Low serum testosterone levels in men predict the future development of insulin resistance and Type 2 diabetes. Furthermore, men with Type 2 diabetes have lower testosterone levels than nondiabetic men. Testosterone is known to be positively correlated with insulin sensitivity. It has also been demonstrated that low levels of circulating androgens are associated with coronary artery disease, dyslipidaemia, hypertension and visceral obesity. The purpose of this study was to determine the prevalence of hypogonadism in men with Type 2 diabetes.
This study was approved by the BDGH ethics committee. 240 male patients above the age of 30 with Type 2 diabetes registered with the diabetes centre at BDGH have been recruited so far. Patients with elevated CRP [greater than 10 milligrames / litre] were excluded. Blood was taken between 8 and 10am and analysed for levels of total testosterone, SHBG and HbAIc. Body mass index and waist hip ratios were recorded. Obesity was defined as a body mass index of >30 and or waist hip ratio of >0.95.
17.92% had total testosterone <7.5 nanomoles per litre and 50.53% had total testosterone <12 nanomoles per litre. Plasma testosterone levels were significantly lower in men with obesity [p<0.001]. Comparing patients with good diabetic control HbAIc less than 7% [n=124] with those with inadequate control HbAIc greater than 7% [n =116], testosterone levels [less than 12 nanomoles / litre] were significantly lower in the group with poor control [p <0.005] .
This study confirms that there is a high prevalence of low testosterone levels in men with Type 2 diabetes. This finding implies that men with Type 2 diabetes should be routinely tested. The fact that low testosterone levels are associated with poor control implies that testosterone may be involved with the degree of insulin sensitivity. Further studies to answer these questions are underway.
22 - 24 Mar 2004
British Endocrine Societies