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Effects of testosterone replacement on HDL subfractions and apolipoprotein A-I containing lipoproteins.
Clin Endocrinol (Oxf). 1998 Feb; 48(2):187-94.CE

Abstract

OBJECTIVES

Gonadal steroids are important regulators of lipoprotein metabolism. The aims of this study were to determine the effects of a minimum effective dose of testosterone replacement on high density lipoprotein (HDL) subfractions and apolipoprotein (apo) A-I containing particles (lipoprotein (Lp)A-I) and LpA-I:A-II) in hypogonadal men with primary testicular failure and to investigate the underlying mechanisms of these changes.

MEASUREMENTS

Eleven Chinese hypogonadal men were started on testosterone enanthate 250 mg intramuscularly at 4-weekly intervals. HDL was subfractionated by density gradient ultracentrifugation and LpA-I was analysed by electro-immunodiffusion after 3, 6 and 12 weeks of treatment. Plasma cholesteryl ester transfer protein (CETP) activity and lipolytic enzymes activities in post-heparin plasma were measured to determine the mechanisms underlying testosterone-induced changes in HDL.

RESULTS

The dosage of testosterone enanthate used in the present study resulted in suboptimal trough testosterone levels. No changes were seen in plasma total cholesterol, triglyceride, low density lipoprotein cholesterol (LDL-C,) apo B and apo(a) after 12 weeks. There was a drop in HDL3-C compared to baseline (0.82 +/- 0.17 mmol/l vs. 0.93 +/- 0.13, P < 0.01) whereas a small but significant increase was seen in HDL2-C (0.21 +/- 0.13 mmol/l vs. 0.11 +/- 0.09, P < 0.05). Plasma apo A-I decreased after treatment (1.34 +/- 0.25 g/l vs. 1.50 +/- 0.29, P < 0.01), due to a reduction in LpA-I:A-II particles (0.86 +/- 0.18 g/l vs. 0.99 +/- 0.24, P < 0.01). No changes were observed in the levels of LpA-I particles. No significant changes were seen in plasma CETP and lipoprotein lipase activities after testosterone replacement but there was a transient increase in hepatic lipase (HL) activity at weeks 3 and 6. The decrease in HDL correlated with the increase in HL activity (r = 0.62, P < 0.05).

CONCLUSIONS

Testosterone replacement in the form of parenteral testosterone ester given 4-weekly, although unphysiological, was not associated with unfavourable changes in lipid profiles. The reduction in HDL was mainly in HDL3-C and in LpA-I:A-II particles and not in the more anti-atherogenic HDL2 and LpA-I particles. The changes in HDL subclasses were mainly mediated through the effect of testosterone on hepatic lipase activity.

Authors+Show Affiliations

Department of Medicine, University of Hong Kong, Hong Kong.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9579231

Citation

Tan, K C., et al. "Effects of Testosterone Replacement On HDL Subfractions and Apolipoprotein A-I Containing Lipoproteins." Clinical Endocrinology, vol. 48, no. 2, 1998, pp. 187-94.
Tan KC, Shiu SW, Pang RW, et al. Effects of testosterone replacement on HDL subfractions and apolipoprotein A-I containing lipoproteins. Clin Endocrinol (Oxf). 1998;48(2):187-94.
Tan, K. C., Shiu, S. W., Pang, R. W., & Kung, A. W. (1998). Effects of testosterone replacement on HDL subfractions and apolipoprotein A-I containing lipoproteins. Clinical Endocrinology, 48(2), 187-94.
Tan KC, et al. Effects of Testosterone Replacement On HDL Subfractions and Apolipoprotein A-I Containing Lipoproteins. Clin Endocrinol (Oxf). 1998;48(2):187-94. PubMed PMID: 9579231.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of testosterone replacement on HDL subfractions and apolipoprotein A-I containing lipoproteins. AU - Tan,K C, AU - Shiu,S W, AU - Pang,R W, AU - Kung,A W, PY - 1998/5/14/pubmed PY - 1998/5/14/medline PY - 1998/5/14/entrez SP - 187 EP - 94 JF - Clinical endocrinology JO - Clin Endocrinol (Oxf) VL - 48 IS - 2 N2 - OBJECTIVES: Gonadal steroids are important regulators of lipoprotein metabolism. The aims of this study were to determine the effects of a minimum effective dose of testosterone replacement on high density lipoprotein (HDL) subfractions and apolipoprotein (apo) A-I containing particles (lipoprotein (Lp)A-I) and LpA-I:A-II) in hypogonadal men with primary testicular failure and to investigate the underlying mechanisms of these changes. MEASUREMENTS: Eleven Chinese hypogonadal men were started on testosterone enanthate 250 mg intramuscularly at 4-weekly intervals. HDL was subfractionated by density gradient ultracentrifugation and LpA-I was analysed by electro-immunodiffusion after 3, 6 and 12 weeks of treatment. Plasma cholesteryl ester transfer protein (CETP) activity and lipolytic enzymes activities in post-heparin plasma were measured to determine the mechanisms underlying testosterone-induced changes in HDL. RESULTS: The dosage of testosterone enanthate used in the present study resulted in suboptimal trough testosterone levels. No changes were seen in plasma total cholesterol, triglyceride, low density lipoprotein cholesterol (LDL-C,) apo B and apo(a) after 12 weeks. There was a drop in HDL3-C compared to baseline (0.82 +/- 0.17 mmol/l vs. 0.93 +/- 0.13, P < 0.01) whereas a small but significant increase was seen in HDL2-C (0.21 +/- 0.13 mmol/l vs. 0.11 +/- 0.09, P < 0.05). Plasma apo A-I decreased after treatment (1.34 +/- 0.25 g/l vs. 1.50 +/- 0.29, P < 0.01), due to a reduction in LpA-I:A-II particles (0.86 +/- 0.18 g/l vs. 0.99 +/- 0.24, P < 0.01). No changes were observed in the levels of LpA-I particles. No significant changes were seen in plasma CETP and lipoprotein lipase activities after testosterone replacement but there was a transient increase in hepatic lipase (HL) activity at weeks 3 and 6. The decrease in HDL correlated with the increase in HL activity (r = 0.62, P < 0.05). CONCLUSIONS: Testosterone replacement in the form of parenteral testosterone ester given 4-weekly, although unphysiological, was not associated with unfavourable changes in lipid profiles. The reduction in HDL was mainly in HDL3-C and in LpA-I:A-II particles and not in the more anti-atherogenic HDL2 and LpA-I particles. The changes in HDL subclasses were mainly mediated through the effect of testosterone on hepatic lipase activity. SN - 0300-0664 UR - https://www.unboundmedicine.com/medline/citation/9579231/Effects_of_testosterone_replacement_on_HDL_subfractions_and_apolipoprotein_A_I_containing_lipoproteins_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&amp;sid=nlm:pubmed&amp;issn=0300-0664&amp;date=1998&amp;volume=48&amp;issue=2&amp;spage=187 DB - PRIME DP - Unbound Medicine ER -