Accumulation of triglyceride-rich lipoprotein in subjects with abdominal obesity - The Biguanides and the Prevention of the Risk of Obesity (BIGPRO) 1 study

The present study represents a new insight into the Biguanides and the Prev ention of the Risk of Obesity (BIGPRO) 1 study population at inclusion. Thi s population, selected basically on the basis of a high waist-to-hip ratio (greater than or equal to0.95 for men and greater than or equal to0.80 for women), is supposed to represent a group of patients with insulin resistanc e. The present study was undergone to establish whether apolipoprotein C-II I (apoC-III) and apolipoprotein E (apoE) associated with apo B (apoC-III Lp B and apoE LpB, respectively), considered to be markers of remnant accumula tion, play a role in the hypertriglyceridemia associated with insulin resis tance and whether they are related to other biological abnormalities freque ntly observed in this syndrome. In this population, the concentration of th e markers of remnant accumulation increases with triglyceride levels. There fore, correlation studies were realized to assess the relative effect of in sulin and the markers of remnant accumulation on triglyceride plasma level, As a first attempt, a simple correlation analysis revealed that insulin is positively related to the markers of remnant accumulation only in hypertri glyceridemic patients (triglycerides greater than or equal to1.7 mmol/L), T o assess the independent contribution of these markers, insulin, and other parameters related to the plasma triglyceride concentration, a stepwise mul tiple regression analysis was run. Results revealed that insulin and the ma rkers of remnant accumulation (specifically, apoE LpB) are independent cont ributors to the plasma triglyceride concentration. Markers of the endotheli al damage, plasminogen activator inhibitor-1, tissue plasminogen activator, and von Willebrand factor, which are often increased in the case of insuli n resistance, were tested for their correlation with the markers of remnant accumulation. Plasminogen activator inhibitor-1 is positively correlated w ith these markers only in hypertriglyceridemic male subjects. It is conclud ed that increased insulin levels found in insulin resistance syndrome are a ssociated with an increased production of triglyceride-rich lipoproteins en riched in apoC-III and apoE. The accumulation of these remnants and/or thei r abnormal composition in apoC-III and apoE could be an explanation for the development of hypertriglyceridemia in this syndrome.