Serum cholesterol levels, blood pressure response to stress and incidence of stable hypertension in young subjects with high normal blood pressure

Using Machine Learning to Evaluate the Value of Genetic Liabilities in the Classification of Hypertension within the UK Biobank

Background and Objective: Hypertension increases the risk of cardiovascular diseases (CVD) such as stroke, heart attack, heart failure, and kidney disease, contributing to global disease burden and premature mortality. Previous studies have utilized statistical and machine learning techniques to develop hypertension prediction models. Only a few have included genetic liabilities and evaluated their predictive values. This study aimed to develop an effective hypertension classification model and investigate the potential influence of genetic liability for multiple risk factors linked to CVD on hypertension risk using the random forest and the neural network. Materials and Methods: The study involved 244,718 European participants, who were divided into training and testing sets. Genetic liabilities were constructed using genetic variants associated with CVD risk factors obtained from genome-wide association studies (GWAS). Various combinations of machine learning models before and after feature selection were tested to develop the best classification model. The models were evaluated using area under the curve (AUC), calibration, and net reclassification improvement in the testing set. Results: The models without genetic liabilities achieved AUCs of 0.70 and 0.72 using the random forest and the neural network methods, respectively. Adding genetic liabilities improved the AUC for the random forest but not for the neural network. The best classification model was achieved when feature selection and classification were performed using random forest (AUC = 0.71, Spiegelhalter z score = 0.10, p-value = 0.92, calibration slope = 0.99). This model included genetic liabilities for total cholesterol and low-density lipoprotein (LDL). Conclusions: The study highlighted that incorporating genetic liabilities for lipids in a machine learning model may provide incremental value for hypertension classification beyond baseline characteristics.

Dyslipidemia and the Prevalence of Hypertension: A Cross-Sectional Study Based on Chinese Adults Without Type 2 Diabetes Mellitus

Background

In clinical practice, it is frequently observed that patients with hypertension often coexist with dyslipidemia. However, studies on atherosclerotic indices and the prevalence of hypertension are still limited. The purpose of this study was to assess the relationship between atherosclerotic indices and the prevalence of hypertension in Chinese adults without type 2 diabetes mellitus.

Methods

In this paper, a cross-sectional study was conducted based on 117,056 adults in 11 Chinese cities (Shanghai, Beijing, Wuhan, Suzhou, Shenzhen, Changzhou, Nantong, Guangzhou, Hefei, Nanjing, and Chengdu) from 2010 to 2016. Besides, the raw data was obtained from the public database (www.Datadryad.org), while eight atherosclerosis indices namely the atherogenic coefficient (AC), Castelli's risk index I (CRI-I) and II (CRI-II), the atherogenic index of plasma (AIP), the cholesterol index, the lipoprotein combined index (LCI), non-high-density lipoprotein cholesterol (non-HDL-C) and triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) were analyzed in this study. Apart from that, two groups of continuous variables were measured using the Mann-Whitney test, and categorical variables were analyzed using the Chi-square test. Differences between multiple groups of continuous variables were investigated using Kruskal-Wallis one-way analysis of variance (ANOVA) and Dunn's test. Furthermore, Spearman correlation analysis and multivariate logistic regression analyses were performed to assess the relationship between atherosclerotic indices and blood pressure levels, and the prevalence of hypertension, respectively. The results of multivariate logistic regression analyses were expressed as the odds ratio (OR) and their corresponding 95% confidence intervals (CIs). Moreover, the receiver operating characteristic (ROC) curve was depicted to further analyze the predictive value of the atherosclerotic indices on the prevalence of hypertension.

Results

The atherosclerosis indices were higher in the hypertensive population compared to those in the normotensive population. Meanwhile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were linearly and positively correlated with atherosclerotic indices. In addition, multivariate logistic regression analysis showed that the cholesterol index and non-HDL-C were observed to be positively associated with the prevalence of hypertension (p for trend < 0.05). Moreover, the prevalence of hypertension increased by 3.7% (OR: 1.037; 95% CI: 1.009-1.065; p = 0.009) and 6.1% (OR: 1.06; 95% CI: 1.033–1.091; p < 0.001), respectively, as per 1-standard deviation (SD) increase in the cholesterol index and non-HDL-C. Beyond that, ROC analysis demonstrated that the cholesterol index and non-HDL-C have a good predictive value for the prevalence of hypertension in women, with under the ROC curve (AUC) of 0.659 and 0.684 and cut-off values of 47.94 and 134.34 mg/dl, accordingly.

Conclusions

In Chinese adults without type 2 diabetes mellitus, atherosclerotic indices were significantly higher in hypertensive populations compared with those in normotensive populations, regardless of hypertension levels. Meanwhile, SBP and DBP were linearly and positively related to atherosclerotic indices. Besides, the cholesterol index and non-HDL-C were independent risk factors for the prevalence of hypertension, and they could be adopted for effectively predicting the prevalence of hypertension in women.

Relationship Between Lipid Profiles and Hypertension: A Cross-Sectional Study of 62,957 Chinese Adult Males

Background

Patterns of dyslipidemia and incidence of hypertension have been rarely reported in Asian populations with inconsistent findings. To accumulate further evidence in Asian populations, the study aimed to investigate the relationship between lipid profiles and hypertension in Chinese adult males.

Methods

We conducted a cross-sectional study based on the data from the DATADRYAD database. The overall population was divided into hypertensive and non-hypertensive groups based on baseline blood pressure levels. For continuous variables, Mann-Whitney test was performed between two groups, while Kruskal-Wallis and Dunn tests were used among multiple groups. The chi-square test was carried out for dichotomous variables. Spearman's correlation coefficient was employed to assess the association between systolic blood pressure (SBP), diastolic blood pressure (DBP) and lipid profiles, whereas the relationship between lipid profiles and the incidence of hypertension was evaluated using multivariate logistic regression. The Bayesian network (BN) model was adopted to investigate the relationship between clinical characteristics and hypertension, and the importance of related predictor to the incidence of hypertension was obtained to make conditional probability analysis.

Results

Finally, totally 62,957 participants were included in this study. In the lipid profiles, total cholesterol (TC), low-density cholesterol (LDL-c), and non- high-density lipoprotein cholesterol (non-HDL-c) were higher in the hypertensive population (p <0.001). In the fully multivariate model, for every 1 mg/dl increase in TC, LDL-c and non-HDL, the risk of hypertension increased by 0.2% [1.002 (1.001–1.003)], 0.1% [1.001 (1.000–1.002)], and 0.1% [1.001 (1.000–1.002)]. Meanwhile, HDL-c became positively associated with the incidence of hypertension (p for trend < 0.001) after adjusting for the body mass index (BMI), and 1 mg/dl increment in HDL-c increased the risk of hypertension by 0.2% [1.002 (1.000–1.002)] after fully adjusting for multiple variables. Furthermore, the BN showed that the importance of age, BMI, fasting plasma glucose (FPG), and TC to the effect of hypertension is 43.3, 27.2, 11.8, and 5.1%, respectively.

Conclusion

Elevated TC, LDL-c, and non-HDL-c were related to incidence of hypertension in Chinese adult males, whereas triglycerides (TG) was not significantly associated. The relationship between HDL-c and hypertension incidence shifted from no association to a positive correlation after adjusting for the BMI. Moreover, the BN model displayed that age, the BMI, FPG, and TC were strongly associated with hypertension incidence.

The relationship between lipid risk score and new-onset hypertension in a prospective cohort study

BACKGROUND

Dyslipidemia and hypertension are both important risk factors for atherosclerotic cardiovascular diseases. However, the relationship between dyslipidemia and incident hypertension remains to be elucidated comprehensively. The main purpose of this study was to construct the lipid risk score to explore the risk prediction effect of integrated lipid indices on new-onset hypertension.

METHODS

This prospective cohort study with 2116 non-hypertensive subjects was conducted from 2009 to 2020. New hypertension events during the follow-up period were recorded and verified. The lipid risk score was calculated by summing coded total cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol weighted with corresponding effect sizes. Cox regression analysis was used to estimate the association between the lipid risk score or lipid indices and incident hypertension in the subgroup of age (< 55 and≥ 55 years at baseline).

RESULTS

After a median of 10.75-year follow-up, 637 incident hypertension cases were identified. The restricted cubic spline showed that the lipid risk score had a positive linear correlation with hypertension (P< 0.001). Among people< 55 years, with every increase of 0.94 in lipid risk score, the risk of hypertension increased by 37% (adjusted HR [95%CI]: 1.369 [1.164-1.610]). This association was not modified by overweight or obesity.

CONCLUSIONS

The integrated lipid risk score, independent of traditional risk factors, has a significantly predictive effect on hypertension in people younger than 55 years. This finding may aid in identifying high-risk individuals for hypertension, as well as facilitating early intervention and management to reduce adverse cardiovascular events. Comprehensive lipid management should be attached importance in the prevention and control of hypertension.

Usefulness of the corporate wellness projects in primary prevention at the population level: a study on the prevalence, awareness, and control of hypertension in the Ferrari company

The aim of our study was to evaluate the prevalence, awareness, and control of hypertension in an apparently healthy company population. We conducted a cross-sectional study on a total sample of 2058 individuals with a mean age of 38 ± 9 years, enrolled for the first time to the Ferrari corporate wellness program "Formula Benessere". Hypertension was defined as systolic blood pressure (SBP) level ≥140 mmHg or diastolic BP (DBP) ≥90 mmHg or use of antihypertensive medication, whereas BP control was defined as BP level <130/80 mmHg. All 2058 participants were divided into three groups based on age: Group 1 aged <40 years (n = 1177, 57%), Group 2 aged 40-50 years (n = 627, 30%), and Group 3 aged >50 years (n = 254, 13%). Four-hundred and one subjects had BP levels ≥130/80 mmHg (19.5%). Two-hundred and sixty-one individuals (12.7%) had high-normal BP values and 140 subjects had rest SBP ≥140 mmHg and/or DBP ≥90 mmHg (6,8%), of which 41 (29.3%) with grade 2 hypertension. In the overall population, 259 individuals (12.5%) were affected by hypertension, the prevalence increasing with age. Only a minority (51%) was aware of being hypertensive and already treated with antihypertensive medications (45.9%). An adequate BP control was achieved in only 57% of subjects who received BP-lowering therapy. Corporate wellness programs may represent an essential tool in identifying apparently healthy subjects with an inadequate control of cardiovascular (CV) risk factors, such as hypertension. These preventive programs in the workplace may help to improve and spread primary CV prevention at the population level.

Hypertension and Hypercholesterolemia: is it Time for Anti-«Lipitensive» Therapy?

Despite the widespread awareness that hypertension and dyslipidemia are risk factors of prime importance for cardiovascular disease, the prevalence of these risk factors is still high, and the success of their control can hardly be considered satisfactory. The latest European guidelines for the management of hypertension strengthened the position of fixed-dose combinations, the main advantage of which is increased adherence to treatment. The purpose of this review was to discuss the background and the possibility of using fixed-dose combinations containing antihypertensive drugs and a statin in the treatment of patients with hypertension and dyslipidemia. We outlined the theoretical concepts that substantiate the possibility of using such therapy and discussed the results of randomized clinical trials investigating the efficacy of combined administration of antihypertensive and lipidlowering drugs. Illustrated by single pill combination of indapamide, perindopril and rosuvastatin, the requirements for fixed drug combinations are discussed, as well as clinical scenarios when their use is considered justified.

Preventive effect of pravastatin on the development of hypertension in patients with hypercholesterolemia: A post-hoc analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study

BACKGROUND

It remains unclear whether treatment of dyslipidemia with 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) reduces the risk of developing hypertension.

OBJECTIVE

In this post-hoc analysis of the Management of Elevated Cholesterol in the Primary Prevention Group of Adult Japanese (MEGA) Study, a large-scale primary prevention trial with pravastatin, we examined the preventive effect of pravastatin on the future development of hypertension in patients with hypercholesterolemia.

METHODS

Of the overall (MEGA) Study population, 3397 nonhypertensive patients at baseline were enrolled in this study. The patients were randomly assigned to either the diet alone group (n = 1722) or the diet plus pravastatin group (n = 1675) and then were followed-up for a median of 36 months to determine new-onset hypertension.

RESULTS

During the follow-up period, 1595 patients developed hypertension (49.1% in the diet alone group and 44.7% in the diet plus pravastatin group). After adjusting for multiple covariates, the diet plus pravastatin group showed a 10% reduction in the risk of developing hypertension (hazard ratio 0.90, 95% confidence interval 0.81-0.998), compared with the diet alone group. Subgroup analyses revealed that the preventive effect of pravastatin on the development of hypertension was pronounced in patients aged ≥60 years, men, those with chronic kidney disease or diabetes mellitus and those without obesity.

CONCLUSIONS

Pravastatin reduced the risk of developing hypertension in Japanese patients with hypercholesterolemia. The risk reduction of cardiovascular disease with statins could be partly explained by their preventive effect on the development of hypertension.

Dyslipidemia and the Risk of Developing Hypertension in a Working-Age Male Population

BACKGROUND

Hypertension is one of the main comorbidities associated with dyslipidemia. This study aimed to examine the extent to which dyslipidemia increases the risk of developing hypertension in a Japanese working-age male population.

METHODS AND RESULTS

We analyzed data from 14 215 nonhypertensive male workers (age 38±9 years) who underwent annual medical checkups. Subjects were followed up for a median of 4 years to determine new-onset hypertension, defined as blood pressure (BP) ≥140/90 mm Hg or use of antihypertensive medication. The associations between serum lipid levels and development of hypertension were examined. During the follow-up period, 1483 subjects developed hypertension. After adjusting for age, body mass index, impaired fasting glucose/diabetes, baseline BP category, alcohol intake, smoking, exercise, and parental history of hypertension, subjects with a total cholesterol (TC) level ≥222 mg/dL were at a significantly increased risk of developing hypertension (hazard ratio: 1.28; 95% CI: 1.06-1.56) compared to subjects with a TC level ≤167 mg/dL. Similar results were observed for subjects with high low-density lipoprotein cholesterol (LDLC) and non-high-density lipoprotein cholesterol (HDLC) levels. A U-shaped relationship was found between HDLC level and risk of hypertension; compared to the third quintile, the multiadjusted hazard ratio was 1.22 (95% CI: 1.03-1.43) in the lowest quintile and 1.34 (95% CI: 1.12-1.60) in the highest quintile.

CONCLUSIONS

Elevated serum levels of TC, LDLC, and non-HDLC were associated with an increased risk of hypertension in working-age Japanese men. For HDLC, risk of hypertension was increased at both low and high levels.

Resting Plasma Lipids and Cardiovascular Reactivity to Acute Psychological Stress

Abstract. Prior research suggests that hyperlipidemia is associated with elevated blood pressure responses to acute stress but whether lipid levels influence underlying cardiac and vascular determinants of blood pressure during stress is not known. Thus, we examined whether lipids were associated with stress-induced blood pressure responses and responses of stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR). In 19 healthy university students (15 men), blood was drawn to measure lipid levels (triglycerides, low-density lipoprotein cholesterol [LDL-c], high-density lipoprotein cholesterol [HDL-c], total cholesterol) after a 10-min rest period. Participants then completed a 6-min mental arithmetic stressor and a 3-min cold pressor (separated by a 10-min recovery). This procedure was repeated twice, approximately 6 weeks apart. Lipids and hemodynamic values were averaged across the two sessions. Multiple linear regression analyses revealed that a model including LDL-c, HDL-c, and triglycerides significantly predicted diastolic blood pressure (DBP), R2adj = .45, p = .007, and systolic blood pressure (SBP) cold pressor reactivity, R2adj = .35, p = .023. Individually, only LDL-c significantly predicted DBP, β = .64, p = .003, and SBP cold pressor reactivity, β = .64, p = .005. The same model marginally predicted CO, R2adj = .24, p = .069, and TPR, R2adj = 21, p = .091, reactivity to mental arithmetic, but only triglycerides were independently associated with CO, β = −.63, p = .012, and TPR, β = .54, p = .029 reactivity. Lipids were not associated with heart rate (HR) or SV reactivity. LDL-c was positively associated with the blood pressure response to the cold pressor, whereas triglycerides were positively and negatively associated with the TPR and CO responses, respectively, to mental arithmetic. Endothelial dysfunction and greater release of vasoconstrictors in those with high lipids may explain these relationships.

Subjects at risk of discontinuation of lipid-lowering agents: a 6-month cohort study among 12,875 patients in a chinese population

BACKGROUND

Dyslipidemia is a significant health problem, and persistent use of lipid-lowering agents among dyslipidemic patients is clinically important. However, few studies have evaluated the profiles of medication discontinuation among ethnic Chinese patients.

OBJECTIVE

The objective of this study was to evaluate the level of medication adherence among Chinese patients who were prescribed a lipid-lowering drug and to investigate factors that could help physicians identify patients at risk for discontinuing their medication.

METHODS

All patients who attended any primary care clinic in 1 territory of Hong Kong and were prescribed at least 1 lipid-lowering agent from January 2004 to June 2007 were included. The incidences of drug discontinuation within 180 days after drug prescriptions were measured, and the factors associated with discontinuation using binary logistic regression analyzes were evaluated.

RESULTS

Of the 12,875 eligible patients, the majority were prescribed fibrates (54.4%) and statins (45.1%). Among the patients, 17.0% discontinued their medication. Older patients (adjusted odds ratio [aOR] = 0.72-0.79 for patients >50 years), male subjects (aOR = 0.87; 95% CI, 0.78-0.97; P = 0.009), fee payers (aOR = 0.88; 95% CI, 0.78-0.99; P = 0.029), attendees in family medicine specialist clinics (aOR = 0.82; 95% CI, 0.70-0.96; P = 0.013), residents in rural districts (aOR = 0.52; 95% CI, 0.44-0.60; P < 0.001), follow-up visitors (aOR = 0.60; 95% CI, 0.54-0.66; P < 0.001), patients with comorbidities (aOR = 0.39; 95% CI, 0.35-0.44; P < 0.001 for 1 comorbidity and aOR = 0.28; 95% CI, 0.25-0.33; P < 0.001 for at least 2 comorbidities), and persons who use fibrates (aOR = 0.56; 95% CI, 0.49-0.64; P < 0.001) were significantly less likely to discontinue their medication.

CONCLUSIONS

The findings of these associated factors were new for ethnic Chinese patients. These findings could help physicians identify patients who had been prescribed a lipid-lowering agent who were at higher risk of discontinuing their medication. Their medication-taking behavior should be monitored more closely, and future studies should evaluate the reasons of drug discontinuation.

Cardiovascular and metabolic predictors of progression of prehypertension into hypertension: the Strong Heart Study

Prehypertension (defined by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure) frequently evolves to hypertension (HTN) and increases cardiovascular risk. It is unclear whether metabolic and/or cardiac characteristics favor development of HTN in prehypertensive subjects. We evaluated baseline anthropometric, laboratory, and echocardiographic characteristics of 625 untreated prehypertensive participants in the Strong Heart Study, without prevalent cardiovascular disease (63% women; 22% with diabetes mellitus; mean age: 59+/-7 years) to identify predictors of the 4-year incidence of HTN. Diabetes mellitus was assessed by American Diabetic Association criteria, and a diabetes-specific definition of HTN was used. Four-year incidence of HTN was 38%. Incident HTN was independently predicted by baseline systolic blood pressure (odds ratio [OR]: 1.60 per 10 mm Hg; 95% CI: 1.30 to 2.00; P<0.0001), waist circumference (OR: 1.10 per 10 cm; 95% CI: 1.01 to 1.30; P=0.04), and diabetes mellitus (OR: 2.73; 95% CI=1.77 to 4.21; P<0.0001), with no significant effect for age, sex, hemoglobin A1c, homeostatic model assessment index, C-reactive protein, fibrinogen, low-density lipoprotein and high-density lipoprotein cholesterol, triglycerides, plasma creatinine, or urine albumin:creatinine ratio. Higher left ventricular mass index (OR: 1.15 per 5 g/m(2.7); 95% CI: 1.01 to 1.25; P=0.03) or stroke volume index (OR: 1.25 per 5 mL/m(2.04); 95% CI: 1.10 to 1.50; P=0.03) was also identified, together with baseline systolic blood pressure and the presence of diabetes mellitus, as an independent predictor of incident HTN, without an additional predictive contribution from other anthropometric, metabolic, or echocardiographic parameters (all P>0.10). Thus, progression to HTN in 38% of Strong Heart Study prehypertensive participants could be predicted by higher left ventricular mass and stroke volume in addition to baseline systolic blood pressure and prevalent diabetes mellitus.

Effect of psychological stress on blood pressure increase: a meta-analysis of cohort studies

Studies have suggested that chronic exposure to stress may have an influence on increased blood pressure. A systematic review followed by a meta-analysis was conducted aiming to assess the effect of psychological stress on blood pressure increase. Research was mainly conducted in Ingenta, Psycinfo, PubMed, Scopus and Web of Science. Inclusion criteria were: published in any language; from January 1970 to December 2006; prospective cohort design; adults; main exposure psychological/emotional stress; outcome arterial hypertension or blood pressure increase > 3.5mmHg. A total of 2,043 studies were found, of which 110 were cohort studies. Of these, six were eligible and yielded 23 comparison groups and 34,556 subjects. Median follow-up time and loss to follow-up were 11.5 years and 21%. Results showed individuals who had stronger responses to stressor tasks were 21% more likely to develop blood pressure increase when compared to those with less strong responses (OR: 1.21; 95%CI: 1.14-1.28; p < 0.001). Although the magnitude of effect was relatively small, results suggest the relevance of the control of psychological stress to the non-therapeutic management of high blood pressure.

Changes in plasma lipids with psychosocial stress are related to hypertension status and the norepinephrine stress response

Hypertension is a known risk factor for cardiovascular disease. Hypertensive individuals show exaggerated norepinephrine (NE) reactivity to stress. Norepinephrine is a known lipolytic factor. It is unclear if, in hypertensive individuals, stress-induced increases in NE are linked with the elevations in stress-induced circulating lipid levels. Such a mechanism could have implications for atherosclerotic plaque formation. In a cross-sectional, quasi-experimentally controlled study, 22 hypertensive and 23 normotensive men (mean +/- SEM, 45 +/- 3 years) underwent an acute standardized psychosocial stress task combining public speaking and mental arithmetic in front of an audience. We measured plasma NE and the plasma lipid profile (total cholesterol [TC], low-density-lipoprotein cholesterol [LDL-C], high-density-lipoprotein cholesterol, and triglycerides) immediately before and after stress and at 20 and 60 minutes of recovery. All lipid levels were corrected for stress hemoconcentration. Compared with normotensives, hypertensives had greater TC (P = .030) and LDL-C (P = .037) stress responses. Independent of each other, mean arterial pressure (MAP) upon screening and immediate increase in NE predicted immediate stress change in TC (MAP: beta = .41, P = .003; NE: beta = .35, P = .010) and LDL-C (MAP: beta = .32, P = .024; NE: beta = .38, P = .008). Mean arterial pressure alone predicted triglycerides stress change (beta = .32, P = .043) independent of NE stress change, age, and BMI. The MAP-by-NE interaction independently predicted immediate stress change of high-density-lipoprotein cholesterol (beta = -.58, P < .001) and of LDL-C (beta = -.25, P < .08). We conclude that MAP and NE stress reactivity may elicit proatherogenic changes of plasma lipids in response to acute psychosocial stress, providing one mechanism by which stress might increase cardiovascular risk in hypertension.

Left ventricular mass and incident hypertension in individuals with initial optimal blood pressure: the Strong Heart Study

OBJECTIVE

Metabolic abnormalities have been shown to predict 8-year incident arterial hypertension in individuals with optimal blood pressure. As echocardiographic left ventricular mass has also been reported to predict incident hypertension in individuals with baseline blood pressure of less than 140/90 mmHg, we determined whether left ventricular mass predicts 4-year incident hypertension also in individuals with initial optimal blood pressure (<120/80 mmHg), independent of metabolic factors influencing blood pressure.

METHODS

We studied 777 of 3257 members of the American Indian population-based Strong Heart Study cohort with optimal blood pressure (34% men, 45% obese, and 35% diabetic), aged 57 +/- 7 years, and without prevalent cardiovascular disease.

RESULTS

Over 4 years, 159 individuals (20%, group H) developed hypertension (blood pressure >/=140/90 mmHg). They had a greater baseline BMI, waist girth, and blood pressure (112/69 vs. 109/68 mmHg, all P < 0.03) than those remaining normotensive (group N), with similar lipid profile and renal function. At baseline, left ventricular mass was significantly greater in group H than in group N (P < 0.004). The difference in left ventricular mass was confirmed after controlling for initial BMI, systolic blood pressure, homeostatic model assessment index, and diabetes. The probability of incident hypertension increased by 36% for each standard deviation of left ventricular mass index (P = 0.006), independent of covariates. Participants with left ventricular mass of more than 159 g (75th percentile of distribution) had 2.5-fold (95% confidence interval, 1.4-3.6; P < 0.001) higher adjusted risk of incident hypertension than those below this value.

CONCLUSION

Left ventricular mass predicts incident arterial hypertension in individuals with initially optimal blood pressure. This association is independent of body build, prevalent diabetes, and initial blood pressure.

Beyond lipid lowering: the anti-hypertensive role of statins

INTRODUCTION

The management of the hypercholesterolemic patient has evolved tremendously with the introduction of the HMG-CoA Reductase inhibitors, a class of drugs better known as the statins. Statins modify cholesterol metabolism by inhibiting the rate-limiting enzyme of cholesterol biosynthesis, producing greater decreases in plasma cholesterol levels than previously realized with hypolipidemic therapy. With the advent of the classic statin-megatrials such as the Scandinavian Simvastatin Survival Study (4S), WOSCOPS, CARE, and the more recent Heart Protection Study (HPS), the role of statins in both the primary and secondary prevention and ultimate risk reduction of patients with coronary disease has been firmly established.

DISCUSSION

With an increase in use and popularity, a number of beneficial actions of the statins unrelated to their cholesterol-lowering ability have been reported. These effects have generated greater interest in the possible additional roles and indications for the use of these drugs. Of central focus in this paper is the cholesterol-independent benefit of this group of agents on the cardiovascular system, particularly on the lowering of systemic blood pressure. A number of hypotheses have been proposed for this action and these shall be reviewed within this paper.

CONCLUSION

We explore recent data that suggests that statins may provide substantial reduction of blood pressure in the hypertensive, hypercholesterolemic patient independent of their lipid-lowering effect. In addition, we review several notable publications that postulate unique mechanisms for this action and benefit. We also present plausible explanations as to why some of the larger statin trials did not report similar such findings.

Interaction between serum cholesterol levels and the renin–angiotensin system on the new onset of arterial hypertension in subjects with high-normal blood pressure

OBJECTIVES

To investigate the possible interactions between serum cholesterol levels and the renin-angiotensin system on the development of stable hypertension in subjects with high-normal blood pressure (BP).

BACKGROUND

Hypercholesterolemia increases angiotensin-II type 1 (AT1) receptor density and pressor responsiveness to angiotensin II, and has been reported to contribute to the development of hypertension. The effects of elevated serum cholesterol levels on BP control might be exaggerated by concomitant activation of the renin-angiotensin system, and their combination might contribute to the development of stable hypertension.

METHODS

We investigated the relationship between serum cholesterol levels, plasma renin activity (PRA) and the long-term development of hypertension in 66 young (age < 45 years) patients with high-normal BP and elevated (> 200 mg/dl, n = 46: HC) or normal (</=200 mg/dl, n = 20: NC) serum cholesterol levels and in 20 normotensive, normocholesterolemic controls (C). The main outcome measure was the prospective evaluation of the 15-year incidence of stable hypertension in the different populations.

RESULTS

New-onset hypertension was higher in patients with high-normal BP and HC when compared to NC patients [relative risk (RR) = 1.9; 95% confidence interval (CI), 1.1-4.3, P < 0.001] and control subjects (RR = 3.1; 95% CI = 1.4-5.3, P < 0.001). High PRA increased the overall rate of hypertension in both HC and NC. The interaction between HC and PRA was more evident in patients with borderline high cholesterol levels (200-240 mg/dl) where the adjusted relative risk of new onset of hypertension was 2.17 (95% CI 1.2-3.74; P < 0.05) in high PRA subjects and 1.17 (95% CI 0.67-2.23; P = 0.87) in subjects with normal PRA.

CONCLUSION

We support the hypothesis that the presence of hypercholesterolemia can promote the development of stable hypertension through its interaction with the circulating renin-angiotensin system in patients with high-normal blood pressure.

High cholesterol and coronary heart disease in younger men: the potential role of stress induced exaggerated blood pressure response

It is well known that by far the strongest association between serum cholesterol levels and the risk of coronary heart disease or related adverse events is found in younger men. The question is - what is different about this age-gender subgroup? It has been suggested that this enhanced risk is seen in younger men because of unique exposure to stress. While stress is known to raise cholesterol levels, the magnitude of the elevation appears insufficient to account for the observed association between cholesterol levels and CHD in young men. An hypothesis is presented which suggests that part and perhaps all of this association is due to the relationship between cholesterol levels and exaggerated blood pressure response to stress, i.e. individuals who exhibit this hyper-response also tend to have significantly elevated cholesterol levels. Given that both stress and an exaggerated blood pressure response to stress are also risk factors for CHD, this could influence the relationship between CHD risk and cholesterol in this age group even if multivariate analysis includes casual blood pressure. This is important since in risk assessment, especially among young men, cholesterol levels play an important role.

Estimate of white-coat effect and arterial stiffness

OBJECTIVES

Blood pressure (BP) measured in the office is usually higher than the average ambulatory BP, a difference generally taken as an estimate of the white-coat effect. This study was designed to assess whether such a difference is associated with impairment of the conduit arterial system.

METHODS

We calculated the difference between office and average daytime peak systolic blood pressure (DeltaSBP) in 2778 hypertensive participants (1240 women) of the Progetto Ipertensione Umbria Monitoraggio Ambulatoriale cohort. Arterial stiffness was evaluated using an adjusted office pulse pressure to stroke volume ratio (PP/SV), measured at rest, which has previously been shown to predict cardiovascular outcome independent of echocardiographic left ventricular hypertrophy. Effective arterial elastance was also estimated.

RESULTS

Across quintiles of PP/SV, significant linear, positive trends were found with age, the proportion of women, plasma glucose and triglyceride levels (0.05 > P < 0.0001). Heart rate measured in the office increased mildly with quintiles of PP/SV (P < 0.05). After adjusting for age, sex, body weight and office heart rate, DeltaSBP progressively increased with increasing quintiles of PP/SV (P for trend < 0.0001), whereas stroke volume decreased, paralleling the increase in left ventricular relative wall thickness (both P < 0.0001) and left ventricular mass index (P < 0.05). The significant increase in effective arterial elastance with quintiles of PP/SV was also independent of peak systolic BP, in addition to age, sex, heart rate and body weight.

CONCLUSIONS

The difference between office BP and ambulatory BP, an estimate of the white-coat effect, is strongly associated with increased arterial stiffness, evaluated by a two-element fluid system accumulator.

Risk factors for arterial hypertension in adults with initial optimal blood pressure: the Strong Heart Study

Whether metabolic factors and their change over time influence development of arterial hypertension in adults with initially optimal blood pressure (BP) is unknown. We analyzed associations of BP in the optimal range (<120/80 mm Hg), metabolic risk factors, and their changes over 4-year follow-up, with 8-year incident hypertension, in a cohort of American Indians with a high prevalence of obesity. At baseline, 967 participants with optimal BP and no prevalent cardiovascular disease (69.5% women; mean age, 54+/-7 years) were evaluated and reexamined after 4 (second examination) and 8 years to evaluate predictors of 8-year incident arterial hypertension. In participants with normal glucose tolerance, baseline BP and decrease in high-density lipoprotein cholesterol from baseline to the second examination were the most potent predictors of 8-year arterial hypertension (both P<0.0001), with additional effects of baseline waist circumference and its increase, increase in BP, and presence of diabetes at the second examination (all P<0.04). In participants with impaired glucose tolerance or diabetes, the most potent predictor of 8-year incident hypertension was diabetes at the second examination (P<0.0001) followed by a increase in BP and LDL cholesterol over the first 4 years (both P<0.001). Thus, incident arterial hypertension can be predicted by initial metabolic profile and unfavorable metabolic variations over time, in addition to initial BP. At optimal levels of initial BP, increasing abdominal obesity, and abnormal lipid profile are major predictors of development of arterial hypertension. Possible implications of these findings for primary cardiovascular prevention should be tested in prospective studies.

Prediction of future hypertension by casual blood pressure or invasive hemodynamics? A 30-year follow-up study

Blood pressure elevation in young age is associated with a risk of developing hypertension. However, not all subjects will progress to clinical hypertensives in need of pharmacological therapy. In younger subjects, there is essential to find clinical or experimental characteristics to predict the future risk of hypertension. In the present study, the long-term relationship between casual blood pressure measurement and future hypertension has been examined. The initial study group consisted of 20-year-old men (n = 44) with mild blood pressure elevation and a normotensive male control group (n = 29). After 30 years, we re-examined 32 (72%) of the subjects with previous mild blood pressure elevation and 21 (73%) of the controls. We further analyzed possible associations between blood pressure level at follow-up and anthropometric data, and invasively measured hemodynamic variables at baseline. After 30 years, 38% in the group with blood pressure elevation at baseline had developed hypertension, as compared to 10% in the control group. There was a significant positive relationship between baseline systolic blood pressure (r = 0.56; p < 0.001) and diastolic blood pressure (r = 0.36; p < 0.01) and systolic blood pressure 30 years later. In further regression analyses, there were no associations between cardiac output, vascular resistance or anthropometric data at baseline and blood pressure at follow-up. In conclusion, casual blood pressure measurements predict the risk of future hypertension, whereas invasive hemodynamic and anthropometric measurements do not in young men with mild blood pressure elevation.