The Relationship Between Endogenous Testosterone and Lipid Profile in Middle-Aged and Elderly Chinese Men
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N Zhang, H Zhang, X Zhang Association between 170:4 487–494 Clinical Study and others testosterone and lipids The relationship between endogenous testosterone and lipid profile in middle-aged and elderly Chinese men Nan Zhang1,2,*, Haiqing Zhang1,2,*, Xu Zhang1,2,*, Bingchang Zhang3, Furong Wang4, Chenggang Wang5, Meng Zhao1,2, Chunxiao Yu1,2, Ling Gao6, Jiajun Zhao1,2 and Qingbo Guan1,2 1Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan 250021 Shandong, China, 2Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, 324 Jingwu Road, Jinan 250021 Shandong, China, 3Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan 250021 Shandong, China, 4Department of Pharmacology, Shandong University of Traditional Chinese Medicine, 4665 University Road, University of Science and Technology Correspondence Park, Changqing District, Jinan 250355 Shandong, China, 5Department of Preventive Medicine, Shandong should be addressed to University of Traditional Chinese Medicine, 4665 University Road, University of Science and Technology Park, J Zhao or Q Guan Changqing District, Jinan 250355 Shandong, China and 6Department of Central Laboratory, Shandong Provincial Email Hospital affiliated to Shandong University, 324 Jingwu Road, Jinan 250021 Shandong, China [email protected] or *(N Zhang, H Zhang and X Zhang contributed equally to this work) guanqingbo@medmail. com.cn Abstract Objective: To evaluate the relationship between serum total testosterone (TT) level and lipid profile after adjusting for some traditional confounding factors, free thyroid hormones and TSH in Chinese men. Methods: This was a retrospective study based on an epidemiological investigation including 11 000 subjects. Bivariate and partial correlation analysis, multiple linear regression analysis, and a general linear model were used to assess the influence of TT on the lipid profile. Additionally, the odds ratios (ORs) (95% CIs) for hypertriglyceridemia and low HDL-C in relation European Journal of Endocrinology to TT categories were calculated using logistic regression analysis. Results: A total of 4114 subjects whose mean age was 56.04G8.75 years were finally analyzed. There was a significant linear trend toward lower total cholesterol (TC), lower triglycerides (TG), and higher HDL-C with increasing serum TT, which remained significant after adjusting for age, BMI, fasting blood glucose, systolic blood pressure, free triiodothyronine, free thyroxine, and TSH. Compared with the bottom quartile of TT, the adjusted OR (95% CI) for hypertriglyceridemia and low HDL-C was 0.082 (0.048–0.138, PZ0.000) and 0.669 (0.503–0.891, PZ0.006) respectively in the top quartile of TT. Conclusions: TT was correlated negatively and linearly with TC, TG, and LDL-C and positively and linearly with HDL-C. Low TT might have adverse effects on the lipid profile and thus represent a risk factor for hypercholesterolemia, hypertriglycer- idemia, high LDL-C, and low HDL-C, suggesting the importance of maintaining an appropriate TT level in men. European Journal of Endocrinology (2014) 170, 487–494 Introduction For a long time, testosterone was deemed to have adverse possess higher risks of mortality than women (2, 3). This effects on lipid profile. A low concentration of HDL-C has difference has been partly attributed to sex hormones. been associated with an increase in the plasma testo- Nonetheless, new evidence has emerged in the last few sterone concentration in male adolescents (1). Men are years that challenges this traditional notion. In men, also more prone to coronary heart disease (CHD) and endogenous testosterone is inversely related to the www.eje-online.org Ñ 2014 European Society of Endocrinology Published by Bioscientifica Ltd. DOI: 10.1530/EJE-13-0802 Printed in Great Britain Downloaded from Bioscientifica.com at 09/24/2021 08:08:19PM via free access Clinical Study N Zhang, H Zhang, X Zhang Association between 170:4 488 and others testosterone and lipids severity of carotid atherosclerosis as well as the incidence there has been an increase in dyslipidemia prevalence in and severity of CHD (4, 5, 6, 7, 8). Furthermore, low China. Therefore, in this study, we aimed to explore the testosterone is related to a number of metabolic diseases association between serum testosterone level and lipid or disorders, such as insulin resistance (9), type 2 diabetes profile after adjusting for classic confounding factors and mellitus (T2DM) (10), metabolic syndrome (MetS) (11), the thyroid hormones and TSH in middle-aged and elderly and all-cause mortality (12). Therefore, testosterone Han Chinese men. replacement therapy (TRT) is now recommended to ameliorate signs and symptoms of some metabolic and vascular diseases in middle-aged and elderly men with low Subjects and methods serum testosterone (13, 14). Subjects Dyslipidemia, one of the main risk factors for hypertension, T2DM, MetS, and CHD, is among the most This population-based cross-sectional study was carried important threats to public health. Hence, the relationship out in Ningyang County (Taian, Shandong Province, between testosterone and lipid levels needs intensive China) from June to November 2011. During the study. Epidemiological evidence has shown that low recruiting phase, the local-registered residents aged 40 testosterone is related to elevated total cholesterol (TC) years and older who have lived there for at least 5 years (15, 16), triglycerides (TG) (15, 16, 17, 18), LDL-C (16) and were invited to receive a screening examination, and decreased HDL-C (15, 16, 17, 18), and an increased nearly 11 000 persons participated. All participants incidence of dyslipidemia (19) in men in some but not in provided an overnight fasting blood sample and were all studies (20, 21). Corona et al. (22) found that TRT was asked to complete a self-reported questionnaire. associated with a significant reduction of TG and an For our analysis, the exclusion criteria were as follows: increase of HDL-C and was able to improve central obesity i) female; ii) no information on vital statistics (such as age (subjects with MetS) and glycometabolic control (patients or sex) or missing data on serum total testosterone (TT) with MetS and T2DM) (23). Other studies observed no or lipid levels; iii) taking medications that might affect relationship between TRT and lipid profile, although some TT level or lipid profile in the past 3 months (such as even reported unfavorable effects of TRT on serum lipids androgens, steroid hormones, Proscar, opiates, anti- (24, 25, 26). This suggests that the relationship between convulsants, statins, or fibrates); and iv) neurologic testosterone and lipid profile is complex (27). diseases, severe hepatic or renal disorders, lung diseases, In addition, in the previous studies, the estimates were acute systemic illness, hypothalamus and/or pituitary European Journal of Endocrinology not adjusted or were only adjusted for the traditional gland diseases, or tumors that might affect TT level (such serum lipid confounding factors, such as age, BMI, and as brain cancer or prostate cancer). Finally, a total of 4114 fasting blood glucose (FBG). Recent evidence indicates male subjects from the general population were evaluated. that thyroid hormones and thyrotropin (TSH) might affect The Ethics Committee of Shandong Provincial serum lipids. Our previous studies have shown that high Hospital affiliated to Shandong University approved the TSH is associated with an atherogenic lipid profile retrospective review of the patients’ medical records and independent of thyroid hormone (28, 29),although licensed the records for research purposes only. many other clinical studies have also indicated that free thyroxine (FT ) as well as TSH are associated with lipid 4 Anthropometric measurements and metabolism (30). The associations might be weak but laboratory methods significant. However, the effects of these hormones on the relationship between testosterone and lipids have not Weight was measured adjusting by 0.1 kg for subjects not been addressed elsewhere, and no study has excluded the wearing shoes. Height was measured adjusting by 0.1 cm potential influences of the thyroid hormones or TSH when for subjects in light clothes. BMI was calculated by assessing the relationship between testosterone and the dividing weight (kg) by the square of height (m). Waist lipid status. circumference (WC) and hip circumference (HC) were The inconsistent results of studies concerning the assessed with an accuracy of 0.1 cm, and the waist/hip associations between testosterone and lipid profile may ratio was calculated by dividing WC by HC. Blood pressure also be partly due to relatively small samples. In addition, was measured at least three times in the sitting position data about the association between testosterone and lipids after a 5-min rest and estimated as the average of are lacking in Chinese men on a large scale. Importantly, three readings of systolic and diastolic blood pressure. www.eje-online.org Downloaded from Bioscientifica.com at 09/24/2021 08:08:19PM via free access Clinical Study N Zhang, H Zhang, X Zhang Association between 170:4 489 and others testosterone and lipids Past medical history was assessed with a questionnaire. FT K5:1685 FT K17:3740 Factor 2 Z 0:511! 3 C0:134! 4 The diseases (hypertension, diabetes mellitus, and CHD) 1:43428 2:85390 were based on previous diagnosis by a physician. TSHK2:3367 C0:914! : Venous