Serum Nonesterified Fatty Acids and Incident Stroke: The CHS

Background

Significant associations between total nonesterified fatty acid (NEFA) concentrations and incident stroke have been reported in some prospective cohort studies. We evaluated the associations between incident stroke and serum concentrations of nonesterified saturated, monounsaturated, polyunsaturated, and trans fatty acids.

Methods and Results

CHS (Cardiovascular Health Study) participants (N=2028) who were free of stroke at baseline (1996–1997) and had an archived fasting serum sample were included in this study. A total of 35 NEFAs were quantified using gas chromatography. Cox proportional hazards regression models were used to evaluate associations of 5 subclasses (nonesterified saturated, monounsaturated, omega (n)‐6 polyunsaturated, n‐3 polyunsaturated, and trans fatty acids) of NEFAs and individual NEFAs with incident stroke. Sensitivity analysis was conducted by excluding cases with hemorrhagic stroke (n=45). A total of 338 cases of incident stroke occurred during the median 10.5‐year follow‐up period. Total n‐3 (hazard ratio [HR], 0.77 [95% CI, 0.61–0.97]) and n‐6 (HR, 1.32 [95% CI, 1.01–1.73]) subclasses of NEFA were negatively and positively associated with incident stroke, respectively. Among individual NEFAs, dihomo‐γ‐linolenic acid (20:3n‐6) was associated with higher risk (HR, 1.29 [95% CI, 1.02–1.63]), whereas cis‐7‐hexadecenoic acid (16:1n‐9c) and arachidonic acid (20:4n‐6) were associated with a lower risk (HR, 0.67 [95% CI, 0.47–0.97]; HR, 0.81 [95% CI. 0.65–1.00], respectively) of incident stroke per standard deviation increment. After the exclusion of cases with hemorrhagic stroke, these associations did not remain significant.

Conclusions

A total of 2 NEFA subclasses and 3 individual NEFAs were associated with incident stroke. Of these, the NEFA n‐3 subclass and dihomo‐γ‐linolenic acid are diet derived and may be potential biomarkers for total stroke risk.

Associations of Serum Nonesterified Fatty Acids With Coronary Heart Disease Mortality and Nonfatal Myocardial Infarction: The CHS (Cardiovascular Health Study) Cohort

Background

Significant associations have been reported between serum total nonesterified fatty acid (NEFA) concentrations and coronary heart disease (CHD) mortality and incident nonfatal myocardial infarction (MI) in some prospective cohort studies. Little is known about whether individual or subclasses (saturated, polyunsaturated [n‐6 and n‐3], and trans fatty acids) of serum NEFAs relate to CHD mortality and nonfatal MI.

Methods and Results

CHS (Cardiovascular Health Study) participants (N=1681) who had no history of MI, angina, or revascularization or were free of MI at baseline (1996–1997) were included. NEFAs were quantified using gas chromatography. Cox regression analysis was used to evaluate associations of 5 subclasses and individual NEFAs with CHD composite (CHD mortality and nonfatal MI), CHD mortality, and incident nonfatal MI. During a median follow‐up of 11.7 years, 266 cases of CHD death and 271 cases of nonfatal MI occurred. In the fully adjusted model, no significant associations were identified between individual NEFA and CHD composite. Exploratory analyses indicated that lauric acid (12:0) was negatively associated (hazard ratio [HR], 0.76; 95% CI, 0.59–0.98; P=0.0328) and dihomo‐γ‐linolenic acid (20:3n‐6) was positively associated with CHD mortality (HR, 1.34; 95% CI, 1.02–1.76; P=0.0351). Elaidic acid (18:1n‐7t) was positively associated with incident nonfatal MI (HR, 1.46; 95% CI, 1.01–2.12; P=0.0445). No significant associations were observed for NEFA subclass and any outcomes.

Conclusions

In CHS participants, 2 NEFAs, dihomo‐γ‐linolenic and elaidic acids, were positively associated with CHD mortality and nonfatal MI, respectively, suggesting potential susceptibility biomarkers for risks of CHD mortality and nonfatal MI.