The role of sex hormone-binding globulin and testosterone in the risk of incident metabolic syndrome.
OBJECTIVE
The aim of this study was to further evaluate the suggested independent association of sex hormone-binding globulin (SHBG) with incident metabolic syndrome (MetS) in men.


METHODS
We used data from 1906 men aged 20-79 years from the population-based Study of Health in Pomerania (SHIP). Multivariable logistic regression models were implemented to analyse cross-sectional and longitudinal associations of total testosterone (TT), SHBG, and free testosterone (free T) concentrations with MetS. Furthermore, we associated changes between baseline and follow-up concentrations of TT, SHBG, and free T with incident MetS.


RESULTS
Cross-sectional logistic regression models revealed a significant inverse association of TT (odds ratio [OR] per standard deviation [SD] decrease: 1.28; 95% confidence interval (CI): 1.10-1.50), and free T (OR per SD decrease: 1.29; 95% CI: 1.11-1.51), but not SHBG (OR per SD decrease: 1.13; 95% CI: 0.98-1.30) with prevalent MetS. At the 5-year follow-up 1435 men were repeatedly examined and of the 956 men without baseline MetS, 328 men (34.3%) had incident MetS. Longitudinal analyses showed, after adjustment for the respective sex hormone, that lower baseline SHBG (OR per SD decrease: 1.30; 95% CI: 1.03-1.65), but not TT (OR per SD decrease: 1.14; 95% CI: 0.93-1.39) was associated with incident MetS. Change analyses revealed an inverse association between TT change and incident MetS (OR per SD decrease between baseline and follow-up: 1.19; 95% CI: 1.01-1.39), independent of SHBG; whereas SHBG change was not associated with incident MetS until adjustment for TT.


CONCLUSIONS
Although baseline SHBG predicts incident MetS independent of testosterone, change analyses suggest the testosterone decline as the main driver of the association between sex hormones and MetS.
Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Germany.
Robin
R
Haring
Henry
H
Völzke
Christin
C
Spielhagen
Matthias
M
Nauck
Henri
H
Wallaschofski
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011379:Prognosis; D012307:Risk Factors; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D013739:Testosterone / Q000097:blood*; D013997:Time Factors; D055815:Young Adult
D015415:Biomarkers; D012738:Sex Hormone-Binding Globulin; D013739:Testosterone