People living with type 2 diabetes are well known to face a higher risk of serious heart problems, including heart attacks and strokes.
Doctors have understood this connection for many years, yet an important mystery remains.
Not everyone with diabetes faces the same level of risk.
In particular, women with diabetes often experience worse heart outcomes than men, even when they receive similar medical care. Until recently, the biological reasons behind this difference were not clear.
A new study led by researchers at Johns Hopkins Medicine suggests that sex hormones may help explain why heart disease risk differs between men and women with type 2 diabetes.
Hormones such as testosterone and estradiol are best known for their role in reproduction, but they also influence metabolism, blood vessels, inflammation, and heart function. Because diabetes already places stress on the heart and blood vessels, changes in hormone levels could play an important role in shaping long-term cardiovascular health.
The research was led by Dr. Wendy Bennett, an associate professor of medicine at Johns Hopkins University School of Medicine.
She and her colleagues wanted to better understand why women with diabetes tend to have a higher risk of heart disease compared to men. According to the research team, sex hormones may be one of the missing pieces needed to explain these differences.
To explore this question, the researchers used data from the Look AHEAD study, a large and long-running research project focused on people with type 2 diabetes. The original study examined how weight loss affected heart health over time.
Even after the main trial ended, participants continued to be followed, giving scientists a rare opportunity to study long-term health changes in detail.
For this analysis, the research team looked closely at blood samples collected from participants at the start of the study and again one year later.
These samples allowed researchers to measure levels of key sex hormones, including testosterone and estradiol. By tracking how these hormone levels changed over time, the team could examine whether hormone patterns were linked to future heart disease events.
When the researchers analyzed the data, they found clear patterns among male participants. Men who had higher testosterone levels at the beginning of the study tended to have a lower risk of developing heart disease later on.
This suggests that testosterone may have a protective effect on the cardiovascular system in men with diabetes. At the same time, men who experienced an increase in estradiol levels after one year showed a higher risk of heart disease.
These findings suggest that shifts in hormone balance, rather than hormone levels alone, may influence heart health in men with diabetes. Estradiol is typically considered a female hormone, but it is also present in men at lower levels.
Changes in estradiol levels may affect blood vessel function, inflammation, or fat distribution, all of which can influence cardiovascular risk.
In contrast, the researchers did not find strong or consistent links between hormone levels and heart disease outcomes among female participants. This does not mean hormones are unimportant for women, but rather that the relationship may be more complex.
Women experience natural hormonal shifts throughout life, especially during menopause, which may interact with diabetes in ways that are harder to measure. Other factors such as inflammation, blood pressure, cholesterol levels, and duration of diabetes may also play a larger role in determining heart risk for women.
The study highlights the idea that heart disease risk cannot be explained by blood sugar levels alone. Traditional risk factors like smoking, high cholesterol, and high blood pressure remain important, but hormones may provide additional clues about who is most at risk.
By tracking hormone changes alongside standard measurements, doctors may one day be able to create more personalized strategies for preventing heart disease in people with diabetes.
Looking ahead, the research team plans to expand their work in several important directions. Future studies will examine how weight loss and hormone changes affect bone health, especially fracture risk, in people with diabetes.
The researchers are also preparing studies focused on hormonal changes during the transition to menopause, a period when many women experience shifts in heart disease risk. Understanding how these hormonal changes interact with chronic conditions like diabetes could help guide better prevention strategies.
In reviewing and analyzing the findings, this study suggests that sex hormones play a meaningful role in shaping heart disease risk in people with type 2 diabetes, particularly among men.
The lack of clear hormone links in women does not weaken the results but instead highlights how complex female cardiovascular biology may be.
Overall, the research supports a move toward more personalized medicine, where hormone levels are considered alongside traditional risk factors.
Rather than relying on a one-size-fits-all approach, future diabetes care may benefit from recognizing how sex, hormones, and long-term metabolic health work together to influence heart disease outcomes.
If you care about diabetes, please read studies about diabetes and vitamin B12, and the right diet for people with type 2 diabetes.
For more health information, please see recent studies about how to eat smart with diabetes, and turmeric and vitamin D: a duo for blood pressure control in diabetic patients.
The study is published in Diabetes Care.
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