AcknowledgmentsWe thank members of Nutrition and Chronic Disease of the GBD Study expert panel (D. Mozzaffarin, M. Ezzati, R. Micha, G. Danaie), and the advisory expert panel on salt and chronic disease (G. MacGregor, P. Elliot, M. Law, B. Neal, I. Brawn, and F. He.)

Literature cited1. World Cancer Research Fund / American Institute for

Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective. Washington, DC: American Institute for Cancer Research; 2007.

2. He FJ, MacGregor GA. Effect of modest salt reduction on blood pressure: a meta-analysis of randomized trials. Implications for public health. J Hum.Hypertens. 2002 Nov;16(11):761-70.

Conclusions(Provisional)

Preparing central estimates of the GBD attributable to higher than optimal sodium intakes is feasible.

The most difficult outstanding challenge is estimating the uncertainty around these estimates.

The Global Burden of Disease attributable to excess salt intake: estimating exposures and effects

John Powles and Saman FahimiDepartment of Public Health and Primary Care, University of Cambridge, CB2 0SR

Methods (cont)

4. Effect estimation

i. Stomach cancer: World Cancer Research Fund (WCRF) meta-analysis1 (risk related to intakes)

ii. Usual sbp – mean and (inter-individual) standard deviation (effect related to urinary excretion)Meta-analysis of sodium reduction RCTs of >4 wks2, re-analysed for mean effect by age. Assumed linear down to optimal exposure. Common to both sexes (for energy adjusted exposures).

Results (work is ongoing.)

Global sodium exposure , Central Europe as a sample GBD Study region.

ntroduction

Adding salt to food is not part of our evolutionary background and evidence that it harms health is persuasive.We are making the first global estimates of health losses attributable to excess salt intake as members of the Nutrition and Chronic Disease Expert Group in the current iteration of the Global Burden of Disease, Injuries, and Risk Factors (GBD) Study. Estimates of burdens in 1990 and 2005, attributable to a wide range of risk factors, are due to be reported later this year

Materials and methods

1. Identified causal effectsDirect: stomach cancerMediated: usual systolic blood pressure (sbp)2. Analytic approachComparative Risk AssessmentAttributable, not avoidable risk i.e. optimal exposure as counterfactual with no modeling of temporal transition.3. Exposure estimationAge and sex specific estimates for 21 GBD Study regions using best available data.Preferred: 24-hr urinary excretion (assumed to be 0.9 * intake)Imputed where data missing

Methods (cont)

Effect modification

By sex: exposure levels adjusted to mean energy intake of both sexes

By race: slope adjusted for African ancestry (+3.5 mmHg at age 50 per 100 mmol of daily urinary Na excretion) (2 RCTs)

Effects of changes in usual sbp and associated uncertainty propagated forward by blood pressure group of the GBD Study to estimate outcomes attributable to higher than optimal salt intakes.