Salt intake and prevalence of overweight/obesity in Japan, China, the United Kingdom, and the United States: the INTERMAP Study

• Published in: The American journal of clinical nutrition Vol. 110; no. 1; pp. 34 - 40
• Main Authors: Zhou, Long, Stamler, Jeremiah, Chan, Queenie, Van Horn, Linda, Daviglus, Martha L, Dyer, Alan R, Miura, Katsuyuki, Okuda, Nagako, Wu, Yangfeng, Ueshima, Hirotsugu, Elliott, Paul, Zhao, Liancheng
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2019; Oxford University Press; American Society for Clinical Nutrition, Inc
• Subjects: 24-h urine sodium; Adult; Blood pressure; Body Mass Index; Body size; Body weight; China; China - epidemiology; cross-sectional studies; cross-sectional study; Data collection; diet recall; Dietary intake; Energy intake; Female; Humans; International studies; Japan; Japan - epidemiology; linear models; Male; men; Middle Aged; Nutrients; Obesity; Obesity - epidemiology; Original Research Communications; Overweight; Overweight - epidemiology; prospective studies; Regression analysis; Regression coefficients; Regression models; Risk analysis; Risk factors; Salt; salt intake; Salts; Sodium Chloride, Dietary - administration & dosage; table salt; United Kingdom; United Kingdom - epidemiology; United States; United States - epidemiology; Urine; women; United Kingdom; United States; China; Japan; United Kingdom > UK; United States > US; salt intake; 24-h urine sodium; cross-sectional study; body mass index; obesity
• ISSN: 0002-9165; 1938-3207; 1938-3207
• DOI: 10.1093/ajcn/nqz067

Several studies have reported that dietary salt intake may be an independent risk factor for overweight/obesity, but results from previous studies are controversial, reflecting study limitations such as use of a single spot urine or dietary recall to estimate daily salt intake rather than 24-h urine collections, and population samples from only a single country or center. The aim of this study was to use data from the International Study of Macro-/Micro-nutrients and Blood Pressure (INTERMAP Study) to explore the relation between dietary salt intake estimated from 2 timed 24-h urine collections and body mass index (BMI; in kg/m2) as well as prevalence of overweight/obesity in Japan, China, the United Kingdom, and the United States. Data were from a cross-sectional study of 4680 men and women aged 40–59 y in Japan (n = 1145), China (n = 839), the United Kingdom (n = 501), and the United States (n = 2195). General linear models were used to obtain the regression coefficients (β) of salt intake associated with BMI. Multivariable logistic regression models were used to determine the ORs and 95% CIs of overweight/obesity associated with a 1-g/d higher dietary salt intake. After adjustment for potential confounding factors including energy intake, salt intake 1 g/d higher was associated with BMI higher by 0.28 in Japan, 0.10 in China, 0.42 in the United Kingdom, and 0.52 in the United States, all P values < 0.001. Salt intake 1 g/d higher was associated with odds of overweight/obesity 21% higher in Japan, 4% higher in China, 29% higher in the United Kingdom, and 24% higher in the United States, all P values < 0.05. Salt intake is positively associated with BMI and the prevalence of overweight/obesity in Japan, China, the United Kingdom, and the United States. This association needs to be further confirmed in well-designed prospective studies with repeated dietary and BMI measurements.This trial was registered at clinicaltrials.gov as NCT00005271.