Abstract 3643: Consciousness of Reduced Salt Diet and Actual Achievement of Salt Reduction Estimated from 24hr Urinary Na Excretions in General Populations in Japan, PRC, UK and US: The INTERMAP Study
OBJECTIVES: Assess the percentage of persons with consciousness of reduced salt diet (RSD) in general population samples and estimate actual differences in Na intake between RSD participants and others based on two timed 24hr urinary (24hr-U) Na excretions.
METHODS: Data from 4680 men and women ages 40 –59yr randomly selected from 17 general populations in four countries, Japan (n=1145), PRC (n=839), UK (n=501) and US (n=2195), in the International Study of Macro- and Micro-nutrients and Blood Pressure (INTERMAP). Awareness of RSD was surveyed by questionnaire. Participants provided timed 24hr-U samples twice; Na and K were measured. Means of 24hr-U Na, K excretions and Na/K ratio were compared between RSD and non-RSD participants. Values were also estimated adjusted for body weight, age and sex (multiple regression analysis).
RESULTS: RSD participants were few, 3.1% (Japan), 1.3% (PRC), 4.8% (UK) and 7.2% (US). Similarly among hypertensive (HTN) participants, 9.0% (Japan), 5.8% (PRC), 10.3% (UK) and 14.7% (US). Mean 24hr-U Na excretions (SE)(mmol) for RSD and non-RSD participants were 184.3(7.8) vs. 198.8(1.7)(p=0.129) (Japan); 191.2(19.3) vs. 228.0(3.5)(p=0.228) (PRC); 167.3(14.0) vs. 144.1(2.2)(p=0.114) (UK); and 150.9(4.7) vs. 163.5(1.3)(p=0.010) (US); adjusted Na excretions, 180.0(8.6) vs. 198.9(1.5)(p=0.031) (Japan); 172.4(27.4) vs. 228.2(3.1)(p=0.043) (PRC); 156.3(9.2) vs. 144.6(2.0)(p=0.217) (UK); 149.9(4.2) vs. 163.6(1.2)(p=0.002) (US). There were no significant differences in adjusted K excretions; Na/K ratios gave results similar to those for Na for all four countries. Adjusted Na excretions for HTN participants were significantly lower than for non-HTN participants in Japan (186.5(4.0) vs. 200.3(1.6)(p=0.002)); significant differences were not observed for other countries.
CONCLUSIONS: Only a small percent of all and of HTN participants reported following consciously RSD. While 24hr-U Na excretions tended to be significantly lower for RSD participants, total salt intakes were still high. To prevent CVD, it is important to implement salt reduction guidelines more aggressively.