Chubb S A Paul, Hyde Zoë, Almeida Osvaldo P, Flicker Leon, Norman Paul E, Jamrozik Konrad, Hankey Graeme J, Yeap Bu B
PathWest, Department of Biochemistry, Fremantle Hospital, Western Australia, 6160 Australia.
Eur J Endocrinol. 2008 Jun;158(6):785-92. doi: 10.1530/EJE-07-0893.
Reduced circulating testosterone and sex hormone-binding globulin (SHBG) are implicated as risk factors for metabolic syndrome. As SHBG increases with age while testosterone declines, we examined the relative contributions of SHBG and testosterone to the risk of metabolic syndrome in older men.
We conducted a cross-sectional study of 2502 community-dwelling men aged > or = 70 years without known diabetes. Metabolic syndrome was defined using the National Cholesterol Education Program-Third Adult Treatment Panel (NCEP-ATPIII) criteria. Early morning fasting sera were assayed for total testosterone, SHBG and LH. Free testosterone was calculated using mass action equations.
There were 602 men with metabolic syndrome (24.1%). The risk of metabolic syndrome increased for total testosterone < 20 nmol/l, SHBG < 50 nmol/l and free testosterone < 300 pmol/l. In univariate analyses SHBG was associated with all five components of metabolic syndrome, total testosterone was associated with all except hypertension, and free testosterone was associated only with waist circumference and triglycerides. In multivariate analysis, both total testosterone and especially SHBG remained associated with metabolic syndrome, with odds ratios of 1.34 (95% confidence interval (CI): 1.18-1.52) and 1.77 (95% CI: 1.53-2.06) respectively. Men with hypogonadotrophic hypogonadism (total testosterone < 8 nmol/l, LH < or = 12 IU/l) had the highest prevalence of metabolic syndrome (53%, P<0.001).
Lower SHBG is more strongly associated with metabolic syndrome than lower total testosterone in community-dwelling older men. SHBG may be the primary driver of these relationships, possibly reflecting its relationship with insulin sensitivity. Further studies should examine whether measures that raise SHBG protect against the development of metabolic syndrome in older men.
循环睾酮和性激素结合球蛋白（SHBG）水平降低被认为是代谢综合征的危险因素。由于SHBG随年龄增长而升高，而睾酮水平随年龄下降，我们研究了SHBG和睾酮对老年男性代谢综合征风险的相对影响。
我们对2502名年龄≥70岁、无已知糖尿病的社区居住男性进行了横断面研究。采用美国国家胆固醇教育计划成人治疗专家组第三次报告（NCEP-ATPIII）标准定义代谢综合征。测定清晨空腹血清中的总睾酮、SHBG和促黄体生成素（LH）。使用质量作用方程计算游离睾酮。
共有602名男性患有代谢综合征（24.1%）。总睾酮<20 nmol/l、SHBG<50 nmol/l和游离睾酮<300 pmol/l时，代谢综合征风险增加。在单因素分析中，SHBG与代谢综合征的所有五个组分相关，总睾酮与除高血压外的所有组分相关，游离睾酮仅与腰围和甘油三酯相关。在多因素分析中，总睾酮尤其是SHBG仍与代谢综合征相关，比值比分别为1.34（95%置信区间（CI）：1.18-1.52）和1.77（95%CI：1.53-2.06）。性腺功能减退性性腺功能减退（总睾酮<8 nmol/l，LH≤12 IU/l）的男性代谢综合征患病率最高（53%，P<0.001）。
在社区居住的老年男性中，较低的SHBG比较低的总睾酮与代谢综合征的关联更强。SHBG可能是这些关系的主要驱动因素，可能反映了其与胰岛素敏感性的关系。进一步研究应探讨提高SHBG的措施是否能预防老年男性代谢综合征的发生。
