Jin-Wook Chung

High Sodium Intake in Women with Metabolic Syndrome

Background and Objectives Metabolic syndrome and high sodium intake are associated with frequent cardiovascular events. Few studies have estimated sodium intake in subjects with metabolic syndrome by 24-hour urine sodium excretion. We evaluated sodium intake in individuals with metabolic syndrome. Subjects and Methods Participants were recruited by random selection and through advertisement. Twenty four-hour urine collection, ambulatory blood pressure measurements, and blood test were performed. Sodium intake was estimated by 24-hour urine sodium excretion. Participants receiving antihypertensive medications were excluded from analysis. Results Among the 463 participants recruited, subjects with metabolic syndrome had higher levels of 24-hour urine sodium excretion than subjects without metabolic syndrome (p=0.0001). There was a significant relationship between the number of metabolic syndrome factors and 24-hour urine sodium excretion (p=0.001). The proportion of subjects with metabolic syndrome was increased across the tertile groups of 24-hour urine sodium excretion (p<0.0001). The association of high sodium intake and metabolic syndrome was significant only among women. Among the factors related to metabolic syndrome, body mass index had an independent association with 24-hour urine sodium excretion (p<0.0001). Conclusion Women with metabolic syndrome exhibited significantly higher sodium intake, suggesting that dietary education to reduce sodium consumption should be emphasized for women with metabolic syndrome.

Subclinical Renal Insufficiency Range of Estimated Glomerular Filtration Rate and Microalbuminuria Are Independently Associated with Increased Arterial Stiffness in Never Treated Hypertensives

Background and Objectives Microalbuminuria (MAU) and decreased estimated glomerular filtration rate (eGFR) are risk factors for cardiovascular disease (CVD) in patients with hypertension. However, in hypertensive patients with normal or minimally reduced eGFR (≥60 mL/min/1.73 m2) and with normo- or MAU, the value of combined estimation of eGFR and urine microalbumin for the risk assessment has not been widely reported. We evaluated the association between arterial stiffness and the combined estimation of eGFR and urine microalbumin. Subjects and Methods Subjects with never treated hypertension and normal or minimally reduced eGFR were evaluated (n=491, 50.1±10.4 years). eGFR was calculated by the simplified Modification of Diet in Renal Disease formula. Urinary albumin-to-creatinine ratio (UACR) was assessed with spot urine. Arterial stiffness was assessed with heart-femoral pulse wave velocity (hfPWV). All subjects were divided into four groups; group 1, eGFR ≥90 mL/min/1.73 m2 (normal eGFR) and normo-albuminuria (NAU); group 2, eGFR 89.9-60 mL/min/1.73 m2 (minimally reduced eGFR) and NAU; group 3, normal eGFR and MAU; group 4, minimally reduced eGFR and MAU. Results Group 1 had the lowest hfPWV (964.6±145.4; group 2, 1013.5±168.9; group 3, 1058.2±238.0; group 4, 1065.8±162.9 cm/sec). Analysis adjusting age, sex, body mass index, heart rate and mean arterial pressure showed significantly lower hfPWV of group 1 compared to group 2 (p=0.032) and 3 (p=0.007). Multiple regression analysis showed a significant association of hfPWV with logUACR {beta=0.096, 95% confidence interval (CI) 8.974-60.610, p=0.008} and eGFR (beta=-0.069, 95% CI -1.194 - -0.005, p=0.048). Conclusion Minimally reduced eGFR or MAU is independently associated with increased arterial stiffness, indicating greater CVD risk.

Glucose-Insulin-Potassium Solution Protects Ventricular Myocytes of Neonatal Rat in an In Vitro Coverslip Ischemia/Reperfusion Model

Background and Objectives The benefit of high glucose-insulin-potassium (GIK) solution in clinical applications is controversial. We established a neonatal rat ventricular myocyte (NRVM) in vitro coverslip ischemia/reperfusion (I/R) model and investigated the effects of GIK solution on suppressing reactive oxygen species (ROS) and upregulating O-GlcNacylation, which protects cells from ischemic injury. Materials and Methods NRVMs were isolated from postnatal day 3-4 Sprague-Dawley rat pups and grown in Dulbeccos modified Eagles medium containing high glucose (4.5 g/L), fetal bovine serum, and penicillin/streptomycin. The effects of the GIK solution on ROS production, apoptosis, and expression of O-GlcNAc and O-GlcNAc transferase (OGT) were investigated in the coverslip I/R model. Results Covering the 24-well culture plates for 3 hr with 12 mm diameter coverslips resulted in the appropriate ischemic shock. Glucose and insulin synergistically reduced ROS production, protected NRVM dose-dependently from apoptosis, and altered O-GlcNAc and OGT expression. Conclusion The high GIK solution protected NRVM from I/R injury in vitro by reducing ROS and altering O-GlcNacylation.

Elevation of heart-femoral pulse wave velocity by short-term low sodium diet followed by high sodium diet in hypertensive patients with sodium sensitivity.

BACKGROUND/OBJECTIVES We compared changes in heart-femoral pulse wave velocity (hfPWV) in response to low sodium and high sodium diet between individuals with sodium sensitivity (SS) and resistance (SR) to evaluate the influence of sodium intake on arterial stiffness. SUBJECTS/METHODS Thirty-one hypertensive and 70 normotensive individuals were given 7 days of low sodium dietary approach to stop hypertension (DASH) diet (LSD, 100 mmol NaCl/day) followed by 7 days of high sodium DASH diet (HSD, 300 mmol NaCl/day) during 2 weeks of hospitalization. The hfPWV was measured and compared after the LSD and HSD. RESULTS The hfPWV was significantly elevated from LSD to HSD in individuals with SS (P = 0.001) independently of changes in mean arterial pressure (P = 0.037). Conversely, there was no significant elevation of hfPWV from LSD to HSD in individuals with SR. The percent change in hfPWV from the LSD to the HSD in individuals with SS was higher than that in individuals with SR. Subgroup analysis revealed that individuals with both SS and hypertension showed significant elevation of hfPWV from LSD to HSD upon adjusted analysis using changes of the means arterial pressure (P = 0.040). However, there was no significant elevation of hfPWV in individuals with SS and normotension. CONCLUSION High sodium intake elevated hfPWV in hypertensive individuals with SS, suggesting that high sodium intake increases aortic stiffness, and may contribute to enhanced cardiovascular risk in hypertensive individuals with SS.

The effects of fencing specific training on physical fitness in elite fencers

[Purpose] The purpose of this study was to investigate the effects of 3 weeks of fencing specific training on physical fitness in elite fencers. [Methods] Forty eight elite fencers participated in this program (Male= 24, Female= 24). Training program consists of dynamic stretching, step and agility training, and it was conducted with the general fencing practice during 3 weeks. Body composition and physical fitness (muscle strength/power, agility, anaerobic power and flexibility) were measured before and after training. Data were analyzed using IBM SPSS Statistics ver. 23.0 (IBM Co., Armonk, NY, USA). Paired t-test (pre vs. post) was used for comparison between groups. [Results] Muscle mass and body fat(%) were significantly changed after training in male group. Agility was significantly improved in change-step jump and reaction time after training both in male and female group. In Anaerobic power, peak power (relative power, absolute power) was significantly increased after training in female group. Flexibility was also significantly improved after training in left ankle ROM of female group. [Conclusion] Application of fencing specific training program focused on fencing movement seems to be effective on agility in both groups, muscle mass and body fat(%) in male group, and anaerobic power and flexibility in female group.

Effects of Long Term Periodization Training in Korean Male Elite Golfers

[Purpose] The purpose of this study was to develop the periodization training for elite golfers and investigate the effect of the program for elite golfers. [Methods] Eighteen male participants were divided into training group (TG: n=8) and control group (CG: N=10). The periodization consists of flexibility and strength training and conducted for 20weeks. To examine the effects of training program, physical fitness (isometric muscle strength, flexibility, isotonic maximum strength, muscle power, muscle endurance, isokinetic trunk muscle strength) and driver performance (launch angle, club head speed, ball speed, and carry distance of the driver shot) were measured after 20 weeks of training. [Results] Back muscle strength, shoulder flexibility, isotonic maximum strength, muscle power, club-head speed, ball speed, carry distance showed significant interaction. [Conclusion] These results suggest that periodization training for 20-weeks turned out to be an effective in improving physical fitness and driver performance in Korean elite golfers. Therefore, not only during the preparation period but also the competition period, scientific physical training should be maintained in order to improve the physical function and driver performance.