Serum urate determines antioxidant capacity in middle-aged men - a controlled, randomized diet and exercise intervention study.

OBJECTIVES

To study whether advice on diet and/or exercise, given in order to reduce cardiovascular risk factors in middle-aged men, affects the intake of antioxidants, urate concentration and the total antioxidant capacity in serum.

DESIGN

A 6-month randomized controlled intervention study.

SETTING

Primary Health Care in Sollentuna, Stockholm, and the Department of Medicine, Karolinska Hospital, Stockholm, Sweden.

SUBJECTS

One hundred and fifty-eight healthy men (46.2 +/- 5.0 years) with moderately raised cardiovascular risk factors.

INTERVENTIONS

Advice on diet (D, n = 40), exercise (E, n = 39), diet and exercise (DE, n = 39) and a control group (C, n = 39).

MAIN OUTCOME MEASURES

Dietary intake, exercise habits, S-urate and the antioxidant capacity in serum (TAOC).

RESULTS

After 6 months, changes in dietary and exercise habits were seen in all three intervention groups and favourable effects were seen on BMI, waist circumference, blood pressure, S-cholesterol and fasting insulin. The intake of alpha-tocopherol was decreased in groups D and E (P < 0.01) and beta-carotene was increased in groups D and DE (P < 0.01). In group DE, the intake of vitamin C was increased (P < 0.05). S-urate was reduced in group D from 345 to 325 micromol L-1 (P < 0.05). No significant changes in TAOC were seen in any group. S-urate and TAOC were correlated (r = 0. 58, P < 0.001) and S-urate was correlated to several parameters in the metabolic syndrome.

CONCLUSION

Favourable changes in diet and exercise reduced several cardiovascular risk factors but did not affect the total antioxidant capacity in serum. S-urate was a strong determinant of the antioxidant capacity.