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BACKGROUND The effect of sodium intake on the cardiovascular system remains controversial. The purpose of this study is to investigate the relation between sodium intake and cardiovascular structure and function in the nonhypertensive population. METHODS We performed a cross-sectional analysis in 1,586 nonhypertensive subjects who participated in the Korean Genome Epidemiology Study (2007-2008). Sodium intake was assessed by estimating the 24-hour urinary sodium excretion from a spot urine sample. Changes in cardiovascular structure and function were assessed by using tissue Doppler echocardiography, the carotid intima-media thickness (CIMT), and the brachial-ankle pulse wave velocity (baPWV). RESULTS Systolic and diastolic blood pressures increased with increasing tertiles of estimated 24-hour urinary sodium excretion. In multivariate analyses adjusting for covariates, there were stepwise decreases in the baPWV (P = 0.003) and CIMT (P = 0.001) values as the estimated 24-hour urinary sodium excretion increased, whereas no significant differences in left ventricular (LV) structural and functional parameters were observed across the tertiles of estimated 24-hour urinary sodium excretion. Multiple linear regression analyses revealed that the estimated 24-hour urinary sodium excretion was independently and inversely associated with baPWV (P < 0.001) and CIMT (P = 0.001), but not with LV parameters. CONCLUSIONS In the nonhypertensive population, urinary sodium excretion was inversely related to baPWV and CIMT. However, there were no associations between urinary sodium excretion and LV structure or function. [ABSTRACT FROM AUTHOR]

BackgroundPrehypertension is associated with increased cardiovascular morbidity and mortality. However, there are few population-based studies on the changes of cardiovascular structure and function that characterize prehypertension. The aim of this study was to assess whether prehypertension is associated with abnormalities of cardiovascular structure and function in the general Korean population.MethodsWe analyzed the cross-sectional relationships between prehypertension and cardiovascular structure and function in a sample from the Korean Genome Epidemiology Study. A total of 1,671 individuals (54.5% women; mean age: 53 ± 6 years) without hypertension and diabetes mellitus were enrolled. Cardiovascular structure and function were assessed by conventional echocardiography, tissue Doppler imaging (TDI), carotid ultrasonography, and pulse wave velocity (PWV).ResultsThe left ventricular (LV) mass index was significantly higher in subjects with prehypertension than in those with normotension (41 ± 8 g/m2.7 vs. 38 ± 7 g/m2.7, P < 0.001). LV diastolic parameters, such as the E/A ratio, TDI Ea velocity, and E/Ea ratio, were also impaired in subjects with prehypertension (all P < 0.001). Compared with normotension, prehypertension was characterized by a significantly higher common carotid artery intima-media thickness and a higher brachial-ankle PWV (all P < 0.001). These abnormalities of cardiovascular structure and function remained significant after adjustment for covariates.ConclusionsIn this population-based cohort, we found that subtle alterations in cardiovascular structure and function were already present at the prehypertensive stage. Whether such subtle alterations convey an increased risk of cardiovascular events and whether the changes are reversible with treatment warrant further study.American Journal of Hypertension (2011). doi:10.1038/ajh.2010.213 [ABSTRACT FROM AUTHOR]

Background Obesity and low muscle mass may coexist as age-related changes in body composition. We aimed to investigate the effect of visceral adiposity and skeletal muscle mass on left ventricular (LV) structure and function in the general population. Methods A total of 1941 participants without known cardiovascular disease were enrolled from the Korean Genome and Epidemiology Study. Visceral fat area (VFA) was assessed by computed tomography. Appendicular skeletal muscle mass (ASM) was estimated by dual-energy X-ray absorptiometry and was used as a percentage of body weight (ASM/Wt). LV structure and function were assessed by tissue Doppler imaging (TDI) echocardiography. Results Across VFA tertiles, ASM increased, but ASM/Wt decreased (all P < 0.001). In multivariate models adjusted for conventional cardiovascular risk factors, LV mass index and LV diastolic parameters, such as left atrial dimension, TDI Ea velocity, and E/Ea ratio, were significantly impaired as VFA increased. On the other hand, an increase in ASM/Wt was associated with a decrease in LV mass index and improvement of LV diastolic parameters. With regard to LV mass index and TDI Ea velocity, VFA and ASM/Wt showed synergistic effects (all P interaction < 0.05). When both VFA and ASM/Wt were simultaneously included in the same model, both remained independent predictors of LV mass index and TDI Ea velocity. Conclusions More visceral fat and less muscle mass are independently and synergistically associated with an increase in LV mass index and impairment of LV diastolic parameters. Further research is needed to explore the complex mechanisms underlying these associations. [ABSTRACT FROM AUTHOR]