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

Abstract

. Testosterone administration to men increases hepatic lipase activity and decreases HDL and LDL size in 3 wk. Am J Physiol Endocrinol Metab 284: E1112-E1118, 2003; 10.1152/ ajpendo.00524.2002.-Testosterone administration to men is known to decrease high-density lipoprotein cholesterol (HDL-C) and the subclasses HDL 2 and 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 Ͼ60% above baseline levels, and HDL-C, HDL 2, and HDL3 significantly 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, HDL 2, and HDL3 as well as increasing LDL particle density changes, all associated with increased cardiovascular risk.androgen; lipoprotein particle density TESTOSTERONE (T) administration to men is known to decrease HDL-cholesterol (HDL-C) (6-8, 25, 39), although not necessarily in hypogonadal men (27,30,42). When HDL-C declines with T administration in both eugonadal and hypogonadal men, it is unclear whether this decrease is in the subclasses HDL 2 (22) or HDL 3 (32-34) or both. That HDL-C decreases with T administration might be important for long-term use of T in men, because low HDL-C, including low HDL 2 and low HDL 3 , is associated with an increased risk for cardiovascular disease (3,14,26).The decrease in HDL-C with T administration is likely mediated by an increase in hepatic lipase (HL) activity. Consistent with this is the fact that HL activity is higher overall in men than in women (4) and is higher with central obesity (11,12). HL is produced primarily by the liver and is located on the luminal surface of sinusoidal endothelial cells. It catalyzes the hydrolysis of triacylglycerols and phospholipids, mediating the removal of lipoproteins from plasma (23). This hydrolysis converts the more buoyant HDL 2 to the smaller, denser HDL 3 , which can be taken up by the liver, thereby decreasing HDL-C. In addition, HL by the same mechanism converts large, buoyant LDL to small, dense LDL (41), the latter also being a risk factor for cardiovascular disease (2,24,31). One study demonstrated an increase in one population of small, dense LDL particles with T administration to hypogonadal men (32), but a cross-sectional study demonstrated an inverse association between serum T levels and small, dense LDL (29), although the T levels in that study have been called into questi...

Atherosclerosis is enhanced by testosterone deficiency and attenuated by CETP expression in transgenic mice

“…Administration of androgenic steroids to humans caused increases in HL activity (3,61), whereas no effect or increases (62,63) in LPL activity have been reported. We show here that deficiency of testosterone in mice did not alter the expression of either lipolytic enzyme, which excludes their participation in the changes of LDL and HDL levels observed in castrated mice.…”

“…Gender differences in coronary artery disease (CAD) risk observed during the reproductive life period have been attributed to an attenuating effect of estrogen on atherogenesis (1,2) and/or to a proatherogenic action of androgens (3,4). However, the unexpected outcomes from the Women's Health Initiative and Heart and Estrogen Replacement Study trials (5,6) and other controversies about the role of androgens (7) necessitate further investigation of the role of sex steroids, especially in sexmatched individuals.…”

The CAG Repeat Polymorphism in the Androgen Receptor Gene Is Associated with HDL-Cholesterol but Not with Coronary Atherosclerosis or Myocardial Infarction

“…Testosterone stimulates SR-BI gene expression in both macrophages and the liver, thereby enhancing cholesterol efflux and selective cholesterol uptake, respectively (18 ). Furthermore, administration of supraphysiologic concentrations of testosterone in men increases hepatic lipase (19 ), which leads to lower HDL-C through increased phospholipid hydrolysis on the surface of HDL. This process again facilitates hepatic removal of HDL via receptor-mediated processes.…”

Metabolic Syndrome: Bridging the Gap from Childhood to Adulthood

“…Sex hormones (particularly androgens) regulate hepatic lipase mass and activity. Observations indicate that low SHBG levels after puberty increase the free androgen levels, and androgens are known to enhance HDL-C catabolism by increasing hepatic lipase activity [23].…”