SODIUM INTAKE IN MALAYSIAN ADULTS: VALIDATION OF ESTIMATIONS BY DIETARY AND SPOT URINE EXCRETION METHODS VERSUS 24-HOUR URINE EXCRETION

Abstract

Introduction: There are, several methods available for assessment of sodium intake, including dietary and urinary excretion, which are fraught with methodological difficulties. Therefore, the aim of this study was to validate dietary and urinary excretion methods against 24-hour urinary excretion method in estimating sodium intake in Malaysian adults. Methods: A cross-sectional study has been carried out between November to December 2015. About 1568 adults aged 18 to 59 years old have participated from 16 study sites located in the 13 states and two federal territories of Malaysia. The study collected basic sociodemographic data and habitual dietary intake by Food Frequency Questionnaire (FFQ). Respondents were also asked to complete a two-day food intake diary (2FD) and collect their 24-hours urine and spot urine using standard protocols. Results: A total of 1116 adults successfully completed the survey, yielding a response rate of 71%.  Sodium intake from 24-hour urine excretion was estimated at 2585.9mg/day which is above the recommendation by World Health Organization (WHO). The 2FD showed the nearest mean estimate to the reference method but the spot urine with Tanaka’s predictive equation showed the least bias. The estimation of sodium from spot urine alone or with Kawasaki’s predictive equation and FFQ method showed poor mean estimates and a large bias compared to the reference method. Conclusions: The 2FD and spot urine with Tanaka’s prediction equation can be good alternatives for estimating daily sodium intake at the population level but not at the individual level.