Sex-dependent variables in the modulation of postalimentary lipemia
Received 15 December 2004; received in revised form 3 May 2005 published online 13 October 2005.
Abstract
Objective
To quantify in young adults the sex-dependent differences in lipemic responses to a fat meal, we measured the association of these responses with markers of atherosclerosis and determined their metabolic regulators.
Methods
Forty-nine normolipidemic volunteers, 25 women and 24 men, were matched according to age, body mass index, waist circumference, diet, physical activity, and apolipoprotein-E phenotyping. After receiving a standardized fat meal (40 g of fat/m2 of body surface area), serial blood samples were drawn for laboratory analysis. Common carotid intima-media thickness was measured.
Results
The lipemic responses were much greater in men than in women for plasma triacylglycerol (TAG), cholesterol, and TAG in TAG-rich lipoproteins, non-esterified fatty acids, phospholipids, and apolipoprotein-B100. Men presented with increased blood pressure, carotid intima-media thickness, TAG, hepatic lipase, and insulin and lower high-density lipoprotein cholesterol, apolipoprotein-AI, and non-esterified fatty acid concentrations. Only in men did carotid intima-media thickness correlate marginally with titers of autoantibodies to epitopes of oxidized low-density lipoprotein; in addition, phospholipids and cholesteryl esters were negatively related to autoantibodies. Multivariate analysis indicated that age (R2 = 45%), waist circumference (R2 = 19%), phospholipids (R2 = 39%), non-esterified fatty acids (R2 = 29%), insulin (R2 = 17%), lipoprotein lipase activity (R2 = 16%), and cholesteryl ester transfer protein (an exploratory variable; R2 = 6%) are strong determinants of postalimentary lipemia in women and that only insulin (R2 = 55%) and phospholipids (R2 = 37%) are determinants in men.
Conclusions
We have provided data explaining that postalimentary lipemia is differently regulated by sex. Several risk factors for coronary heart disease and significant associations with atherosclerosis biomarkers were found only in men.
This work was supported in part by grants from the Fundação de Amparo à Pesquisa do Estado de São Paulo, Fundo de Apoio ao Ensino e Pesquisa da Universidade de Campinas, and Coordenadoria de Pessoal de Ensino Superior.
ABSTRACT