From the Guidelines
Increasing testosterone levels in individuals with type 1 diabetes typically requires an increase in insulin doses to maintain blood glucose control, with a potential increase of approximately 10-20% in insulin dosage, though this varies by individual. This is because testosterone promotes muscle growth and alters fat distribution, which affects how the body processes glucose and responds to insulin 1. The effect is more pronounced with injectable testosterone compared to topical formulations.
When considering the management of type 1 diabetes in the context of increasing testosterone levels, it's essential to understand that dosing insulin based solely on premeal glucose levels does not account for basal insulin requirements or caloric intake, increasing the risk of both hypoglycemia and hyperglycemia 1. Typically, basal insulin dosing schemes are based on body weight, with some evidence suggesting that patients with renal insufficiency should be treated with lower doses.
Key considerations for type 1 diabetics starting testosterone therapy include:
- Monitoring blood glucose more frequently (at least 4-6 times daily)
- Maintaining detailed records of readings
- Being prepared to adjust both basal and bolus insulin doses under medical supervision
- Regular communication with both an endocrinologist and the provider managing hormone therapy to safely manage these changes and prevent complications like hyperglycemia. The insulin resistance effect usually stabilizes within 2-3 months after testosterone levels reach a steady state. Given the most recent guidelines from 2025 1, it's clear that managing type 1 diabetes requires a comprehensive approach, especially when introducing factors like testosterone therapy that can impact insulin sensitivity and glucose control.
From the FDA Drug Label
In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, insulin requirements The metabolic effects of increasing testosterone levels may decrease blood glucose in type 1 diabetic patients, which could lead to a decrease in insulin requirements 2.
- Key points:
- Decrease in blood glucose levels
- Potential decrease in insulin requirements However, this information is not specific to type 1 diabetes, and the label does not provide explicit guidance on adjusting insulin doses.
From the Research
Impact of Increasing Testosterone Levels on Type 1 Diabetic's Insulin Needs
- The current evidence does not directly address how increasing testosterone levels impacts type 1 diabetic's insulin needs 3, 4, 5, 6, 7.
- However, studies suggest that testosterone levels may be associated with insulin sensitivity and glucose metabolism in individuals with type 1 and type 2 diabetes 4, 5, 7.
- A study found that adolescent males with type 1 diabetes had normal total testosterone and free androgen index levels, unrelated to insulin sensitivity 4.
- Another study found that testosterone supplementation did not improve insulin sensitivity, glucose effectiveness, or acute insulin response in male patients with type 2 diabetes 5.
- A study in adolescents and young men with type 1 diabetes found that total testosterone levels were higher in patients with type 1 diabetes than in controls, and were positively correlated with 24-h urine albumin levels 6.
- Testosterone treatment has been shown to reduce fat mass and insulin resistance, and may have a potential role in preventing type 2 diabetes in men 7.
- The relationship between testosterone levels and insulin needs in type 1 diabetes is complex and requires further research to fully understand the potential impacts of increasing testosterone levels on insulin needs 3, 4, 5, 6, 7.