Abstract P137: Walking Impairment and Vitamin D Deficiency in the Elderly, National Health and Nutrition Examination Survey 2001 to 2004

Abstract

Introduction: Vitamin D deficiency has been reported in 36% of otherwise healthy adults and 57% of inpatients in the US. Vitamin D deficiency (< 15 ng/ml) is linked to increased muscle weakenss, cardiovascular disease and abnormal bone mineral metabolism. The elderly are more prone to vitamin D deficiency because of decrease dietary intake, diminished sunlight exposure and reduced skin thickness among other risk factors. We hypothesized that walking impairment in subjects older than 60 years old is associated to abnormal serum levels of 25-hydroxyvitaminD levels independent of traditional cardiovascular risk factors. Methods: A multivariable adjustment was performed using the National Health and Nutrition Examination Survey database and a graded association was present between serum 25-hydroxyvitaminD levels and walking impairment. We analyzed data from 2,322 participants of the NHANES 2001-2004 survey ages 60 years or older who responded to the walking impairment (WI) questionnaire and had serum 25-hydroxyvitamin D levels measured. Walking impairment was defined as an affirmative answer to the question: “have you had pain in either leg while walking?” A 25 hydroxyvitamin D deficiency level was defined as a serum level of 15ng/dl or less. PAD was defined as an ABI of less than 0.9 in either leg. Results: The prevalence of individuals 60 year or older with walking impairment due to leg pain in the United States is 25 % (S.E, 1.3). Mexican Americans (31.43%) had a higher prevalence of WI than Whites (24.28%) or African Americans (28.67%). Walking impairment was also statistically significant among those with a history of diabetes mellitus, cardiovascular disease, and peripheral arterial disease. Results also showed that C-reactive protein and alkaline phosphates were higher among those with walking impairment. A multivariable adjustment was performed and a graded association was present between serum 25-hydroxyvitaminD levels and walking impairment. An odds ratio of 1.526186(p= 0.013) for walking impairment was present among vitamin D deficient subjects after adjusting for age, gender, and race-ethnicity. The association remained after further adjusting for C-reactive protein, chronic kidney disease, smoking, history of diabetes, PAD, and history of cardiovascular disease (O.R. =1.416255, p=0.045). Conclusion: Walking impairment is associated with 25-hydroxyvitaminD deficiency in the elderly independent of traditional cardiovascular risk factors. These results warrant further studies to determine if vitamin D supplementation improves functional capacity and reduces cardiovascular disease in the elderly.