Vol.:(0123456789) 1 3 European Journal of Nutrition https://doi.org/10.1007/s00394-018-1712-3 ORIGINAL CONTRIBUTION High sodium intake and sodium to potassium ratio may be linked to subsequent increase in vascular damage in adults aged 40 years and older: the Korean multi-rural communities cohort (MRCohort) Sukyoung Jung 1,2  · Mi Kyung Kim 2,3  · Jinho Shin 4  · Bo Youl Choi 2,3  · Young‑Hoon Lee 5  · Dong Hoon Shin 6  · Min‑Ho Shin 7 Received: 4 February 2018 / Accepted: 7 May 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Purpose Subclinical vascular damage is a chronic intermediate process in cardiovascular disease (CVD) and high sodium (Na) has been regarded as an adverse factor in subclinical vascular health; however, the longitudinal relationship between Na intake and subclinical vascular damage has not been studied. We aimed to evaluate the longitudinal relationship of dietary Na intake and sodium to potassium ratio (Na:K) with brachial-ankle pulse wave velocity (baPWV) and carotid intima media thickness (cIMT) in healthy adults aged 40 years and older in Korea. Methods The present study was based on participants (n = 2145 for baPWV analysis and n = 2494 for cIMT analysis) who visited three times during 2005–2013 (median 5.3 years of follow-up). We used both dietary Na intake and Na:K at baseline and its average (baseline, 2nd, 3rd), which was obtained from food frequency questionnaire (FFQ) as exposure at every visit. baPWV and cIMT levels at the third visit and change from baseline to the third visit were used to represent the level of subclinical vascular damage. Results After adjustment for potential confounders, signifcant positive relationships between dietary Na intake and both baPWV 3rd and cIMT 3rd were observed (baPWV: p for trend ≤ 0.0001 for Na average ; cIMT: p for trend = 0.013 for Na average ). Compared with Na:Ks less than 1.0, the levels of both baPWV and cIMT were higher for participants with Na:Ks over 1.0 (baPWV: p for trend = 0.0002 for Na:K average ; cIMT: p for trend = 0.005 for Na:K average ). Similar signifcant trends were shown in relationships between dietary Na intake and Na:K and changes in baPWV and cIMT levels. Conclusions In conclusion, dietary Na intake and Na:K may be positively linked to subsequent baPWV and cIMT levels in adults aged 40 years and older in Korea. Our fndings may provide informative evidence on subclinical vascular damage, particularly for populations with relatively high dietary Na intake and low dietary K intake. Keywords Sodium intake · Subclinical vascular damage · Carotid intima media thickness · Brachial-ankle pulse wave velocity · Longitudinal study Introduction Subclinical vascular damage, which is characterized by increased arterial stiffness and subclinical atheroscle- rosis, has been appreciated as a surrogate endpoint of cardiovascular disease (CVD) development [1]. In general, it is likely to precede the onset of CVD by decades [2–4] and then be revealed as severe events [5]. Accordingly, early detection of subclinical vascular damage and then pri- mary prevention of CVD are important in terms of public health [4, 5]. Various biomarkers to measure the presence of CVD have been proposed including circulating, genetic, and imaging biomarkers; vascular imaging is a non-invasive biomarker for subclinical vascular damage [2]. In particular, brachial-ankle pulse wave velocity (baPWV) [6] and carotid intima media thickness (cIMT) [7] have been suggested as signifcant indicators of arterial stifness and subclinical ath- erosclerosis, respectively [8, 9]. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00394-018-1712-3) contains supplementary material, which is available to authorized users. * Mi Kyung Kim kmkkim@hanyang.ac.kr Extended author information available on the last page of the article