Lipoprotein lipase and hepatic lipase: their relationship with HDL subspecies Lp(A-I) and Lp(A-I,A-II)

: their relationship with HDL subspecies Lp(A-I) and Lp(A-I,A-II) Marian C. Cheung 1 ,* , Shalamar D. Sibley 2 ,* , Jerry P. Palmer * , , John F. Oram * and John D. Brunzell * * Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington, Seattle, WA 98103 Veterans Administration, Puget Sound Health Care System, Seattle, WA 98108 1 To whom correspondence should be addressed. e-mail: mccheung{at}u.washington.edu HDL subspecies Lp(A-I) and Lp(A-I,A-II) have different anti-atherogenic potentials. To determine the role of lipoprotein lipase (LPL) and hepatic lipase (HL) in regulating these particles, we measured these enzyme activities in 28 healthy subjects with well-controlled Type 1 diabetes, and studied their relationship with Lp(A-I) and Lp(A-I,A-II). LPL was positively correlated with the apolipoprotein A-I (apoA-I), cholesterol, and phospholipid mass in total Lp(A-I), and with the apoA-I in large Lp(A-I) ( r 0.58, P 0.001). HL was negatively correlated with all the above Lp(A-I) parameters plus Lp(A-I) triglyceride ( r -0.53, P 0.003). No correlation was detected between LPL and Lp(A-I,A-II). However, HL was inversely correlated with total Lp(A-I,A-II) phospholipid, and with large Lp(A-I,A-II) ( r 0.50, P 0.006). Similar studies were performed with phospholipid transfer protein (PLTP). Only total Lp(A-I) triglyceride in women (not men) ( r = 0.71, P = 0.009) was significantly correlated with PLTP activity. These observations indicate that LPL and HL play major roles in determining the level and composition of plasma Lp(A-I), particularly large Lp(A-I), but not with Lp(A-I,A-II) level. Furthermore, select correlations of LPL and/or HL with the apoA-I, cholesterol, and triglyceride of Lp(A-I) but not Lp(A-I,A-II) imply that the apoA-I and lipid of Lp(A-I) and Lp(A-I,A-II) are not fully equilibrated. Supplementary key words phospholipid transfer protein • high density lipoprotein size profile • Type 1 diabetes CiteULike     Complore     Connotea     Del.icio.us     Digg     Reddit     Technorati     What's this?