Assessing the Relationship between Vitamin D Status and Impairments in Cognitive and Physical Performance in Older Adults Using a Dual Task Physical Performance Test.

BACKGROUND: Vitamin D deficiency has been associated with an increased risk of falls in older adults. Several studies have demonstrated an association between vitamin D deficiency and gait and cognitive impairments, which are two risk factors for falls in the elderly. There is lack of research about the role of vitamin D in cognitive function in the context of mobility. OBJECTIVE: The purpose of this study was to evaluate the association between vitamin D status with the age-related changes in mobility through higher order cognitive function using a dual task physical performance test. DESIGN: Cross-sectional. SETTING: Community-dwelling older adult population located in Miami, Fl. PARTICIPANTS: Healthy participants over the age of 55 (n=97) who participated in the parent interventional study. MEASUREMENTS: Participants completed assessments that included serum levels of vitamin D, surveys, and dual task physical performance tests. Spearman's correlations, independent t-tests, repeated measures ANOVAs and multiple logistic regressions were used to examine the relationship between vitamin D insufficiency (25-hydroxyvitamin D <30 ng/ml) and sufficiency (≥30 ng/ml) and dual task physical performance variables. The significance level was set at α=0.05. RESULTS: There were no significant associations between vitamin D insufficiency and gait velocity during either task. Using Spearman correlations, slower single (P=0.011) and dual task counting rates (P=0.006) were significantly associated with vitamin D insufficiency. Independent t-tests showed dual and single task counting rates were significantly lower in the vitamin D insufficient group compared to the sufficient group (P=0.018 and P=0.028, respectively). The results for the ANOVAs indicated that velocities and counting rates were not significantly different by vitamin D status (Wilk's Lambda =0.999; F (1, 95) =.11, P=.740) (Wilk's Lambda =.999, F(1,95)=.13, P=.718). Vitamin D status was not significantly associated with dual task physical performance (defined as the difference in dual and single task) in gait velocity (OR=1.00, 95% CI: 0.98; 1.02, P=0.772) and counting rate (OR=1.684, 95% CI: 0.15; 19.57, P=0.677), when controlling for confounders. CONCLUSIONS: Since counting backward is a mental tracking task, which is a component of executive function, our results suggest a relationship between vitamin D insufficiency and executive dysfunction. Executive dysfunction has been previously associated with fall risks in the elderly, and it could be a possible mediator between vitamin D and falls. Our data suggest that cognition may play a significant role in vitamin D's influence on falls, while motor function may play a lesser role.

Rheumatology and care for the rheumatic diseases in cuba.

The Cuban state guarantees free medical assistance to the people as well as social security benefits. In general, 23.7% of the 1,352,165 pensioners in 1995 were disabled and, of disabled pensioners, more than 50% had disabilities secondary to rheumatic diseases. Expenses associated with public health reached 1382, 9 million pesos. Cuba has one rheumatologist for each 150,000 inhabitants throughout the country. The development of post-graduate teaching over the last 12 years has produced 125 rheumatologists. Major national attention is directed at the disabled elderly patients with musculoskeletal disease, with important roles of the Cuban Rheumatological Society and the Cuban Action Program for the Attention of the Handicapped. Arthroscopy has developed as a prominent technique used by Cuban rheumatologists. Objective evaluations of its impact may lead to expanded use in other countries. The Cuban Rheumatical Society has been working systematically in training rheumatologists and educating patients to minimize the impact of rheumatic diseases in Cuba.