[Lp(a) and weight loss in obese patients]

High concentrations of lipoprotein (a) (Lp(a)) are associated with an increased risk of atherosclerotic vascular disease. Lp(a) synthesis is mainly under genetic control but many endocrine disturbances may modulate Lp(a) plasmatic concentrations. There is no agreement upon Lp(a) variations in patients under a hypocaloric diet. This study was undertaken to assess this point in obese females subjected to a 1100 kcal/d diet. Ninety-two obese patients (42.4 +/- 10.4 yr old, BMI 33.9 +/- 5.6 kg/m2) came once a week as out patients during 9 weeks. Lp(a) concentrations distribution was highly skewed. The threshold Lp(a) concentration for a significant cardiovascular risk is estimated at 0.3 g/l. Concentrations above 0.3 g/l were found in 29/92 patients (31%). If the patients were distributed in 2 groups according to their Lp(a) values (< or = ou > 0.3 g/l), the BMI, total cholesterol or triglycerides were not different. There were no significant correlation between Lp(a) and age, total cholesterol or triglycerides. After 9 weeks BMI and total cholesterol values decreased (-1.6 +/- 3.4 kg/m2 and -0.17 +/- 0.68 mmol/l, respectively). Lp(a) concentrations were unchanged (0.3 +/- 0.3 vs 0.3 +/- 0.3 g/l). There were no significant correlation between Lp(a) variations and age, BMI or initial Lp(a) concentrations. No significant decrease of Lp(a) could be detected even in the sub-group of patients with initial concentrations of Lp(a) > 0.3 g/l or even in a sub-group with Lp(a) > 0.7 g/l (n = 7). Under our conditions, weight loss is not associated with a decrease of Lp(a) concentrations suggesting that in a given obese a single determination is enough to assess his Lp(a)-related atherosclerotic risk.