Summaries of Research Articles
A Summary of Selected Scientific Research, References and Reviews Relating to Sodium Supplementation in POTS, EDS and Elderly Orthostatic Intolerance. Jonathan Toker, Ph.D.
Healthy, free-living individuals can achieve sodium balance through normal diet alone. It is recognized that, on average, people with Western-style diets already consume sufficient (or excess) sodium. It is the purpose of SaltStick Vitassium to supply additional dietary sodium to specific populations who may benefit from higher sodium intake than average. In many cases, consumers seek to increase sodium intake as a first-line attempt to resolve certain underlying symptoms relating to high sodium excretion or poor sodium retention that is characteristic of conditions such as Postural Orthostatic Tachycardia Syndrome (POTS), Ehlers-Danlos syndrome (EDS) and Cystic Fibrosis (CF), often under the recommendation and guidance of their physician as a first line non-drug treatment along with additional fluid intake, exercise and other lifestyle changes.
Additional sodium intake can also be of benefit for certain people to assist with proper hydration. In the absence of sodium replacement, intake of fluid is associated with a decrease in thirst and an increased diuresis despite the continued presence of a significant fluid deficit. In combination with increased salt intake, proper hydration is key to preventable and treatable fluid imbalance.
The following references are available as hyperlinks below, and major bullet points relating to the implementation of sodium supplementation are outlined for each article.
Gupta, Vishal, and Lewis A. Lipsitz. “Orthostatic hypotension in the elderly: diagnosis and treatment.” The American journal of medicine 120.10 (2007): 841-847. PDF Link
- Orthostatic hypotension is a common problem among elderly patients, associated with significant morbidity and mortality. While acute orthostatic hypotension is usually secondary to medication, fluid or blood loss, or adrenal insufficiency, chronic orthostatic hypotension is frequently due to altered blood pressure regulatory mechanisms and autonomic dysfunction. Previous studies have revealed an increased prevalence of orthostatic hypotension with age. In community dwelling individuals _65 years of age, its prevalence is approximately 20%; in those _75 years of age it is as high as 30%. In frail elderly individuals living in nursing homes, the prevalence of orthostatic hypotension is even higher, up to 50% or more.
- Orthostatic hypotension may be symptomatic or asymptomatic. However, even in asymptomatic patients it remains a risk for future falls and syncope, and should therefore be minimized as much as possible. Common symptoms at all ages include dizziness, light headedness, weakness, syncope, nausea, paracervical pain, low back pain, angina pectoris, and transient ischemic attacks. In elderly people, disturbed speech, visual changes, falls, confusion, and impaired cognition are more commonly seen
- Nonpharmacologic Treatment Options for Orthostatic Hypotension: Increase salt and water intake
- Liberal intake of salt and water to achieve a 24-hour urine volume of 1.5 to 2 liters may attenuate fluid loss commonly seen in autonomic insufficiency.
Guzman, Juan C., Luciana V. Armaganijan, and Carlos A. Morillo. “Treatment of neurally mediated reflex syncope.” Cardiology clinics 31.1 (2013): 123-129. PDF Link
- Several nonpharmacologic therapies have been developed, which include…salt and fluid intake.
- Simple measures, such as increased water and NaCl intake, should be routinely implemented as first-line therapy
Paturel, Amy. “Take a Stand: A neurologic disorder known as POTS causes dizziness and fainting—and frustration, due to lack of awareness and inadequate treatment.” Neurology Now 11.1 (2015): 44-47. PDF Link
- It’s estimated that between 1 and 3 million Americans are affected by the syndrome.
- POTS can strike at any age, but it primarily affects women between the ages of 15 and 50
- Salt helps the body retain water, which in turn increases blood volume.
- Drinking more fluids, especially in combination with salt, helps expand blood volume and increase blood flow. Most doctors recommend two to three liters per day of hydrating fluids such as vegetable or tomato juice, coconut water, decaffeinated tea with salt, or chicken broth.
Thieben, Mark J., et al. “Postural orthostatic tachycardia syndrome: the Mayo clinic experience.” Mayo Clinic Proceedings. Vol. 82. No. 3. Elsevier, 2007. PDF Link
- POTS is a relatively common condition
- An important first step in the assessment and treatment of patients with POTS is to determine their volume status and institute salt and fluid replacement in those with hypovolemia.
Low, Phillip A., et al. “Postural tachycardia syndrome (POTS).” Journal of cardiovascular electrophysiology 20.3 (2009): 352-358. PDF Link
- POTS is defined as the development of orthostatic symptoms associated with a heart rate (HR) increment ≥30, usually to ≥120 bpm without orthostatic hypotension. Symptoms of orthostatic intolerance are those due to brain hypoperfusion and those due to sympathetic overaction.
- Patients with POTS require a high salt diet, copious fluids, and postural training.
- The hypovolemic patient will do well with expanding plasma volume with generous salt intake and fludrocortisone. The salt intake should be between 150–250 mEq of sodium (10–20 g of salt). Some patients are intensely sensitive to salt intake and can fine-tune their plasma volume and BP control with salt intake alone
- The patient should have at least 1 glass or cup of fluids with their meals and at least 2 at other times each day to obtain 2–2.5 L/day.
- Management always involves expansion of plasma volume with high salt and high fluid intake.
Lynn Moore (Boston University School of Medicine), Martha Singer (Boston University School of Medicine), M. Loring Bradlee (Boston University School of Medicine). “Low-sodium diet might not lower blood pressure” Experimental Biology 2017. PDF Link
- There is no evidence that a diet lower in sodium had any long-term beneficial effects on blood pressure.
- All participants started with normal blood pressure readings, and participants who consumed less than 2,500 milligrams of sodium a day had higher blood pressure than participants who consumed higher amounts of sodium.
- High blood pressure (HBP) is a major modifiable risk factor for cardiovascular disease. To reduce blood pressure, current U.S. Dietary Guidelines recommend limiting sodium intake to 2.3 g/day for healthy individuals under the age of 50, while adults over age 50 as well as all African-Americans, and anyone with HBP, diabetes or chronic kidney disease is advised to limit sodium intake to 1.5 g/day. Very limited evidence is available to support these recommendations. Recent studies have called these guidelines into question and identified the need to consider the intakes of other minerals such as potassium, magnesium, and calcium in addition to sodium in relation to BP regulation.
- These long-term data from the Framingham Study provide no support for lowering sodium intakes among healthy adults to below 2.3 g/day as recommended.
- This study does support the finding of a clear inverse association between potassium, magnesium, and calcium and blood pressure change over time.
Ganio, Matthew S., et al. “Mild dehydration impairs cognitive performance and mood of men.” British Journal of Nutrition 106.10 (2011): 1535-1543. PDF Link
- Mild dehydration without hyperthermia in men induced adverse changes in vigilance and working memory, and increased tension/anxiety and fatigue.
- Individuals with medical conditions that increase susceptibility to dehydration such as diabetics, as well as children and elderly individuals, may be more likely to experience adverse behavioural effects of mild dehydration.
Ferry, Monique. “Strategies for ensuring good hydration in the elderly.” Nutrition reviews 63.suppl 1 (2005): S22-S29. PDF Link
- Extracellular dehydration, also called hypotonic hydration, is caused by a loss of sodium, leading to a proportional loss of water. Natremia is then low (<135 mmol/L), as is osmolality (<280 mOsm/L). Diuretic treatment resulting in salt loss is the main etiology. Hyponatremia is responsible for the increased morbidity and mortality associated with this type of dehydration.
- Those at risk for dehydration must drink abundantly, meaning that he or she must therefore be conscious and cooperative. Furthermore, the decrease of thirst perception and a thirst more quickly quenched often make it difficult to achieve sufficient liquid intake. It is therefore necessary to stimulate drinking using either low-osmolarity drinks such as water, broth, or sport drinks or high-osmolarity drinks such as carbonated, sugared drinks or fruit juices.
Fu, Qi, et al. “Cardiac origins of the postural orthostatic tachycardia syndrome.” Journal of the American College of Cardiology 55.25 (2010): 2858-2868. PDF Link
- Postural orthostatic tachycardia syndrome (POTS) (also called chronic orthostatic intolerance), in which patients are unable to stand or remain upright for prolonged periods because of intolerable light headedness, weakness, and near syncope. This disorder affects more than 500,000 Americans
- Patients were encouraged to increase their daily salt intake to 6 to 8 g/day and water intake to 3 to 4 l/day and to elevate the head of the bed during sleeping at night.
- It may be difficult to attribute the improvements in POTS symptoms after exercise training only to the training program because patients were encouraged to increase their daily salt and water intake and to elevate the head of the bed during sleeping at night.
- These results suggest that POTS per se is indeed a consequence of deconditioning and that carefully prescribed exercise training can be used as an effective nondrug therapy for POTS patients.
Geleijnse, Johanna M., Diederick E. Grobbee, and Albert Hofman. “Sodium and potassium intake and blood pressure change in childhood.” Bmj 300.6729 (1990): 899-902. PDF Link
- Dietary potassium and the dietary sodium to potassium ratio are related to the rise in blood pressure in childhood and may be important in the early pathogenesis of primary hypertension.
- Additional potassium intake may help offset any deleterious effects of sodium on blood pressure.
McLeod, Karen A. “Dizziness and syncope in adolescence.” Heart 86.3 (2001): 350-354. PDF Link
- Advice should be given to drink plenty (with the exception of caffeine containing drinks as they tend to dehydrate) such that the urine always looks clear. Many families now restrict the amount of salt in the diet because of concerns about future hypertension. We advise an increase in dietary salt to what might be termed a “normal” salt diet.
- Often with the above simple measures of reassurance, fluid, posture and salt, symptoms will improve significantly.
El-Sayed, H., and R. Hainsworth. “Salt supplement increases plasma volume and orthostatic tolerance in patients with unexplained syncope.” Heart 75.2 (1996): 134-140. PDF Link
- A double blind placebo controlled study in 20 patients and an open study in 11 of the effects of giving 120 mmol/day of sodium chloride (2700 mg sodium)
- In patients with unexplained syncope who had a relatively low salt intake administration of salt increased plasma volume and orthostatic tolerance, and in the absence of contraindications, salt is suggested as a first line of treatment.
Claydon, Victoria E., and Roger Hainsworth. “Salt supplementation improves orthostatic cerebral and peripheral vascular control in patients with syncope.” Hypertension 43.4 (2004): 809-813. PDF Link
- Salt supplementation improves orthostatic tolerance in many patients with posturally related syncope (PRS). This study aimed to examine whether in those patients who responded to salt loading there was also evidence of improved cerebral autoregulation and more powerful peripheral vasoconstriction during orthostasis
- Patients … were administered 100 mmol/d (6 g) slow-release sodium chloride tablets (HK Pharma) and were reassessed after 2 months
- We had established from a previous study in our laboratory using a randomized crossover design and with placebo control that salt supplementation does significantly improve orthostatic tolerance. In this earlier study, 71% of the subjects who received salt tablets had an improvement in orthostatic tolerance, whereas only 3 of 10 subjects who received placebo showed an improvement in orthostatic tolerance. Also, in those who improved on placebo, it became apparent from urine sodium analysis that they had voluntarily increased their sodium intake during the course of the trial. Thus, we considered that we had already established that salt loading improves orthostatic tolerance in the majority of subjects
- Salt loading in PRS patients increases orthostatic tolerance and improves cerebrovascular and peripheral vascular control without affecting blood pressures. These changes are likely to contribute to the beneficial effects of salt loading in these patients.
- Salt supplementation is, in our experience, well tolerated. We have now shown that in addition to its known effect of expanding plasma volume, it also increases the vascular resistance responses to standing (and hence improves postural blood pressure control). It also improves cerebral perfusion by enhancing control of cerebral autoregulation. Perhaps equally as important, we have also demonstrated that in the patients studied, salt supplementation had no adverse effect on resting supine blood pressures.
D’Anci, Kristen E., Florence Constant, and Irwin H. Rosenberg. “Hydration and cognitive function in children.” Nutrition reviews 64.10 (2006): 457-464. PDF Link
- Many POTS patients are hypovolemic.
- Most experts would recommend that there be some effort to increase dietary salt in POTS patients by around 2-4g/day. Particularly symptomatic patients may benefit from as much as 6-8g sodium/day if recommended by a doctor. Initial efforts should be made through dietary salt, and if necessary salt tablet may be used if part of a treatment plan.