Free fatty acid levels not associated with sudden cardiac death

31 January 2012

MedWire News: Plasma levels of non-esterified fatty acids (NEFA) are not associated with risk for sudden cardiac death (SCD) in older adults, US researchers report.

Writing in Circulation Arrhythmia and Electrophysiology, Luc Djoussé (Brigham and Women’s Hospital, Boston, Massachusetts) and colleagues explain that previous studies have shown positive associations between plasma NEFA and coronary heart disease (CHD) risk factors.

“CHD accounts for a large proportion of SCD cases,” they say, adding: “Limited and inconsistent data are available on the relation between NEFA and SCD.”

The researchers therefore studied data on 4657 older men and women (mean age 74.9 years) who participated in the 1992–2006 Cardiovascular Health Study. They evaluated the association between plasma NEFA levels and SCD.

SCD was defined as a sudden pulseless condition, presumed due to cardiac arrhythmia, that occurred out of the hospital or in the emergency room in a previously stable individual.

During an average follow up of 10 years, 221 cases of SCD occurred.

Crude incidence rates of SCD were 5.15, 5.45, 4.56, and 3.78 cases per 1000 person–years from the lowest to the highest quartile of plasma NEFA.

Multivariate analysis revealed no significant association between NEFA and SCD after adjustment for age, gender, race, and clinic site. Additional control for smoking, alcohol consumption, self-reported health status, prevalent CHD, and heart failure did not alter these findings.

In secondary analyses restricted to the first 5 years of follow up, no significant association was observed between NEFA and SCD.

The authors note that NEFA concentrations were measured late in life, and, therefore, changes in plasma NEFA over time could not be accounted for.

“Further investigation in other cohorts and experimental models is needed to clarify the role of NEFA in the development of SCD,” they conclude.

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Circ Arrhythm Electrophysiol 2012; Advance online publication