The Interplay Between Uric Acid and Antioxidants in Relation to Physical Function in Older Persons

Autor: Fulvio Lauretani, Jack M. Guralnik, Luigi Ferrucci, Stefania Bandinelli, Antonio Cherubini, Richard D. Semba, Carmelinda Ruggiero, Shari M. Ling, Marcello Maggio, Umberto Senin
Rok vydání: 2007
Předmět:
Zdroj: Journal of the American Geriatrics Society. 55:1206-1215
ISSN: 1532-5415
0002-8614
DOI: 10.1111/j.1532-5415.2007.01260.x
Popis: Uric acid (UA), a constituent of the cell cytosol generated by nucleotide catabolism, reflects cell death and turnover and dietary intake composition. Based on biochemical evidence, UA is considered to be a reactive oxygen species (ROS) scavenger, and the genetic mutation that allows for higher UA circulating levels in humans than in all other species1,2 has been interpreted as an evolutionary strategy to counteract ROS-mediated damage, an unavoidable by-product of aerobic metabolism.3–5 Despite this interpretation, epidemiological studies have demonstrated that hyperuricemia is a strong predictor of mortality in women,6–8 older persons9,10 and those with preexisting cardiovascular disease.11–12 In subjects with chronic heart failure, UA levels have been positively associated with impaired oxidative metabolism, hyperinsulinemia, high levels of proinflammatory cytokine activation, and impaired endothelial function.13–14 Although an association between serum UA levels and various cardiovascular morbidity exists, most scientists believe that UA is a compensatory mechanism aimed at limiting oxidative stress, rather than having a causal role in the pathogenesis of these conditions.4 In partial contrast with this hypothesis, an association was recently demonstrated between UA and several proinflammatory parameters in humans.15 Consistently preclinical studies showed that UA can directly trigger an immunological response.16 In practice, the potential effects of UA on health status remain uncertain. To gain insight into the relationship between UA levels and oxidative processes and its effect on general health status, it was proposed that the relationship between circulating UA and antioxidant levels, such as carotenoids, tocopherols, and selenium, and between UA and measures of physical function that in the geriatric literature are generally considered to be good indicators of global health status be studied. This approach may help discover whether UA behaves as an antioxidant compound in humans and whether levels of circulating antioxidants modulate the effect of UA on health status, with the final aim being to provide insight into the pathophysiology of disability in older persons.
Databáze: OpenAIRE
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