Comparison between 24-hour diet recall and 24-hour urine collection for estimating sodium and potassium intakes and their ratio among Korean adults.

BACKGROUND/OBJECTIVES: This study aimed to compare 24-h diet recall (DR) and 24-h urine collection (UC) for estimating sodium and potassium intakes and their ratio (Na/K), identifying factors associated with sodium and potassium intakes and Na/K, and identifying those who were likely to underestimate sodium and potassium intakes by DR. SUBJECTS/METHODS: A total of 640 healthy adults aged 19-69 yrs completed a questionnaire survey, salty taste assessment, anthropometric measurement, two 24-h DRs, and two 24-h UCs. RESULTS: The mean sodium and potassium intakes and Na/K were 3,755 mg/d, 2,737 mg/d, and 1.45 according to DR, and 4,145 mg/d, 2,812 mg/d, and 1.57 according to UC, with percentage differences of -9.4%, -2.7%, and -7.6% in the values between the two methods, respectively. Men, older adults, smokers, obese individuals, those who consumed all the liquid in the soup, and those who were found to be salty in the salty taste assessment consumed significantly more sodium; older adults, the heavy- activity group, and obese individuals consumed more potassium; and men, younger adults, smokers, and obese individuals had a significantly higher Na/K, according to UC. Compared with UC, DR was more likely to underestimate sodium intake in older adults, smokers, obese individuals, those who consumed all the liquid in the soup, and those who consumed eating-out/delivery food at least once a day, and potassium intake in older adults, the heavy-activity group, and obese individuals. CONCLUSIONS: The mean sodium and potassium intakes and Na/K estimated by DR were comparable to those measured by UC. However, the association of sodium and potassium intakes with sociodemographic and health-related factors showed inconsistent results when estimated by DR and UC. Factors influencing the underestimation of sodium intake by DR compared to UC should be further investigated.

Development and application of the sodium index to estimate and assess sodium intake for Korean adults.

BACKGROUND/OBJECTIVES: The purpose of this study was to develop a sodium index, which is a tool for estimating and assessing sodium intake easily and quickly, to assist in the prevention of various diseases induced by excess sodium intake in Korean adults. SUBJECTS/METHODS: The 24-h urine collection and dietary behavior surveys were performed on 640 healthy people in 4 regions of South Korea, and an equation for the estimation of 24-h sodium intake was developed. The validity and reliability of the equation were verified with 200 adults. The sodium index was developed by converting the estimated sodium intake using the equation. Finally, the sodium intake status of 1,600 adults was assessed using the sodium index. RESULTS: The equation included sex, age, body mass index, eating habit and dietary behaviors related to sodium intake. In validity test of the equation, the mean bias between sodium intake using 24-h urine analysis and using the equation from the Bland-Altman plots was -1.5 mg/day. The sensitivity and specificity of the equation for estimation of sodium intake were 80.5% and 64.4%, respectively. In the reliability test of the equation, there was no significant difference between the first and second sodium intakes calculated using the equations, and Spearman's correlation coefficient between the 2 sodium intakes was 0.98. Sodium intake can be assessed as 'very moderate' for 75-100 on the sodium index, 'moderate' for 100-150, 'careful' for less than 75 or 150-200, and 'severe' for 250 or more. When sodium intake was assessed using the sodium index in 1,600 subjects, 54.3% and 24.3% of the subjects were assessed to be in the 'careful' and 'severe' categories, respectively. CONCLUSIONS: Using a simple questionnaire, the sodium index can be used to monitor and assess sodium intake status, assisting in nutrition education and counseling in a large population.

Association between the Frequency of Dining Out and the Risk of Obesity, Diabetes Mellitus, and Dyslipidemia among Korean Adults.

This study aimed to clarify the association between the frequency of dining out and the risk of obesity, diabetes mellitus, and dyslipidemia among Korean adults. This cross-sectional study surveyed 640 participants aged 20-69 years in Korea. Daily intake of energy, fat, protein, and cholesterol significantly increased as the frequency of dining out increased (P < .001). Energy derived from carbohydrates significantly decreased with the frequency of dining out, while that derived from fat and protein increased (P < .001). Among participants who rarely dined out, the fully adjusted odds ratios (ORs) for hyperglycemia were significantly lower at 0.35 (95% CI, 0.16-0.76). Decreased risk of being hyperglycemia among participants who rarely dined out suggests that the frequency of dining out can be related to diabetes risk.

Estimation model for habitual 24-hour urinary-sodium excretion using simple questionnaires from normotensive Koreans.

This study was conducted to develop an equation for estimation of 24-h urinary-sodium excretion that can serve as an alternative to 24-h dietary recall and 24-h urine collection for normotensive Korean adults. In total, data on 640 healthy Korean adults aged 19 to 69 years from 4 regions of the country were collected as a training set. In order to externally validate the equation developed from that training set, 200 subjects were recruited independently as a validation set. Due to heterogeneity by gender, we constructed a gender-specific equation for estimation of 24-h urinary-sodium excretion by using a multivariable linear regression model and assessed the performance of the developed equation in validation set. The best model consisted of age, body weight, dietary behavior ('eating salty food', 'Kimchi consumption', 'Korean soup or stew consumption', 'soy sauce or red pepper paste consumption'), and smoking status in men, and age, body weight, dietary behavior ('salt preference', 'eating salty food', 'checking sodium content for processed foods', 'nut consumption'), and smoking status in women, respectively. When this model was tested in the external validation set, the mean bias between the measured and estimated 24-h urinary-sodium excretion from Bland-Altman plots was -1.92 (95% CI: -113, 110) mmol/d for men and -1.51 (95% CI: -90.6, 87.6) mmol/d for women. The cut-points of sodium intake calculated based on the equations were ≥4,000 mg/d for men and ≥3,500 mg/d for women, with 89.8 and 76.6% sensitivity and 29.3 and 64.2% specificity, respectively. In this study, a habitual 24-hour urinary-sodium-excretion-estimation model of normotensive Korean adults based on anthropometric and lifestyle factors was developed and showed feasibility for an asymptomatic population.

Association between 24-h urinary sodium excretion and obesity in Korean adults: A multicenter study.

OBJECTIVE: The aim of this study was to explore the association between sodium intake, as assessed by 24-h urinary sodium excretion, and various obesity parameters among South Korean adults. The associations of 24-h urinary sodium excretion and sodium intake calculated from the dietary questionnaire with obesity parameters also were compared. METHODS: This multicenter, cross-sectional study analyzed data of 640 healthy adults from eight provinces in South Korea. Obesity was assessed by body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Mean 24-h urinary sodium excretion was calculated from repeatedly collected 24-h urine samples. Participants' dietary intake was assessed by 24-h dietary recall interview on the days before 24-h urine collection. RESULTS: In both sexes, the means of all anthropometric measurements tended to increase proportionally with 24-h urinary sodium excretion quartiles, regardless of adjustment. Men in the highest quartile (Q4) of 24-h urinary sodium excretion had increased odds of obesity (as assessed by BMI, WC, WHR, and WHtR) compared with men in the three lower quartiles (Q1-Q3) of 24-h urinary sodium excretion. Women in Q4 of 24-h urinary sodium excretion exhibited a higher chance of general obesity and abdominal obesity. Sodium intake calculated from the dietary questionnaire was not significantly associated with obesity in either sex. CONCLUSIONS: In Korean adults, there was a positive association between higher sodium intake as assessed by 24-h urinary sodium excretion and obesity independent of energy intake.

Daily Copper and Manganese Intakes and Their Relation to Blood Pressure in Normotensive Adults.

Although it has been proposed that trace minerals have anti-oxidative functions and are related to the control of blood pressure, only a limited number of studies directly address the issue. Thus, the purpose of our study was to assess the intake of copper and manganese, which are trace minerals, and to clarify their relation to blood pressure. In a cross-sectional study, the blood pressure of 640 normotensive adults, from 19 to 69 year-old (320 males and 320 females), was measured, and its correlation with the intake of copper and manganese was assessed using a 24-hour dietary recall method. The average value of the blood pressure was 126.4/80.2 mmHg for the males and 117.8/75.8 mmHg for the females. The daily copper intake was 1.3 mg/day for the males and 1.2 mg/day for the females. For manganese, the daily intake was 4.2 mg/day for the males and 4.1 mg/day for the females. Although the copper intake of all subjects showed a positive correlation with the systolic and diastolic blood pressures, there was no significant correlation when the potential confounding factors were adjusted. The manganese intake of the male subjects had a significantly negative correlation with the systolic blood pressure after adjusting for gender, age, body mass index, and energy intake. In conclusion, the daily manganese intake of the normotensitve adults showed a significantly negative correlation with the systolic blood pressure indicating a possibility of a positive effect of manganese on blood pressure.