People living with type 2 diabetes are at increased risk of heart attack, stroke, and other cardiovascular conditions, but the extent of that risk differs between men and women. New research is shedding light on the potential role of sex hormones – testosterone and estradiol – in explaining these disparities. A study led by Johns Hopkins Medicine, published in Diabetes Care, analyzed data to determine if hormone levels correlate with heart disease risk in individuals with type 2 diabetes.
Understanding the Disparity
“We are very interested in understanding why women who have diabetes have a greater risk for heart disease compared to men,” says Dr. Wendy Bennett, lead researcher and associate professor of medicine at Johns Hopkins University School of Medicine. “Sex hormones matter and could explain some of the differences in heart disease outcomes in women and men.”
The study builds on existing knowledge that individuals with type 2 diabetes face a heightened risk of cardiovascular problems. However, the reasons behind varying risk levels between sexes have remained unclear. Researchers aimed to investigate whether fluctuations and levels of sex hormones could provide some answers.
Analyzing Data from the Look Ahead Study
The research team leveraged data from the Look Ahead study, a long-term project initially designed to assess the impact of weight loss on heart health in people with type 2 diabetes. Crucially, the Look Ahead study continued to follow participants even after the initial trial concluded, providing a valuable source of longitudinal health data.
Researchers analyzed blood samples collected from participants at the beginning of the study and again one year later. These samples were used to measure sex hormone levels, allowing the team to track changes over time and assess any correlation between those changes and the subsequent development of heart disease.
Hormone Patterns and Heart Disease Risk in Men
The analysis revealed distinct patterns in male participants. Higher testosterone levels at the start of the study were associated with a lower risk of heart disease. Conversely, increases in estradiol levels over the one-year period were linked to a higher risk. This suggests that both testosterone and estradiol play a role in cardiovascular health for men with type 2 diabetes.
“We saw that there were differences in the male participants. If they had higher testosterone when they joined the study, they had a lower risk. If they had increases in estradiol levels after one year in the study, they also had a higher risk of heart disease,” explains Dr. Bennett.
Limited Correlation in Women
Interestingly, the study did not find clear connections between hormone levels and cardiovascular outcomes in female participants. This suggests that the relationship between sex hormones and heart disease risk may be more complex in women, or that other biological and clinical factors may be more influential. The researchers acknowledge that other factors beyond hormone levels likely contribute to the increased heart disease risk observed in women with diabetes.
Implications for Personalized Prevention
The findings contribute to a growing understanding of the importance of considering sex-specific factors in heart disease prevention. Dr. Bennett suggests that tracking sex hormone levels in people with diabetes could complement traditional risk assessments, such as monitoring smoking habits and cholesterol levels.
“Results from this study contribute to our understanding of how tracking sex hormones in people with diabetes could complement what we already know about traditional heart disease risk factors [like smoking and cholesterol levels],” Dr. Bennett says. “The results could help clinicians personalize heart disease prevention strategies in the future.”
Future Research Directions
The research team plans to continue investigating the interplay between hormones, diabetes, and overall health. Future studies will explore the impact of weight loss and hormone changes on bone health, as well as identify individuals at higher risk for fractures. They are also preparing new research focused on hormonal changes during perimenopause and their potential influence on cardiovascular risk, particularly in individuals with chronic conditions like diabetes.
Study Details and Funding
The study team included Teresa Gisinger, M.D., Ph.D., Jiahuan Helen He, M.H.S., Chigolum Oyeka, MBBS, M.P.H., Jianqiao Ma, ScM, Nityasree Srialluri, M.D., M.S., M.H.S., Mark Woodward, Ph.D., Erin D. Michos, M.D., M.H.S., Rita R. Kalyani, M.D., M.H.S., Jeanne M. Clark, M.D., M.P.H., Alexandra Kautzky-Willer, M.D., and Dhananjay Vaidya, MBBS, Ph.D., M.P.H.
The research received funding support from the National Institutes of Health through grants R01DK127222 and U01DK57149. Some study authors reported relevant financial disclosures, including Dr. Clark’s role as a scientific advisor to Boehringer Ingelheim and receiving writing support from Novo Nordisk, and Dr. Michos’s consulting work for various pharmaceutical companies including Amgen, AstraZeneca, and Novo Nordisk. These disclosures do not appear to be directly related to the current research findings.
As of , this research highlights the need for continued investigation into sex-specific differences in cardiovascular disease risk among individuals with type 2 diabetes, potentially paving the way for more tailored and effective prevention strategies.
