The available data appear to show that the increased cardiovascular risk among
those with sodium excretion greater than 3.0 grams per day is explained entirely by the variables of BMI, sex and hypertension.
Compared to the sodium reference range of 4 to 6 grams per day, an increased risk of death and CVD events were associated
with sodium excretion of over 7 grams per day (hazard ratio 1.15) and
with sodium excretion of less than 3 grams per day (hazard ratio 1.27).
The researchers determined that the increased risk of sodium excretion above the reference range was due to hypertension while the risk associated
with sodium excretion less than 3 grams per day was due to other causes.
Not exact matches
But approximately 90 percent of the participants in the PURE study had either a high (greater than 5.99 grams per day) or moderate (3 to 5.99 grams per day) level of
sodium excretion; approximately 10 percent excreted less than 3 grams per day, and only 4 percent had
sodium excretion in the range associated
with current U.S. guidelines for
sodium intake (2.3 or 1.5 grams per day).
The levels of hormones associated
with water and
sodium excretion had numerous differences after the sleep - deprivation, and blood pressure and heart rate were significantly higher.
Another 2011 study confirmed this observation; not only was lower
sodium excretion associated
with higher CVD mortality, but baseline
sodium excretion did not predict the incidence of hypertension, and any associations between systolic pressure and
sodium excretion did not translate into less morbidity or improved survival.
Compared
with moderate
sodium excretion, there was an association between low
sodium excretion and cardiovascular (CVD) death and hospitalization for coronary heart failure.
The «wildly speculative values» of 3 to 7 grams per day referred to by Cordain came from a cohort study published in 2011 in The Journal of the American Medical Association in which
sodium intake of almost twenty - nine thousand patients
with established cardiovascular disease or diabetes mellitus was estimated by twenty - four - hour urinary
sodium excretion.26 During the follow - up of fifty - four months, the study found that daily
sodium intake below three grams and above seven grams significantly increased cardiovascular risk.
Urinary
sodium excretion was associated
with all - cause mortality, such that those
with the highest urinary
sodium excretion, as well as the lowest
excretion, had reduced survival.
Data from a study on the characteristics of CKD patients, 55 percent of whom are male, found that typically, 18 percent of CKD patients are of normal weight (BMI < 25), 29 percent are overweight (BMI 25 - 30) and 53 percent are obese (BMI > 30), 84 percent have hypertension and 42 percent have diabetes.8 Obesity is a risk factor for CKD and hypertension, and is associated
with increased
sodium excretion.
Mente, A, O'Donnell M, Rangaranjan S and others: «Associations of urinary
sodium excretion with cardiovascular events in individuals
with and without hypertension: a pooled analysis of four studies:» Lancet 2016 May 20.
The majority of subjects in both studies were overweight and obese.8 Obesity is associated
with increased
sodium excretion and
with increased cardiovascular risk.
From Table 1 it can be seen that both BMI and the percentage of male subjects increased
with increasing
sodium excretion, and that the percentage of subjects who had CVD events increased from the second highest category of
sodium excretion to the highest.
In the lowest category of
sodium excretion,
with an average of 1.9 grams per day, the percentage of subjects that had CVD events was higher (7.2 percent) than that of the second category (6.8 percent),
with average
excretion of 3 grams per day, even though the average BMI and percentage of high - risk males was lower in the lowest category.
The observed increase in mortality and CVD events among those
with daily
sodium excretion less than 3 grams is consistent
with the findings of many other studies.3, 4,6,7,22 During follow - up, one hundred twenty - six patients (4.5 percent) developed end - stage renal disease (ESRD).
SODIUM EXCRETION AND RISK OF CARDIOVASCULAR DISEASE IN PATIENTS WITH KIDNEY DISEASE A second study cited by the CDC under the consistency criteria, «Sodium excretion and risk of cardiovascular disease in patients with chronic kidney disease» 7 included 3757 subjects with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years follow
SODIUM EXCRETION AND RISK OF CARDIOVASCULAR DISEASE IN PATIENTS WITH KIDNEY DISEASE A second study cited by the CDC under the consistency criteria, «Sodium excretion and risk of cardiovascular disease in patients with chronic kidney disease» 7 included 3757 subjects with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years fol
EXCRETION AND RISK OF CARDIOVASCULAR DISEASE IN PATIENTS
WITH KIDNEY DISEASE A second study cited by the CDC under the consistency criteria, «Sodium excretion and risk of cardiovascular disease in patients with chronic kidney disease» 7 included 3757 subjects with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years follow -
WITH KIDNEY DISEASE A second study cited by the CDC under the consistency criteria, «
Sodium excretion and risk of cardiovascular disease in patients with chronic kidney disease» 7 included 3757 subjects with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years follow
Sodium excretion and risk of cardiovascular disease in patients with chronic kidney disease» 7 included 3757 subjects with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years fol
excretion and risk of cardiovascular disease in patients
with chronic kidney disease» 7 included 3757 subjects with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years follow -
with chronic kidney disease» 7 included 3757 subjects
with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years follow -
with chronic kidney disease (CKD), 55 percent males, who experienced 804 CVD events during 6.8 years follow - up.
Mills KT and others: «
Sodium excretion and risk of cardiovascular disease in patients
with chronic kidney disease» JAMA 2016 May 24 - 31; 31 (20): 2200 - 10.
The study also found that those
with hypertension, but not those without hypertension, are at increased risk when
sodium excretion exceeds 7 grams per day.
The authors concluded that «among patients
with CKD, higher urinary
sodium excretion was associated
with increased CVD risk,» a conclusion that is greatly exaggerated.
Most importantly, the study found that
sodium excretion equal to the «adequate intake» promoted by health officials of 1.5 grams per day was associated
with a large increased risk of death and serious CVD events compared to the average reference level of 4.5 grams per day (hazard ratio 1.80).
It is noted that a
sodium intake of less than 2 grams per day, which approximates the
sodium intake of the paleo diet
with no added salt, was associated
with a 68 percent increase in cardiovascular disease risk during follow - up of fifty - four months in the study reviewed in the Kresser blog.26 Another study, which excluded subjects
with cardiovascular disease, hypertension and diabetes, found that after thirty - three months, the cardiovascular risk of those
with daily
sodium excretion of 1.9 grams was 36 percent higher after adjustment for body mass index and sex than the risk of those excreting 3 grams.6
However, in the Hamilton
sodium studies, assessments of the association between
sodium excretion and CVD risk were made in which subjects
with such preexisting conditions were excluded,
with no significant effects on outcomes.
Table 1 below includes pertinent data on BMI and number and percentage of males by category of urinary
sodium excretion, together
with the percentage of subjects in each category who experienced CVD events during follow - up.
Urinary
sodium excretion was inversely associated
with cumulative incidence of ESRD such that those
with the lowest
sodium excretion had the highest incidence of ESRD.
«Both higher and lower levels of estimated
sodium excretion were associated
with increased risk,» the O'Donnell team concluded.
First study: Association of Urinary
Sodium and Potassium
Excretion with Blood Pressure, by Mente et al..
Excess
sodium excretion of greater than 7,000 milligrams and a deficiency of less than 3,000 milligrams per day were both associated
with a higher risk of stroke, heart attack, and death.