Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study

PARTICIPANTS: 103 570 people who provided morning fasting urine samples. MAIN OUTCOME MEASURES: Association of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high (>5 g/day) sodium intakes) by potassium excretion (greater/equal or less than median 2.1 g/day). RESULTS: OBJECTIVE: To evaluate the joint association of sodium and potassium urinary excretion (as surrogate measures of intake) with cardiovascular events and mortality, in the context of current World Health Organization recommendations for daily intake (<2.0 g sodium, >3.5 g potassium) in adults. DESIGN: International prospective cohort study. SETTING: 18 high, middle, and low income countries, sampled from urban and rural communities. ARTICIPANTS: 103 570 people who provided morning fasting urine samples. MAIN OUTCOME MEASURES: Association of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high (>5 g/day) sodium intakes) by potassium excretion (greater/equal or less than median 2.1 g/day). RESULTS: Mean estimated sodium and potassium urinary excretion were 4.93 g/day and 2.12 g/day, respectively. After a median follow-up of 8.2 years, 7884 (6.1%) participants had died or experienced a major cardiovascular event. Increasing urinary sodium excretion was positively associated with increasing potassium excretion (unadjusted r=0.34), and only 0.002% had a concomitant urinary excretion of <2.0 g/day of sodium and >3.5 g/day of potassium. A J-shaped association was observed of sodium excretion and inverse association of potassium excretion with death and cardiovascular events. For joint sodium and potassium excretion categories, the lowest risk of death and cardiovascular events occurred in the group with moderate sodium excretion (3-5 g/day) and higher potassium excretion (21.9% of cohort). Compared with this reference group, the combinations of low potassium with low sodium excretion (hazard ratio 1.23, 1.11 to 1.37; 7.4% of cohort) and low potassium with high sodium excretion (1.21, 1.11 to 1.32; 13.8% of cohort) were associated with the highest risk, followed by low sodium excretion (1.19, 1.02 to 1.38; 3.3% of cohort) and high sodium excretion (1.10, 1.02 to 1.18; 29.6% of cohort) among those with potassium excretion greater than the median. Higher potassium excretion attenuated the increased cardiovascular risk associated with high sodium excretion (P for interaction=0.007). CONCLUSIONS: These findings suggest that the simultaneous target of low sodium intake (<2 g/day) with high potassium intake (>3.5 g/day) is extremely uncommon. Combined moderate sodium intake (3-5 g/day) with high potassium intake is associated with the lowest risk of mortality and cardiovascular events. (AU)

Practice patterns and outcomes after stroke across countries at different economic levels (INTERSTROKE): an international observational study

BACKGROUND: Stroke disproportionately affects people in low-income and middle-income countries. Although improvements in stroke care and outcomes have been reported in high-income countries, little is known about practice and outcomes in low and middle-income countries. We aimed to compare patterns of care available and their association with patient outcomes across countries at different economic levels. METHODS: We studied the patterns and effect of practice variations (ie, treatments used and access to services) among participants in the INTERSTROKE study, an international observational study that enrolled 13447 stroke patients from 142 clinical sites in 32 countries between Jan 11, 2007, and Aug 8, 2015. We supplemented patient data with a questionnaire about health-care and stroke service facilities at all participating hospitals. Using univariate and multivariate regression analyses to account for patient casemix and service clustering, we estimated the association between services available, treatments given, and patient outcomes (death or dependency) at 1 month. FINDINGS: We obtained full information for 12342 (92%) of 13447 INTERSTROKE patients, from 108 hospitals in 28 countries; 2576 from 38 hospitals in ten high-income countries and 9766 from 70 hospitals in 18 low and middle income countries. Patients in low-income and middle-income countries more often had severe strokes, intracerebral haemorrhage, poorer access to services, and used fewer investigations and treatments (p<0·0001) than those in high income countries, although only differences in patient characteristics explained the poorer clinical outcomes in low and middle-income countries. However, across all countries, irrespective of economic level, access to a stroke unit was associated with improved use of investigations and treatments, access to other rehabilitation services, and improved survival without severe dependency (odds ratio [OR] 1·29; 95% CI 1·14­1·44; all p< 0·0001), which was independent of patient casemix characteristics and other measures of care. Use of acute antiplatelet treatment was associated with improved survival (1·39; 1·12­1·72) irrespective of other patient and service characteristics. INTERPRETATION: Evidence-based treatments, diagnostics, and stroke units were less commonly available or used in low and middle-income countries. Access to stroke units and appropriate use of antiplatelet treatment were associated with improved recovery. Improved care and facilities in low-income and middle-income countries are essential to improve outcomes.

Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study

BACKGROUND: The relationship between macronutrients and cardiovascular disease and mortality is controversial. Most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear. METHODS: The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of individuals aged 35-70 years (enrolled between Jan 1, 2003, and March 31, 2013) in 18 countries with a median follow-up of 7·4 years (IQR 5·3-9·3). Dietary intake of 135 335 individuals was recorded using validated food frequency questionnaires. The primary outcomes were total mortality and major cardiovascular events (fatal cardiovascular disease, non-fatal myocardial infarction, stroke, and heart failure). Secondary outcomes were all myocardial infarctions, stroke, cardiovascular disease mortality, and non-cardiovascular disease mortality. Participants were categorised into quintiles of nutrient intake (carbohydrate, fats, and protein) based on percentage of energy provided by nutrients. We assessed the associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality. We calculated hazard ratios (HRs) using a multivariable Cox frailty model with random intercepts to account for centre clustering...

Association of urinary sodium and potassium excretion with blood pressure

Higher levels of sodium intake are reported to be associated with higher bloodpressure. Whether this relationship varies according to levels of sodium or potassiumintake and in different populations is unknown.MethodsWe studied 102,216 adults from 18 countries. Estimates of 24-hour sodium andpotassium excretion were made from a single fasting morning urine specimen andwere used as surrogates for intake. We assessed the relationship between electrolyteexcretion and blood pressure, as measured with an automated device.ResultsRegression analyses showed increments of 2.11 mm Hg in systolic blood pressureand 0.78 mm Hg in diastolic blood pressure for each 1-g increment in estimatedsodium excretion. The slope of this association was steeper with higher sodiumintake (an increment of 2.58 mm Hg in systolic blood pressure per gram for sodiumexcretion >5 g per day, 1.74 mm Hg per gram for 3 to 5 g per day, and 0.74 mm Hgper gram for 55 years of age, 2.43 mm Hg pergram at 45 to 55 years of age, and 1.96 mm Hg per gram at <45 years of age;P<0.001 for interaction). Potassium excretion was inversely associated with systolicblood pressure, with a steeper slope of association for persons with hypertensionthan for those without it (P<0.001) and a steeper slope with increased age (P<0.001).ConclusionsIn this study, the association of estimated intake of sodium and potassium, as determinedfrom measurements of excretion of these cations, with blood pressurewas nonlinear and was most pronounced in persons consuming high-sodium diets,persons with hypertension, and older persons. (Funded by the Heart and StrokeFoundation of Ontario and others).