A high level of “bad” cholesterol, or LDL-C, has long been considered a risk factor for heart attacks and strokes, because it indicates that arteries may be clogged with dangerous deposits called plaque. However, a recent small study found that men under the age of 45, and women under 50, who suffer heart attacks are far more likely to have abnormally low HDL-C, or “good” cholesterol, than elevated bad cholesterol.
In the bloodstream, HDL-C acts like a scavenger, scouring the arteries to get rid of excess fat and bad cholesterol, reduce inflammation and prevent blood clots. For that reason, healthy levels of HDL-C [defined as above 40 mg/dL in men and above 50 mg/dL in women] may be protective against heart attacks.
In this study, researchers at Harvard Medical School reviewed billing data and medical records at two large medical centers, and identified 813 younger men and women who had been treated for heart attacks over the past 16 years. The patients’ average age was 48; 38 percent were women.
“In this study of younger heart attack patients, low HDL-C was the most common abnormality, seen in approximately 90 percent of the men and 75 percent of the women,” said Bradley Collins, a fourth-year student at Harvard and the study’s lead author. “This finding suggests that low HDL-C should be considered a marker of increased heart attack risk in younger patients particularly.”
The researchers said their results show that low HDL-C levels in younger patients should prompt their physicians to recommend preventive measures, including lifestyle changes, improved control of glucose and blood pressure, and use of medications to lower LDL-C. Combining all these measures together can lead to significant improvement in overall cardiovascular health, Collins said.