The Yanomami Indians in the INTERSALT Study.
ABSTRACT To study the distribution and interrelationship among constitutional and biochemical variables with blood pressure (BP) in an population of Yanomami indians. To compare these findings with those of other populations.
The Yanomami indians were part of the INTERSALT, a study comprising 10,079 males and females, aged from 20 to 59 years, belonging to 52 populations in 32 countries in Africa, the Americas, Asia, and Europe. Each of the 52 centers was required to accrue 200 individuals, 25 participants in each age group. The variables analyzed were as follows: age, sex, arterial BP, urinary sodium and potassium excretion (24-hour urine), body mass index, and alcohol ingestion.
The findings in the Yanomami population were as follows: a very low urinary sodium excretion (0.9 mmol/24 h); mean systolic and diastolic BP levels of 95.4 mmHg and 61.4 mmHg, respectively; no cases of hypertension or obesity; and they have no knowledge of alcoholic beverages. Their BP levels do not elevate with age. The urinary sodium excretion relates positively and the urinary potassium excretion relates negatively to systolic BP. This correlation was maintained even when controlled for age and body mass index.
A positive relation between salt intake and blood pressure was detected in the analysis of a set of diverse populations participating in the INTERSALT Study, including populations such as the Yanomami Indians. The qualitative observation of their lifestyle provided additional information.
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ABSTRACT: Background To investigated the influence of dietary potassium on the sodium effect on BP in the general population and the adherence of current recommendations for sodium and potassium intake. Methods An overnight (12 h) urine sample was collected in a population-based study to investigate cardiovascular risk. A sub-sample of 1,285 subjects (25-64 years) free from any medication interfering with BP or potassium excretion was studied. Results 86.0% of participants consumed over 6 g of salt/day and 87.7% less than the recommended intake of potassium (4.7 g). Potassium excretion and the sodium to potassium ratio were significantly related to systolic and diastolic BP only in subjects consuming more than 6 g/day of salt. Subjects in the highest sodium to potassium ratio quartile (surrogate of unhealthy diet) presented 8 mmHg and 7 mmHg higher values of systolic and diastolic BP, respectively, when compared with the first quartile whilst individuals in the fourth quartile of urinary potassium excretion (healthier diet) showed 6 mmHg and 4 mmHg lower systolic and diastolic BP, respectively, compared with the first quartile. Conclusion Our data indicate that when people have an increased intake of potassium, high intake of sodium is not associated with higher BP.Journal of the American Society of Hypertension (JASH) 04/2014; DOI:10.1016/j.jash.2014.01.001 · 2.68 Impact Factor
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ABSTRACT: BACKGROUND Although the trajectory of blood pressure (BP) with aging is well known, there is a lack of data on how cardiorespiratory fitness (hereafter referred to as fitness) affects age-associated changes in BP. OBJECTIVES The objective of the study was to investigate whether fitness alters the aging-BP trajectory. METHODS A cohort from the Aerobics Center Longitudinal Study totaling 13,953 men between 20 and 90 years of age who did not have hypertension, cardiovascular disease, or cancer completed 3 to 28 (mean of 3.8) follow-up medical examinations between 1970 and 2006. Fitness was measured by a maximal treadmill exercise test. Longitudinal data were analyzed using linear mixed models. RESULTS Diastolic blood pressure (DBP) tended to increase until nearly 60 years of age, when a decrease was observed. Systolic blood pressure (SBP) tended to increase over all age periods. On multivariate analysis, average SBP increased by 0.30 mm Hg (95% confidence interval: 0.29 to 0.31) with 1-year age increment after adjusting for body fat percent, fitness, resting heart rate, glucose level, triglyceride level, cholesterol level, current smoking, heavy alcohol consumption, and parental history of hypertension. DBP had a yearly increase of 0.14 mm Hg (95% confidence interval: 0.13 to 0.15) before age 60 years. Overall, abnormal SBP (> 120 mm Hg) began to occur at approximately 50 years of age and abnormal DBP (> 80 mm Hg) began to occur at 60 years of age. Men with higher fitness levels experienced abnormal SBP later than those with low fitness levels. CONCLUSIONS Our findings underscore the potential modifying effect of fitness on BP trajectory with aging over the male adult life span. Improving fitness levels might extend the normal SBP and DBP ranges, delaying the development of hypertension. (C) 2014 by the American College of Cardiology Foundation.Journal of the American College of Cardiology 09/2014; 64(12):1245-53. DOI:10.1016/j.jacc.2014.06.1184 · 15.34 Impact Factor
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ABSTRACT: A low Na, high K diet (LNaHK) is associated with a low rate of cardiovascular (CV) disease in many societies. Part of the benefit of LNaHK relies on its diuretic effects; however, the role of aldosterone (aldo) in the diuresis is not understood. LNaHK mice exhibit an increase in renal K secretion that is dependent on the large, Ca-activated K channel, (BK-α with accessory BK-β4; BK-α/β4). We hypothesized that aldo causes an osmotic diuresis by increasing BK-α/β4-mediated K secretion in LNaHK mice. We found that the plasma aldo concentration (P[aldo]) was elevated by 10-fold in LNaHK mice compared with control diet (Con) mice. We subjected LNaHK mice to either sham surgery (sham), adrenalectomy (ADX) with low aldo replacement (ADX-LA), or ADX with high aldo replacement (ADX-HA). Compared to sham, the urinary flow, K excretion rate, transtubular K gradient (TTKG), and BK-α and BK-β4 expressions, were decreased in ADX-LA, but not different in ADX-HA. BK-β4 knockout (β4KO) and WT mice exhibited similar K clearance and TTKG in the ADX-LA groups; however, in sham and ADX-HA, the K clearance and TTKG of β4KO were less than WT. In response to amiloride treatment, the osmolar clearance was increased in WT Con, decreased in WT LNaHK, and unchanged in β4KO LNaHK. These data show that the high P[aldo] of LNaHK mice is necessary to generate a high rate of BK-α/β4-mediated K secretion, which creates an osmotic diuresis that may contribute to a reduction in CV disease.PLoS ONE 01/2015; 10(1):e0115515. DOI:10.1371/journal.pone.0115515 · 3.53 Impact Factor