Aldosterone, Sodium Deficiency, and Insulin Resistance
The Randle Cycle
Free Fatty Acids Suppress Cellular Respiration
Aldosterone as an endogenous cardiovascular toxin
Aldosterone and Thrombosis
Low Sodium Diet: High FFA, Insulin Resistance, Atherosclerosis
Sodium and Mortality – An Inverse Relationship
J Hypertens. 1993 Dec;11(12):1381-6.
Effect of dietary salt restriction on urinary serotonin and 5-hydroxyindoleacetic acid excretion in man.
Sharma AM, Schorr U, Thiede HM, Distler A.
To determine the effect of dietary salt restriction on urinary excretion of serotonin and its principal metabolite 5-hydroxyindoleacetic acid (5-HIAA) in man.
We studied 16 healthy male volunteers (age range 20-28 years) who ate a standard diet containing 20 mmol/day NaCl, to which either 220 mmol/day NaCl or placebo was added as a supplement for 1 week each, according to a randomized, single-blind crossover design.
Urinary excretion of serotonin, 5-HIAA, noradrenaline and vanillylmandelic acid (VMA) were measured during the low- and high-salt periods using reverse-phase high-performance liquid chromatography.
During the low-salt diet, 24-h urinary excretion of serotonin increased by 42%, accompanied by a 52% rise in the excretion of 5-HIAA. Salt restriction also increased noradrenaline excretion by 77% and VMA excretion by 40%. Regression analysis revealed a strong positive relationship between the excretion of serotonin and of noradrenaline (r = 0.84, P < 0.001) and between that of 5-HIAA and of VMA (r = 0.74, P < 0.001).
Salt restriction stimulates the serotonergic system in man. Stimulation of this system, in conjunction with the sympathetic nervous system, may contribute to renal sodium conservation during dietary salt restriction in man.
J Clin Endocrinol Metab. 1991 Nov;73(5):975-81.
Effects of sodium supplementation during energy restriction on plasma norepinephrine levels in obese women.
Gougeon R, Mitchell TH, Larivière F, Abraham G, Montambault M, Marliss EB.
We tested whether sodium restriction would counteract the decrease in sympathetic nervous system activity usually associated with marked energy restriction. The effects of two levels of energy restriction, with different sodium intakes, on plasma norepinephrine (NE) levels while supine and in response to standing were studied. Twenty-two healthy normotensive obese female subjects (body mass index, 34 +/- 1 kg/m2; weight, 90 +/- 2 kg) followed one of three 3-week protocols: 1) total fasting with 80 mmol/day NaCl, 2) a very low energy diet (VLED) containing 1.7 MJ, 93 g protein, and 90 mmol Na/day, with an additional 60 mmol/day NaCl supplement, or 3) total fasting without NaCl (0 Na fast). At the end of the baseline isocaloric diet and of total fasts or VLED, pulse, blood pressure, and plasma NE were measured after 4 h of recumbency and 5 and 10 min after assuming the upright posture. These measurements were repeated after 1 L physiological saline was infused into the 0 Na fast subjects. Cumulative negative sodium balance was observed only in the 0 Na fasting subjects. Supine blood pressure decreased from baseline with fasting, but not with the VLED. The decreases in systolic pressure and increases in heart rate on standing observed with all diets were greatest with the 0 Na fast. Supine plasma NE (vs. baseline value) declined (P less than 0.05) with the VLED, remained unchanged with the Na supplemented fast, but increased with the 0 Na fast (P less than 0.05). The upright plasma NE values were highest in the 0 Na fast subjects, but lower after the saline infusion as well as in the subjects on the VLED. Thus, the decrease in NE due to energy restriction with normal sodium intake was counteracted by moderate sodium restriction, and levels increased with zero sodium intake. Therefore, sodium depletion can override the suppressive effect of energy restriction and, instead, increase the activity of the sympathetic nervous system, as reflected by plasma NE.
J Card Fail. 2009 Dec;15(10):864-73.
Long-term effects of dietary sodium intake on cytokines and neurohormonal activation in patients with recently compensated congestive heart failure.
Parrinello G, Di Pasquale P, Licata G, Torres D, Giammanco M, Fasullo S, Mezzero M, Paterna S.
A growing body of evidence suggests that the fluid accumulation plays a key role in the pathophysiology of heart failure (HF) and that the inflammatory and neurohormonal activation contribute strongly to the progression of this disorder.
METHODS AND RESULTS:
The study evaluated the long-term effects of 2 different sodium diets on cytokines neurohormones, body hydration and clinical outcome in compensated HF outpatients (New York Heart Association Class II). A total of 173 patients (105 males, mean age 72.5+/-7) recently hospitalized for worsening advanced HF and discharged in normal hydration and in clinical compensation were randomized in 2 groups (double blind). In Group 1, 86 patients received a moderate restriction in sodium (120mmol to 2.8g/day) plus oral furosemide (125 to 250mg bid); in Group 2, 87 patients: received a low-sodium diet (80mmol to 1.8g/day) plus oral furosemide (125 to 250mg bid). Both groups were followed for 12 months and the treatment was associated with a drink intake of 1000mL daily. Neurohormonal (brain natriuretic peptide, aldosterone, plasma rennin activity) and cytokines values (tumor necrosis factor-alpha, interleukin-6) were significantly reduced with a significant increase of the anti-inflammatory cytokine interleukin-10 at 12 months in normal, P < .0001) than low-sodium group. The low-sodium diet showed a significant activation of neurohormones and cytokines and worsening the body hydration, whereas moderate sodium restriction maintained dry weigh and improved outcome in the long term.
Our results appear to suggest a surprising efficacy of a new strategy to improve the chronic diuretic response by increasing Na intake and limiting fluid intake. This counterintuitive approach underlines the need for a better understanding of factors that regulate sodium and water handling in chronic congestive HF. A larger sample of patients and further studies are required to evaluate whether this is due to the high dose of diuretic used or the low-sodium diet.