Diabetes, Low Testosterone and the “Quiet” Risk Men Miss

Diabetes, Low Testosterone and the “Quiet” Risk Men Miss

In a TRT clinic, it is common for a man to come in because he feels flat, tired, heavier around the middle, or stuck in his training — and for his blood tests to quietly show something else going on in the background.

Yes, his testosterone is low.
But his HbA1c or fasting glucose is also higher than it should be. Sometimes the first real warning is not “you have low testosterone,” but “you are in the pre-diabetes range” or “you have tipped into type 2 diabetes.”

Most men have never been told that low testosterone and insulin resistance often travel together, especially with weight gain around the middle, high stress and poor sleep. That is exactly the overlap Dr Angela and Dr Andy explore in the podcast: not scare tactics, but the real-world reality of how hormones and blood sugar quietly shape long-term health.

You Don’t Have to “Look Diabetic” to Be at Risk

One of the biggest misconceptions is that diabetes is obvious.

The stereotype is clear: someone much older, visibly unwell, with obvious symptoms like constant thirst and going to the toilet all the time. In reality, the early problem for many men is insulin resistance — where the body needs more and more insulin to keep blood sugar under control — and this can be present for years before any classic symptoms appear.

Low testosterone often shows up in the same men who are developing insulin resistance. Large studies have found that lower serum testosterone is associated with higher insulin resistance and a greater risk of type 2 diabetes in men.

On the surface, what they feel is “just life” or “just low T”:

• Feeling tired or sleepy after meals, especially carb-heavy ones.
• Mid-afternoon crashes and foggy thinking.
• Craving sugar or carbs “for a boost.”
• Weight shifting around the middle, even if training hasn’t changed.
• Poor sleep or waking unrefreshed.
• Slow recovery from sessions that used to feel fine.
• Brain fog that comes and goes with energy swings.

Plenty of men in this position still train, still work hard, still function — they just feel like they’re dragging themselves through it. Testosterone can be part of that story, but so can early pre-diabetes. Blood testing is what reveals that second piece.

How Diabetes and Pre-Diabetes Are Actually Diagnosed

Pre-diabetes and diabetes are not diagnoses made on “vibes,” age or body shape — they’re made on blood tests.

The most commonly used markers are:

• HbA1c – a measure of your average blood sugar over the past 2–3 months.
• Fasting plasma glucose – your blood sugar level after an overnight fast.

UK and NHS-aligned guidance broadly use thresholds in this range for adults (local pathways may vary slightly):

Normal:

• HbA1c up to around 41 mmol/mol
• Fasting glucose up to around 5.4–5.5 mmol/L

Pre-diabetes (non-diabetic hyperglycaemia):

• HbA1c roughly 42–47 mmol/mol
• Fasting glucose around 5.5/6.1 to 6.9 mmol/L

Diabetes:

• HbA1c 48 mmol/mol or higher
• Fasting glucose 7.0 mmol/L or higher

You cannot reliably “feel” where you sit on this spectrum. You can have low energy, central weight gain and poor recovery long before the numbers cross into type 2 diabetes. Equally, you can feel fine and still sit in the pre-diabetes range. The only way to know is to measure.

The Double-Edged News: Low T + High Blood Sugar

When a man in a TRT clinic is told, “Your testosterone is low and your blood sugar is in the pre-diabetes range,” the result is the same on paper – but it lands very differently depending on the person.

1) The under-reactors

These men nod, shrug and say something like:

“Right… okay. So do I just start testosterone and carry on?”

Because they still feel “functional,” they underestimate what long-term high blood sugar, visceral fat and low testosterone can do to their heart, brain and sexual health.

They often need the clinician to gently but clearly drive home three points:

• This is not just a label. It is a warning light.
• You can change direction — but it will take action.
• TRT may help your symptoms and insulin resistance, but it cannot cancel out a lifestyle that keeps pushing you towards diabetes and cardiovascular disease.

2) The over-reactors

These men have seen diabetes up close — a father with complications, a relative on multiple medications, someone who lost their vision or had an amputation.

They hear “pre-diabetes” and their brain jumps straight to worst-case scenario. They often need the opposite style of conversation:

• Calm, steady reassurance.
• Clear explanation of what the numbers mean right now.
• A realistic plan that covers both testosterone and metabolic risk.
• A reminder that catching this early massively improves the odds of changing course.

In both cases, it is not just what you tell someone; it is how you tell them. Good care recognises that hormones and metabolism are part of the same story, and the conversation needs to reflect that.

TRT and Blood Sugar: What the Evidence Actually Says

For men with true hypogonadism (clinically low testosterone and symptoms), testosterone replacement therapy can do more than just improve libido and mood. Several clinical studies in men with type 2 diabetes or metabolic syndrome show that TRT can:

• Improve insulin resistance by roughly 15–20% over 6–12 months (measured by HOMA-IR).
• Modestly reduce HbA1c and fasting glucose in some men.
• Reduce waist circumference and visceral fat, while increasing lean muscle mass.
• Improve sexual function, mood, energy and quality of life, which can make it easier to maintain lifestyle changes.

Long-term registry data even suggest that, in carefully selected men with hypogonadism and type 2 diabetes, sustained TRT over many years can support better glycaemic control and higher rates of diabetes remission compared with men who remain untreated.

So, does that mean TRT is a “treatment” for diabetes?
Not on its own. It is a powerful adjunct for the right man: someone with clear low testosterone, symptoms, and a willingness to address lifestyle.

The Uncomfortable Truth: TRT Can’t Outrun Lifestyle

This is the part that can feel uncomfortable in clinic, but it is also the most honest.

If the lifestyle around your TRT treatment is completely misaligned, then the full benefits of therapy will be blunted. The research is very clear that lifestyle modification is central to preventing progression from pre-diabetes to diabetes and improving long-term outcomes.

TRT cannot fully outwork:

• Regular binge or heavy drinking.
• Chronic, unaddressed sleep deprivation.
• A diet based on ultra-processed, high-sugar foods.
• High stress with no proper recovery.
• A completely sedentary routine, especially if work is desk-based.

In contrast, when lifestyle and TRT are aligned, the effect can be genuinely transformative. Large lifestyle programmes show that structured changes in diet, activity and weight can reduce progression from pre-diabetes to type 2 diabetes by around 30–60%. In hypogonadal men, adding appropriate TRT may amplify improvements in body composition, energy and insulin sensitivity, making those lifestyle changes more sustainable.

Being direct about this is not about blame. It is about matching treatment intensity to reality, so your blood tests and your life are pointing in the same direction.

TRT, Diabetes and Heart Risk: Is It Safe?

Many men with, or at risk of, type 2 diabetes worry about whether TRT is “safe for the heart.” The answer is nuanced.

Some analyses suggest that, in hypogonadal men with type 2 diabetes but without established cardiovascular disease, TRT may be associated with lower rates of heart attack and better overall cardiometabolic profiles compared with not treating low testosterone.

In men with long-standing diabetes and existing cardiovascular disease, certain studies have found higher rates of heart attack and stroke in those on TRT, especially if they are not carefully selected or monitored.

This is why good practice includes:

• Confirmed biochemical hypogonadism (not just “borderline” levels once).
• A full cardiovascular and metabolic risk assessment before starting TRT.
• Ongoing monitoring of blood pressure, lipids, HbA1c, haematocrit and symptoms.

The right takeaway is not that TRT is inherently dangerous or inherently protective — but that it should be used where it is genuinely indicated, and always in the context of the bigger metabolic and cardiovascular picture.

So What Should Happen After You Find Out?

Finding out you have low testosterone and pre-diabetes (or type 2 diabetes) should not trigger panic. It should trigger a structured, joined-up plan.

Step 1: Confirm where you actually are

Your clinician should not guess. They should confirm your status with appropriate tests, typically including:

• Testosterone, sex hormone-binding globulin and related hormone markers.
• HbA1c and/or fasting plasma glucose.
• Lipid profile, kidney function, blood pressure and weight/waist measurements.

If needed, a repeat test is used to confirm a diagnosis or clarify borderline results.

Step 2: Understand your personal drivers

Not everyone arrives at low T and pre-diabetes the same way. A good assessment will explore:

• Food pattern (meal timing, quality, portion size, sugary drinks, takeaways).
• Alcohol intake (both average and binge patterns).
• Sleep quantity and quality, including shift work.
• Daily movement and training style.
• Stress load and recovery.
• Family history, ethnicity and weight distribution (especially central fat).
• Other medications or health conditions that may affect hormones or metabolism.

These factors help explain why your bloods look the way they do and highlight where change will give the biggest return.

Step 3: Decide if TRT should be part of the plan

If you meet clinical criteria for hypogonadism and have symptoms, TRT may be appropriate alongside lifestyle change. Evidence suggests that in this context it can:

• Improve insulin resistance and glycaemic control.
• Reduce central fat and increase lean mass.
• Improve energy, mood and libido, which can make behaviour change more achievable.

Your clinician should also factor in any cardiovascular history and ongoing diabetes risk when deciding how to proceed.

Step 4: Build changes you can repeat on a random Tuesday

The most effective plans are not glamorous; they are repeatable. Large prevention programmes that cut diabetes risk by 30–60% focus on:

• Improving food quality and reducing calorie excess, especially from ultra-processed and high-sugar foods.
• Increasing daily movement (for example, walking after meals, consistent step targets).
• Structured resistance training to preserve and build muscle.
• Supporting better sleep routines and stress management.

The “perfect” plan that collapses after 10 days is far less useful than a slightly imperfect plan you can still do when life is busy.

Step 5: Re-test and track progress

Finally, you want proof that the plan is working.

• Re-checking testosterone confirms whether TRT is achieving its goals.
• Re-checking HbA1c and related markers over time shows whether you’re moving away from, or towards, diabetes.

Seeing numbers shift — for example, HbA1c moving out of the diabetic or pre-diabetic range, or waist circumference and fasting glucose coming down — is not just clinically important. It is also incredibly motivating.

The Real “Secret” in a TRT Clinic

Most men do not come to a TRT clinic because they are worried about diabetes. They come because they feel tired, heavier, foggy, flat or not themselves.

But low testosterone frequently coexists with insulin resistance and early type 2 diabetes, especially in men with central weight gain. A single, joined-up blood panel often picks up both.

The real “secret” is simple:

Do not wait until symptoms are loud or complications appear.
Do not assume you’re fine just because you train or don’t fit the stereotype.
If you have been feeling “off” for a while — tired after meals, gaining fat around the middle, struggling to recover, brain fog that won’t shift — it is worth testing not just testosterone, but also blood sugar and metabolic markers.

Catching both early gives you options. It lets you combine TRT (when appropriate) with realistic lifestyle change, reduce long-term risk, and aim not just to feel better now, but to protect your future health.

References

ZOE. Feeling sleepy after eating and diabetes.​
Diabetes.co.uk. Tiredness and diabetes.​
NHS. Symptoms of type 2 diabetes and how it’s diagnosed.​
NHS Lothian RefHelp. Pre‑Diabetes guidance.​
PMC. Effects of Lifestyle Modifications on Prediabetic Patients.​
HWE Clinical Guidance. Pre‑Diabetes – Prescribing, Policies and Pathways.​
PMC. Lifestyle Modification in Prediabetes and Diabetes.​
HWE Clinical Guidance. Pre Diabetes – Clinical Pathways.​
PMC. Lifestyle intervention approaches in prediabetes.​
ONS. Analysis of risk factors for pre‑diabetes and undiagnosed type 2 diabetes.​
Royal Devon & Exeter. Diagnosing Diabetes – routine cases.​
PMC. Association between serum testosterone and insulin resistance.​
PubMed. Testosterone and insulin resistance in men.​
PubMed. Low testosterone levels are common and associated with insulin resistance.​
PMC. Testosterone replacement in hypogonadal men with type 2 diabetes.​
Healthcare Bulletin. Testosterone Replacement Therapy in Male Hypogonadism with Type 2 Diabetes Mellitus.​
Healthline. Low testosterone and blood sugar levels.​
PMC. Influence of testosterone replacement therapy on metabolic parameters.​
PMC. Cardiovascular risks with testosterone replacement therapy in patients with type 2 diabetes.​
Diabetes Care. Insulin resistance and inflammation in hypogonadotropic hypogonadism and their reduction after TRT in men with type 2 diabetes.​
PMC. Remission of type 2 diabetes following long‑term treatment with injectable testosterone undecanoate.​
PMC. STRIDE study – TRT effects on glycaemic control in hypogonadal men with uncontrolled type 2 diabetes.​
JCEM. Low testosterone in men with type 2 diabetes.​

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