Small Increases in Plasma Sodium Are Associated with Higher Risk of Mortality in a Healthy Population

Elevated blood pressure (BP) is the most common cause of cardiovascular disease. Salt intake has a strong influence on BP, and plasma sodium (pNa) is increased with progressive increases in salt intake. However, the associations with pNa and BP had been reported inconsistently. We evaluated the association between pNa and BP, and estimated the risks of all-cause-mortality according to pNa levels. On the basis of data collected from health checkups during 1995-2009, 97,009 adult subjects were included. Positive correlations between pNa and systolic BP, diastolic BP, and pulse pressure (PP) were noted in participants with pNa > or =138 mM/L (P or =50 yr, SBP, DBP, and PP were positively associated with pNa. In participants with metabolic syndrome components, the differences in SBP and DBP according to pNa were greater (P or =50 yr during the median 4.2-yr-follow-up (P or =145 mM/L was related to mortality. The positive correlation between pNa and BP is stronger in older subjects, women, and subjects with metabolic syndrome components. The incidence and adjusted risks of mortality increase with increasing pNa in women aged > or =50 yr.

Levels of plasma sodium and potassium as well as alterations in adrenal cortex of Rattus norvegicus in response to sublethal heroin administration.

In order to record the effects of sublethal heroin administration on plasma mineral metabolism, the drug was administered intramuscularly (16.4 mg kg-1 body weight day-1; 0.75 LD50 dose) in Rattus norvegicus for 30 days. Plasma sodium and potassium levels of the control rats fluctuated between 153.14 ± 2.88-157.23 ± 2.16 meq l-1 and 5.04 ± 0.32-5.63 ± 0.41 meq l-1, respectively. Plasma sodium level of the treated rats registered a progressive decline (p<0.01) at 24 hr with the minimum value (126.53 ± 2.68 meq l-1) on day 30 whereas plasma potassium level registered a progressive increase during entire period of the treatment with peak (8.78 ± 0.23 meq l-1) on day 30. Though sublethal herion adminstration for 30 days elcited cytoplasmic vacuolation in all the three zones of adrenal cortex, much of cytological alterations were observed in zona glomerulosa and zona fasciculata cells. In zona glomerulosa cells, degenerative changes in the organelles were more pronounced as evident by the loss of typical cristae in the mitochondria and hormone granules were rarely seen in these cells. Though rough endoplasmic reticula were scanty, many lipid granules encountered in zona glomerulosa cells of the treated rats.