Association of serum fatty acid and estimated desaturase activity with hypertension in middle-aged and elderly Chinese population

Abstract

We aimed to investigate the cross-sectional associations of serum fatty acid (FA) and related Δ-desaturase with hypertension among 2,447 community-dwellers aged 35-79 years living in Zhejiang Province, China. Individual FA was determined in serum, Δ(5)-desaturase (D5D) and Δ(6)-desaturase (D6D) activities were indirectly estimated by FA product/precursor ratios. Participants in the highest quartile of D5D component scores (20:4n-6, 20:5n-3, 22:6n-3 and D5D) have significantly lower odds of hypertension compared with individuals in the lowest (multivariate-adjusted odds ratio (OR) = 0.68, 95% CI: 0.46-0.98). When further stratified by gender, high D5D component scores were significantly associated with lower odds of hypertension in women (OR = 0.53, 95% CI: 0.35-0.80), but not in men (OR = 0.78, 95% CI: 0.52-1.18). Multivariate-adjusted prevalent OR for an interquartile increment of individual FA and estimated desaturase was 1.27 (95% CI: 1.08-1.50) for 16:0, 1.15 (95% CI: 1.01-1.30) for 16:1n-7, 0.89 (95% CI: 0.80-0.99) for 22:6n-3, 1.32 (95% CI: 1.01-1.72) for D6D (18:3n-6/18:2n-6), and 0.74 (95% CI: 0.56, 0.98) for D5D (20:4n-6/20:3n-6). Present findings suggested that high serum 22:6n-3 and D5D as well as low 16:0, 16:1n-7 and D6D were associated with a low prevalence of hypertension in this Chinese population.

Figure 1. The prevalence of hypertension by tertiles of serum SFA, MUFA and MUFA in the middle-aged and elderly Chinese population.

The prevalence of hypertension by tertiles of serum compositions of SFA, MUFA and MUFA was shown in figure (a–c), respectively. The prevalence of hypertension with 95% confidence interval (CI) and corresponding P for trend across increasing tertiles were estimated by non-adjusted logistic regression model, age, gender and BMI-adjusted model (all P for trend < 0.01) and multivariate-adjusted model (all P for trend < 0.01), respectively. The prevalence across each tertile was separately represented by black circles, squares and triangles, and error bars denoted corresponding 95% CI.

Figure 2. Rotated loading plot of individual FA and estimated desaturase index by principal component analyses.

Varimax rotation loading of individual FA and estimated desaturase index revealed 3 major FA-components: Comp 1, Comp 2 and Comp 3. Comp 1 (D6D component) comprised higher positive loadings from serum 16:0, 16:1n–7, 18:3n–6, 20:3n–6, 22:5n–3, SCD-1 and D6D as well as a negative loading from 18:2n–6. Comp 2 (SCD-2 component) mainly comprised higher positive loadings from SCD-2 and 18:1n–9 as well as negative loadings from 18:3n–3 and 18:0. Comp 3 (D5D component) mainly comprised higher loadings from serum 20:5n–3, 20:4n–6, 22:6n–3 and D5D.

Figure 3. Associations of individual fatty acid and estimated desaturase index with prevalent hypertension in the middle-aged and elderly Chinese population.

The multivariate-adjusted odds ratio (OR) with 95% confidence interval (CI) for prevalent hypertension in relation to an interquartile increment of individual FA and estimated desaturase index were estimated by logistic regression models adjusted for age, gender, BMI, lifestyle and clinical factors. Prevalent OR was represented by black circles, and error bars denoted corresponding 95% CI.