Prediabetes in men: what an HbA1c of 42 to 47 means and what to do next

An HbA1c of 42 to 47 mmol/mol is not diabetes. In UK practice it is called non-diabetic hyperglycaemia, or prediabetes: blood sugar that runs higher than it should, below the point where type 2 diabetes is diagnosed. [1]

Prediabetes in men usually has no symptoms, so the first a man hears of it is often a number on a blood test report. [3]

This article explains what the figure means and why one result is not a diagnosis. It covers insulin resistance, why waist size matters more for men, and the next steps the NHS and NICE set out.

What does an HbA1c of 42 to 47 mmol/mol mean?

It means your average blood sugar has been higher than normal over the previous two to three months. It is not high enough for a diagnosis of type 2 diabetes. [1] [4]

HbA1c (glycated haemoglobin) is the share of the haemoglobin in your red blood cells that has sugar attached to it. Because red cells live for about three months, the figure reflects your average blood sugar over that time rather than the level on the day. [4]

UK laboratories report HbA1c in mmol/mol. Older reports, US sources and some apps use a percentage. The same thresholds in both units: [1] [2]

HbA1c thresholds used in UK practice

HbA1c (mmol/mol)	HbA1c (%)	What it indicates
Below 42	Below 6.0	Within the normal range
42 to 47	6.0 to 6.4	Non-diabetic hyperglycaemia (prediabetes): high risk of type 2 diabetes
48 or above	6.5 or above	The cut-off for diagnosing type 2 diabetes, confirmed by a repeat test in a person without symptoms

NICE's prevention guideline treats the 42 to 47 range as high risk of type 2 diabetes, and Diabetes UK advises that anyone in it has their HbA1c checked at least once a year. [1]

Why one result is not a diagnosis

A diagnosis of type 2 diabetes is not made on a single HbA1c result in someone without symptoms. If a first result is 48 mmol/mol or above, the test is repeated, and only a second result at or above 48 confirms it. [1]

The same caution applies in the other direction. One reading of 44 is a prompt to look closer and to recheck, not a label.

When HbA1c is not the right test

HbA1c is the standard test for most adults, but Diabetes UK lists situations in which it should not be used to diagnose diabetes: [1]

• children and young people;
• when type 1 diabetes is suspected;
• symptoms of diabetes for less than 2 months;
• acute illness, or a condition serious enough to need hospital admission;
• acute damage to the pancreas, or after pancreatic surgery;
• pregnancy;
• genetic, blood or illness-related factors that change how haemoglobin behaves, including some types of anaemia.

In those cases a GP uses a different test. For men who are otherwise well, HbA1c is the test that will be used, and the thresholds above apply.

What is insulin resistance, and how does it lead to prediabetes?

Insulin is the hormone that moves sugar out of the blood and into muscle, liver and fat cells. Insulin resistance is when those cells respond less well to it.

When cells respond less, the pancreas makes more insulin to compensate. For a long time that keeps blood sugar in range. Prediabetes is the stage where the compensation starts to fall short and the average blood sugar drifts upwards, which is what HbA1c picks up.

The NHS links metabolic syndrome, a cluster of raised waist, blood pressure, blood sugar and blood fats, to insulin resistance and to fat carried around the abdomen. [5] The two overlap heavily. Many men with an HbA1c of 42 to 47 also have raised triglycerides, low HDL cholesterol or raised blood pressure. The same changes help with all of them.

The article on metabolic syndrome in men covers the cluster in full, and the metabolic syndrome page gives the short version.

Does prediabetes cause symptoms men would notice?

Usually not. Diabetes UK's position is plain: "There aren't usually any symptoms if you have prediabetes." [3]

That is why it turns up on a blood test rather than in the mirror. A man can carry it for years without knowing.

Visible prompts worth a check

Two things a man can see or measure are associated with insulin resistance. Neither is a diagnosis; both are a reason to get HbA1c checked.

• Dark, velvety skin at the back of the neck or in the armpits. Called acanthosis nigricans, it appears at the neck in about 85% of cases and in the armpits in about 75%. It is associated with obesity and insulin resistance, though insulin resistance is common rather than universal in people who have it, and it has other causes. [8]
• A waist above 94 cm. The World Health Organization's cut point for increased risk of metabolic complications in men, explained in the next section. [6]

Lists of "prediabetes symptoms" online (tiredness, thirst, cravings) describe diabetes itself or have no source behind them. If you have symptoms such as thirst, passing more urine or unexplained weight loss, that is a reason to see a GP now, not a prediabetes sign to watch.

Why does waist size matter more for men?

Because men store proportionally more fat deep inside the abdomen, around the organs. That visceral fat tracks with insulin resistance more closely than fat under the skin does.

Three thresholds are used in UK and international guidance: [6] [7]

• 94 cm: above this, the World Health Organization describes increased risk of metabolic complications in men of European origin.
• 102 cm: above this, substantially increased risk.
• 90 cm: the International Diabetes Federation cut point for men of South Asian, Chinese or Japanese family background, whose risk rises at a smaller waist.

NICE now also recommends keeping your waist to less than half your height as a check alongside BMI (body mass index). A ratio of 0.5 to 0.59 is increased central fat; 0.6 or more is high. [6]

Measure at the midpoint between your lowest rib and the top of your hip bone, breathing out, with the tape snug but not tight. [6] The article on visceral fat in men explains why this fat behaves differently.

How many men are at risk, and why do fewer men get checked?

Diabetes UK estimates that around one in 12 people has prediabetes. [3] Across the UK, an estimated 6.9 million people are at increased risk of type 2 diabetes based on their blood sugar. Almost 1.3 million could be living with type 2 diabetes without a diagnosis. [9]

Public Health England's analysis of Health Survey for England blood samples used the same definition: an HbA1c between 6.0% (42 mmol/mol) and 6.4% (47 mmol/mol). [2]

Men are less likely to be checked. In England, the NHS Health Check is offered free every 5 years to adults aged 40 to 74 without an existing cardiovascular diagnosis. It can include a blood sugar test. In the last published breakdown, 38% of eligible men attended against 44% of women. [10]

That gap matters for a condition with no symptoms. The article on why men ignore weight gain looks at the pattern behind it.

What lowers the risk of moving on to type 2 diabetes?

Weight, activity and diet, supported by a structured programme, and a recheck at least once a year. [1]

The evidence for lifestyle change in this group is strong. The US Diabetes Prevention Program was a trial of 3,234 adults with raised blood sugar. A lifestyle programme aiming for 7% weight loss and 150 minutes of activity a week reduced the incidence of type 2 diabetes by 58% over an average of 2.8 years. [11] That is a population result from a trial in which 68% of participants were women; it describes groups, not what any one man will see.

The NHS route: Healthier You

In England, the Healthier You NHS Diabetes Prevention Programme takes people with non-diabetic hyperglycaemia through a 9-month lifestyle change programme. [12]

1. Get into the programme. Referral comes through your GP after a blood test, through an NHS Health Check, or by using the NHS Know Your Risk tool and asking your practice. [12]
2. Choose the format. It runs as a face-to-face group service or as a digital service with wearables, an app with health coaches and online peer support. [12]
3. Work through the 9 months. The content is diet, physical activity and weight management, the same levers as the trial above. [12]
4. Recheck HbA1c. At least once a year while the result sits in the 42 to 47 range. [1]

At population level, GP practices where the programme had been running for two years recorded about 6% fewer new type 2 diabetes diagnoses than expected. [13] NHS England reports a larger effect for people who complete the programme: more than a third lower risk. Its page gives no citation for that figure. [12]

The vocabulary matters. The aim is to reduce the risk of progressing to type 2 diabetes and, where it happens, to return HbA1c to below 42 mmol/mol. Nobody can promise either for an individual, and any wording that promises more than that overstates what the evidence shows.

What can a blood test show, and when should you see your GP?

A blood test is the only way to know where your HbA1c sits. It can show whether the figure is in the normal range or in the 42 to 47 range. It can also show the level at which a GP would repeat the test and consider a diagnosis. [1]

HbA1c is one of the 10 markers in HeMed's blood test: your average blood sugar over roughly the past three months. A clinician reads the result alongside your blood fats, liver enzymes and thyroid marker, so a raised figure is seen in context rather than alone.

A HeMed result is never a diagnosis. HeMed does not diagnose or treat prediabetes or type 2 diabetes; a GP does that, with a repeat test and, where needed, a referral.

Your GP can also arrange a fasting glucose test or an oral glucose tolerance test if HbA1c is not suitable for you. Those tests are not part of HeMed's panel.

See your GP if

• any blood test puts your HbA1c at 48 mmol/mol or above;
• your result is 42 to 47 and you have not discussed it with a GP, so the recheck and the Healthier You referral are on record;
• you have symptoms such as thirst, passing more urine, blurred vision or unexplained weight loss, whatever the result;
• you have one of the conditions above in which HbA1c is not the right test.

The articles on what a men's health blood test checks for and what HeMed tests cover the other nine markers.

Whether HeMed is suitable for you is a clinical decision made after your blood test and health review, not a promise. The programme includes nutrition guidance and diet and exercise advice; it does not replace your GP for a condition that needs its own care.

Frequently asked questions

Is an HbA1c of 42 to 47 mmol/mol diabetes?

No. It is non-diabetic hyperglycaemia, also called prediabetes. The diagnostic cut-off for type 2 diabetes is 48 mmol/mol (6.5%), confirmed by a repeat test in someone without symptoms. The 42 to 47 range means a high risk of type 2 diabetes and a recheck at least once a year.

Does prediabetes always become type 2 diabetes?

No. It marks a high risk, not a certainty. In the Diabetes Prevention Program trial, a lifestyle programme reduced new cases of type 2 diabetes by 58% over an average of 2.8 years. That is a population figure; what happens for one man depends on his weight, activity, diet and the rest of his health.

How often should HbA1c be rechecked?

At least once a year while the result is 42 to 47 mmol/mol, according to Diabetes UK. Because HbA1c reflects about three months of blood sugar, testing more often than every three months tells you little that the last result did not.

Can HbA1c go back below 42?

For some people, yes. Weight loss, more activity and changes to diet are the levers the trials and the NHS programme use, and a repeat test shows whether the figure has moved. Nobody can promise it for an individual, and a result that returns to the normal range still warrants the yearly recheck.

Next step: see what the HeMed blood test measures.

Sources (13)

1. Diabetes UK, "Diagnostic criteria for diabetes" (clinical recommendations for professionals, following WHO 2011): "An HbA1c of 48mmol/mol (6.5%) is recommended as the cut-off point for diagnosing diabetes"; "If the first HbA1c is 48 mmol/mol (6.5%) or above the test should be repeated. If the second test is also 48 mmol/mol (6.5%) or above, then a diabetes diagnosis is confirmed"; "HbA1c between 42-47 mmol/mol indicates non diabetic hyperglycaemia and people should have their HbA1c checked at least once a year"; the list of situations in which HbA1c is not appropriate for diagnosis. NICE PH38, "Type 2 diabetes: prevention in people at high risk", classes this range as high risk. diabetes.org.uk/for-professionals; nice.org.uk/guidance/ph38. Accessed 13 October 2026.
2. Public Health England, National Cardiovascular Intelligence Network. "NHS Diabetes Prevention Programme (NHS DPP) Non-diabetic hyperglycaemia." August 2015: "Non-diabetic hyperglycaemia was defined as an HbA1c value between 6.0% (42mmol/mol) and 6.4% (47mmol/mol)", from Health Survey for England blood samples 2009 to 2013. assets.publishing.service.gov.uk. Accessed 13 October 2026.
3. Diabetes UK, "Prediabetes", content last reviewed 27 January 2026: "There aren't usually any symptoms if you have prediabetes"; "Prediabetes is estimated to affect around one in 12 people"; normal level below 42 mmol/mol. diabetes.org.uk/about-diabetes/type-2-diabetes/prediabetes. Accessed 13 October 2026.
4. NHS England Digital, Health Survey for England 2024, Adults' health: HbA1c reflects average blood sugar over the previous two to three months and can detect undiagnosed diabetes. digital.nhs.uk, HSE 2024. Accessed 13 October 2026.
5. NHS, "Metabolic syndrome": linked to insulin resistance and to fat around the abdomen; raises the likelihood of type 2 diabetes and cardiovascular disease. nhs.uk/conditions/metabolic-syndrome. Accessed 13 October 2026.
6. World Health Organization, "Waist circumference and waist-hip ratio: report of a WHO expert consultation", 2008 (above 94 cm in men increased risk of metabolic complications, above 102 cm substantially increased; measurement at the midpoint between the lowest rib and the iliac crest). NICE NG246 (2025), "Overweight and obesity management": waist-to-height ratio 0.5 to 0.59 increased central adiposity, 0.6 or more high. iris.who.int/handle/10665/44583; nice.org.uk/guidance/ng246. Accessed 13 October 2026.
7. Alberti KGMM and colleagues. "Harmonizing the metabolic syndrome: a joint interim statement." Circulation 2009;120(16):1640 to 1645 (waist cut points by population: Europid men 94 cm; South Asian, Chinese and Japanese men 90 cm). doi.org/10.1161/CIRCULATIONAHA.109.192644. Accessed 13 October 2026.
8. Brady MF, Rawla P. "Acanthosis nigricans." StatPearls (neck in 85% and axilla in 75% of cases; associated with obesity and insulin resistance; insulin resistance common but not universal). ncbi.nlm.nih.gov/books/NBK431057. Accessed 13 October 2026.
9. Diabetes UK, "Diabetes statistics" (2024 to 2025 figures): an estimated 6.9 million people at increased risk of type 2 diabetes based on blood sugar levels; almost 1.3 million could be living with undiagnosed type 2 diabetes. diabetes.org.uk/about-us/about-the-charity/our-strategy/statistics. Accessed 13 October 2026.
10. Healthwatch England, "Time to get serious about men's NHS Health Checks", 18 September 2025 (last published uptake breakdown, 2017 to 2018: 44% of eligible women against 38% of men). NHS, "NHS Health Check": free for adults aged 40 to 74 in England without an existing cardiovascular diagnosis, every 5 years. healthwatch.co.uk; nhs.uk/conditions/nhs-health-check. Accessed 13 October 2026.
11. Diabetes Prevention Program Research Group. "Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin." New England Journal of Medicine 2002;346(6):393 to 403 (3,234 adults, 68% women; lifestyle intervention reduced incidence by 58%, 95% CI 48 to 66, over a mean 2.8 years). doi.org/10.1056/NEJMoa012512. Accessed 13 October 2026.
12. NHS England, "NHS Diabetes Prevention Programme (NHS DPP)": the Healthier You programme "identifies people at risk of developing type 2 diabetes and refers them onto a nine-month, evidence-based lifestyle change programme"; "available both as a face-to-face group service and as a digital service"; routes through the Know Your Risk tool, NHS Health Checks and GPs; "It cuts the risk of developing type 2 diabetes by more than a third for people completing the programme" (no citation given on the page). england.nhs.uk/diabetes/diabetes-prevention. Accessed 13 October 2026.
13. McManus E, Meacock R, Parkinson B, Sutton M. "Population level impact of the NHS Diabetes Prevention Programme on incidence of type 2 diabetes in England: an observational study." The Lancet Regional Health Europe 2022;19:100420 (difference-in-differences across 6,476 practices; incidence in wave 1 practices in 2018 and 2019 lower than expected, incident rate ratio 0.938, 95% CI 0.905 to 0.972). doi.org/10.1016/j.lanepe.2022.100420. Accessed 13 October 2026.

Numbered markers in the page text link to these entries. Statistics describe populations, not any one person’s results.