Prehypertension: should we be treating with pharmacologic therapy?

Cardiovascular risk screening: a 10-year prediction cross-sectional study in a Nigerian agrarian community

Introduction

cardiovascular disease (CVD) is a major public health issue with a high global death rate and a significant death contribution from low-and middle-income countries. Modifiable and non-modifiable risk factors assessment and screening are important in their effective prevention and control. This study was designed to screen and assess cardiovascular risk factors in an agrarian community in Nigeria and to predict their 10-year CVD risk.

Methods

this was a cross-sectional study carried out in the Umueri community in Anambra State, Nigeria. Each participant responded to an epidemiologic survey using the World Health Organization (WHO) cardiovascular risk factors assessment tool with point-of-care screening procedures. The risk assessment for 10-year CV risk was conducted using region-specific WHO/ISH charts. Patients´ characteristics were analyzed and presented in frequencies and percentages.

Results

the mean age, systolic blood pressure, fasting plasma glucose, and total cholesterol of the study population were 54 years ± 1.27, 132 mmHg ± 2.088, 130 mg/dl ± 4.608, and 215 mg/dl ± 10.355 respectively. However, 98 (48.8%) have never had their blood pressure checked. About a quarter of the population had a high predicted risk of developing CVD within 10 years.

Conclusion

most of the assessed cardiovascular risk factors in the community are on average above the normal ranges and their probability risk of developing CVD within the next 10 years is high.

Prehypertension--prevalence, health risks, and management strategies

Prehypertension (blood pressure 120-139/80-89 mmHg) affects ~25-50% of adults worldwide, and increases the risk of incident hypertension. The relative risk of incident hypertension declines by ~20% with intensive lifestyle intervention, and by 34-66% with single antihypertensive medications. To prevent one case of incident hypertension in adults with prehypertension and a 50% 5-year risk of hypertension, 10 individuals would need to receive intensive lifestyle intervention, and four to six patients would need to be treated with antihypertensive medication. The relative risk of incident cardiovascular disease (CVD) is greater with 'stage 2' (130-139/85-89 mmHg) than 'stage 1' (120-129/80-84 mmHg) prehypertension; only stage 2 prehypertension increases cardiovascular mortality. Among individuals with prehypertension, the 10-year absolute CVD risk for middle-aged adults without diabetes mellitus or CVD is ~10%, and ~40% for middle-aged and older individuals with either or both comorbidities. Antihypertensive medications reduce the relative risk of CVD and death by ~15% in secondary-prevention studies of prehypertension. Data on primary prevention of CVD with pharmacotherapy in prehypertension are lacking. Risk-stratified, patient-centred, comparative-effectiveness research is needed in prehypertension to inform an acceptable, safe, and effective balance of lifestyle and medication interventions to prevent incident hypertension and CVD.

Prehypertension: Underlying pathology and therapeutic options

Prehypertension (PHTN) is a global major health risk that subjects individuals to double the risk of cardiovascular disease (CVD) independent of progression to overt hypertension. Its prevalence rate varies considerably from country to country ranging between 21.9% and 52%. Many hypotheses are proposed to explain the underlying pathophysiology of PHTN. The most notable of these implicate the renin-angiotensin system (RAS) and vascular endothelium. However, other processes that involve reactive oxygen species, the inflammatory cytokines, prostglandins and C-reactive protein as well as the autonomic and central nervous systems are also suggested. Drugs affecting RAS have been shown to produce beneficial effects in prehypertensives though such was not unequivocal. On the other hand, drugs such as β-adrenoceptor blocking agents were not shown to be useful. Leading clinical guidelines suggest using dietary and lifestyle modifications as a first line interventional strategy to curb the progress of PHTN; however, other clinically respected views call for using drugs. This review provides an overview of the potential pathophysiological processes associated with PHTN, abridges current intervention strategies and suggests investigating the value of using the "Polypill" in prehypertensive subjects to ascertain its potential in delaying (or preventing) CVD associated with raised blood pressure in the presence of other risk factors.

The AGT and the GNB3 polymorphisms and insulin resistance in prehypertension

OBJECTIVE

This study surveyed the frequencies of single nucleotide polymorphisms (SNPs) M235T AGT and C825T GNB3, and their association with insulin resistance, other biochemical markers and qualitative variables in subjects with high normal blood pressure and/or prehypertension in the Greek population.

DESIGN

330 men and women of Greek origin were divided into 3 groups: a) hypertensive, b) prehypertensive and c) control group. These groups were genetically tested for these polymorphisms and insulin resistance with the HOMA index.

RESULTS

No statistically significant differences were found among the polymorphisms of the compared groups. However, the ? allele carriers (CT/TT vs. CC) of the C825T polymorphism were associated with an increased BMI in all 3 groups (p=0.004). The HOMA index was higher in the hypertensive (p=0.006) and prehypertensive (p=0.016) versus the control group, and similar results were found for insulin (hypertensive vs. control p=0.012, prehypertensive vs. control p=0.001) without statistical significance between the first 2 groups (p=0.522). Additionally, there was a statistically significant difference between the control group and the hypertensive and prehypertensive groups regarding cholesterol (control vs. hypertensive p=0.001, control vs. prehypertension p=0.018) and triglycerides (control vs. hypertensive p=0.0001, control vs. prehypertension p=0.007). Differences were also noted between the control and the hypertensive group regarding the value of HDL (p=0.005) and LDL (p=0.013).

CONCLUSION

This study failed to demonstrate a correlation between specific SNPs, blood pressure and insulin resistance in the 3 groups. However, T allele carriers of the polymorphism C825T were found to have an increased BMI. Similarly, increased insulin resistance and lipidemia were more common in the hypertensive and prehypertensive populations.

Differential Impact of Stress Reduction Programs upon Ambulatory Blood Pressure among African American Adolescents: Influences of Endothelin-1 Gene and Chronic Stress Exposure

Stress-activated gene × environment interactions may contribute to individual variability in blood pressure reductions from behavioral interventions. We investigated effects of endothelin-1 (ET-1) LYS198ASN SNP and discriminatory stress exposure upon impact of 12-week behavioral interventions upon ambulatory BP (ABP) among 162 prehypertensive African American adolescents. Following genotyping, completion of questionnaire battery, and 24-hour ABP monitoring, participants were randomized to health education control (HEC), life skills training (LST), or breathing awareness meditation (BAM). Postintervention ABP was obtained. Significant three-way interactions on ABP changes indicated that among ET-1 SNP carriers, the only group to show reductions was BAM from low chronic stress environments. Among ET-1 SNP noncarriers, under low chronic stress exposure, all approaches worked, especially BAM. Among high stress exposure noncarriers, only BAM resulted in reductions. If these preliminary findings are replicated via ancillary analyses of archival databases and then via efficacy trials, selection of behavioral prescriptions for prehypertensives will be edging closer to being guided by individual's underlying genetic and environmental factors incorporating the healthcare model of personalized preventive medicine.

Storied experiences of nurse practitioners managing prehypertension in primary care

PURPOSE

The purpose of this study was to explore the nurse practitioner (NP) experience with caring for prehypertensive patients. Lifestyle modifications are the primary recommendation for management of prehypertension. Given the historical foundation of health promotion and disease prevention as a fundamental component of NP professional identity, gaining insight into the experience of caring for prehypertensive patients in the current healthcare environment is valuable to the profession, patients, and communities. Therefore, the NP role in health promotion and disease prevention related to prehypertension was explored as well.

DATA SOURCES

Narrative inquiry was the chosen methodology to gather narrative accounts of eight NPs caring for prehypertensive patients in primary care. The three-dimensional narrative inquiry space was used to guide the researcher during data analysis.

CONCLUSIONS

Three themes emerged from the NPs' narratives: realities of practice, ambiguous role identity, and bridging models. Time constraints, financial considerations, and bridging the nursing and medical models while adapting to practice environments were barriers identified as components of the NP experience caring for patients with prehypertension.

IMPLICATIONS FOR PRACTICE

This study revealed that caring for prehypertensive patients is a complex and multilayered experience.

An overview of candesartan in clinical practice

Hypertension is a major risk factor for coronary heart disease, stroke, heart failure and renal disease. The Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure 7 defined hypertension as a blood pressure of more than 140/90 mmHg and recommended to initiate treatment with a two-drug combination for stage 2 hypertension (blood pressure of 160-179/100-109 mmHg). The need for drug combinations is clear from a patient and physician perspective as they provide more effective blood pressure lowering, reduce pill burden, improve compliance and decrease hypertension-related morbidity and mortality. Angiotensin II receptor blocker therapy has been proven to be well tolerated and effective in the management of hypertension, chronic heart failure with left ventricular dysfunction and the prevention and progression of diabetic renal disease. Blockers of the renin-angiotensin system are an important component of antihypertensive combination therapy. Thiazide-type diuretics are usually added to increase the blood pressure lowering efficacy. Fixed drug-drug combinations of both principles, such as candesartan/hydrochlorothiazide, are highly effective in lowering blood pressure while providing improved compliance, a good tolerability and largely neutral metabolic profile. In this article, we review the literature for the role of candesartan-based therapy for hypertension, stroke, diabetes mellitus and heart failure.

Candesartan: widening indications for this angiotensin II receptor blocker?

Candesartan cilexetil is one of a number of drugs of the angiotensin II receptor blocker (ARB) class. Their principal mode of action involves competitive blockade of the angiotensin II type 1 receptor, thereby modulating the activity of the rennin-angiotensin-aldosterone system. Angiotensin II receptor blocker therapy has been proven to be well tolerated and effective in the management of hypertension, chronic heart failure with left ventricular dysfunction and the prevention and progression of diabetic renal disease. Candesartan is a highly potent, long-acting and selective angiotensin II type 1 receptor blocker. It was launched in 1998 for the treatment of hypertension. Its use has increased dramatically, with recently published data suggesting benefit in the treatment of stroke, heart failure, diabetic renal disease and most recently in preventing the development of or delaying the progression of diabetic retinopathy. In this article we review the literature on the use of ARB drugs in general before focusing on candesartan.

Exercise capacity and all-cause mortality in prehypertensive men

BACKGROUND

Prehypertension is associated with increased risk for mortality, a fact that generated a debate regarding the use of antihypertensive therapy in prehypertensives. Increased exercise capacity is associated with lower mortality risk, but little is known about its effects in prehypertensives. Thus, we evaluated the association between exercise capacity and all-cause mortality in prehypertensives.

METHODS

A graded exercise test was performed in 4,478 prehypertensive men at the Veterans Affairs Medical Centers in Washington, DC and Palo Alto, CA. Four fitness categories (quartiles) were defined based on peak metabolic equivalents (METs) achieved. All-cause mortality was assessed for both younger (<or=60 years) and older individuals. The mean follow-up period was 9.0 +/- 6.0 years.

RESULTS

Exercise capacity was a strong predictor of all-cause mortality, independent of traditional risk factors. The adjusted risk for all-cause mortality was reduced by 15% for every 1-MET increase in exercise capacity in the entire cohort, 18% for younger and 12% for older individuals. Compared to the Very-Low-Fit individuals (<or=6 METs) the adjusted mortality risk was 40% lower in Low-Fit (6.1-8.0 METs); 58% lower in Moderate-Fit (8.1-10 METs), and 73% lower in High-Fit individuals (>10 METs). The trends were similar but more pronounced among younger than older individuals.

CONCLUSIONS

A strong, inverse and graded association between exercise capacity and all-cause mortality was observed in prehypertensive individuals. The protective effects of increased fitness were more pronounced in younger than older individuals, suggesting that age should be more closely considered when assessing fitness and mortality relationships.

Effects of acute exercise on atherogenic lipids in untreated mild hypertensive patients

BACKGROUND/AIM

Exercise can positively influence risk factors associated with cardiovascular disease. The mechanisms by which exercise reduces atherogenic risk remain unknown. The aim of the present study was to investigate the effect of acute exercise (cardiopulmonary exercise cycle ergometer test) on atherogenic lipids in untreated mild hypertensive patients with or without hypercholesterolemia. This testing allows determination of exercise capacity, peak heart rate, and ventilation per minute (VE), peak oxygen uptake (pVO2) and exercise time (ET).

METHODS

The study group included 85 untreated mild hypertensive patients (according to VII Joint National Committee--JNC 7) divided into two subgroups: hypertensive hypercholesterolemic and hypertensive normocholesterolemic. The control grouip included 35 normotensive subjects divided into two subgroups: normotensive hypercholesterolemic and normotensive normocholesterolemic. Lipid profiles to determine were oxidized LDL (OxLDL)--a marker of oxidative stress, triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol, which were measured at rest and 30 minutes after the acute bout of cardiopulmonary exercise cycle ergometer test. Lipids profiles were measured by enzymatic methods. Oxidized LDL was determined by a commercially available sandwich ELISA (Mercodia AB, Uppsala, Sweden). C-reactive protein (CRP) was measured using chemiluminiscent methods (Immulite-DPC).

RESULTS

In our study OxLDL was significantly higher in hypertensive patients with atherogenic lipid profiles in basal condition, compared to the hypertensive patients without atherogenic lipid profiles and controls. There was a significant difference in CRP (p < 0.001) between hypercholesterolemics (hypertensive and normotensive) and normocholesterolemics (hypertensive and normotensive). We found increased OxLDL after exercise in both groups (hypertensive patients and normotensive), but only in the hypertensive hypercholesterolemic patients the difference was statistically significant (90.47 +/- 15.31 vs. 105.94 +/- 14.17 IU/L, p < 0.001). Systolic and diastolic blood pressures were significantly higher during exercise only in the hypertensive patients. There were significantly lower values of pVO2 only in hypertensive hypercholesterolemic patients. There were no significant differences between hypertensive and normotensive ones for ET and VE. In hypertensive ones we found after exercise a negative correlation between pVO2 and OxLDL (r = -0.473; p < 0.05), and pVO2 and CRP (r = -0.478; p < 0.05). We also found in normotensive normocholesterolemic patients a positive correlation between VE and systolic blood pressure (r = 0.420; p < 0.05), a negative correlation between VE and OxLDL (r= -0.421; p < 0.05), and VE and CRP (r = -0.561; p < 0.05).

CONCLUSION

This study showed that acute exercise induces and increases oxidative stress only in untreated mild hypertensive patients with atherogenic lipid profiles. These results imply the need to normalize atherogenic lipid profile in untreated patients with mild hypertension in order to prevent an increased lipid peroxidation under acute exercise.