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.