SHBG Is an Independent Predictor of Cardio-Metabolic Risk Profile on Long Term Follow up in Men with Type 2 Diabetes

Presentation Number: SAT 519
Date of Presentation: April 1st, 2017

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

Abstract

Sex Hormone Binding Globulin (SHBG) is specific binding protein which binds to sex hormones regulating their availability in the circulation. Studies have shown that a lower SHBG strongly predict insulin resistance and diabetes and higher SHBG is favourably linked with a wide range of cardiovascular (CV) risk factors. There is no long term study looking into the effect of SHBG levels on the CV risk profile in men with type 2 diabetes.

We have investigated if the SHBG is associated with adverse CV risk profile in men with type 2 diabetes on long-term follow up. This is a 7-year follow up of 203 patients with type 2 diabetes from our research cohort. Baseline data for co morbidities, concomitant medication, anthropometric measurements and biochemical results were obtained from the research database and hospital records. Correlation analysis was performed with baseline SHBG and follow up HbA1c. Further baseline SHBG values were divided into quartiles and analysed for associations with the different cardiovascular risk profiles. Statistical analysis was done using SPSS software, general linear model and repeated measures.

Mean age at baseline 56.6+8.7 years (range 34-75). At baseline testosterone was significantly correlated with the HbA1c (r=-0.16; p=0.04. Mean baseline testosterone 12.4 +5.1nmol/l; follow up 12. ±6nmol (NS) SHBG increased from baseline 30.9nmol/l +17.8 to 34.7nmol/l+17.1 (p=.001) at follow up, probably an effect of ageing. During the follow up HbA1c deteriorated from 7.3 ±1.2% to 7.7±1.5% (p= <0.001). There was a significant improvement in diastolic blood pressure (82.9 +11 mmHg to 77.2 +11.7 mmHg p<0.00). Lipid profile, weight, body mass index, waist circumference, waist-hip ratio and diastolic blood pressure did not differ significantly when adjusted for age and medications.

There was significant negative correlation between SHBG and the follow up HbA1c (correlation coefficient = -0.194, p=0.007). When analysed in SHBG quartiles (quartile ranges: up to 18.9, 19 to 26.5, 26.6 to40.1, 40.2 and above) the HbA1c deterioration was significantly worse in the lower SHBG quartile (Q1=7.6(±1.2) to 8.6(±19); Q2 =7.1(±1.1) to 7(±0.9); Q3=7.2(±1.4) to 7.6(±1.3); Q4=7.3(±1.2) to 7.5(±1.4) p=0.042) as compared to the other 3 quartiles. Systolic blood pressure reduction was also significantly lower (Q1= 145.4(±17.6) to 136.7(±13.9); Q2=141.2(±18) to 139.6(±16); Q3=141.3(±18) to 136.8(±17.3); Q4= 145.9(±21.9) to 134.6(±20.3 p= 0.04) in the highest quartile as compared to the lowest quartile. The significance persisted after adjusting for age, testosterone levels and concomitant medications. There were no significant changes in body composition, lipid profile and diastolic blood pressure in the different quartiles.

In conclusion this study suggests baseline SHBG is an independent risk factor for cardio-metabolic risk profile in Men with type 2 diabetes on the long term follow up.

 

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