Effects of oral potassium on blood pressure: meta-analysis of randomized controlled clinical trials
Por: WheltonP K, HeJ, CutlerJ A, BrancatiF L, AppelL J, FollmannD and KlagM J, . Effects of oral potassium on blood pressure: meta-analysis of randomized controlled clinical trials. JAMA 1997;277(20) :1624-1632.
Authors’ objectives
To assess the effects of supplementation with oral potassium on blood-pressure (BP) in humans.
Searching
MEDLINE was searched using the terms ‘blood pressure’, ‘dietary potassium’, ‘potassium’ and ‘potassium chloride’. Bibliographies of original articles and reviews, and the authors’ own reference files were also examined. Only English-language articles published before 1995 were considered.
Study selection: study designs
Randomised controlled trials (RCTs) of either parallel or crossover design were included. The duration of the studies varied from 4 days to 3 years.
Study selection: specific interventions
Potassium supplementation administered as a pill (in the form of potassium chloride, potassium citrate and bicarbonate) or as part of the diet. Dosage of potassium prescribed in the intervention arm was at least 60 mmol/day in all but 2 trials, and at least 100 mmol/day in 10 trials (median, 75 mmol/day). The intervention arm was compared to a control group of either placebo, lower dose of potassium, or no supplementation. Antihypertensive medications were administered concurrently in 4 of the trials.
Study selection: participants
Both hypertensive and normotensive participants (aged 19 years) were included in the review.
Study selection: outcomes
The net change from pre-treatment to end of follow-up in urinary excretion of sodium and potassium, body weight, and BP (systolic and diastolic) for treatment and control conditions. The mean 24-hour urinary sodium excretion during follow-up, recorded at the trial’s end.
Study selection: how were decisions on the relevance of primary studies made?
The primary studies were assessed independently for relevance by two of the review’s authors. Areas of disagreement or uncertainty were adjudicated by other authors.
Validity assessment
No formal validity assessment was carried out, although study design details were recorded during the data extraction phase; these included whether the trial was of parallel, crossover or open design, single-blind or double-blind. Details of the study design were recorded independently by two of the authors who were blinded to each other’s coding. This process was carried out during the data extraction phase.
Results of the review
Thirty-three RCTs (1,560 hypertensive and 1,005 normotensive participants) were included: 3 of crossover open design, 2 crossover single-blind, 16 crossover double-blind, 4 parallel open, 1 parallel single, and 7 parallel double-blind.
Due to significant variation in effect size across the 33 trials, only results from the random-effects model are presented.
CRD database number: DARE-11997008171
Index terms
Subject index terms
Subject indexing assigned by NLM: Medical Subject Headings (MeSH): Administration, Oral; Blood Pressure[drug effects]; Food, Fortified; Hypertension[prevention & control]; Potassium[administration & dosage]; Potassium[pharmacology]; Potassium[urine]; Randomized Controlled Trials as Topic; Sodium[urine]; Statistics as Topic
A multimodal blood pressure control intervention in 3 healthcare systems.
Por: Magid DJ, Ho PM, Olson KL, Brand DW, Welch LK, Snow KE, Lambert-Kerzner AC, Plomondon ME y Havranek EP.
Source: Am J Manag Care. 2011 Apr;17(4):e96-103.
Institute for Health Research, Kaiser Permanente Colorado, Denver, USA. david.j.magid@kp.org
OBJECTIVE:
To determine if a multimodal intervention composed of patient education, home blood pressure (BP) monitoring, BP measurement reporting to an interactive voice response (IVR) phone system, and clinical pharmacist follow-up improves BP control compared with usual care.
STUDY DESIGN:
Prospective study with patient enrollment, medication consultation and adjustment, remote BP monitoring, and follow-up at 6 months.
METHODS:
This randomized controlled trial was conducted at 3 healthcare systems in Denver, Colorado, including a large health maintenance organization, a Veterans Affairs medical center, and a county hospital. At each site, patients with uncontrolled BP were randomized to the multimodal intervention vs usual care for 6 months, with the primary end point of BP reduction.
RESULTS:
Of 338 patients randomized, 283 (84%) completed the study, including 138 intervention patients and 145 usual care patients. Baseline BP was higher in the intervention group vs the usual care group (150.5/89.4 vs 143.8/85.3 mm Hg). At 6 months, BPs were similar in the intervention group vs the usual care group (137.4 vs 136.7 mm Hg, P = .85 for systolic; 82.9 vs 81.1 mm Hg, P = .14 for diastolic). However, BP reductions were greater in the intervention group vs the usual care group (−13.1 vs −7.1 mm Hg, P = .006 for systolic; −6.5 vs −4.2 mm Hg, P = .07 for diastolic). Adherence to medications was similar between the 2 groups, but intervention patients had a greater increase in medication regimen intensity.
CONCLUSIONS:
A multimodal intervention of patient education, home BP monitoring, BP measurement reporting to an IVR system, and clinical pharmacist follow-up achieved greater reductions in BP compared with usual care.
PMID: 21774100.
Por: A Januszewicz, E Ritz, G Viberti, A Mimran, A J Rabelink, L C Rump, L M Ruilope, S Katayama, S Ito, J L Izzo Jr. y H Haller. Journal of Human Hypertension (2011) 25, 679–685.
Para investigar la asociación entre las consultas y el metodo ambulatorio de 24 horas de la presión del pulso (PP), con características clínicas y factores de riesgo cardiovascular con pacientes del tipo de normoalbuminúricos 2 y en pacientes diabéticos que toman olmesartán de manera aleatoria, se realizó un estudio para la prevención de la microalbuminuria en 4449 pacientes (2054 hombres y 2395 mujeres, con una media edad 57.7 ± 8.7 años) con diabetes tipo 2, normoalbuminuria y al menos un factor de riesgo cardiovascular adicional se incluyeron en el análisis.
Prehypertension and the Continuum of Stroke Risk
Prehypertension, especially in the higher range, is associated with incident stroke.
To assess whether so-called prehypertension is associated with incident stroke, researchers
conducted a meta-analysis of prospective cohort studies. The analysis included 518,520
participants from 12 studies originating in the U.S., China, Japan, and India. Prehypertension was
defined as systolic blood pressure of 120–139 mm Hg or diastolic blood pressure of 80–89 mm Hg.
In seven of the studies, prehypertension was further subdivided into a low range (120–129 mm Hg
systolic or 80–84 mm Hg diastolic) and a high range (130–139 mm Hg systolic or 85–89 mm Hg
diastolic).
Overall, prehypertension was associated with a significantly increased risk for stroke (relative risk,
1.55) that was driven by higher-range prehypertension (RR, 1.79). Lower-range prehypertension was
not significantly associated with increased stroke risk. In subgroup analyses by baseline
characteristics, the association was not affected by race/ethnicity, stroke endpoint (fatal vs. all
stroke), stroke subtype (ischemic vs. hemorrhagic), or follow-up duration (<10 vs. ≥10 years). The
association did not remain significant for people older than 65 and when study quality was only
“fair.”
The authors conclude that prehypertension, especially in the higher range, is associated with incident stroke.
Hypertension is associated with stroke on a continuum of risk (Lancet Neurol 2002; 1:149). For example, mild, moderate, and severe hypertension are all associated with stroke risk, with the
highest relative risk for stroke among those with the highest blood pressure, and the greatest
absolute number of strokes in those with mild or “high-normal” blood pressure, a designation that
includes prehypertension. The current findings support the concept of a continuum of risk for stroke
with increasing blood pressure, especially among patients with higher-range prehypertension.
However, whether lowering blood pressure in the prehypertension range will reduce stroke risk
remains uncertain; this hypothesis deserves additional efficacy, safety, and cost-effectiveness
testing. Currently, rigorous lifestyle modification is recommended for people with prehypertension. A
blood pressure target <130/80 mm Hg has been recommended for those with, for example, diabetes
mellitus, chronic renal disease, or carotid artery disease and for those with 10-year Framingham risk scores of ≥10% (Circulation 2007; 115:2761).
(Fuente: neurology.jwatch.org)
La enfermedad renal es la patología concomitante que más empeora la calidad de vida relacionada con la salud de los pacientes hipertensos, según revela el trabajo ‘Influencia del riesgo cardiovascular y factores predictores de la calidad de vida en pacientes hipertensos. Estudio Alhambra’, presentado recientemente en Sevilla, en el marco del ‘XLI Congreso Nacional de la Sociedad Española de Nefrología’.
El objetivo de este estudio, al que ha tenido acceso Europa Press, ha sido precisamente el de establecer la relación entre la calidad de vida relacionada con la salud y el nivel de riesgo cardiovascular, además de estudiar los factores predictores de esta calidad de vida relacionada con la salud en una población de pacientes hipertensos españoles.
Para tal fin, sus autores llevaron a cabo un estudio epidemiológico, transversal, multicéntrico y nacional en pacientes adultos con hipertensión arterial esencial con al menos un año de evolución.
La estratificación del riesgo cardiovascular (RCV) se realizó agrupando a los pacientes en cinco estratos en los próximos 10 años (RCV promedio, adicional bajo, adicional moderado, adicional alto y adicional muy alto), según cifras de presión arterial, presencia de factores de RCV, enfermedades concominantes, lesiones orgánicas subclínicas o patología cardiovascular o renal establecida.
La calidad de vida relacionada con la salud se determinó mediante el cuestionario MINICHAL, que evalúa las dimensiones del estado de ánimo y las manifestaciones somáticas en los últimos siete días, siendo las puntuaciones más elevadas indicativas de peor calidad de vida relacionada con la salud.
Además, se realizó un análisis de agresión múltiple para determinar factores predictores de esta calidad de vida, incluyendo como variables independientes las patologías concomitantes, entre otras.
Esta investigación incluyó a 6.654 pacientes evaluables (55,2% de varones), con una edad media de 62,7 años y con una media de años transcurridos desde el diagnóstico de la hipertensión arterial de 7,9 años. Al analizar los datos, un 3,5 por ciento presentó riesgo cardiovascular promedio, un 13,6 por ciento adicional bajo, un 12,8 por ciento adicional moderado, un 39 por ciento adicional alto y un 31 por ciento adicional muy alto.
Del mismo modo, los autores de esta investigación observaron un aumento progresivo en las puntuaciones de las dos dimensiones del cuestionario a mayor riesgo cardiovascular tuvieran los pacientes.
Según el análisis multivariado, el factor que más influyó negativamente en la calidad de vida relacionada con la salud del paciente hipertenso fue la presencia de enfermedad renal. También empeoró esta calidad de vida, aunque en menor grado, la presencia de obesidad, de diabetes o de enfermedad cardiovascular.
Por todo ello, los investigadores de este trabajo concluyen que a mayor riesgo cardiovascular, “peor calidad de vida presentan los pacientes hipertensos, tanto a nivel emocional como somático”. Entre las variables analizadas, la enfermedad renal “es la patología concomitante que más empeora la calidad de vida relacionada con la salud de los pacientes hipertensos”.
(Fuente: Europapress.es)
Comentarios recientes