Results from the Hormones and Biomarkers Predicting Stroke study showed that high triglyceride levels, independent of other lipids and risk factors, nearly doubled risk for stroke in older women.
In this prospective study of women participating in the Women’s Health Initiative, researchers examined data from 972 postmenopausal women aged 50 to 79 years who experienced ischemic stroke and matched 744 to control participants. Researchers assessed the relationships between fasting lipids, lipoproteins and risk for ischemic stroke.
Sylvia Wassertheil-Smoller, PhD, principal investigator of WHI and HaBPS and professor at Albert Einstein College of Medicine in New York, told Endocrine Today that the idea of the study was to predict which patients are at risk for stroke, so high-risk patients can take preventive measures.
“We can’t assume that the same lipids or biomarkers that are implicated in heart disease are also implicated in stroke,” she said.
A bivariate analysis showed that women with ischemic stroke had higher levels of baseline triglycerides, intermediate-density lipoprotein, LDL particles and size, VLDL triglycerides, particles and size, and total cholesterol/HDL ratio. However, levels of HDL and HDL size were lower in women with ischemic stroke. Researchers also found that triglyceride levels were the only traditional lipid biomarkers associated with future ischemic stroke, with an unadjusted OR of 1.96 (95% CI, 1.46-2.1) for the highest vs. lowest quartile of biomarkers, according to study results.
In multivariable analysis, triglycerides (OR for highest vs. lowest quartile=1.56; 95% CI, 1.13-2.17), VLDL size (OR=1.59; 95% CI, 1.10-2.28) and intermediate-density lipoprotein particle number (OR=1.46; 95% CI, 1.04-2.04) were also associated with ischemic stroke. Women with triglyceride levels higher than the median and LDL below the median had a 32% (OR=1.32; 95% CI, 0.99-1.76) risk for developing ischemic stroke. This risk was 52% (OR=1.52; 95% CI, 1.14-2.03) in women with LDL equal to or higher than the median. Study results also showed that women with HDL lower than the median (OR=1.38; 95% CI, 1.02-1.87) and equal to or higher than the median (OR=1.34; 95% CI, 0.99-1.79) had an increased risk for stroke.
“The results were a little bit surprising,” Wassertheil-Smoller said. “Whether you have high LDL or low LDL, high triglycerides independently predict a higher stroke risk. LDL itself, which is very important in prediction of heart disease risk, was not important independently in prediction of stroke risk. It’s the triglycerides that are really important.”
Overall, Wassertheil-Smoller said although LDL levels are important predictors of heart disease risk, physicians should focus on triglyceride levels as risk factors for stroke.
“Both doctors and patients should pay attention to high triglyceride levels as an independent stroke risk factor,” she said. “Physicians should also try to counsel women in the particular lifestyle changes that will lower triglycerides.
For more information:
Berger JS. Stroke. 2012;doi:10.1161/STROKEAHA.111.641324.