Two recent studies reported a strong association between elevated levels of nonfasting, but not fasting, triglycerides and increased risk of myocardial infarction, ischemic heart disease, and death and total cardiovascular events.  However, to date the evidence regarding the risk of nonfasting triglyceride levels has been less clear.

13 956 men and women aged 20 through 93 years in the Copenhagen Heart Study were enrolled in a prospective study examining baseline levels of nonfasting triglycerides, other risk factors at baseline and at follow-up examinations, and incidence of ischemic stroke. A cross-sectional study, including 9637 individuals attending the 1991-1994 examination of the prospective study, was also performed and looked at levels of nonfasting triglycerides, levels of remnant cholesterol, and prevalence of ischemic stroke.

In the prospective study, 1529/13956 patients developed ischaemic stroke, and the cumulative incidence of ischaemic stroke increased with increasing levels of nonfasting triglycerides (log-rank trend, P < .001). For those men found to have elevated nonfasting triglyceride levels of 89 to 176 mg/dL, the multivariate-adjusted hazard ratios (HRs) for ischaemic stroke was 1.3 (95% CI, 0.8-1.9; 351 events); for 177 through 265 mg/dL, 1.6 (95% CI, 1.0-2.5; 189 events); for 266 through 353 mg/dL, 1.5 (95% CI, 0.9-2.7; 73 events); for 354 through 442 mg/dL, 2.2 (95% CI, 1.1-4.2; 40 events); and for 443 mg/dL or greater, 2.5 (95% CI, 1.3-4.8; 41 events), compared to men with nonfasting levels less than 89 mg/dL (HR, 1.0; 85 events) (P < .001 for trend). The corresponding values for women were 1.3 (95% CI, 0.9-1.7; 407 events), 2.0 (95% CI, 1.3-2.9; 135 events), 1.4 (95% CI, 0.7-2.9; 26 events), 2.5 (95% CI, 1.0-6.4; 13 events), and 3.8 (95% CI, 1.3-11; 10 events), compared to women with nonfasting triglyceride levels less than 89 mg/dL (HR, 1.0; 159 events)  (P < .001 for trend). The absolute 10-year risk of ischaemic stroke ranged from 2.6% in men under 55 years with nonfasting triglyceride levels of less than 89 mg/dL to 16.7% in men aged 55 years or older with levels of 443 mg/dL or greater. Corresponding values in women were 1.9% and 12.2%. In the cross-sectional study, men with a previous ischaemic stroke, when compared to controls, had nonfasting triglyceride levels of 191 (IQR, 131-259) mg/dL vs 148 (IQR, 104-214) mg/dL (P < .01); corresponding values for women were 167 (IQR, 121-229) mg/dL vs 127 (IQR, 91-181) mg/dL (P < .05).

Nonfasting triglycerides were associated with increased risk of ischemic stroke, with the risk being three times higher in men and four times higher in women.  Although triglyceride levels are increased in those with larger BMIs and in patients with diabetes, in this trial the risk associated with increased triglycerides persisted even after adjustment for BMI.  Ideally, a trial examining whether triglyceride lowering can lower stroke rates would be the next step.

• Freiberg JJ, Tybjærg-Hansen A, Jensen JS, Nordestgaard BG. Nonfasting triglycerides and risk of ischemic stroke in the general population. JAMA 2008; 300:2142-2152.