Inverse association of testosterone and sex hormone binding globulin levels with leukocyte count in middle-aged and elderly men

Objective: The inverse associations of testosterone and sex hormone-binding globulin (SHBG) levels with cardiometabolic diseases are well established and are increasingly viewed as inflammatory diseases. This study aimed to examine the associations of testosterone and SHBG levels with leukocyte count in 451 Korean men aged ≥50 years. Methods: Serum testosterone and SHBG levels were categorized into tertiles. High leukocyte count was defined as ≥7340 cells/μl, which corresponded to the 75th percentile of the current sample. The odds ratios (ORs) and 95% confidence intervals (95% CIs) for high leukocyte count were calculated across testosterone and SHBG tertiles using multiple logistic regression analysis. Results: The mean leukocyte counts significantly decreased with increasing testosterone and SHBG tertiles. The ORs (95% CIs) of high leukocyte count for the first tertile of testosterone and SHBG were 3.27 (1.34–7.95) and 2.38 (1.05–5.96), respectively, compared with the referent third tertile, after adjusting for age, smoking status, alcohol drinking, regular exercise, body mass index, blood pressure, fasting plasma glucose, triglyceride, and high-density lipoprotein (HDL) cholesterol level. Conclusion: We found inversely graded associations of low testosterone and SHBG levels with leukocyte count. These findings suggest that low testosterone and SHBG levels may be interpreted as a state of low-grade inflammation.