From the Guidelines
Hypogonadism is significantly more prevalent in men with diabetes mellitus and prediabetes, with approximately 30-50% of men with type 2 diabetes having low testosterone levels, and those with prediabetes showing intermediate rates of about 25-35%. The relationship between hypogonadism and diabetes appears to be bidirectional, as low testosterone increases the risk of developing diabetes, and diabetes can contribute to testicular dysfunction 1. Several mechanisms underlie this connection, including insulin resistance promoting reduced sex hormone-binding globulin (SHBG) production, leading to lower total testosterone, and visceral adiposity increasing aromatase activity, converting testosterone to estradiol.
The prevalence of hypogonadism in men with diabetes and prediabetes can be attributed to various factors, including:
- Insulin resistance and reduced SHBG production
- Visceral adiposity and increased aromatase activity
- Chronic inflammation and oxidative stress associated with diabetes
- Diabetic complications like neuropathy affecting the hypothalamic-pituitary-gonadal axis
Men with diabetes should be screened for hypogonadism if they present with symptoms such as reduced libido, erectile dysfunction, fatigue, or depression, with testing ideally performed in the morning when testosterone levels are highest, as recommended by the standards of medical care in diabetes-2020 1. Treatment decisions should consider both testosterone levels and clinical symptoms, with potential benefits of testosterone replacement therapy including improved insulin sensitivity, reduced fat mass, and enhanced quality of life in appropriately selected patients. Screening for hypogonadism in men with diabetes and prediabetes is crucial, as early detection and treatment can improve morbidity, mortality, and quality of life.
From the Research
Prevalence of Hypogonadism in Men with Diabetes and Prediabetes
- The prevalence of hypogonadism in men with diabetes is estimated to be around 40% 2.
- A study found that 30% of prediabetic men had late-onset hypogonadism (LOH), compared to 13.6% of normoglycemic men 2.
- Another study reported that the prevalence of hypogonadism was higher in men with early-onset type 2 diabetes (48.0%) compared to those with late-onset type 2 diabetes (26.7%) 3.
- The prevalence of hypogonadism in men with prediabetes and hypogonadism was found to be significant, with one study reporting that 90% of men with hypogonadism and prediabetes achieved normal glucose regulation after testosterone therapy 4.
Relationship between Hypogonadism and Diabetes
- There is a negative relationship between calculated free testosterone (cFT) and HbA1c levels in men with prediabetes 2.
- Testosterone therapy has been shown to improve glycemic control in men with hypogonadism and type 2 diabetes 4.
- However, a recent study found that testosterone replacement therapy did not improve glycemic control in men with hypogonadism and prediabetes or diabetes 5.
- Hypogonadism and erectile dysfunction have emerged as predictors of cardiovascular disease in men with type 2 diabetes mellitus (T2DM) 6.
Screening and Treatment
- Routine testosterone screening is recommended for all prediabetic men 2.
- Testosterone therapy may be beneficial for men with hypogonadism and prediabetes, but its effectiveness in preventing progression to type 2 diabetes is still unclear 4, 5.
- Primary care providers should be aware of the dysmetabolic cluster affecting male patients with hypogonadism, erectile dysfunction, and T2DM, and diagnosis of one of these conditions should elicit inquiry into the other two conditions 6.