High Triglycerides Linked to Elevated Stroke Risk

According to study results published recently in JAMA, elevated nonfasting triglyceride levels, previously associated with an increased risk for heart attack, also appear to be associated with an increased risk for ischemic stroke.

A news release announcing publication of the study results noted that recent studies have found “a strong association between elevated levels of nonfasting triglycerides, which indicate the presence of remnant lipoproteins, and increased risk of ischemic heart disease.” Based on these findings, the authors of the JAMA study speculated that nonfasting triglyceride levels might also be associated with increased risk of ischemic stroke.

They also identified a potential gap in the research in this area, as many trials have focused on studying fasting triglyceride levels. “Triglyceride levels are usually measured after an 8- to 12-hour fast, thus excluding most remnant lipoproteins; however, except for a few hours before breakfast, most individuals are in the nonfasting state most of the time. Therefore, by mainly studying fasting rather than nonfasting triglyceride levels, several previous studies may have missed an association between triglycerides and ischemic stroke,” the authors said.

To determine if increased levels of nonfasting triglycerides are associated with risk of ischemic stroke, the study authors examined data from the Copenhagen City Heart Study, a Danish population-based study initiated in 1976 with follow-up through July 2007, including 13,956 men and women age 20-93 years. Participants had their nonfasting triglyceride levels measured at the beginning of the study and at follow-up examinations.

The researchers found that 1,529 participants developed ischemic stroke and that the cumulative incidence of ischemic stroke increased with increasing levels of nonfasting triglycerides. They reported that “men with elevated nonfasting triglyceride levels of 89 through 176 mg/dL had a 30 percent higher risk for ischemic stroke; for levels 177 through 265 mg/dL, there was a 60 percent increased risk; for 266 through 353 mg/dL, a 50 percent higher risk; for 354 through 442 mg/dL, a 2.2 times elevated risk; and for 443 mg/dL or greater, the risk of ischemic stroke was 2.5 times greater compared to men with nonfasting levels less than 89 mg/dL.”

They also identified elevated risk levels in women, including a “30 percent increased risk of ischemic stroke for nonfasting triglyceride levels of 89 through 176 mg/dL; twice the risk for levels 177 through 265 mg/dL; a 40 percent higher risk for levels of 266 through 353 mg/dL; 2.5 times the risk for 354 through 442 mg/dL; and 3.8 times the risk for ischemic stroke for women with nonfasting triglyceride levels of 443 mg/dL or greater compared to women with nonfasting triglyceride levels less than 89 mg/dL.”

“By using levels of nonfasting rather than fasting triglycerides and by having more statistical power than any previous study, we detected a previously unnoticed association between linear increases in levels of nonfasting triglycerides and stepwise increases in risk of ischemic stroke,” the study authors said. “Even the most recent European and North American guidelines on stroke prevention do not recognize elevated triglyceride levels as a risk factor for stroke… Our results, together with those from two previous studies, suggest that elevated levels of nonfasting triglycerides and remnant lipoprotein cholesterol could be considered together with elevated levels of low-density lipoprotein cholesterol for prediction of cardiovascular risk. However, these findings require replication in other populations.”