Sex-Dimorphic Association of Plasma Fatty Acids with Cardiovascular Fitness in Young and Middle-Aged General Adults: Subsamples from NHANES 2003⁻2004

Abstract

To explore the potential association of plasma fatty acids (FAs) and cardiovascular fitness level (CVFL), data of 449 subjects from 2003⁻2004 National Health and Nutrition Examination Survey (NHANES) were analyzed. Among these 249 men and 200 women, aged 20⁻50 years (33.4 ± 8.4 year, mean ± Standard Deviation), 79 low, 166 moderate and 204 high CVFL were categorized by age- and gender- specific percentile, respectively. Twenty-four fatty acids were quantified from fasting plasma. Higher levels of 2 very long-chain saturated FAs (VLSFAs): Arachidic acid (AR1, C20:0) and Docosanoic acid (DA1, C22:0) as well as 2 n-6 polyunsaturated FAs (PUFAs): Arachidonic acid (AA, C20:4n-6) and Docosatetraenoic acid (DTA, C22:4n-6) were observed in the subjects with low CVFL. Notably this association exists only in men. Estimated maximal oxygen consumption (VO_2max), the marker for cardiorespiratory fitness, was used for further regression analysis. After the adjustment of potential confounding factors (age, smoking, hypertension status, body mass index (BMI), insulin resistance status, and C-reactive protein (CRP), AA was the only FA correlated with low VO_2max in women; while in men AR1, DA1, AA, and DTA remain negatively associated with VO_2max. This preliminary analysis suggests a sex-dimorphic relationship between these plasma VLSFAs and n-6 PUFAs with CVFL and merits further investigation.

Keywords: cardiovascular disease; cardiovascular fitness; fatty acids; omega-6 polyunsaturated fatty acid; plasma; very long chain saturated fatty acid.

Figure 1

Boxplots of concentrations of 4 FAs (A: Arachidic acid, B: Docosanoic acid, C: Arachidonic Acid, and D: Docosatetraenoic Acid) with significant association with CVFL stratified by sex. CVFLs were categorized into low (white), moderate (light gray), and high (dark gray). The levels of Men and Women were shown at the left and right side, respectively. In addition to ANOVA test among 3 CVFL groups, post-hoc pairwise t-test analysis was implemented in Men. Significant t-test p values comparing Low vs. Moderate + High CVFLs in men were shown in the figures. FAs: fatty acids; CVFL: cardiovascular fitness level; ANOVA: Analysis of Variance; FDR: false discovery rate.