Is serum sex hormone-binding globulin a dominant risk factor for metabolic syndrome?

Abstract

This multi-center, cross-sectional study investigated the association between serum testosterone (T) levels, serum sex hormone-binding globulin (SHBG) levels, and the risk of metabolic syndrome (MS) in 3332 adult Chinese men. The prevalence of MS was 34.7%, and men with MS had lower serum levels of total T (TT) and SHBG than those without MS (P < 0.001). There was no significant difference in serum free T (FT) levels between subjects with and without MS (P = 0.627). In logistic regression analysis, the association between MS and serum SHBG levels persisted after adjusting for age, body mass index (BMI), smoking and drinking status, and serum TT (odds ratio [OR] 0.962, 95% confidence interval [95% CI] 0.954−0.969, P< 0.01). However, the association between serum TT level and the risk of MS was weak after adjusting for age, BMI, SHBG level, and smoking and drinking status (OR 0.981, 95% CI 0.960−1.007). Our study reveals that both serum TT and SHBG levels, but not serum FT, are inversely associated with the prevalence of MS and that serum SHBG is an independent and dominant risk factor for MS.

Lower SHBG level is associated with higher leptin and lower adiponectin levels as well as metabolic syndrome, independent of testosterone

“… 23 , only TT and SHBG, but not FT were significant predictors for the risk of incident MetS in men. These results suggest that the impact of FT on MetS may be weak or confounded by several factors like discrepancy in the measurement of FT, definition of MetS and baseline characteristics of the different study populations 15 , 16 , 24 . Further studies are needed to clarify the real relationship between FT and MetS.…”

“…In our study, both low TT and SHBG were significant predictors for the risk of prevalent MetS, but FT showed no significant association. Several cross-sectional studies also reported no significant difference in FT level between subjects with and without MetS 16 , 19 – 21 . In the longitudinal studies of Kupelian et al .…”

“…A large number of epidemiological studies have also reported that both low T and SHBG levels can increase the risk of MetS in men 15 . Some studies even suggested that serum SHBG levels may play a more dominant role than T levels in determining the risk of MetS 16 – 18 .…”

Relationship Between Gonadal Function and Cardiometabolic Risk in Young Men With Chronic Spinal Cord Injury

“…Interestingly in this regard, we previously reported that men with low TT had significantly lower serum SHBG levels compared to men with normal TT [18]. It is well established that low SHBG levels are correlated with increased insulin resistance and predict the development of metabolic syndrome [39,40].…”

Relationships between <em>FTO</em> rs9939609, <em>MC4R</em> rs17782313, and <em>PPAR&gamma;</em> rs1801282 polymorphisms and the occurrence of selected metabolic and hormonal disorders in middle-aged and elderly men &ndash; a preliminary study

“…Both cross-sectional and longitudinal epidemiological studies indicate that the level of SHBG is lower in men with MetS 38–40. Other researchers emphasize, however, that the relationships between MetS and either TS or SHBG are stronger in younger men 34,35.…”