they tracked 50 “biomarkers” tied to cardiovascular health, including low-density lipoprotein (LDL) cholesterol (“bad” cholesterol) and hemoglobin A1C (a measure of blood sugar levels).
Both of those factors had weaker associations with heart disease onset in women younger than 55 than lipoprotein insulin resistance (LPIR,) a newer metric for insulin resistance.
Insulin resistance occurs when cells in muscles, fat and the liver don’t respond well to insulin and can’t use glucose. It’s typically a precursor to diabetes.
Whereas LDL cholesterol was only associated with a 40% increase in the risk of heart disease onset in women under 55, an unhealthy LPIR measurement was tied to a 600% increase. And overall, the study found that women under 55 with type 2 diabetes had a tenfold greater risk of having heart disease over the next two decades.
So, “in otherwise healthy women, insulin resistance, type 2 diabetes, and its sister diagnosis, metabolic syndrome, were major contributors to premature coronary events,” Mora explained. “Women under 55 who have obesity had about a fourfold increased risk for coronary events, as did women in that age group who smoked or had hypertension. Physical inactivity and family history are all part of the picture as well.”
One other expert said such research is long overdue.
“For many years, cardiovascular research was done only in men and the older patient population,” noted Dr. Roshini Malaney, a cardiologist at Staten Island University Hospital in New York City.
But waiting until later in life to address health issues is suboptimal, she said, so a focus on younger women is welcome.
By the time a woman reaches her senior years, “there is no time to intervene prior to having a cardiac event,” Malaney said.
The new data “helps primary care doctors and cardiologists hone in on other identifying factors in order to prevent heart disease,” she believes. “While we can’t control our genes, this study gives us more data to promote lifestyle changes early on and have numbers to back us up.”
Mora agreed.
“Diabetes is mostly preventable, but it’s a systemwide problem, and we urgently need further research into new strategies to address it,” she said. “These could be innovative lifestyle-based strategies, like community efforts, greater public health efforts, ways to medically target metabolic pathways, or new surgical approaches.”
“We need new strategies to improve outcomes in these younger individuals and address the risk of diabetes because we’re only seeing the beginning of this epidemic now.”
The report was published online Jan. 20 in the journal JAMA Cardiology.
More information
For more on heart disease in women, head to the U.S. Centers for Disease Control and Prevention.