Understanding lipoproteins as transporters of cholesterol and other lipids

2004 ◽  
Vol 28 (3) ◽  
pp. 105-106 ◽  
Author(s):  
Kyle D. Biggerstaff ◽  
Joshua S. Wooten
Keyword(s):  
Physiological Function ◽  
Particle Density ◽  
Low Density Lipoprotein ◽  
Critical Role ◽  
Lipoprotein Metabolism ◽  
Density Lipoprotein ◽  
Protein Composition ◽  
Lipoprotein Cholesterol ◽  
Low Density Lipoprotein Cholesterol ◽  
Lipid Transporters

A clear picture of lipoprotein metabolism is essential for understanding the pathophysiology of atherosclerosis. Many students are taught that low-density lipoprotein-cholesterol is “bad” and high-density lipoprotein-cholesterol is “good.” This misconception leads to students thinking that lipoproteins are types of cholesterol rather than transporters of lipid. Describing lipoproteins as particles that are composed of lipid and protein and illustrating the variation in particle density that is determined by the constantly changing lipid and protein composition clarifies the metabolic pathway and physiological function of lipoproteins as lipid transporters. Such a description will also suggest the critical role played by apolipoproteins in lipid transport. The clarification of lipoproteins as particles that change density will help students understand the nomenclature used to classify lipoproteins as well.

scholarly journals Low density lipoprotein cholesterol and all-cause mortality rate: findings from a study on Japanese community-dwelling persons

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ryuichi Kawamoto ◽  
Asuka Kikuchi ◽  
Taichi Akase ◽  
Daisuke Ninomiya ◽  
Teru Kumagi
Keyword(s):  
Low Density Lipoprotein ◽  
Critical Role ◽  
Density Lipoprotein ◽  
Community Dwelling ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Adjusted Relative Risk ◽  
Low Density Lipoprotein Cholesterol ◽  
All Cause Mortality

Abstract Background Low-density lipoprotein cholesterol (LDL-C) independently impacts aging-related health outcomes and plays a critical role in cardiovascular diseases (CVDs). However, there are limited predictive data on all-cause mortality, especially for the Japanese community population. In this study, it was examined whether LDL-C is related to survival prognosis based on 7 or 10 years of follow-up. Methods Participants included 1610 men (63 ± 14 years old) and 2074 women (65 ± 12 years old) who participated in the Nomura cohort study conducted in 2002 (first cohort) and 2014 (second cohort) and who continued throughout the follow-up periods (follow-up rates: 94.8 and 98.0%). Adjusted relative risk estimates were obtained for all-cause mortality using a basic resident register. The data were analyzed by a Cox regression with the time variable defined as the length between the age at the time of recruitment and that at the end of the study (the age of death or censoring), and risk factors including gender, age, body mass index (BMI), presence of diabetes, lipid levels, renal function, serum uric acid levels, blood pressure, and history of smoking, drinking, and CVD. Results Of the 3684 participants, 326 (8.8%) were confirmed to be deceased. Of these, 180 were men (11.2% of all men) and 146 were women (7.0% of all women). Lower LDL-C levels, gender (male), older age, BMI under 18.5 kg/m2, and the presence of diabetes were significant predictors for all-cause mortality. Compared with individuals with LDL-C levels of 144 mg/dL or higher, the multivariable-adjusted Hazard ratio (and 95% confidence interval) for all-cause mortality was 2.54 (1.58–4.07) for those with LDL-C levels below 70 mg/dL, 1.71 (1.15–2.54) for those with LDL-C levels between 70 mg/dL and 92 mg/dL, and 1.21 (0.87–1.68) for those with LDL-C levels between 93 mg/dL and 143 mg/dL. This association was particularly significant among participants who were male (P for interaction = 0.039) and had CKD (P for interaction = 0.015). Conclusions There is an inverse relationship between LDL-C levels and the risk of all-cause mortality, and this association is statistically significant.

Testosterone administration to men increases hepatic lipase activity and decreases HDL and LDL size in 3 wk

2003 ◽  
Vol 284 (6) ◽  
pp. E1112-E1118 ◽  
Author(s):  
Karen L. Herbst ◽  
John K. Amory ◽  
John D. Brunzell ◽  
Howard A. Chansky ◽  
William J. Bremner
Keyword(s):  
Lipase Activity ◽  
Particle Density ◽  
Hepatic Lipase ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Low Density Lipoprotein Cholesterol ◽  
Hepatic Lipase Activity ◽  
Testosterone Administration ◽  
Baseline Levels

Testosterone administration to men is known to decrease high-density lipoprotein cholesterol (HDL-C) and the subclasses HDL2and HDL3. It also might increase the number of small, dense, low-density lipoprotein cholesterol (LDL-C) particles in hypogonadal men. The decrease in HDL-C and in LDL-C size is potentially mediated by hepatic lipase activity, which hydrolyzes lipoprotein phospholipids and triacylglycerol. To determine how HDL-C and LDL-C particles are affected by testosterone administration to eugonadal men, testosterone was administered as a supraphysiological dose (600 mg/wk) for 3 wk to elderly, obese, eugonadal men before elective hip or knee surgery, and lipids were measured by routine methods and by density gradient ultracentrifugation. Hepatic lipase activity increased >60% above baseline levels, and HDL-C, HDL2, and HDL3significantly declined in 3 wk. In addition, the LDL-C peak particle density and the amount of LDL-C significantly increased. Testosterone is therefore a potent stimulator of hepatic lipase activity, decreasing HDL-C, HDL2, and HDL3as well as increasing LDL particle density changes, all associated with increased cardiovascular risk.

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