Caloric restriction lowers plasma lipoprotein (a) in male but not female rhesus monkeys

Many age-associated pathophysiological changes are retarded by caloric rest riction (CR). The present study has investigated the effect of CR on plasma lipoprotein (a) [Lp(a)], an independent risk factor for the age-associated process of atherosclerosis. Rhesus monkeys were fed a control diet (n = 19 males, 12 females) or subjected to CR (n = 20 males, 11 females fed 30% le ss calories) for >2 years. All female animals were premenopausal, Plasma Lp (a) levels in control animals were almost two fold higher for males than fe males (47 +/- 9 vs 25 +/- 5 mg/dl mean SEM, p = 0.05). CR resulted in a red uction in circulating Lp(a) in males to levels similar to those measured in calorie-restricted females, (27 +/- 5 vs. 24 +/- 4 mg/dl mean +/- SEM). Fo r all animals, plasma Lp(a) was correlated with total cholesterol (r = 0.27 , p = 0.03) and LDL cholesterol (r = 0.50, p = 0.0001) whether unadjusted o r after adjustment for treatment, gender or group. These studies introduce a new mechanism whereby CR may have a beneficial effect on risk factors for the development of atherosclerosis in primates. (C) 2001 Elsevier Science Inc. All rights reserved.