1051 ESTIMATES OF NEW ZEALAND POPULATION SODIUM INTAKE

Abstract

Background: Spot urinary sodium measurement represents a practical alternative to the ‘gold standard’ of 24-hour urinary sodium excretion, especially in large population samples. Design and methods: The New Zealand Adult Nutrition Survey (2008/09) analysed sodium excretion from spot urine samples from a representative sample of 3315 adults 15 years and over. Three published formulae were modelled to estimate 24-hour sodium excretion. A WHO conversion protocol was chosen as the most likely approach to reflect actual 24 hour sodium excretion.(1) The 24-hour estimates have been compared estimates from 24-hour diet recall assessment. Results: Mean estimated population 24-hour urinary sodium excretion was 3544mgs/day (4013mgs/day for men, and 3116mgs/day for women), indicating a mean dietary intake of approximately 3900mgs sodium per day. Sixty five percent of New Zealanders had an estimated 24-hour sodium excretion that exceeded the recommended upper level (UL) of intake 2300mgs sodium/day (74% of men and 57% of women). There are significant differences in mean excretion by age and sex. Mean estimated sodium intake by dietary recall assessment was 2504mgs/day (2953mgs/day for men and 2094 mg/day for women) an inevitable underestimate of actual intake as discretionary salt use was not included. Conclusions: Spot urinary sodium assessment is a useful way to estimate dietary sodium intake in large representative population samples, and might help explain the increase in blood pressure in New Zealand since 2002. New Zealanders’ mean sodium intake is in excess of current nutrient reference values. Public Health interventions to reduce population sodium intake in New Zealand are warranted. References WHO/PAHO Regional Expert Group for Cardiovasular Disease Prevention through Population-wide Dietary Salt Reduction. Protocol for Population Level Sodium Determination in 24-hour Urine Samples. Geneva: World Health Organization 2010.