Higher uric acid levels are associated with better functional recovery in elderly patients receiving cardiac rehabilitation.

BACKGROUND AND AIMS: Whether uric acid (UA) serves as risk factor for cardiovascular diseases or as antioxidant defense has not yet been completely clarified. In this study we investigated the effects of UA on functional recovery in patients receiving cardiac rehabilitation. METHODS AND RESULTS: 306 patients, 209 men and 97 women, age range 25-87 years (mean 68 ± 11), performed the 6-min walk test (6mWT) before and after the rehabilitation, and the increase in walking distance was considered as the outcome measure of the study. Baseline UA serum levels ranged from 1.0 to 10.9 mg/dL (mean 5.2 ± 1.7). As there was a significant (p = 0.005) age*UA levels interaction, patients were divided into two subgroups, less then 65 years (n. 103, 68 men and 35 women, mean age 56 ± 9) and 65 years or more (n. 203, 141 men and 62 women, mean age 74 ± 5). After adjusting for relevant confounders, higher UA levels remained independent positive predictors of the increase in walking distance in older (p < 0.001) but not in younger patients (p = 0.807). CONCLUSIONS: Our findings show an independent association of higher UA levels with better functional recovery after cardiac rehabilitation selectively in elderly patients, suggesting that higher UA levels might reflect the decline in antioxidant defenses that occurs with advancing age. Future studies aimed at understanding the several contradictions concerning UA should, probably, address the issue within this perspective.

Clinical, biochemical and therapeutical aspects of amiodarone-induced hypothyroidism (AIH) in geriatric patients with cardiac arrhythmias.

The clinical features and the laboratory aspects of the amiodarone-induced hypothyroidism (AIH) in the elderly as well as the effects of amiodarone treatment in aged AIH people have not yet been well clarified. In the present paper, we evaluated 18 subjects of both sexes (7 females, 11 males), aged 65-83 years, affected by AIH, recruited in Central Tuscany, Italy. The patients were divided in two subsets on the basis of thyroid stimulating hormone (TSH) values: mild (TSH < 20 mU/l; Group A, n=11) and severe (TSH > 20 mU/l; Group B, n=7) hypothyroid patients. On the basis of clinical features, hypothyroidism was diagnosed only in two patients (out of Group B). Concerning the hormonal pattern, we found that free tetraiodothyronine (fT4) levels were significantly lower than the normal range only in Group B subjects; TSH and thyroglobulin were higher than normal in both groups; free triiodothyronine (fT3) were always in the normal range. Thyroid autoantibodies were found positive only in one patient out of Group A and in two patients out of Group B. In 5/18 patients T4 substitutive therapy was rapidly assigned, because of severe degree of hypothyroidism. In the remaining 13/18 patients, we evaluated the clinical behavior of AIH. After additional cardiac evaluation, amiodarone was withdrawn in 5/13 patients: during follow-up period (4-10 months) four patients became quickly euthyroid while one worsened. In 8/13 patients, amiodarone treatment had to be carried on; during follow-up (2-48 months), four patients remained mildly hypothyroid, while other four patients became severely hypothyroid. In conclusion, in amiodarone treated elderly people, diagnosis of hypothyroidism is reliable only on the basis of high values of TSH; clinical features and fT3 serum levels never enable diagnosis.