Associations of the serum n-6 PUFA with exercise cardiac power in men

Low intake or tissue concentrations of the n-6 PUFA, especially to the major n-6 PUFA linoleic acid (LA), and low exercise cardiac power (ECP) are both associated with CVD risk. However, associations of the n-6 PUFA with ECP are unknown. The aim of the present study was to explore cross-sectional associations of the serum total n-6 PUFA, LA, arachidonic acid (AA), γ-linolenic acid (GLA) and dihomo-γ-linolenic acid (DGLA) concentrations with ECP and its components. In total, 1685 men aged 42–60 years from the Kuopio Ischaemic Heart Disease Risk Factor Study and free of CVD were included. ANCOVA was used to examine the mean values of ECP (maximal oxygen uptake (VO(2max))/maximal systolic blood pressure (SBP)) and its components in quartiles of the serum total and individual n-6 PUFA concentrations. After multivariable adjustments, higher serum total n-6 PUFA concentration was associated with higher ECP and VO(2max) (for ECP, the extreme-quartile difference was 0·77 ml/mmHg (95 % CI 0·38, 1·16, P (for trend) across quartiles < 0·001) and for VO(2max) 157 ml/min (95 % CI 85, 230, P (for trend) < 0·001), but not with maximal SBP. Similar associations were observed with serum LA concentration. Higher serum AA concentration was associated with higher ECP but not with VO(2max) or maximal SBP. The minor serum n-6 PUFA GLA and DGLA were associated with higher maximal SBP during exercise test and DGLA also with higher VO(2max) but neither with ECP. In conclusion, especially LA concentration was associated with higher ECP. This may provide one mechanism for the cardioprotective properties of, especially, LA.