A normal A1C level for a man is below 5.7%. This threshold is the same regardless of sex. The American Diabetes Association uses three categories: below 5.7% is normal, 5.7% to 6.4% indicates prediabetes, and 6.5% or higher means diabetes. These cutoffs apply to both men and women and remain unchanged in the 2025 Standards of Care.
What A1C Actually Measures
A1C reflects your average blood sugar over the previous two to three months. It works by measuring the percentage of hemoglobin (the oxygen-carrying protein in red blood cells) that has glucose attached to it. The higher your blood sugar has been running, the more glucose sticks to hemoglobin. Because red blood cells live about 90 to 120 days, the test captures a longer window than a single finger stick or fasting glucose reading.
To put those percentages in practical terms: an A1C of 5% corresponds to an estimated average blood sugar of about 97 mg/dL, while a 6% A1C translates to roughly 126 mg/dL. At 7%, the average climbs to around 154 mg/dL. So the jump from a normal A1C (below 5.7%) into the prediabetes range means your blood sugar is averaging somewhere around 117 to 137 mg/dL over the course of a day, including after meals.
Why Men Tend to Run Slightly Higher
Although the diagnostic cutoffs don’t differ by sex, research shows that men’s A1C levels tend to be slightly higher than women’s, particularly between ages 30 and 49. A large study of adults without a prior diabetes diagnosis found that men had significantly higher A1C values than women in the 30 to 39 and 40 to 49 age groups. That gap narrowed with age and largely disappeared after 50. The reasons aren’t fully settled, but hormonal differences and differences in red blood cell metabolism likely play a role.
This means a man in his 30s or 40s sitting at 5.6% is still technically normal, but may be closer to the prediabetes threshold than a woman of the same age with the same lifestyle. It’s worth paying attention to the trend over time rather than treating a single result as the final word.
How Age Changes the Picture
A1C rises naturally with age, even in people who never develop diabetes. For men already diagnosed with diabetes, target A1C levels are actually loosened as they get older or develop other health conditions. A healthy older man with diabetes might aim for an A1C below 7.5%, while someone with multiple chronic conditions or cognitive decline might have a target of 8% or even 8.5%. These relaxed targets exist because pushing blood sugar too low in older adults increases the risk of dangerous drops (hypoglycemia) and falls.
For men without diabetes, though, the goal remains straightforward: stay below 5.7%.
When and How Often to Get Tested
The U.S. Preventive Services Task Force recommends screening for prediabetes and type 2 diabetes in adults aged 35 to 70 who are overweight or obese (a BMI of 25 or higher). If you’re Asian American, screening is recommended at a BMI of 23 or higher. Men who are Black, Hispanic, American Indian, Alaska Native, or Native Hawaiian/Pacific Islander should consider screening earlier than 35, since these populations face a disproportionately high prevalence of diabetes.
If your result comes back normal, retesting every three years is a reasonable interval. If you’re in the prediabetes range (5.7% to 6.4%), your doctor will likely recheck more frequently, often annually.
Factors That Can Skew Your Results
Certain conditions can make your A1C reading inaccurate, and this matters more than many people realize. Iron deficiency anemia, which is common in men with poor diets or gastrointestinal bleeding, can push A1C falsely high. Vitamin B-12 and folate deficiency have the same effect. On the other hand, conditions that destroy red blood cells faster than normal, like hemolytic anemia or significant blood loss, can make A1C appear falsely low.
Hemoglobin variants, which are inherited differences in the structure of hemoglobin, can also throw off results. These variants are more common in people of African, South Asian, Southeast Asian, and Mediterranean descent. A hemoglobin variant won’t increase your diabetes risk, but it can cause the test to read higher or lower than your actual blood sugar warrants. If your A1C seems inconsistent with your daily glucose readings, a hemoglobin variant may be the explanation, and your doctor can use alternative testing methods.
Health Risks for Men With Elevated A1C
Persistently high blood sugar damages nerves and blood vessels throughout the body, but some consequences hit men specifically. Erectile dysfunction is one of the most common: men with diabetes are three times more likely to experience it. High blood sugar damages the small blood vessels and nerves that enable erections. The good news is that 95% of cases are treatable.
Beyond erectile dysfunction, nerve damage from poorly controlled blood sugar can cause overactive bladder, urinary incontinence, urinary tract infections, and retrograde ejaculation (where semen enters the bladder instead of exiting the body). These complications generally develop after years of elevated blood sugar, not from a single high A1C reading, which is why catching prediabetes early matters.
Lowering A1C Through Lifestyle Changes
If your A1C comes back in the prediabetes range, lifestyle changes are the first and most effective intervention. The combination of diet and exercise can produce dramatic results. In one clinical study, people with type 2 diabetes who followed a strict low-calorie diet saw their A1C drop from 7.4% to 6.0% in just eight weeks, with fasting blood sugar normalizing within the first week.
Timing of exercise matters more than you might expect. Research on post-meal exercise, specifically walking or light activity after eating, shows better blood sugar control than exercising before meals. In one documented case, a person who combined post-breakfast exercise with dietary changes achieved their lowest A1C ever (5.8%) after six weeks, having previously plateaued at 6.4% with pre-meal exercise alone.
The most reliable combination is reducing refined carbohydrates, maintaining a moderate calorie intake, staying physically active most days, and losing even a modest amount of weight. You don’t need to hit a perfect number overnight. Dropping your A1C by even half a percentage point reduces your risk of complications meaningfully and can shift you from prediabetes back into the normal range.