Testosterone and SHBG Show Independent Negative Correlation with Cardiovascular Risk Profile in Men Which Improves with Testosterone Replacement in Men with Type 2 Diabetes

Presentation Number: SAT 520
Date of Presentation: April 1st, 2017

Vakkat Muraleedharan*1, Dheeraj Kapoor2 and Thomas Hugh Jones3
1Kings Mill Hospital, United Kingdom, 2Barnsley Hospital NHSFT, Barnsley, United Kingdom, 3Barnsley Hospital NHSFT, Barnsley S Yorkshire, United Kingdom

Abstract

Testosterone levels and SHBG levels have been negatively correlated with adverse cardiovascular risk (CV) profiles. Studies suggest testosterone replacement therapy (TRT) has a beneficial effect on CV profile. We have evaluated whether or not testosterone and SHBG levels negatively correlate with CV risk profile in men and physiological TRT has a beneficial effect on the CV risk profile in those with low testosterone.
This is a cross sectional study results of a cohort of 203 type 2 diabetic men from our research database. The cohort was divided into three groups, 1- Total testosterone (TT) <10.4nmol/l, no TRT (n=77); 2 – TT¬> 10.4nmol/l ( n=81); 3 – TRT >3 months (n=45). The effect of SHBG was analysed by correlation coefficients and ANOVA in the quartiles of SHBG.
Effect of TT- there was an inverse relationship between the TT and HbA1c (R2 linear =0.065). In the multivariate adjusted model (adjusted for medications, smoking and co morbidities) HbA1c (Group-1 =7.9±1.7%; Group-2 =7.3±1.2%; Group-3 =7.5±1.2% p=0.001) was significantly higher in low testosterone group compared to the high T group and no significant differences between TRT and normal TT groups. Hip circumference (Group-1=114.1±14; Group-2=107±9cm; Group-3=112.8±10.3cm p=0.033), waist Circumference (Group-1=114.1±15.9cm; Group-2=108.3±12.6cm; Group-3 119.1±13.6cm p=0.002), ), waist hip ratio (Group-1=1.03±0.08; Group-2=1±0.06; Group-3=1.06±0.08 p=0.019)weight (Group-1=98.2±20; Group-2=30.1±4.7kg; Group-3=103.9±16.5p=0.006 and BMI (Group1=32.5±6; Group2=30.2±4.8; Group3=34.4±5.6 p=0.001) were significantly higher in the low T group.

The SHBG-after adjusting for age and testosterone, HbA1c (Q1=8.4±1.5%; Q2=7.4±1.5 Q3=7.7±1.5%; Q4=7.2±1.4% p=0.037), percentage body fat (35.8±8.7%; Q4 =29.7±8.4% p=0.009), weight (Q1=108.4±17.9kg and Q4=92.7±23.5kg, p=0.002), BMI ( Q1=35.8±6.2 and Q4=30.6±6.4,p=0.001), waist circumference (Q1=119.5±14.9cm and Q4=109.7±17.4cm, p=0.013) and triglycerides (Q1=3.7±4mmol/l and Q4=1.3±0.7mmol/l, p=0.02) showed inverse relation with SHBG levels. HDL was higher in the lowest quartile (Q1=0.96±0.2mmol/l and Q4=1.2±0.3, p=<0.00).There was no significant effect of SHBG on LDL, total cholesterol, hip circumference, systolic and diastolic blood pressure.
This study reports that low TT and low SHBG levels are independently associated with worsening of cardiovascular risk profile in men. TRT group had similar glycaemic control as normal T group suggesting a beneficial effect.
Testosterone deficiency should be evaluated and treated, if appropriate, in men with metabolic syndrome and diabetes. TRT has been shown to reduce mortality (1). SHBG is a surrogate marker of insulin resistance so this may be the reason for the CV risk profile results in the study. This may be mediated through a beneficial effect of testosterone itself (2).

 

Disclosure: THJ: Clinical Researcher, educational lectures, advisory board member, Clinical Researcher, Pro Strakan, Consultant, Clarus, Clinical Researcher, advisory board member, Clinical Researcher, advisory board memeber. Nothing to Disclose: VM, DK