Effect of potassium-enriched salt on cardiovascular mortality and medical expenses of elderly men 1–3 Hsing-Yi Chang, Yu-Whuei Hu, Ching-Syang Jack Yue, Yu-Wen Wen, Wen-Ting Yeh, Li-San Hsu, Shin-Yin Tsai, and Wen-Harn Pan ABSTRACT Background: The beneficial effects of potassium-enriched salt on blood pressure have been reported in a few short-term trials. The long-term effects of potassium-enriched salt on cardiovascular mor- tality have not been carefully studied. Objective: The objective was to examine the effects of potassium- enriched salt on cardiovascular disease (CVD) mortality and medi- cal expenditures in elderly veterans. Design: Five kitchens of a veteran retirement home were random- ized into 2 groups (experimental or control) and veterans assigned to those kitchens were given either potassium-enriched salt (experi- mental group) or regular salt (control group) for 31 mo. Informa- tion on death, health insurance claims, and dates that veterans moved in or out of the home was gathered. Results: Altogether, 1981 veterans, 768 in the experimental [x  (SD) age: 74.8  7.1 y] and 1213 in the control (age: 74.9  6.7 y) groups, were included in the analysis. The experimental group had better CVD survivorship than did the control group. The inci- dence of CVD-related deaths was 13.1 per 1000 persons (27 deaths in 2057 person-years) and 20.5 per 1000 (66 deaths in 3218 person- years) for the experimental and control groups, respectively. A sig- nificant reduction in CVD mortality (age-adjusted hazard ratio: 0.59; 95% CI: 0.37, 0.95) was observed in the experimental group. Persons in the experimental group lived 0.3– 0.90 y longer and spent signif- icantly less (US $426/y) in inpatient care for CVD than did the control group, after control for age and previous hospitalization expenditures. Conclusions: This study showed a long-term beneficial effect on CVD mortality and medical expenditure associated with a switch from regular salt to potassium-enriched salt in a group of elderly veterans. The effect was likely due to a major increase in potassium and a moderate reduction in sodium intakes. Am J Clin Nutr 2006;83:1289 –96. KEY WORDS Potassium-enriched salt, elderly, cardiovascu- lar mortality, health expenditure, Taiwan INTRODUCTION Hypertension is one of the major risk factors for cardiovascu- lar disease (CVD) and atherosclerosis. The strong associations between blood pressure and the occurrence of stroke and coro- nary artery disease have been well established (1– 4). Dietary sodium, potassium, calcium, and fatty acid composition and obe- sity are considered among the contributing factors for the devel- opment of hypertension (5). Both observational and experimen- tal studies have repeatedly shown that the level of sodium intake is positively associated with blood pressure (6 –9). Although there were many contradictory findings, they were primarily due to the limitations of the study designs and methods such as not measuring confounders, low statistical power of within- population studies, and regression dilution bias caused by large within-person variations in sodium intake. The Nutrition and Health Survey in Taiwan found that the average (SE) sodium intake of the general elderly male popu- lation of Taiwan was 5.0  0.3 g (10). In Taiwan or China, where salt intake is high and the intake range is large, the relation between the amount of dietary salt and blood pressure was often evident (11–13). Examples include findings from the Chinese sample of the World Health Organization Cardiovascular Dis- eases and Alimentary Comparison (12) study and those from the Government Employee Health Examination study (13) in Tai- wan. A strong evidence of the sodium-blood pressure theory came from the difference in the degree of blood pressure eleva- tion with aging. In societies where salt is not commonly used, people’s blood pressures do not increase as they age. On the other hand, in societies with high-salt diets, people’s blood pressures increase tremendously as they age (6, 7). Sodium reduction trials showed blood pressure–lowing ef- fects of a low-sodium diet (8, 9). The Trial of Nonpharmacologi- cal Intervention in the Elderly showed that the incidence of hy- pertension in the low-sodium group was significantly lower than that of the control group (9). Even with such strong evidence of 1 From the Institute of Biomedical Sciences, Academia Sinica, Nan-Kang, Taipei, Taiwan, ROC (W-TY, L-SH, and W-HP); the Center for Health Policy Research and Development, National Health Research Institutes, Zhunan, Taiwan, ROC (H-YC and Y-WW); the Department of Economics, National Tong-Hua University, Hualien, Taiwan, ROC (Y-WH); the Depart- ment of Statistics, National Cheng-Chi University, Taipei, Taiwan, ROC (C-SJY); the Graduate Institute of Applied Science of Living, Chinese Cul- ture University, Taipei, Taiwan, ROC (S-YT); and the Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Tai- pei, Taiwan, ROC (W-HP). 2 Supported by Taiwan Salt Work Company and by Academia Sinica. 3 Reprints not available. Address correspondence to W-H Pan, Institute of Biomedical Sciences, Academia Sinica, Taipei 115-29, Taiwan, ROC. E- mail: pan@ibms.sinica.edu.tw. Received September 2, 2005. Accepted for publication February 10, 2006. 1289 Am J Clin Nutr 2006;83:1289 –96. Printed in USA. © 2006 American Society for Nutrition by guest on January 13, 2016 ajcn.nutrition.org Downloaded from