Casual Urine Research Articles

Iodine Status and Consumption of Key Iodine Sources in the U.S. Population with Special Attention to Reproductive Age Women.

We estimated iodine status (median urinary iodine concentration (mUIC (µg/L))) for the US population (6 years and over; n = 4613) and women of reproductive age (WRA) (15–44 years; n = 901). We estimated mean intake of key iodine sources by race and Hispanic origin. We present the first national estimates of mUIC for non-Hispanic Asian persons and examine the intake of soy products, a potential source of goitrogens. One-third of National Health and Nutrition Examination Survey (NHANES) participants in 2011–2014 provided casual urine samples; UIC was measured in these samples. We assessed dietary intake with one 24-h recall and created food groups using the USDA’s food/beverage coding scheme. For WRA, mUIC was 110 µg/L. For both non-Hispanic white (106 µg/L) and non-Hispanic Asian (81 µg/L) WRA mUIC was significantly lower than mUIC among Hispanic WRA (133 µg/L). Non-Hispanic black WRA had a mUIC of 124 µg/L. Dairy consumption was significantly higher among non-Hispanic white (162 g) compared to non-Hispanic black WRA (113 g). Soy consumption was also higher among non-Hispanic Asian WRA (18 g compared to non-Hispanic black WRA (1 g). Differences in the consumption pattern of key sources of iodine and goitrogens may put subgroups of individuals at risk of mild iodine deficiency. Continued monitoring of iodine status and variations in consumption patterns is needed.

Abstract 008: Casual and 24-hour Urinary Sodium-to-potassium Ratio and Intakes of Sodium and Potassium Among Men and Women From Multi-ethnic General Populations: The Intersalt Study

Background: Urinary sodium-to-potassium ratio may be more strongly related to blood pressure and cardiovascular disease than either urinary sodium or potassium alone. The casual urine sodium-to-potassium ratio is readily obtained, can provide prompt on-site feedback, and with repeated measurements may provide useful individual estimates of 24-hour urinary sodium-to-potassium ratio. The World Health Organization (WHO) has recently published guidelines for sodium and potassium intakes, but no generally accepted guideline prevails for favorable sodium-to-potassium ratio. Objective: Our primary aim was to compare the level of urinary Na/K ratio with the current recommended levels of Na and K intakes suggested in WHO guidelines. Methods: INTERSALT is an international study on associations of multiple urinary variables, with blood pressure (BP), based on standardized data on 24-hour and casual urinary electrolyte excretion in 10,065 individuals from 52 population samples in 32 countries. The associations between casual urinary sodium-to-potassium ratio and 24-hour urinary sodium and potassium excretion of individuals were assessed by correlation and stratification analysis. Results: Mean 24-hour sodium and potassium excretions were 156.0 mmol/24h and 55.2 mmol/24h; mean 24-hour urinary sodium-to-potassium ratio was 3.24. Pearson-r correlation coefficients of casual urinary sodium-to-potassium ratio with 24-hour sodium and potassium excretions were 0.42 and -0.34, respectively, and these were 0.57 and -0.48 for 24-hour urinary sodium-to-potassium ratio. The proportion of participants with estimated sodium chloride intake below the WHO recommended guideline of 85 mmol/day was 61.1% for those with casual urinary sodium-to-potassium ratio less than 1, and 96.3% where the 24-hour ratio was less than 1. For potassium, the proportion of people with potassium intake more than the WHO recommended guideline of 90 mmol/day was 21.3% where the casual urinary sodium-to-potassium ratio was less than 1 and 28.6% for the 24-hour urinary sodium-to-potassium ratio. Conclusions: Casual urinary sodium-to-potassium ratio less than 1 may be a useful indicator of adherence to the World Health Organization recommended levels of sodium intake, and to a lesser extent potassium intake in diverse different populations.

Prevalence of goiter and associated factors among pregnant mothers residing in a district with poor socioeconomic status in Rajasthan state, India.

Background:National survey documented that none of the Indian state is free from iodine deficiency (ID). Hence, the study was conducted with the objective to assess prevalence of goiter and associated factors among pregnant mothers (PMs) in a backward district of Indian state, Rajasthan.Methods:A cross-sectional survey was conducted during January to March 2015. Multistage random sampling was utilized to select PMs. A total of 1,183 villages were enlisted with their respective population, and 30 villages were selected using population proportionate to size sampling. Subjects were included from a cluster till the numbers reached to 17. PMs were clinically examined for goiter by palpation method. Casual urine (n = 226) and salt samples (n = 220), were collected from a subgroup of subjects, and iodine concentrations were analyzed by using wet digestion and iodometric titration methods, respectively.Results:The prevalence of goiter was found to be 14.2% (95% CI; 11.2–17.2). Goiter prevalence did not significantly differ with respect to trimesters of pregnancy (P = 0.09), iodine content in salt (P = 0.8), and urinary iodine concentrations (UIC, P = 0.69). The median UIC was 174 μg/L (IQR; 116–300 μg/L), which indicated adequate iodine intake. There was higher prevalence of goiter in PMs consuming salt with inadequate iodine than those with adequate, which was not significant (P = 0.8). Goiter prevalence was also insignificantly higher among PMs with UIC <150 μg/L than those with UIC ≥150 μg/L (P = 0.69).Conclusion:The study population is in transition phase from mild ID (goiter prevalence 14.1%) to sufficiency (median UIC 174 μg/L).

Socioeconomic Status Associated With Urinary Sodium and Potassium Excretion in Japan: NIPPON DATA2010.

BackgroundAlthough socioeconomic status (SES) may affect food and nutrient intakes, few studies have reported on sodium (Na) and potassium (K) intakes among individuals with various SESs in Japan. We investigated associations of SES with Na and K intake levels using urinary specimens in a representative Japanese population.MethodsThis was a cross-sectional study of 2,560 men and women (the NIPPON DATA2010 cohort) who participated in the National Health and Nutrition Survey Japan in 2010. Casual urine was used to calculate estimated excretion in 24-hour urinary Na (E24hr-Na) and K (E24hr-K). The urinary sodium-to-potassium (Na/K) ratio was calculated from casual urinary electrolyte values. An analysis of covariance was performed to investigate associations of aspects of SES, including equivalent household expenditure (EHE), educational attainment, and job category, with E24hr-Na, E24hr-K, and the Na/K ratio for men and women separately. A stratified analysis was performed on educational attainment and the job category for younger (<65 years) and older (≥65 years) participants.ResultsIn men and women, average E24hr-Na was 176.2 mmol/day and 172.3, average E24hr-K was 42.5 and 41.3, and the average Na/K ratio was 3.61 and 3.68, respectively. Lower EHE was associated with a higher Na/K ratio in women and lower E24hr-K in men and women. A shorter education was associated with a higher Na/K ratio in women and younger men, and lower E24hr-K in older men and women.ConclusionLower EHE and a shorter education were associated with a lower K intake and higher Na/K ratio estimated from casual urine specimens in Japanese men and women.

Association of Salt Intake Estimated from Casual Urine Samples and Blood Pressure in Ningen Dock Examinees

Association of Salt Intake Estimated from Casual Urine Samples and Blood Pressure in Ningen Dock Examinees

Effect of amlodipine, efonidipine, and trichlormethiazide on home blood pressure and upper-normal microalbuminuria assessed by casual spot urine test in essential hypertensive patients

ABSTRACTThe aim of this study was to assess the effects of irbesartan alone and combined with amlodipine, efonidipine, or trichlormethiazide on blood pressure (BP) and urinary albumin (UA) excretion in hypertensive patients with microalbuminuria (30≤UA/creatinine (Cr) ratio [UACR] <300 mg/g Cr) and upper-normal microalbuminuria (10≤UACR<30 mg/g Cr). This randomized controlled trial enrolled 175 newly diagnosed and untreated hypertensive patients (home systolic blood pressure [SBP]≥135 mmHg; 10≤UACR<300 mg/g Cr of casual spot urine at the first visit to clinic). All patients were treated with irbesartan (week 0). Patients who failed to achieve home SBP ≤125 mmHg on 8-week irbesartan monotherapy (nonresponders, n = 115) were randomized into three additional drug treatment groups: trichlormethiazide (n = 42), efonidipine (n = 39), or amlodipine (n = 34). Irbesartan monotherapy decreased home SBP and first morning urine samples (morning UACR) for 8 weeks (p < 0.0001). At 8 weeks after randomization, all three additional drugs decreased home SBP (p < 0.0002) and trichlormethiazide significantly decreased morning UACR (p = 0.03). Amlodipine decreased morning UACR in patients with microalbuminuria based on casual spot urine samples (p = 0.048). However, multivariate analysis showed that only higher home SBP and UACR at week 8, but not any additional treatments, were significantly associated with UACR reduction between week 8 and week 16. In conclusion, crucial points of the effects of combination therapy on UACR were basal UACR and SBP levels. The effect of trichlormethiazide or amlodipine treatment in combination with irbesartan treatment on microalbuminuria needs to be reexamined based on a larger sample size after considering basal UACR and SBP levels.

Abstract P333: Repeated Measurementof Casual Urine Na/K Ratio May Provide Useful Information to Screen Early Stage Chronic Kidney Disease Patients With Higher Sodium and Lower Potassium Intake

Objective: Lowering sodium-to-potassium ratio has been reported to benefit people for hypertension prevention and control in epidemiological studies. Four to seven repeated measurements of casual urine sodium-to-potassium ratio is known to provide high correlation and good agreement quality with less bias to estimate 7-day 24-hour urinary Na/K ratio in normotensive and hypertensive individuals. However, little is known about urinary Na/K ratio in patients with chronic kidney disease (CKD). The aim of this study was to clarify the relationship of the repeated measurement of casual and 24-hour urinary sodium-to-potassium ratio in patients with CKD. Design and Method: A total of 61 inpatients with CKD, 31 in stage 1-3 (eGFR ≥ 30 ml/min/1.73m 2 ) and 30 in stage 4-5 (eGFR &lt; 30 ml/min/1.73m 2 ), aged 20 to 85 under low-sodium diet (NaCl 6 g/day) were recruited in Okayama University hospital. Sodium-to-potassium ratio in casual urine at 4 points/day (first void after rising, each urine after breakfast, lunch or dinner) for 2 days and 2-day 24-hr urine at the same day were measured. Correlation and the quality of agreement by Bland and Altman between casual urine and 24-hour urine samples were analyzed. Results: Mean 24-hour Na and K excretion was lower in participants in stage 4-5 (Na: 87.5 mmol/24h, K: 18.8 mmol/24h) than in participants in stage 1-3 (Na: 99.0 mmol/24h, K: 26.1 mmol/24h), whereas mean 24-hour urine Na/K ratio was higher in participants in stage 4-5 (5.1) than in participants in stage 1-3 (4.1). Casual urine Na/K ratio was strongly correlated with 2-day 24-hour urinary Na/K ratio by sampling 2 casual urine specimens per day for 2 days in participants in stage 1-3 (r = 0.69-0.78), but not in stage 4-5 (r = 0.12-0.19). The bias for mean Na/K ratio between 2-day 24-hour urine and sampling 2 casual urine per day for 2 days in participants in stage 1-3 ranged from -0.86 to 0.16, and the quality of agreement for the mean of this casual urine sampling was similar to that of all 8 points of casual urine samples for estimating 2-day 24-hour values. Conclusion: Repeated casual urine Na/K ratio measurement may provide good estimate of 24-hour urine Na/K ratio, in stage 1-3 CKD patients as well as normotensive and hypertensive people; however, not in stage 4-5 CKD patients.

Time to Consider Use of the Sodium-to-Potassium Ratio for Practical Sodium Reduction and Potassium Increase.

Pathogenetic studies have demonstrated that the interdependency of sodium and potassium affects blood pressure. Emerging evidences on the sodium-to-potassium ratio show benefits for a reduction in sodium and an increase in potassium compared to sodium and potassium separately. As presently there is no known review, this article examined the practical use of the sodium-to-potassium ratio in daily practice. Epidemiological studies suggest that the urinary sodium-to-potassium ratio may be a superior metric as compared to separate sodium and potassium values for determining the relation to blood pressure and cardiovascular disease risks. Higher correlations and better agreements are seen for the casual urine sodium-to-potassium ratio than for casual urine sodium or potassium alone when compared with the 24-h urine values. Repeated measurements of the casual urine provide reliable estimates of the 7-day 24-h urine value with less bias for the sodium-to-potassium ratio as compared to the common formulas used for estimating the single 24-h urine from the casual urine for sodium and potassium separately. Self-monitoring devices for the urinary sodium-to-potassium ratio measurement makes it possible to provide prompt onsite feedback. Although these devices have been evaluated with a view to support an individual approach for sodium reduction and potassium increase, there has yet to be an accepted recommended guideline for the sodium-to-potassium ratio. This review concludes with a look at the practical use of the sodium-to-potassium ratio for assistance in practical sodium reduction and potassium increase.

Iodine Deficiency Disorder Among Filipino School Children, Pregnant and Lactating Women and the Elderly 20 Years After the Act for Salt Iodization Nationwide Law

Background: Iodine deficiency disorder (IDD) is still a public health problem globally. In response to this, universal salt iodization (USI) has been implemented. This is the most cost-effective strategy to prevent and control it. In the Philippines, an Act for Salt Iodization Nationwide (ASIN Law) was passed in 1995, in response to the increasing goiter rates. This paper describes the prevalence and severity of IDD among Filipino school-aged children (SAC), pregnant and lactating women and the elderly, 20 years after the implementation of the ASIN Law. Methods: Casual urine samples were collected from SAC, pregnant and lactating women and elderly of 1998, 2003, 2008 and 2013, of selected households of the National Nutrition Survey (NNS). Urinary iodine (UI) levels were determined using the acid digestion method. UI levels and prevalence of IDD in the 2013 NNS were compared with those in previous NNSs. Results: Iodine nutrition among the SAC has improved from mild deficiency with a median of 71 ug/L in 1998 to 201 ug/L in 2003. It has remained “optimal” till the 2013 NNS, almost 20 years after ASIN Law. UI was 107 ug/L among the elderly in 2008, but decreased to 80 ug/L in 2013, also indicating “mild” iodine deficiency. Among the lactating women, UI was 111 ug/L in 2003, indicating iodine sufficiency, but decreased to 81 and 77 ug/L in 2008 and 2013 NNS, respectively, indicating “mild” iodine deficiency. Median UI among the pregnant women was 142, 105 and 105 ug/L, also indicating the presence of IDD for the 2003, 2008 and 2013 NNS, respectively. Conclusion: Twenty years after ASIN Law, Filipino SAC have achieved optimum iodine status while the pregnant and lactating women and the elderly remain to be iodine deficient. Strict monitoring of iodization of salt at the production site should be implemented, since iodine levels in salt have remained at levels below the standard. J Endocrinol Metab. 2017;7(3):86-93 doi: https://doi.org/10.14740/jem414w

Diurnal variation of urinary sodium-to-potassium ratio in free-living Japanese individuals

High sodium-to-potassium ratios are associated with elevated blood pressure levels and an increased risk of cardiovascular diseases. We aimed to determine whether urinary sodium-to-potassium ratios fluctuate diurnally during the day to understand measured values of casual urinary sodium-to-potassium ratios. A total of 13,277 casual urine specimens were collected under free-living conditions from 122 Japanese normotensive and hypertensive individuals. Participants collected all casual urine samples in aliquot tubes, reported urine volumes and the time at each voiding for 10–22 days. Then, specimens were classified into hourly data. Diurnal patterns of urinary sodium-to-potassium ratios and urinary concentrations of sodium and potassium were evaluated. Overall mean values of hourly urinary sodium-to-potassium ratios were highest (4.1–5.0) in the early morning, lower (3.3–3.8) in the daytime and higher (4.0–4.4) toward evening hours. The mean urinary sodium and potassium concentrations were the lowest (90–110 and 24–32 mmol l−1, respectively) during the early morning and higher (110–140 and 35–43 mmol l−1, respectively) after mid-morning. Diurnal variability of potassium concentrations was larger than for sodium concentrations. Diurnal variations in urinary sodium-to-potassium ratios were comparable between normotensive and hypertensive individuals, between hypertensive individuals with and without antihypertensive medications, and among age and gender-specific subgroups. Overall mean hourly urinary sodium-to-potassium ratios fluctuated diurnally under free-living conditions and were higher during the morning and evening and lower during the daytime compared with 24-h urinary sodium-to-potassium ratios. Diurnal variation in urinary sodium-to-potassium ratios should be considered to understand actual daily dietary levels and avoid over- and under-estimation in clinical practice.

Iodine Deficiency Disorder Among Filipino School Children, Pregnant and Lactating Women and the Elderly 20 Years After the Act for Salt Iodization Nationwide Law

Background: Iodine deficiency disorder (IDD) is still a public health problem globally. In response to this, universal salt iodization (USI) has been implemented. This is the most cost-effective strategy to prevent and control it. In the Philippines, an Act for Salt Iodization Nationwide (ASIN Law) was passed in 1995, in response to the increasing goiter rates. This paper describes the prevalence and severity of IDD among Filipino school-aged children (SAC), pregnant and lactating women and the elderly, 20 years after the implementation of the ASIN Law. Methods: Casual urine samples were collected from SAC, pregnant and lactating women and elderly of 1998, 2003, 2008 and 2013, of selected households of the National Nutrition Survey (NNS). Urinary iodine (UI) levels were determined using the acid digestion method. UI levels and prevalence of IDD in the 2013 NNS were compared with those in previous NNSs. Results: Iodine nutrition among the SAC has improved from mild deficiency with a median of 71 ug/L in 1998 to 201 ug/L in 2003. It has remained “optimal” till the 2013 NNS, almost 20 years after ASIN Law. UI was 107 ug/L among the elderly in 2008, but decreased to 80 ug/L in 2013, also indicating “mild” iodine deficiency. Among the lactating women, UI was 111 ug/L in 2003, indicating iodine sufficiency, but decreased to 81 and 77 ug/L in 2008 and 2013 NNS, respectively, indicating “mild” iodine deficiency. Median UI among the pregnant women was 142, 105 and 105 ug/L, also indicating the presence of IDD for the 2003, 2008 and 2013 NNS, respectively. Conclusion: Twenty years after ASIN Law, Filipino SAC have achieved optimum iodine status while the pregnant and lactating women and the elderly remain to be iodine deficient. Strict monitoring of iodization of salt at the production site should be implemented, since iodine levels in salt have remained at levels below the standard. J Endocrinol Metab. 2017;7(3):86-93 doi: https://doi.org/10.14740/jem414w

Estimating 24-h urinary sodium/potassium ratio from casual ('spot') urinary sodium/potassium ratio: the INTERSALT Study.

BackgroundAssociation between casual and 24-h urinary sodium-to-potassium (Na/K) ratio is well recognized, although it has not been validated in diverse demographic groups. Our aim was to assess utility across and within populations of casual urine to estimate 24-h urinary Na/K ratio using data from the INTERSALT Study.MethodsThe INTERSALT Study collected cross-sectional standardized data on casual urinary sodium and potassium and also on timed 24-h urinary sodium and potassium for 10 065 individuals from 52 population samples in 32 countries (1985–87). Pearson correlation coefficients and agreement were computed for Na/K ratio of casual urine against 24-h urinary Na/K ratio both at population and individual levels.ResultsPearson correlation coefficients relating means of 24-h urine and casual urine Na/K ratio were r = 0.96 and r = 0.69 in analyses across populations and individuals, respectively. Correlations of casual urine Na/creatinine and K/creatinine ratios with 24-h urinary Na and K excretion, respectively, were lower than correlation of casual and 24-h urinary Na/K ratio in analyses across populations and individuals. The bias estimate with the Bland–Altman method, defined as the difference between Na/K ratio of 24-h urine and casual urine, was approximately 0.4 across both populations and individuals. Spread around, the mean bias was higher for individuals than populations.ConclusionWith appropriate bias correction, casual urine Na/K ratio may be a useful, low-burden alternative method to 24-h urine for estimation of population urinary Na/K ratio. It may also be applicable for assessment of the urinary Na/K ratio of individuals, with use of repeated measurements to reduce measurement error and increase precision.

The Use and Interpretation of Sodium Concentrations in Casual (Spot) Urine Collections for Population Surveillance and Partitioning of Dietary Iodine Intake Sources.

In 2013, the World Health Organization (WHO) called for joint surveillance of population salt and iodine intakes using urinary analysis. 24-h urine collection is considered the gold standard for salt intake assessment, but there is an emerging consensus that casual urine sampling can provide comparable information for population-level surveillance. Our review covers the use of the urinary sodium concentration (UNaC) and the urinary iodine concentration (UIC) from casual urine samples to estimate salt intakes and to partition the sources of iodine intakes. We reviewed literature on 24-h urinary sodium excretion (UNaE) and UNaC and documented the use of UNaC for national salt intake monitoring. We combined information from our review of urinary sodium with evidence on urinary iodine to assess the appropriateness of partitioning methods currently being adapted for cross-sectional survey analyses. At least nine countries are using casual urine collection for surveillance of population salt intakes; all these countries used single samples. Time trend analyses indicate that single UNaC can be used for monitoring changes in mean salt intakes. However; single UNaC suffers the same limitation as single UNaE; i.e., an estimate of the proportion excess salt intake can be biased due to high individual variability. There is evidence, albeit limited, that repeat UNaC sampling has good agreement at the population level with repeat UNaE collections; thus permitting an unbiased estimate of the proportion of excess salt intake. High variability of UIC and UNaC in single urine samples may also bias the estimates of dietary iodine intake sources. Our review concludes that repeated collection, in a sub-sample of individuals, of casual UNaC data would provide an immediate practical approach for routine monitoring of salt intake, because it overcomes the bias in estimates of excess salt intake. Thus we recommend more survey research to expand the evidence-base on predicted-UNaE from repeat casual UNaC sampling. We also conclude that the methodology for partitioning the sources of iodine intake based on the combination of UIC and UNaC measurements in casual urine samples can be improved by repeat collections of casual data; which helps to reduce regression dilution bias. We recommend more survey research to determine the effect of regression dilution bias and circadian rhythms on the partitioning of dietary iodine intake sources.

Sodium intake in Germany.

For many years, a high sodium intake has been discussed as a potential risk factor in the development of hypertension and, consequently, cardiovascular diseases. As part of the German Health Interview and Examination Survey for Adults (DEGS1), which was conducted between 2008 and 2011, sodium excretion in casual urine samples was used as a biomarker to measure sodium intake. DEGS1 observed that the median daily sodium intake of women (3.4 g) as well as men (4.0 g) exceeds the levels recommended by German and international organisations. Among other factors, men's higher sodium intake could be explained by their higher energy intake. In addition, DEGS1 demonstrates an association between women's sodium intake and age; however, no equivalent correlation was identified for men. Furthermore, although high socio-economic status is associated with lower sodium intake in men, no comparable correlation was observed among women.

PP.30.07] DIURNAL PATTERN OF URINARY SODIUM/POTASSIUM RATIO IN FREE LIVING JAPANESE IN DIVIDUALS

Objective: High dietary sodium (Na), low dietary potassium (K) intakes and high Na/K ratio are associated with adverse blood pressure levels and excess risks of cardiovascular diseases. Handy urinary Na/K ratio measurement device provides feedback in several ten seconds with far lower patient burden as compared to conventional methods. Since there is no report on diurnal variation of casual urinary Na/K ratio, we clarified it under free living conditions in Japanese participants.Design and method: This study is a cross sectional study. A total of 122 normotensve and hypertensive individuals (ages 25–69 years) were recruited. Participants were instructed to collect all casual urine samples in aliquot tubes (10 mL), and to report urine volume and the time at each voiding under free living conditions for 10 to 22 days. Urinary sodium and potassium concentration was measured by ion-specific electrodes, and Na/K ratio was calculated. 13,277 specimens were collected and classified into hourly data from 00:00 hours to 23:00 hours on the hour. Diurnal pattern of urinary Na/K ratio, urinary concentrations and excretions of sodium and potassium, and urine volume were evaluated. Results: Mean value of 24-hr urinary Na/K ratio were 4.37 and 3.43 in normotensive and hypertensive individuals, respectively. Of the individuals on anti-hypertensive medications, 14 participants, 9 participants, 15 participants and 5 participants were taking calcium channel blockers (CCB), angiotensin 2 receptor blockers (ARB), both CCB and ARB, and other drugs, respectively. Overall mean value of urinary Na/K ratio was highest (4.1–5.0) in the early morning, lower (3.3–3.8) in daytime and higher (4.0–4.4) toward evening hours. Mean urinary sodium and potassium concentration was lowest (90–110mmol/L, 24–32mmol/L, respectively) in the early morning, and higher (110–140mmol/L, 35–43mmol/L, respectively) after second voiding. Diurnal variability ratio of potassium concentration was larger than sodium concentration. In subgroup analysis, diurnal patterns of mean urinary Na/K ratio were comparable between normotensive and hypertensive individuals. Conclusions: We identified a diurnal pattern in urinary Na/K ratio under free living conditions. This fluctuation of urinary Na/K ratio was 1 to 1.5, and its variation is not likely to be explained by postprandial surges.

Evaluation of Equations for Predicting 24-Hour Urinary Sodium Excretion from Casual Urine Samples in Asian Adults

Background: The collection of 24-h urine samples for the estimation of sodium intake is burdensome, and the utility of spot urine samples in Southeast Asian populations is unclear.Objective: We aimed to assess the validity of prediction equations with the use of spot urine concentrations.Methods: A sample of 144 Singapore residents of Chinese, Malay, and Indian ethnicity aged 18–79 y were recruited from the Singapore Health 2 Study conducted in 2014. Participants collected urine for 24 h in multiple small bottles on a single day. To determine the optimal collection time for a spot urine sample, a 1-mL sample was taken from a random bottle collected in the morning, afternoon, and evening. Published equations and a newly derived equation were used to predict 24-h sodium excretion from spot urine samples.Results: The mean ± SD concentration of sodium from the 24-h urine sample was 125 ± 53.4 mmol/d, which is equivalent to 7.2 ± 3.1 g salt. Bland-Altman plots showed good agreement at the group level between estimated and actual 24-h sodium excretion, with biases for the morning period of –3.5 mmol (95% CI: –14.8, 7.8 mmol; new equation) and 1.46 mmol (95% CI: –10.0, 13.0 mmol; Intersalt equation). A larger bias of 25.7 mmol (95% CI: 12.2, 39.3 mmol) was observed for the Tanaka equation in the morning period. The prediction accuracy did not differ significantly for spot urine samples collected at different times of the day or at a random time of day (P = 0.11–0.76).Conclusion: This study suggests that the application of both our own newly derived equation and the Intersalt equation to spot urine concentrations may be useful in predicting group means for 24-h sodium excretion in urban Asian populations.

Iodine nutrition status in clinically euthyroid pregnant women attending in BSMMU

Background: Iodine deficiency disorders (IDD) are common nutritional problem globally. All groups of people are affected by it, but the pregnant women and their neonates are most vulnerable.Objectives: This study was carried out to see the iodine status of pregnant women using median urinary iodine concentration (MUI) as a measure of outcome. Methods: This cross sectional observational study assessed the MUI in casual urine samples from 225 pregnant women (75 pregnants from each trimester) and 75 non-pregnant healthy controls. The urinary iodine content was estimated in urine sample using the method of Dunn et al. with the modification of Sandell &amp; Kolthoff (wet digestion method).Results: Median value of urinary iodine in pregnant women was 48.21Ug/L compared to 52.27

Iodine Supplementation of Mildly Iodine-Deficient Adults Lowers Thyroglobulin: A Randomized Controlled Trial.

An inverse relationship between thyroglobulin (Tg) and urinary iodine concentration (UIC) has been found in children, potentially making Tg a viable blood marker of iodine status. The application of Tg in adults is unknown. The objective of the study was to determine the efficacy of Tg to assess iodine status in adults. This was a randomized, double-blind, placebo-controlled, clinical trial. The study was conducted in Dunedin, New Zealand. Mildly iodine deficient adults (n = 112) aged 18–40 years participated in the study. Participants were supplemented with 150 μg of iodine as potassium iodate or placebo daily for 24 weeks. At baseline and 24 weeks, participants provided five casual urine samples for UIC determination; serum TSH and free T4 (FT4) was also measured. Tg was determined at baseline and 8, 16, and 24 weeks. A change in Tg concentration between the iodine-supplemented and placebo groups at 24 weeks. At baseline, the overall median UIC was 65 μg/L, confirming that participants were mildly iodine deficient (ie, median UIC between 50 and 99 μg/L). The overall median Tg was 16.6 μg/L; TSH and FT4 were within normal reference ranges. At 24 weeks, the median UIC of the placebo and supplemented groups was significantly different, 79 and 168 μg/L, respectively (P < .001). Tg in the iodine-supplemented group decreased by 12%, 20%, and 27% compared with the placebo group at 8 (P = .045), 16 (P < .001), and 24 weeks (P < .001); there were no significant changes in TSH and FT4. Improved iodine status as assessed by UIC was associated with a concomitant decrease in Tg concentration, demonstrating that Tg is a useful biomarker of iodine status in a group of adults.

Four to seven random casual urine specimens are sufficient to estimate 24-h urinary sodium/potassium ratio in individuals with high blood pressure.

This study was done to clarify the optimal number and type of casual urine specimens required to estimate urinary sodium/potassium (Na/K) ratio in individuals with high blood pressure. A total of 74 individuals with high blood pressure, 43 treated and 31 untreated, were recruited from the Japanese general population. Urinary sodium, potassium and Na/K ratio were measured in both casual urine samples and 7-day 24-h urine samples and then analyzed by correlation and Bland–Altman analyses. Mean Na/K ratio from random casual urine samples on four or more days strongly correlated with the Na/K ratio of 7-day 24-h urine (r=0.80–0.87), which was similar to the correlation between 1 and 2-day 24-h urine and 7-day 24-h urine (r=0.75–0.89). The agreement quality for Na/K ratio of seven random casual urine for estimating the Na/K ratio of 7-day 24-h urine was good (bias: −0.26, limits of agreements: −1.53–1.01), and it was similar to that of 2-day 24-h urine for estimating 7-day 24-h values (bias: 0.07, limits of agreement: −1.03 to 1.18). Stratified analyses comparing individuals using antihypertensive medication and individuals not using antihypertensive medication showed similar results. Correlations of the means of casual urine sodium or potassium concentrations with 7-day 24-h sodium or potassium excretions were relatively weaker than those for Na/K ratio. The mean Na/K ratio of 4–7 random casual urine specimens on different days provides a good substitute for 1–2-day 24-h urinary Na/K ratio for individuals with high blood pressure.

PP.29.06

Objective: Reducing sodium intake and increasing potassium intake are established essential measures for the prevention of cardiovascular diseases and hypertension. Sodium intake in East Asian populations is still higher in the world. However, there were few reports on the characteristics of individuals with high sodium intake or low potassium intake. The aim of this study is to investigate factors related to urinary sodium and potassium excretion in a representative Japanese population from the National Health and Nutrition Survey. Design and method: This is a cross-sectional study of 2,761 men and women (1,179 men and 1,582 women, aged 20 and older) (the NIPPON DATA2010), who participated in the National Health and Nutrition Survey of Japan conducted in 2010 by the Ministry of Health, Labour and Welfare. They participated from 300 randomly selected districts from all-over Japan. Estimated 24-hour urinary sodium (Na) and potassium (K) excretion was calculated using Tanaka's formula (Tanaka T. et al. J Hum Hypertens. 2002; 16: 97–103) from casual urinary mineral concentration. In order to investigate the association of factors with urinary Na, K and casual urine Na/K ratio, multiple linear regression analysis was performed. Results: Means of estimated 24-hour urine mineral excretions were; Na 176 mmol/day and 172 mmol/day, K 42 mmol/day and 41 mmol/day, and Na/K ratio 3.62 and 3.66 (geometric mean) for men and women, respectively. In men, current smoking was positively associated with urinary Na excretion (ß = 7.121, p = 0.018) and log-transformed Na/K ratio (ß = 0.189, p < 0.001) while it was inversely associated with urinary K excretion (ß = -1.412, p = 0.021) after adjusting for confounding factors. In both men and women, high education status was positively associated with urinary K excretion (men; ß = 2.242, p = 0.001, women; ß = 1.651, p = 0.009) and inversely associated with log-transformed Na/K ratio, (men; ß = -0.136, p = 0.005, women; ß = -0.175, p < 0.001) after adjusting for confounding factors. Conclusions: Non smoking and high education status was independently associated with lower sodium and higher potassium intake estimated using casual urine in general Japanese men and women.