# Associations of Serum n–6 Polyunsaturated Fatty Acid Concentrations with Heart Rate-Corrected QT and JT Intervals in Middle-Aged Males

## TL;DR

Higher levels of certain fatty acids in the blood are linked to shorter heart repolarization times, which may reduce the risk of dangerous heart rhythms.

## Contribution

This study identifies a novel inverse association between serum n–6 PUFA concentrations and corrected QT/JT intervals in middle-aged males.

## Key findings

- Higher serum total n–6 PUFA concentrations were associated with shorter QTc and JTc intervals.
- Linoleic acid showed significant inverse associations with both QTc and JTc intervals.
- Other n–6 PUFAs like γ-linolenic acid and arachidonic acid showed no significant associations.

## Abstract

Although n–6 (ω-6) polyunsaturated fatty acids (PUFAs), particularly the main n–6 PUFA linoleic acid (LA), have been shown to be inversely related to cardiovascular disease (CVD) risk, their associations with ventricular repolarization, a marker of ventricular arrhythmias, remain unclear.

This study examined the relationships between serum n–6 PUFA concentrations and heart rate-corrected QT (QTc) and JT (JTc) intervals.

This cross-sectional study included 1420 Finnish males (aged 42–60 y) free of CVD from the Kuopio Ischaemic Heart Disease Risk Factor Study. Fasting serum n–6 PUFA concentrations were determined by gas chromatography, and electrocardiographic intervals were automatically derived. QTc and JTc intervals were calculated using Bazett’s formula. Associations were analyzed using multivariable-adjusted analysis of covariance.

Higher serum total n–6 PUFA concentrations were associated with shorter QTc and JTc intervals [QTc, extreme-quartile difference: −3.36 ms; 95% confidence interval (CI): −6.69, −0.41; P-trend = 0.02; JTc, extreme-quartile difference: −3.38 ms; 95% CI: −6.79, −0.27; P-trend = 0.03]. Similar inverse associations were found for serum LA (QTc: −4.64 ms; 95% CI: −8.00, −1.27; P-trend = 0.009; JTc: −3.99 ms; 95% CI: −7.44, −0.54; P-trend = 0.02). The other n–6 PUFAs—γ-linolenic acid, dihomo-γ-linolenic acid, and arachidonic acid—showed no significant associations.

Higher serum total n–6 PUFA and LA concentrations are associated with shorter QTc and JTc intervals, suggesting a potential protective effect on ventricular arrhythmias.