ABDOMINAL AND FEMORAL ADIPOSE-TISSUE LIPOLYSIS AND CARDIOVASCULAR-DISEASE RISK-FACTORS IN MEN

The relationships between subcutaneous abdominal and femoral fat cell lipolyses, plasma free-fatty acid (FFA) levels and metabolic variables considered as risk factors for cardiovascular disease (CVD) (plasma g lucose, insulin and lipoprotein levels) were investigated in 54 men, a ged 36+/-3 (SD) years, covering a wide range of body fatness values (b ody mass indices from 19 to 34 kg m(-2)). Although there were no consi stent relationships between femoral fat cell weight and the metabolic profile, positive and significant associations were found between abdo minal fat cell weight and most of the metabolic indices. However, abdo minal fat cell lipolysis measured with an alpha(2)-(clonidine) or a be ta-agonist (isoproterenol) was unrelated to metabolic variables. In co ntrast, femoral fat cell lipolysis measured in the presence of clonidi ne was positively associated with fasting plasma insulin, cholesterol (CHOL) and apolipoprotein (ape) B levels, as well as with LDL-CHOL and LDL-apo B concentrations. No association was found between isoprotere nol-stimulated lipolysis of femoral adipocytes and the metabolic profi le. Comparison of two subgroups of men with either low or high femoral residual lipolysis with clonidine revealed that subjects with the low est femoral alpha(2)-adrenergic component (i.e. the highest residual l ipolysis) displayed significant alterations in both plasma lipid-lipop rotein and glucose-insulin levels which could be predictive of an incr eased risk of CVD. Free fatty acid (FFA) levels measured in the fastin g state and during an oral glucose tolerance test (OGTT) were positive ly associated with fasting plasma insulin and triglyceride levels as w ell as with both glucose and insulin areas measured during the OGTT. H owever, regional adipose tissue lipolysis measured in vitro was unrela ted to plasma FFA levels. These results support the view that both fem oral adipose tissue lipolysis and plasma FFA levels are significant co rrelates of plasma glucose-insulin homeostasis and lipoprotein-lipid l evels, in men. However, as adipose tissue lipolysis and plasma FFA are unrelated to each other, they may be associated with risk variables t hrough independent mechanisms.