Low Testosterone and Blood Sugar: What Is the Connection?

By Noophoric Editorial Team Updated August 31, 2026

Low testosterone and high blood sugar often appear together, especially in men with obesity or type 2 diabetes. That does not prove that one directly causes the other. Body composition, insulin resistance, sleep, chronic illness, and medication use can affect both.

The strongest practical conclusion is that men with diabetes or prediabetes who also have symptoms of testosterone deficiency may benefit from proper hormone testing. Testosterone therapy should not be used as a diabetes prevention or blood sugar treatment.

How are testosterone and blood sugar connected?

Insulin helps move glucose from the bloodstream into cells. When tissues become less responsive to insulin, the pancreas must produce more of it to keep blood sugar controlled. Over time, this insulin resistance can contribute to prediabetes and type 2 diabetes.

Men with obesity and type 2 diabetes tend to have lower average testosterone levels than men without these conditions. However, the American Diabetes Association notes that obesity is a major confounder.¹ In other words, excess body fat and related metabolic changes may help explain both the low testosterone result and the higher blood sugar.

Obesity can also lower sex hormone binding globulin, or SHBG. Because SHBG carries testosterone in the blood, a lower SHBG level can reduce measured total testosterone even when the hormone-producing system is not permanently damaged. This is one reason a single low total testosterone result is not enough for diagnosis.

Does low testosterone cause diabetes?

Observational studies show an association between lower testosterone and a greater risk of type 2 diabetes in men. These studies cannot prove which direction the relationship runs. A meta-analysis of cohort studies concluded that reverse causality was plausible, meaning metabolic disease may lower testosterone rather than low testosterone independently causing diabetes.²

The relationship is likely bidirectional in some people:

Obesity and insulin resistance can reduce SHBG and total testosterone.
Chronic illness and poor sleep can disrupt hormone signaling.
Lower muscle mass may reduce glucose disposal.
Low testosterone symptoms can make physical activity and weight management harder.

These overlapping pathways are important, but they do not establish testosterone replacement as a diabetes therapy.

Does testosterone therapy improve blood sugar?

Randomized evidence does not support prescribing testosterone to prevent diabetes. In the large TRAVERSE Diabetes Study, testosterone gel did not significantly reduce progression from prediabetes to diabetes or increase diabetes remission compared with placebo. Glucose and A1C changes were also similar between groups.³

The 2026 American Diabetes Association Standards of Care therefore do not recommend testosterone therapy for prevention of type 2 diabetes in men with hypogonadism.⁴

Some smaller studies and meta-analyses have reported improvements in insulin resistance or body composition. A 2026 systematic review judged the evidence to be low certainty and described effects on glycemic and lipid outcomes as very uncertain.⁵ Differences in study populations, treatment duration, baseline health, and study quality help explain why results vary.

Testosterone may still be appropriate for a man who has symptoms and repeatedly confirmed low levels. In that situation, the goal is to treat diagnosed hypogonadism, not to replace established diabetes care.

When should men with diabetes have testosterone tested?

The 2026 ADA Standards recommend asking men with diabetes or prediabetes about sexual health. A morning total testosterone test is appropriate when symptoms or signs of hypogonadism are present.¹

Possible symptoms include:

Reduced libido
Fewer spontaneous erections
Erectile dysfunction
Infertility
Loss of muscle mass or body hair
Unexplained anemia or low bone density

Fatigue and poor concentration alone are not specific enough to diagnose low testosterone. They can also be related to glucose fluctuations, sleep apnea, depression, medication effects, or other medical conditions.

A low morning result should be repeated on a different day. When total testosterone is near the lower limit, a clinician may assess free testosterone, SHBG, and albumin. Luteinizing hormone, follicle stimulating hormone, and sometimes prolactin can help identify the cause. Our testosterone testing guide explains this process.

What should be treated first?

Blood sugar and testosterone concerns should be evaluated together, but each requires its own diagnosis and treatment plan.

For high blood sugar or diabetes

Follow a clinician-directed plan for nutrition, physical activity, weight management, glucose monitoring, and medication when needed. Do not replace prescribed diabetes treatment with testosterone or an over-the-counter supplement.

For possible low testosterone

Confirm both the symptoms and repeat laboratory results. Address potentially reversible contributors such as obesity, sleep apnea, poor nutrition, severe illness, and medications. If hypogonadism is confirmed, discuss the expected benefits, monitoring, risks, and fertility goals before treatment.

For erectile dysfunction

Diabetes can affect the blood vessels and nerves needed for an erection. Low testosterone may contribute, especially when libido is also reduced, but it may not be the main cause. Read our guide to low testosterone and erectile dysfunction for a fuller evaluation framework.

Lifestyle changes can help both conditions

Regular resistance and aerobic exercise, adequate sleep, treatment of sleep apnea, a sustainable eating pattern, and clinically meaningful weight loss can improve metabolic health. In men with obesity-related reductions in testosterone, improving the underlying metabolic condition may also raise testosterone without hormone therapy.

These changes are not instant testosterone boosters. Their value is that they target common drivers of insulin resistance and hormone disruption. Our article on testosterone and fat loss explains why cause and effect should not be oversimplified.

Frequently asked questions

Can low testosterone make fasting glucose high?

Low testosterone is associated with insulin resistance and type 2 diabetes, but a low testosterone result does not by itself explain high fasting glucose. Obesity, genetics, diet, physical activity, sleep, medications, and pancreatic function may all contribute.

Can lowering blood sugar raise testosterone?

Improving weight, sleep, and metabolic health may improve testosterone in some men, particularly when the reduction is functional rather than caused by permanent testicular or pituitary disease. The response varies and should be confirmed with repeat testing.

Should every man with diabetes take testosterone?

No. Testosterone is considered only when compatible symptoms and consistently low levels establish hypogonadism. It is not recommended simply because a man has diabetes.

Bottom line

Low testosterone, obesity, insulin resistance, and type 2 diabetes frequently overlap. The association is real, but the direction and cause differ from person to person. Current evidence does not support testosterone therapy as a way to prevent diabetes or control blood sugar. Symptoms should prompt proper morning testing, while high blood sugar should receive established metabolic care.

Sources

Evidence reviewed August 2026. This article is educational and is not a substitute for individualized medical diagnosis or treatment.