Could the expectation that men need to be “manly” end up damaging their hearts? In a concerning discovery about men’s health, researchers have found that men who strongly conform to traditional masculine behaviors are less likely to receive important medical diagnoses and treatments for heart disease risk factors.

Researchers from the University of Chicago say this pattern begins as early as adolescence and continues into adulthood, potentially putting these men at greater risk for future cardiovascular problems. Their study, published in JAMA Network Open, followed over 4,000 American men from their teenage years through early adulthood, examining how their degree of “male gender expressivity” (MGE) – essentially, how closely they conform to typical male behavioral patterns – affected their likelihood of being diagnosed with and treated for conditions like high blood pressure and diabetes.

The research team found that men who displayed higher levels of masculine behavior were significantly less likely to receive diagnoses for these conditions, even when medical tests showed they had them. For instance, among men with elevated blood pressure, those with higher MGE scores were 4% less likely to receive a hypertension diagnosis. The effect was even more dramatic for diabetes, where men with higher adolescent MGE scores were 15% less likely to receive a diagnosis when their blood sugar levels indicated they had the condition.

“When we talk about gender expression, we’re not looking at anything physiologic that could be affected by the Y chromosome,” explains Nathaniel Glasser, MD, a general internist and pediatrician at UChicago Medicine and lead author on the paper, in a media release. “We’re purely focused on self-reported behaviors, preferences and beliefs, and how closely these reported behaviors and attitudes resemble those of same-gendered peers.”