Effect of testosterone replacement therapy on lipids and lipoproteins in hypogonadal

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Abstract
We investigated the effects of long-term testosterone replacement in hypogonadal and elderly men on lipids and lipoproteins. Twenty-two men with initial serum testosterone concentrations below 3.5 ng/ml took part in the study: 11 with hypopituitarism (1st group) and 11 otherwise healthy elderly men with low testosterone levels (2nd group). Testosterone deficiency was replaced by intramuscular injections of testosterone enanthate 200 mg every second week. Plasma levels of sex hormones, gonadotropins, SHBG, lipids and lipoproteins were determined before the treatment and after 3, 6 and 12 months of treatment. During the treatment serum testosterone and estradiol increased significantly, reaching normal levels. This was associated with a decrease in total cholesterol (from 225 +/- 16.9 mg/dl to 202 +/- 13.6 mg/dl after 6 months and 198 +/- 12.8 mg/dl after 1 year of testosterone administration, P < 0.0001 in men with hypoandrogenism associated with aging and from 255 +/- 12.1 mg/dl to 214 +/- 10.6 mg/dl after 6 months and 206 +/- 9 mg/dl after 1 year of treatment, P < 0.0001 in men with hypopituitarism) and LDL-cholesterol concentrations (from 139 +/- 12.5 mg/dl to 126 +/- 10.7 mg/dl after 6 months and 118 +/- 9.8 mg/dl after 1 year of testosterone administration, P < 0.0001 in men with hypoandrogenism associated with aging and from 178 +/- 10.3 mg/dl to 149 +/- 10.2 mg/dl after 6 months and 140 +/- 7.3 mg/dl after 1 year of treatment, P < 0.001 in men with hypopituitarism). However, no significant decrease in HDL-cholesterol levels or HDL2- and HDL3-cholesterol subfractions was observed. The effects of testosterone replacement therapy on lipids and lipoproteins were similar in both groups with different aetiology of hypogonadism. No side effects on the prostate were observed. The results of this study indicate that testosterone replacement therapy in hypogonadal and elderly men may have a beneficial effect on lipid metabolism through decreasing total cholesterol and atherogenic fraction of LDL-cholesterol without significant alterations in HDL-cholesterol levels or its subfractions HDL2-C and HDL3-C.

https://www.ncbi.nlm.nih.gov/pubmed/8678922

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

Abstract
Testosterone administration to men is known to decrease high-density lipoprotein cholesterol (HDL-C) and the subclasses HDL(2) and HDL(3). 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, HDL(2), and HDL(3) 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 HDL(3) as well as increasing LDL particle density changes, all associated with increased cardiovascular risk.

https://www.ncbi.nlm.nih.gov/pubmed/12736156