Aging, Author Interviews, Heart Disease, JAMA, Salt-Sodium / 19.01.2015

Andreas Kalogeropoulos, MD MPH PhD Assistant Professor of Medicine (Cardiology) Emory University School of Medicine Emory Clinical Cardiovascular Research Institute Atlanta GA 30322MedicalResearch.com Interview with: Andreas Kalogeropoulos, MD MPH PhD Assistant Professor of Medicine (Cardiology) Emory University School of Medicine Emory Clinical Cardiovascular Research Institute Atlanta GA 30322 Medical Research: What is the background for this study? What are the main findings? Dr. Kalogeropoulos: There is ongoing debate on how low should we go when it comes to dietary sodium (salt) restriction recommendations. In this study, we examined the association between self-reported dietary sodium intake and 10-year risk for death, cardiovascular disease, and heart failure in approximately 2,600 adults 71-80 years old. The subjects (women: 51.2%; white: 61.7%; black: 38.3%) were participants of the community-based Health, Aging, and Body Composition Study, which is sponsored by NIH and focuses on aging processes, i.e. was not specifically designed to address the issue of dietary salt intake. Also, it is important to note that salt intake was self-reported (not objectively measured) using a food frequency questionnaire, which underestimates salt intake. Keeping these limitations in mind, we did not observe a significant association between self-reported sodium intake and 10-year mortality, cardiovascular disease, and heart failure. Ten-year mortality was lower in the group reporting 1500–2300 mg daily sodium intake (30.7%) compared to those reporting daily intake less than 1500 mg (33.8%) or over 2300 mg (35.2%); however, this difference was not statistically significant. The 10-year event rates for cardiovascular disease (28.5%, 28.2%, and 29.7%) and heart failure (15.7%, 14.3%, and 15.5%) were also comparable across the <1500-mg, 1500-2300-mg, and >2300-mg dietary sodium intake groups.
Author Interviews, Blood Pressure - Hypertension, Nutrition, Salt-Sodium / 08.01.2015

MedicalResearch.com Interview with: Zvonko Rumboldt, MD, PhD Professor emeritus Split University School of Medicine; Split, CroatiaMedicalResearch.com Interview with: Zvonko Rumboldt, MD, PhD Professor emeritus Split University School of Medicine; Split, Croatia Medical Research: What is the background for this study? What are the main findings? Dr. Rumboldt: Arterial hypertension is the major common denominator of a number of cardiovascular diseases and untoward outcomes including stroke, myocardial infarction, terminal renal insufficiency, heart failure and death. Excessive salt intake is the leading causative factor of blood pressure elevation across the world. It has been shown beyond any reasonable doubt that reduction in salt consumption decreases the prevalence of arterial hypertension and eases its management. Therefore many endeavors and campaigns aimed at moderation in salt ingestion have been launched with fair but less than expected results. The main source of ingested salt in developed countries is processed food, while in transitional and developing countries it is addition during food preparation (cooking), serving and salting at the table. This study, executed in Mostar, Bosnia and Herzegovina, and Split, Croatia, was designed to evaluate the effects of emphasized warning, consisting in self-adhesive stickers with clear, short message, put on household salt containers. Analyzed were 150 treated hypertensives, randomized in two groups, both receiving oral information and written leaflet concerning salt-hypertension relationship; the intervention group received in addition warning labels to be put on salt containers. In both groups measured were 24-hour urinary sodium excretion (natriuria), blood pressure, and several other parameters at inception of the trial, and one and two months later. In the intervention group observed was a marked decrease in sodium excretion (e.g. from 211 mmol/l at the beginning to 176 mmol/l at two months), much less (from some 207 to 200 mmol/l) in the control group. At the same time, the  mean blood pressure (already fairly well controlled) was reduced by additional 4 mm Hg in the intervention group (from 104 to 100 mm Hg), which was not the case in the control group (from 104 to 103 mm Hg).
Author Interviews, Heart Disease, Nutrition, Salt-Sodium / 27.12.2014

Jordi Salas-Salvadó Professor of Nutrition Human Nutrition Unit Department of Biochemistry & Biotechnology IISPV School of Medicine. Rovira i Virgili University CIBERobn, Instituto Carlos IIIMedicalResearch.com Interview with: Jordi Salas-Salvadó Professor of Nutrition Human Nutrition Unit Department of Biochemistry & Biotechnology IISPV School of Medicine. Rovira i Virgili University CIBERobn, Instituto Carlos III Medical Research: What is the background for this study? What are the main findings? Response: Excess sodium intake is associated with high blood pressure, a major risk factor for cardiovascular disease (CVD). The 2010 Dietary Guidelines for Americans recommended a sodium intake below 2300 mg per day (equivalent to less than 1 teaspoon of salt per day) in the general population. However it is unknown whether decreasing sodium intake below 2300 mg/d has an effect on CVD or all-cause mortality. The recent Institute of Medicine (IOM) explicitly concluded that studies on health outcomes are inconsistent in quality and insufficient in quantity to determine that sodium intake below 2300 mg/d may increase or decrease the risk of heart disease, stroke or all cause of mortality.
Author Interviews, Multiple Sclerosis, Neurology, Salt-Sodium / 28.08.2014

MedicalResearch.com Interview with: Dr. Mauricio Farez Department of Neurology, Raúl Carrea Institute for Neurological Research Buenos Aires, Argentina Medical Research: What are the main findings of the study? Dr. Farez: Our study shows that patients with Multiple Sclerosis (MS) with moderate to high sodium (salt) intake have also increased disease activity (more clinical relapses and more lesions on MRIs).
Author Interviews, Blood Pressure - Hypertension, BMJ, Salt-Sodium / 15.04.2014

Dr. Feng He Wolfson Institute of Preventive Medicine Barts and The London School of Medicine and Dentistry Queen Mary University of London, London, UKMedicalResearch.com Interview with: Dr. Feng He Wolfson Institute of Preventive Medicine Barts and The London School of Medicine and Dentistry Queen Mary University of London, London, UK
MedicalResearch.com: What are the main findings of the study? Dr. He:
  • The UK salt reduction program has led to a fall in population blood pressure and thereby contributed to the reduction in stroke and heart disease deaths.
  •  In 2003, the UK Food Standards Agency and CASH (Consensus Action on Salt & Health) developed a salt reduction program. As approximately 80% of the salt in the diet is added to food by the food industry i.e. in processed foods, fast foods, canteen and restaurant foods etc, the public have no choice about eating it. Therefore progressive incremental targets to limit the amount of salt for each food category were set, which the industry had to achieve in a specified time. Reductions first started in 2003 and are continuing to this day.
  • The salt reduction program has been very successful and led to a 15% reduction in the average salt intake of the population, from 9.5g per day in 2003 to 8.1g per day in 2011 (P<0.05).
  • Over the same time period, blood pressure fell in the adult population by 3 mm Hg systolic and 1.4 mm Hg diastolic (P<0.0001). Stroke and heart disease deaths fell by 42% (P<0.0001) and 40% (P<0.0001) respectively.
  • It is possible that these falls in blood pressure and deaths from stroke and heart disease were attributable to various factors such as changes in diet, lifestyles and the improvement in the treatment of cardiovascular disease and its risk factors. Our further analysis showed that the reduction in salt intake played an important role, particularly in the falls in blood pressure.
  •  In a further analysis, we looked at individuals who were not on any drug treatment for blood pressure and a correction was made for all other variables that could have influenced blood pressure, apart from salt. There was still a fall in adult population blood pressure of 2.7mm Hg systolic/ 1.1mm Hg diastolic, (P <0.0001). This reduction in blood pressure could therefore be largely attributed to the fall in salt intake.
  •  It is well established that raised blood pressure throughout its range is a major cause of stroke and heart disease. The reduction in salt intake that led to a fall in blood pressure would have played an important role in both stroke and heart disease deaths.
  • Despite considerable progress being made on salt reduction, the average salt intake in England is still high. In 2011, it was 8.1 g/day which is over a third more salt than the recommended level of 6g/day. Therefore continuing and much greater efforts are needed to achieve further reductions in salt intake to prevent the maximum number of stroke and heart disease deaths.
AHA Journals, Author Interviews, Blood Pressure - Hypertension, NIH, Nutrition, Salt-Sodium / 03.04.2014

MedicalResearch.com Interview with: Niels Graudal, MD, DrMSc Senior Consultant Department of Internal medicine/Infectious Medicine/Rheumatology IR4242 Copenhagen University Hospital, Rigshospitalet Denmark Dr. Graudal: There are no studies, which show what happens with the risk of cardiovascular death or mortality if you change your sodium intake. Our study shows the association of sodium intake as it is with cardiovascular disease and mortality, which is only the second best way to consider the problem, but as the best way does not exist we have accepted this approach. There have been two different assumptions concerning the risks of sodium intake. One is that there is an increasing risk of heart disease, stroke and death of salt intake above 2300 mg, and one is that salt is not dangerous at all. Our study shows that both positions partially may be true, as a salt intake above 4900 mg is associated with increased risk of cardiovascular disease and mortality, whereas the present normal salt intake of most of the world’s populations between 2300 mg and 4900 mg is not associated with any increased risks. In addition our study shows that a low sodium intake below 2300 mg is also associated with increased risk of cardiovascular disease and death.
Blood Pressure - Hypertension, Mineral Metabolism, Salt-Sodium / 14.09.2013

MedicalResearch.com Interview with: Dr Sandosh Padmanabhan Institute of Cardiovascular and Medical Sciences University of Glascow, ScotlandMedicalResearch.com Interview with: Dr Sandosh Padmanabhan Institute of Cardiovascular and Medical Sciences University of Glascow, Scotland   MedicalResearch.com: What are the main findings of the study? Dr. Padmanabhan: In the study "Serum Chloride Is an Independent Predictor of Mortality in Hypertensive Patients" we analysed data on 12,968 patients with hypertension followed up at the Glasgow Blood Pressure Clinic. We found that patients in the lowest quintile of serum Cl− (<100 mmol/L), compared with all other patients, had a 23% higher mortality (all-cause, cardiovascular, and non-cardiovascular). Each 1-mmol/L increase in serum Cl− was associated with a 1.1% to 1.5% lower all-cause mortality, cardiovascular mortality and non-cardiovascular mortality. This was independent of serum concentrations of sodium, bicarbonate or potassium. We did not find any association with longitudinal blood pressure control.