8). Conclusion Multiple aspects of VI may contribute to mobility limitations in older adults. Addressing more than one component of vision may be needed to reduce the effect of vision impairment on functional decline. [ABSTRACT FROM AUTHOR]

Objectives To examine the relationship between 25-hydroxyvitamin D (25( OH)D) levels and cognitive performance over time in older adults in the Health, Aging and Body Composition (Health ABC) Study. Design Prospective cohort study. Setting Community-dwelling participants in Pittsburgh, Pennsylvania, and Memphis, Tennessee. Participants Well-functioning adults aged 70 to 79 at baseline with serum 25( OH)D measured at the 12-month follow-up visit and cognitive function measured at baseline and 4-year follow-up visit (N = 2,777). Measurements Vitamin D status was categorized as 25(OH)D levels of less than 20.0 ng/mL, 20.0 to 29.9 ng/mL, or 30.0 ng/mL or greater. Cognition was measured using the modified Mini-Mental State Examination (3MS) and Digit Symbol Substitution Test (DSST). Linear regression models adjusting for multiple covariates, including age, education, sex, race, site, season, physical activity, and comorbidities, were used in the analysis. Results Sixty-eight percent of participants had 25(OH)D levels of less than 30.0 ng/mL. Lower 25(OH)D levels were associated with lower baseline cognitive scores on the 3MS (adjusted mean 89.9, 95% confidence interval (CI) = 89.4-90.4 for <20.0 ng/mL; adjusted mean 90.8, 95% CI = 90.4-91.3 for 20.0-29.9 ng/mL; adjusted mean 90.6, 95% CI = 90.2-91.1 for ≥30.0 ng/mL; P trend = .02) and the DSST (adjusted mean 35.2, 95% CI = 34.5-36.0 for <20.0 ng/mL; adjusted mean 35.9, 95% CI = 35.2-36.6 for 20.0-29.9 ng/mL; adjusted mean 37.0, 95% CI = 36.3-37.8 for ≥30.0 ng/mL; P trend = .01). Participants with low 25(OH)D levels had greater declines in 3MS scores over 4 years than those with higher levels (least square mean change −1.0, 95% CI = −1.5 to −0.6 for <20.0 ng/mL; least square mean change −0.8, 95% CI = −1.2 to −0.3 for 20.0-29.9 ng/mL; least square mean change −0.2, 95% CI = −0.7 to 0.2 for ≥30.0 ng/mL; P = .05). There was no significant difference in DSST decline according to 25(OH)D level. Conclusion Low 25( OH)D levels were associated with worse global cognitive function and greater decline over time according to the 3 MS. Intervention trials are needed to determine whether vitamin D supplementation can reduce cognitive decline. [ABSTRACT FROM AUTHOR]

Using data from the Health, Aging, and Body Composition study, we examined whether low 25-hydroxyvitamin D (25[OH]D) concentrations were associated with prevalent or incident cognitive impairment. Serum 25(OH)D concentrations were measured in 2,786 older adults and categorized as <20 ng/mL, 20 to <30 ng/mL, or ≥30 ng/mL. Cognitive impairment was defined as a score >1.5 standard deviations below race and education specific means on either digit symbol substitution test or modified mini-mental state test. Logistic regression determined the odds of cognitive impairment at baseline and year 5 by 25(OH)D category. 25(OH)D concentrations were <30 ng/mL in 57.3% of whites and 84.6% of blacks. After excluding participants with baseline cognitive impairment (n = 340), 13% of whites and 13% of blacks developed cognitive impairment by year 5. In whites, 25(OH)D concentrations <30 ng/mL were not associated with prevalent or incident cognitive impairment. Black participants with 25(OH)D concentrations <20 ng/mL had a higher odds of prevalent, but not incident cognitive impairment (OR (95% CI): 2.05 (1.08-3.91), p = 0.03) compared to participants with 25(OH)D concentrations ≥30 ng/mL. Low 25(OH)D concentrations were associated with twofold higher odds of prevalent cognitive impairment in blacks.