Autoantibodies against oxidized LDL and serum total antioxidant status in active cyclists and ex-cyclists.

There is an apparent paradox between the benefits of aerobic exercise and the potentially deleterious effects of increased free radicals and decreased circulating antioxidants generated during exercise. To assess the oxidative/antioxidative status in competitive cyclists and ex-cyclists, we measured two markers not well studied in these situations, serum total antioxidant status (TAS) and antibodies against oxidized LDL (AuAb-ox-LDL) in 18 competitive male cyclists, 10 ex-competitive cyclists and 14 healthy males. AuAb-ox-LDL was evaluated by enzyme immunoassay, and serum TAS concentration was analyzed by spectrophotometry. Ex-cyclists had serum TAS levels statistically higher than the control group and cyclists group (p = 0.001 and p < 0.001, respectively). Active sportsmen showed significantly less AuAb-ox-LDL than healthy sedentary males, while there was a non-significant trend in the ex-cyclists to have lower AuAb-ox-LDL than the corresponding control group. AuAb-ox-LDL levels were not statistically different between the groups of active and previously active sporting men. There was a positive correlation between TAS and LDL-cholesterol in active cyclists under heavy training. In the ex-cyclist group, there was a negative correlation between serum TAS and the time elapsed since they had ended the competition. Competitive cycling decreases AuAb-ox-LDL levels, suggesting that it may decrease ox-LDL levels. After ending physical training, antioxidative status remains increased for at least one year, but the effect on AuAb-ox-LDL levels is lost.

Venous endothelial function in postmenopausal women after six months of tibolone therapy.

STUDY OBJECTIVE: To test venous endothelial function in long-term climateric therapy with tibolone. DESIGN: Measurement of dorsal hand-vein diameter by venous occlusion plethysmography during infusion of norepinephrine (NE), bradykinin (BK), NG-monomethyl L-arginine (L-NMMA) and sodium nitroprusside (SNP). SETTING: Plethysmography and Menopause Units. University Hospital Valdecilla. Santander. Spain. PATIENTS: Eleven postmenopausal women having continuous treatment with oral tibolone (2.5 mg/day) for 6 months. INTERVENTIONS: Three plethysmography studies were made: at baseline, and at three and six months of treatment. MAIN OUTCOME MEASURES: Dorsal hand-vein diameter measured by venous occlusion plethysmography during infusion of NE, BK, L-NMMA and SNP. RESULTS: (a) Baseline study: maximum dilation with BK was 54.2+/-10.2%. (b) Three-month study: BK dilation of 71.5+/-11.9%, with a significant increase of 17.3% (P=0.019) compared with baseline. (c) Six-month study: BK dilation of 77.5+/-11.9%, with a significant increase 23.3% (P=0.002) compared with baseline. Maximal vasodilation was reached with SNP in the three studies and L-NMMA infusion has a similar vasoconstrictor response in the three studies. CONCLUSIONS: Long-term climateric therapy with tibolone improves vein endothelium-dependent vasodilation suggesting a positive impact of this drug on endothelial function.