The effect of medication compliance on the control of hypertension

The effect of medication-taking patterns on blood pressure was investigated in 24 hypertensive outpatients being treated with once-daily doses of hydrochlorothiazide or chlorthalidone. Medication-taking patterns were measured with a small pill dispenser that electronically records the time of medication removal. Blood pressure reduction was found to correlate better with the total number of doses the patient removed from the pill pack during a month than with any of four other compliance measures that were based on the timing of dose removal. Analysis also suggested that blood pressure is improved if patients ingest omitted doses to "catch up" to the prescribed regimen. It is concluded that a simple pill count may be the most clinically relevant definition of compliance for patients with hypertension being treated with only hydrochlorothiazide or chlorthalidone, and that such patients should ingest all prescribed doses, regardless of the time interval between doses.     

天津市社区居民血压分级管理的效果

目的评价以社区为基础的血压分级管理方式的血压控制效果,探索经济高效的血压管理模式。方法选取天津市城市社区高血压患者897例参加卫生部"维持健康血压和体质量综合干预项目",建立健康档案并根据危险因素分级将研究对象分为4个血压管理组,对各组分别开展为期1年的血压分级管理。结果血压分级管理1年后,研究对象血压水平相较于基线水平收缩压和舒张压分别下降7.74和3.78mmHg(P<0.05);按照危险因素分层后,低危组、中危组、高危组和很高危组舒张压水平分别下降了3.60、3.78、4.04和3.50mmHg(P<0.05),除低危组外,中危组、高危组和很高危组收缩压水平分别下降了7.44、6.77和9.58mmHg(P<0.05)。经过为期1年的管理,研究对象血压控制率由49.3%升高到86.6%(P<0.05);除低危组外,其余3组血压控制率均有明显提高(P<0.05)。血压水平随规范化随访次数的增加呈明显的下降趋势。结论以社区为基础的血压分级管理措施效果明显,能够明显改善城市社区高血压患者的血压控制,同时有助于合理膳食和健康生活方式的推广普及。     

The 2004 Canadian recommendations for the management of hypertension: Part III--Lifestyle modifications to prevent and control hypertension

OBJECTIVE: To provide updated, evidence-based recommendations regarding the role of lifestyle modification in the treatment and prevention of hypertension. OUTCOMES: Lifestyle modification interventions including exercise, weight reduction, alcohol consumption, dietary modification, intake of dietary cations and stress management are reviewed. Antioxidants and fish oil supplements are also reviewed, although specific recommendations cannot be made at present. EVIDENCE: MEDLINE searches were conducted from January 2002 to September 2003 to update the 2001 recommendations for the management of hypertension. Supplemental searches in the Cochrane Collaboration databases were also performed. Reference lists were scanned, experts were contacted, and the personal files of the subgroup members and authors were used to identify additional published studies. All relevant articles were reviewed and appraised independently using prespecified levels of evidence by content and methodology experts. RECOMMENDATIONS: Key recommendations include the following: lifestyle modification should be extended to nonhypertensive individuals who are at risk for developing high blood pressure; 30 min to 45 min of aerobic exercise should be performed on most days (four to five days) of the week; an ideal body weight (body mass index 18.5 kg/m2 to 24.9 kg/m2) should be maintained and weight loss strategies should use a multidisciplinary approach; alcohol consumption should be limited to two drinks or fewer per day, and weekly intake should not exceed 14 standard drinks for men and nine standard drinks for women; a reduced fat, low cholesterol diet that emphasizes fruits, vegetables and low fat dairy products, and maintains an adequate intake of potassium, magnesium and calcium, should be followed; salt intake should be restricted to 65 mmol/day to 100 mmol/day in hypertensive individuals and less than 100 mmol/day in normotensive individuals at high risk for developing hypertension; and stress management should be considered as an intervention in selected individuals. VALIDATION: All recommendations were graded according to the strength of the evidence and voted on by the Canadian Hypertension Education Program Evidence-Based Recommendations Task Force. Individuals with irreconcilable competing interests (declared by all members, compiled and circulated before the meeting) relative to any specific recommendation were excluded from voting on that recommendation. Only those recommendations achieving at least 70% consensus are reported here. These guidelines will continue to be updated annually.     

The age and sex incidence of arterial hypertension

It has often been stated that essential hypertension² is found most frequently among middle-aged and pre-elderly individuals. In only a few instances, however, have the statements been accompanied by statistics. Similarly, although the condition has been said to be more common among men than among women, the basis for establishing this as a fact has not been presented.There are few data available that concern directly either the age or the sex incidence of hypertension. However, a number of contributions appear in the literature, which contain reference to the ages of patients who were presented as illustrations of various aspects of hypertension or sphygmomanometry. Tables I-A-I-E compare the results of some of these investigations calculated and arranged according to the percentage of patients in different age periods.These reports have been separated into four groups as follows: A, hypertension as found in different periods of life; B, age of patients with hypertension at time of death; C, life insurance statistics; D, E, hospital reports. This classification is necessary for a discussion of the age incidence of hypertension because each group possesses characteristics which make it difficult to compare one group with another.     

Blood pressure control and physician management of hypertension in hospital hypertension units in Spain

Goal blood pressure (BP) was defined by the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI) and the World Health Organization-International Society of Hypertension (WHO/ISH) as <140 mm Hg systolic and <90 mm Hg diastolic for the general and <130 mm Hg systolic and <85 mm Hg diastolic for special high-risk populations. However, there are few reports that address BP control among special subgroups of hypertensives by reference to targeted BP. We therefore conducted a study to evaluate BP control of 4049 hypertensives in 47 hospital-based hypertension units in Spain. Overall, 42% of patients achieved goal BP (<140 mm Hg systolic and <90 mm Hg diastolic). Only 13% of diabetic patients and 17% of those with renal disease achieved the BP goal (<130 mm Hg systolic and <85 mm Hg diastolic), and only 10% and 12%, respectively, achieved the even more rigorous goal (<130 mm Hg systolic and <80 mm Hg diastolic). Likewise, only 18% of patients in JNC-VI risk group C and 17% of WHO/ISH high-risk patients attained a goal BP <130 mm Hg systolic and <85 mm Hg diastolic. BP control (<125 mm Hg systolic and <75 mm Hg diastolic) was extremely low (2%) in patients with proteinuria >1 g/d. Poorer BP control was observed among patients at high risk, with diabetes, renal disease, or obesity, than in lower-risk groups. BP control was lower for systolic than for diastolic BP. In >50% of uncontrolled patients, no measures were taken by doctors to optimize pharmacologic treatment, and approximately one-third of patients were still using drug monotherapy. Control of BP, particularly of systolic BP, is still far from optimal in hospital-based hypertension units. Patients at high risk, with diabetes or proteinuria, warrant focused attention. Moreover, a more aggressive behavior of doctors treating uncontrolled hypertension is needed.     

The management of portal hypertension

Portal hypertension is an almost unavoidable complication of cirrhosis, and it is responsible for the more lethal complications of this syndrome. Appearance of these complications represents the major cause of death and liver transplantation in patients who have cirrhosis. This article highlights treatment modalities in use for managing portal hypertension and those that may be available in the future.     

The effect of age on the control of water conservation in the laboratory mouse--metabolic studies

Age-related changes in the intake of food and water, and the output of faeces and urine were investigated in C57BL/Icrfat mice of 6 and 24 months of age. Animals were singly housed in a metabolic cage for a period of 30 days. 14 days were allowed for acclimatization before the animals were dehydrated for 24 hours. 10 days of rehydration were allowed prior to a hyperosmotic challenge with 3% sodium chloride in the drinking water. The animals were then observed for 5 more days of rehydration. Urine was collected and analysed with regard to sodium, potassium, urea and vasopressin output/24 hours (/100g body weight), and the osmotic pressure of the urine was determined. Data were analysed by a 2 factor analysis of variance with repeated measures on one factor. Significant changes were detected in the control of body weight, potassium, sodium and urea outputs. No age-differences were detected in the intake of food or water, the output of faeces or urine, the urine osmotic pressure or the excretion of vasopressin. However, significant changes in these variables were detected in both age groups on the days of physiological challenge. The conclusion drawn is that in the mouse strain studied, and for the period of the lifespan investigated, there is no age related defect in the secretion of vasopressin. However, there are trends in the data suggesting a decreased responsiveness of the kidney with age.     

Blood pressure control in essential hypertension and impairment of renal function with age

Hypertension has been recognized to be an important cause for the development of end-stage renal disease (ESRD). We assessed the quality of blood pressure control in 103 patients with essential hypertension and correlated renal function and age. Patients were stratified into three subgroups by their blood pressure level under current medication. Group 1 were hypertensive patients with normalized blood pressure (<140/90 mmHg, n = 25), group 2 patients with mild hypertension (140-159/90-99 mmHg, n = 43) and group 3 patients with moderate to severe hypertension (> 160/100 mmHg, n = 35). A negative correlation between age and creatinine clearance (Ccr) could be confirmed for patients of group 1 (correlation coefficient r1 = -0.56; p, < 0.01) and group 2 (r2 = -0.55; P2 < 0.001). Furthermore the regression coefficient (m) of decline in C(Cr) versus age was higher in group 2 patients (m2 = -1.83) than in group 1 (m1 = -1.30). In group 3 we found no correlation of renal function with age, indicating that age may not be the leading variable. Patients in group 1 were all within normal limits of age adjusted Ccr, but 12% in group 2 and 23% in group 3 had impaired C(Cr). Furthermore proteinuria was found to be 20% (group 1), 26% (group 2) and 31% (group 3). This analysis provides further evidence of the importance of blood pressure control in essential hypertension to preserve renal function.     

The effect of age on bronchodilator responsiveness

The relationship between age and bronchodilator responsiveness (BDR) in children has not been studied using objective parameters. The aim of this study was to seek such a relationship in young asthmatic children using dose—response curves (DRC). Fourteen asthmatic subjects (age 3–9 years) with a forced expiratory volume in 1 sec (FEV₁) less than 80% predicted were studied after being trained to use a spirometer reliably. Each subject completed a DRC by inhaling 5 doses of salbutamol (albuterol) at 15 min intervals until a cumulative total of 6.84 mg of salbutamol had been administered. FEV₁, forced vital capacity (FVC), and forced expiratory flow at mid vital capacity (FEF_25?75) were measured before and after each nebulization. In addition, arterial oxygen saturation (Sa_O2) and heart rate (HR) were measured in some of the subjects. All lung function parameters, Sa_O2 and HR increased significantly between baseline and completion of the DRC. A significant age effect on BDR was detected in FEV₁ and FVC, with older children showing a greater response than young ones. The response had plateaued after the maximum dose in the younger but not in the older children. These findings suggest that the level of response to a bronchodilator increases significantly with increasing age in young asthmatics. © 1993 Wiley-Liss, Inc.     

The effect of age on methotrexate efficacy and toxicity

We studied the clinical course of 235 patients with rheumatoid arthritis (RA) receiving methotrexate (MTX) over a mean of 1.9 years. Both older (greater than 65 years) and younger (less than or equal to 65 years) patients demonstrated clinical improvement, but older patients had greater improvement in erythrocyte sedimentation rate and hemoglobin than younger patients. Most assessments of laboratory abnormalities and symptoms suggestive of toxicity did not differ between age groups. But more gastrointestinal complaints and pulmonary complaints were reported in older patients, associations that have been noted in older patients not treated with MTX as well. Our data indicate that treatment that includes MTX is effective in older patients with RA, and that older patients improve at least as much as younger.     

The effect of age on central and regional hemodynamics

16 normal subjects, ranging in age from 24 to 79 years, underwent simultaneous central and regional (renal, hepatic and limb) hemodynamic measurements; the purpose of this investigation was to determine the relationship between these measurements and age. Cardiac index was inversely related to age, with a correlation coefficient of -0.53 (p less than 0.05). Renal blood flow correlated inversely with age at an r value of -0.52 (p less than 0.05). Although the correlation coefficients did not achieve statistical significance, several trends were noted with increasing age: systemic vascular resistance, renal, hepatic and limb vascular resistances, and mean systemic blood pressure increase and hepatic and limb flows decrease. In normal human subjects, certain central and regional hemodynamic parameters change with age; these changes may ultimately influence function and perhaps, drug disposition (liver and kidney) as well.     

Positive effect of CPAP treatment on the control of difficult-to-treat hypertension.

The aim of the present study was to analyse the role of continuous positive airway pressure (CPAP) treatment in patients with difficult-to-control hypertension (DC-HT) and sleep apnoea. An Autoset (ResMed, Sydney, Australia) study was performed in 60 patients diagnosed with DC-HT based on two 24-h ambulatory blood pressure monitorisation (ABPM) studies. CPAP was offered to patients with an apnoea/hypopnoea index (AHI) > or =15 events.h(-1). After 3 months of treatment, repeat ABPM was performed to evaluate the effect of CPAP upon the blood pressure values. A total of 39 (65%) patients received CPAP treatment, but only 33 completed the study. The mean+/-sd systolic and diastolic blood pressures (SBP and DBP, respectively) were 154.8+/-14 and 90+/-8.8 mmHg. Patients had a mean+/-sd AHI of 37.7+/-18.2 events.h(-1). Only three patients presented a dipper nocturnal pressure pattern. CPAP treatment significantly reduced SBP (-5.2 mmHg), and particularly the nocturnal values (-6.1 mmHg), but not DBP. Considering only those patients who tolerated CPAP, the decrease in SBP was greater (-7.3 mmHg). Furthermore, CPAP treatment significantly increased the percentage of patients who recovered the dipper pattern (three (9.1%) out of 33 versus 12 (36.4%) out of 33). Continuous positive airway pressure treatment significantly reduces systolic blood pressure, particularly at night, and normalises the nocturnal pressure pattern in patients with difficult-to-control hypertension and sleep apnoea.     

The effects of age on pulse wave velocity in untreated hypertension

Increased arterial stiffness is an important determinant of cardiovascular risk, able to predict morbidity and mortality, and closely associated with ageing and blood pressure. The aims of this study were: (1) To determine the age‐dependent reference pulse wave velocity (PWV), and compare it with values from hypertensive patients, and (2) to evaluate the impact of isolated and untreated hypertension on arterial stiffness. A total of 1079 patients were enrolled and divided into a control group (NT) of asymptomatic normotensive patients and a group of asymptomatic hypertensive patients (HT). Blood pressure, carotid‐femoral PWV, and body mass index were measured in each subject, whose blood was drawn for laboratory tests. Aortic mean PWV in the NT group was 6.85 ± 1.66 m/s, which increased linearly (R² = 0.62; P < .05) with age. In patients over 50 years of age, PWV was significantly higher than in younger patients (8.35 vs 5.92 m/s, respectively, P < .001). This significant difference persisted when observing male and female patients separately. In the hypertensive group, mean PWV value was 8.04 ± 1.8 m/s (range 4.5‐15.8 m/s) and increased (R² = 0.243; P < .05) with age. The PWV increase in HT was significantly higher (0.93 m/s per decade, P < .001) than in NT (0.44 m/s per decade). Our study provides normal values of PVW per decade, and shows that these values increase with age, especially after 50 years of age, particularly in HT patients. This stiffness growth rate may be responsible for increased cardiovascular risk in both groups.