Remission of type 2 diabetes following long-term testosterone therapy
Haider et al. followed 356 men with type 2 diabetes and total testosterone below 350 ng/dL (12.1 nmol/L) in a real-world registry for as long as 11 years. 178 of them received long-acting testosterone therapy prescribed by their physician; the remainder formed the untreated comparison group. Treated men had significant, progressive and sustained reductions in fasting glucose, HbA1c and fasting insulin across the treatment period. As an observational registry, it shows association, not proof that treatment caused the change.
Design
Real-world registry
Prospective, 11 years of follow-up
Participants
356 men
Type 2 diabetes and total testosterone < 350 ng/dL
Treatment
Long-acting testosterone
178 treated · 178 untreated comparison
Primary outcome
34.3% remission
0% in the untreated group
Structured abstract
Method
356 men with type 2 diabetes and total testosterone below 350 ng/dL (12.1 nmol/L) were followed prospectively in a real-world registry for as long as eleven years. 178 of them chose long-acting testosterone therapy prescribed by their physician; the remaining men declined treatment and formed the comparison group. Glucose control, weight and lipid measures were recorded throughout.
Result
34.3% of the treated men achieved complete remission of their type 2 diabetes and 46.6% achieved normal glucose regulation. 83% reached an HbA1c of 47.5 mmol/mol (6.5%) and 90% reached 53 mmol/mol (7%). No remissions at all were recorded among the untreated men. Fasting glucose, HbA1c and fasting insulin fell significantly, progressively and without rebound across the whole treatment period, and weight, glucose control and lipid measures improved alongside them.
Conclusion
In men who have both testosterone deficiency and type 2 diabetes, long-term testosterone therapy was followed by measurable and durable improvement in the metabolic disease itself — not only in the hormone deficiency. The authors describe testosterone therapy as a potential additional therapy for this group.
Why it matters
In men with both low testosterone and type 2 diabetes, 34.3% of treated men reached full diabetes remission over up to 11 years — with 0% remissions in the untreated comparison group. This is an observational registry; it shows association, not proof of cause.
Study design
Eleven years, two parallel groups
The registry followed the same men year after year in ordinary clinical practice rather than inside a trial protocol. That is both its strength — length and realism — and its central limitation.
Group A · treated
178 men
Received long-acting testosterone therapy prescribed by a physician throughout the follow-up period, alongside their usual diabetes care.
Group B · untreated
178 men
Declined testosterone therapy and continued usual diabetes care only. They form the comparison against which every result below is read.
Entry criteria
Both conditions present
Type 2 diabetes together with total testosterone below 350 ng/dL (12.1 nmol/L) — a deficiency confirmed by measurement, not by symptoms alone.
Glucose control
Fasting glucose, HbA1c, fasting insulin
Body composition
Weight and waist measures
Lipids
Recorded throughout follow-up
Comparison
Untreated men in the same registry
The clinical results after 11 years
Every figure below is reported in the published paper. The comparison group is what makes them meaningful: the same clinic, the same disease, the same period, without testosterone.
Full diabetes remission
34.3%
Complete remission of type 2 diabetes among the treated men.
Normal glucose regulation
46.6%
Reached normal glucose regulation during follow-up.
Remissions without treatment
0%
No remissions at all were recorded in the untreated comparison group.
HbA1c target attainment among treated men
83% of treated men
90% of treated men
Treated versus untreated
| Treated (n = 178) | Untreated (n = 178) | |
|---|---|---|
| Complete diabetes remission | 34.3% | None recorded |
| Normal glucose regulation | 46.6% | None recorded |
| HbA1c ≤ 6.5% (47.5 mmol/mol) | 83% | Not reached |
| HbA1c ≤ 7% (53 mmol/mol) | 90% | Not reached |
| Weight, glucose and lipid measures | Progressive improvement | No comparable improvement |
The paper reports the direction and significance of the year-by-year fall in fasting glucose, HbA1c and fasting insulin, but this site does not reproduce a year-by-year curve, because the underlying per-year values are not published in a form we can cite exactly. The bars above use only figures stated in the paper.
Possible mechanisms discussed in the literature
The registry shows the association; it does not measure the mechanism. These are the pathways described in the wider literature cited across this site, and they are stated here as explanation, not as findings of this study.
Insulin sensitivity
In a separate placebo-controlled trial with direct clamp measurement, insulin-stimulated glucose disposal improved by approximately 32% in men with type 2 diabetes and hypogonadotropic hypogonadism.
Dhindsa et al., Diabetes Care, 2016
Fat mass and aromatisation
Testosterone reduces fat mass at higher exposure, and fat tissue in turn aromatises testosterone away. This is a proposed mechanism from the wider literature, not a finding of this study.
Bhasin et al., dose-response trials
Prevention as well as remission
In a two-year randomised trial of 1,007 men, testosterone alongside a lifestyle programme reduced the incidence of type 2 diabetes compared with lifestyle alone.
Wittert et al. (T4DM), Lancet Diabetes & Endocrinology, 2021
Clinical interpretation
How much weight should this study carry?
This was an observational registry, not a randomised trial. The men who chose treatment may differ from the men who did not, in motivation, in engagement with their own care, or in ways nobody recorded. That possibility cannot be removed by the length of follow-up.
What the length does provide is durability. Eleven years makes a purely short-lived effect less likely, and the improvements were progressive rather than an early jump followed by drift. No remissions occurred in the untreated group at any point.
The honest summary is therefore narrow and still important: in men who have both conditions, treating the hormone deficiency was followed by durable improvement in the metabolic disease. That is a conversation to have with a physician — not a reason to treat the two problems as unrelated.
Your own numbers
Find out where you sit on this curve.
Every figure on this page describes men whose testosterone and glucose control were actually measured. The only way to know whether any of it applies to you is to measure yours.
- Total testosterone and SHBG by LC-MS/MS
- HbA1c for glucose control
- Haematocrit as a baseline safety marker
- Oestradiol, LH, FSH and vitamin B12 in the same draw