High blood pressure, smoking and cardiovascular risk

Chronic cigarette smoking is associated with increased arterial stiffness in men and women: evidence from a large population-based cohort

BACKGROUND

Cigarette smoking is a threat to global human health and a leading cause of the cardiovascular disease (CVD) morbidity and mortality. Importantly, sex-specific differences in smoking-induced arterial stiffness, an early key event in the development of atherosclerotic CVD, remain still elusive. Thus, this study sought out to investigate sex-specific associations between smoking and measures of arterial stiffness.

METHODS AND RESULTS

Overall, 15,010 participants (7584 men and 7426 women aged 35-74 years) of the Gutenberg Health Study were examined at baseline during 2007-2012. Smoking status, pack-years of smoking, and years since quitting smoking were assessed by a standardized computer-assisted interview. Arterial stiffness and wave reflection were determined by stiffness index (SI) and augmentation index (AI). In the total sample, 45.8% had never smoked, 34.7% were former smokers, and 19.4% were current smokers. Median cumulative smoking exposure was 22.0 pack-years in current male smokers and 16.0 in current female smokers. In general, multivariable linear regression models adjusted for a comprehensive set of confounders revealed that smoking status, pack-years of smoking, and years since quitting smoking were dose-dependently associated with markers of arterial stiffness. In sex-specific analyses, these associations were overall more pronounced in men and SI was stronger related to the male sex, whereas differences between men and women in the case of AI appeared to be less substantial.

DISCUSSION

The present results indicate that chronic smoking is strongly and dose-dependently associated with increased arterial stiffness in a large population-based cohort regardless of sex but with a stronger association in men.

The long-term health effects of initiating smoking in adolescence: Evidence from a national longitudinal survey

We estimate the long-term effect of initiating smoking in adolescence on a range of health outcomes later in life. We use the second wave (1996) and the fifth wave (2016-2018) of the National Longitudinal Study of Adolescent to Adult Health (Add Health) and estimate instrumental variables models with school-level fixed effects, where the instruments are the average rate of smoking among friends and the respondents' perceptions about their friends' smoking. We find that smoking in adolescence has a negative impact on 15 of the 28 self-reported, diagnosed, and self-identified health outcomes approximately 20 years later.

The prevalence of alcohol dependence and its association with hypertension: a population-based cross-sectional study4 in Xuzhou city, China

Background

To describe the prevalence of alcohol dependence and to explore the relationship between alcohol dependence and newly detected hypertension in China.

Methods

A multistage stratified cluster sampling method was used to obtain samples from February to June 2013. The Michigan Alcoholism Screening Test was used to estimate alcohol dependence level. A standard questionnaire measured other independent variables. Enumeration data were analyzed using chi-square; quantitative data were analyzed using t-tests. Spearman correlation analysis and multivariate logistic regression analysis were performed to identify the relationship between alcohol dependence and hypertension.

Results

The alcohol dependence rate was 11.56%; 22.02% of males (3854/17501) and 1.74% of females (324/18656) were classified as alcohol dependent. The newly detected hypertension rate was 9.46% (3422/36157). Significant associations were found between alcohol dependence levels and blood pressure (P < 0.01). Alcohol dependence was positively correlated with systolic blood pressure (r = 0.071, P < 0.01) and diastolic blood pressure (r = 0.077, P < 0.01) and was an independent risk factor for hypertension after adjusting for confounders (low alcohol dependence: odds ratio [OR] = 1.44, 95% confidence intervals [CI] = 1.14–1.81, P < 0.01; light alcohol dependence: OR = 1.35, 95% CI = 1.11–1.64, P < 0.01; medium alcohol dependence: OR = 1.83, 95% CI = 1.40–2.41, P < 0.01).

Conclusion

Alcohol dependence was high and associated with hypertension. Health education and precautions against alcoholism should be implemented in Xuzhou city.

Association between daily cigarette consumption and hypertension moderated by CYP2A6 genotypes in Chinese male current smokers

The purpose of this study was to assess whether cytochrome P450 enzyme 2A6 (CYP2A6) genotypes moderate the association between smoking and hypertension. In this study, 954 Chinese male current smokers from a community-based chronic disease screening project in Guangzhou were interviewed with a structured questionnaire about socio-demographic status, smoking and other health-related behaviors. Blood was collected for DNA extraction and CYP2A6 genotyping. Hypertension was defined according to 2007 ESH-ESC Practice Guidelines. A multivariate logistic regression was performed to examine the interaction between smoking quantity and CYP2A6 genotypes on hypertension after adjusting for age, education level and other potential confounders. Multivariate analyses indicated that smoking more than 15 cigarettes per day significantly increased the risk of hypertension (odds ratio (OR)=1.59, 95% confidence interval (CI)=1.21-2.10) compared with smoking 1-15 cigarettes per day, and further suggested that smoking interacted with normal CYP2A6 metabolizer genotype to increase the risk of hypertension. Smokers consuming more than 15 cigarettes per day with normal CYP2A6 metabolizer genotypes had the highest risk of hypertension (OR=2.04, 95% CI=1.11-3.75) compared with those consuming 1-15 cigarettes per day with slower CYP2A6 metabolizer genotypes. These findings demonstrated that smoking quantity was positively associated with hypertension and that CYP2A6 genotypes may moderate this relationship.

Exercise training for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a worldwide public health problem. In the National Kidney Foundation Disease Outcomes Quality Initiative guidelines it is stressed that lifestyle issues such as physical activity should be seen as cornerstones of the therapy. The physical fitness in adults with CKD is so reduced that it impinges on ability and capacity to perform activities in everyday life and occupational tasks. An increasing number of studies have been published regarding health effects of various regular exercise programmes in adults with CKD and in renal transplant patients.

OBJECTIVES

We aimed to: 1) assess the effects of regular exercise in adults with CKD and kidney transplant patients; and 2) determine how the exercise programme should be designed (e.g. type, duration, intensity, frequency of exercise) to be able to affect physical fitness and functioning, level of physical activity, cardiovascular dimensions, nutrition, lipids, glucose metabolism, systemic inflammation, muscle morphology and morphometrics, dropout rates, compliance, adverse events and mortality.

SEARCH STRATEGY

We searched the Cochrane Renal Group's specialised register, CENTRAL, MEDLINE, EMBASE, CINAHL, Web of Science, Biosis, Pedro, Amed, AgeLine, PsycINFO and KoreaMed. We also handsearched reference lists of review articles and included studies, conference proceeding's abstracts. There were no language restrictions.Date of last search: May 2010.

SELECTION CRITERIA

We included any randomised controlled trial (RCT) enrolling adults with CKD or kidney transplant recipients undergoing any type of physical exercise intervention undertaken for eight weeks or more. Studies using less than eight weeks exercise, those only recommending an increase in physical activity, and studies in which co-interventions are not applied or given to both groups were excluded.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of study and data quality were performed independently by the two authors. Continuous outcome data are presented as standardised mean difference (SMD) or mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

Forty-five studies, randomising 1863 participants were included in this review. Thirty two studies presented data that could be meta-analysed. Types of exercise training included cardiovascular training, mixed cardiovascular and resistance training, resistance-only training and yoga. Some studies used supervised exercise interventions and others used unsupervised interventions. Exercise intensity was classed as 'high' or 'low', duration of individual exercise sessions ranged from 20 minutes/session to 110 minutes/session, and study duration was from two to 18 months. Seventeen per cent of studies were classed as having an overall low risk of bias, 33% as moderate, and 49% as having a high risk of bias.The results shows that regular exercise significantly improved: 1) physical fitness (aerobic capacity, 24 studies, 847 participants: SMD -0.56, 95% CI -0.70 to -0.42; walking capacity, 7 studies, 191 participants: SMD -0.36, 95% CI-0.65 to -0.06); 2) cardiovascular dimensions (resting diastolic blood pressure, 11 studies, 419 participants: MD 2.32 mm Hg, 95% CI 0.59 to 4.05; resting systolic blood pressure, 9 studies, 347 participants: MD 6.08 mm Hg, 95% CI 2.15 to 10.12; heart rate, 11 studies, 229 participants: MD 6 bpm, 95% CI 10 to 2); 3) some nutritional parameters (albumin, 3 studies, 111 participants: MD -2.28 g/L, 95% CI -4.25 to -0.32; pre-albumin, 3 studies, 111 participants: MD - 44.02 mg/L, 95% CI -71.52 to -16.53; energy intake, 4 studies, 97 participants: SMD -0.47, 95% CI -0.88 to -0.05); and 4) health-related quality of life. Results also showed how exercise should be designed in order to optimise the effect. Other outcomes had insufficient evidence.

AUTHORS' CONCLUSIONS

There is evidence for significant beneficial effects of regular exercise on physical fitness, walking capacity, cardiovascular dimensions (e.g. blood pressure and heart rate), health-related quality of life and some nutritional parameters in adults with CKD. Other outcomes had insufficient evidence due to the lack of data from RCTs. The design of the exercise intervention causes difference in effect size and should be considered when prescribing exercise with the aim of affecting a certain outcome. Future RCTs should focus more on the effects of resistance training interventions or mixed cardiovascular- and resistance training as these exercise types have not been studied as much as cardiovascular exercise.

Human dopamine β-hydroxylase promoter variant alters transcription in chromaffin cells, enzyme secretion, and blood pressure

BACKGROUND

Dopamine β-hydroxylase (DBH) plays an indispensable role in catecholamine synthesis by converting dopamine into norepinephrine. Here, we characterized a DBH promoter polymorphism (C-2073T; rs1989787; minor allele frequency ~16%) that influences not only gene transcription but also enzyme secretion and blood pressure (BP) in vivo.

METHODS

Plasma DBH activity was measured spectrophotometrically. DBH genetic effects on BP were tested in subjects with the most extreme BP values in a large primary care population. Functional effects of promoter variants were studied by site-directed mutagenesis in DBH promoter haplotype/luciferase reporter plasmids transfected into chromaffin cells. Sequence motifs were predicted from position weight matrices, and endogenous transcription factor binding was probed by Chromatin ImmunoPrecipitation (ChIP).

RESULTS

The T-allele of common promoter variant C-2073T was contained in a promoter haplotype that associated with plasma DBH activity, a trait also predicted by that variant itself. Promoter haplotypes including C-2073T predicted BP in the population, and the effect was also referable to C-2073T itself. Computationally, C-2073 disrupted a predicted match for transcription factor c-FOS. Site-directed mutagenesis at C-2073T altered not only basal promoter activity, but also transactivation by c-FOS, as well as the chromaffin cell secretory stimuli nicotine or pituitary adenylate cyclase-activating polypeptide (PACAP). Endogenous c-FOS bound to the motif in chromatin.

CONCLUSIONS

These results suggest that DBH promoter variant C-2073T is functional in vivo: this promoter variant seems to initiate a cascade of transcriptional and biochemical changes including augmented DBH secretion, eventuating in elevation of basal BP, and hence cardiovascular risk. The observations suggest new strategies for probing the pathophysiology, risk, and treatment of hypertension.

Hypertension and its identification among current, past and never smokers in an English population sample

BACKGROUND

Clinical guidelines recommend prioritizing efforts to treat hypertension in people with other cardiovascular risk factors, including smoking, but few contemporary data are available on awareness of hypertension among smokers. This study aimed to determine the prevalence of hypertension awareness in hypertensive smokers and its association with receiving and acting on advice to stop smoking.

DESIGN

Cross-sectional surveys in 2003 and 2006.

METHODS

Data, including socio-demographic, lifestyle and smoking characteristics and provision of advice to stop smoking were collected from 20 202 adults participating in the Health Survey for England. Self-report was used to determine awareness of hypertension; blood pressure readings were taken by a trained nurse to identify hypertension objectively.

RESULTS

Current smokers with objectively defined hypertension were less aware of their hypertension than hypertensive past or never smokers: only half of hypertensive smokers reported having received a diagnosis with hypertension [51.3%, 95% confidence interval (CI): 48.8-53.8]. After adjustment for confounding, this difference in awareness between current and past smokers remained significant [odds ratio (OR): 1.32, 95% CI: 1.12-1.55] but became nonsignificant when comparing current and never smokers (OR: 1.05, 95% CI: 0.88-1.25). However, hypertension awareness increased between 2003 and 2006 irrespective of smoking status. After adjusting for confounders, smokers aware of their hypertension were more likely to have received advice to stop smoking (OR: 3.29, 95% CI: 2.59-4.18) and to have stopped smoking (OR: 1.58, 95% CI: 1.32-1.89) than smokers unaware of their hypertension.

CONCLUSION

The diagnosis of hypertension is picked up less frequently among smokers than nonsmokers. This is particularly important because receiving a diagnosis seems to motivate cessation.

The effect of smoking on arterial stiffness

A systematic literature review was conducted using PubMed, Embase and the Cochrane Library to determine the effect of acute, chronic and passive smoking on arterial stiffness and to determine whether these effects are reversible after smoking cessation. A total of 39 relevant studies were identified and included. Acute smoking was found to cause an acute increase in arterial stiffness. Similarly, passive smoking increased arterial stiffness acutely and chronically. The majority of studies identified chronic smoking as a risk factor for increasing arterial stiffness. However, some studies found no statistical difference in arterial stiffness between nonsmokers and long-term smokers, although chronic smoking seems to sensitize the arterial response to acute smoking. In addition, whether arterial stiffness is reversed after smoking cessation and the timeline in which this may occur could not be determined from the identified literature. The effect of smoking discontinuation on arterial stiffness remains to be established by prospective smoking cessation trials.

Making hypertensive smokers motivated in quitting: developing 'blood pressure equivalence of smoking'

OBJECTIVE

To express the increased risk from smoking in terms of 'blood pressure' so that hypertensive smokers are motivated into quitting.

METHODS

Mortality risks of smokers were compared with nonsmokers in a large worker cohort in Taiwan (n = 23755 with a 17-year follow-up) for all-cause and for cardiovascular diseases. The blood pressure equivalence of smoking was then identified by the difference in mortality risks between smokers and nonsmokers.

RESULTS

Some interaction between hypertension and smoking was found to be synergistic. When hypertension and smoking co-existed, the all-cause mortality outcome [relative risk (RR) = 4.25] was larger than the sum or product of each individual risk for hypertension (RR = 2.16) or for smoking (RR = 1.97). The excess mortality risks of smoking for smokers were converted into a 'blood pressure equivalence'. The results demonstrate that the addition of smoking was similar to an increase of mortality risk approximately equivalent to an increase in blood pressure of 40 mmHg.

CONCLUSIONS

Smoking cessation in hypertensive patients could provide a reduction of mortality risks similar to a permanent reduction of 40 mmHg in blood pressure, over and above any antihypertensive medications. Appreciating this relationship enables physicians to bridge the clinical disconnection and motivates hypertensive smokers to seek smoking cessation. The use of a 'blood pressure equivalence of smoking' can link the two separate risk factors and may lead to a paradigm shift in overcoming an existing clinical challenge.

Common genetic variants in the chromogranin A promoter alter autonomic activity and blood pressure

Chromogranin A (CHGA) is stored and released from the same secretory vesicles that contain catecholamines in chromaffin cells and noradrenergic neurons. We had previously identified common genetic variants at the CHGA locus in several human populations. Here we focus on whether inter-individual variants in the promoter region are of physiological significance. A common haplotype, CGATA (Hap-B), blunted the blood pressure response to cold stress and the effect exhibited molecular heterosis with the greatest blood pressure change found in Hap-A/Hap-B heterozygotes. Homozygosity for three minor alleles with peak effects within the haplotype predicted lower stress-induced blood pressure changes. The G-462A variant predicted resting blood pressure in the population with higher pressures occurring in heterozygotes (heterosis). Using cells transfected with CHGA promoter-luciferase reporter constructs, the Hap-B haplotype had decreased luciferase expression compared to the TTGTC (Hap-A) haplotype under both basal conditions and after activation by pre-ganglionic stimuli. The G-462A variant altered a COUP-TF transcriptional control motif. The two alleles in transfected promoters differed in basal activity and in the responses to COUP-II-TF transactivation and to retinoic acid. In vitro findings of molecular heterosis were also noted with the transfected CHGA promoter wherein the diploid combination of the two G-462A alleles gave rise to higher luciferase expression than either allele in isolation. Our results suggest that common genetic variants in the CHGA promoter may regulate heritable changes in blood pressure.

The management of hypertension in ischaemic heart disease

PURPOSE OF REVIEW

Patients with hypertension and coronary artery disease are often inadequately treated. Blood pressure levels remain unacceptably high in about half of such patients. A significant shortfall exists between guidelines and practice in implementing evidence-based drug therapy.

RECENT FINDINGS

Recent trials underscore the importance of blood pressure reduction. The purported superiority of specific drug classes, notably angiotensin-converting enzyme inhibitors and beta-blockers, is increasingly debated. Conversely, the benefits of calcium channel blockers are increasingly recognized. Irrespective of differences, all three agents are frequently required to achieve blood pressure targets. Beyond blood pressure reduction, statin therapy is undoubtedly the single most important risk factor intervention. New studies suggest that intensive lipid lowering and greater reductions in low-density lipoprotein cholesterol will further reduce major cardiovascular events. Finally, the impact of smoking cessation, exercise, and diet is often underestimated.

SUMMARY

The prognosis for patients is critically dependent on reducing global cardiovascular risk by addressing all modifiable risk factors. The cornerstone of treatment remains blood pressure reduction, using agents with both antihypertensive and antianginal properties.

Sociodemographic characteristics and diabetes predict invalid self-reported non-smoking in a population-based study of U.S. adults

Background

Nearly all studies reporting smoking status collect self-reported data. The objective of this study was to assess sociodemographic characteristics and selected, common smoking-related diseases as predictors of invalid reporting of non-smoking. Valid self-reported smoking may be related to the degree to which smoking is a behavior that is not tolerated by the smoker's social group.

Methods

True smoking was defined as having serum cotinine of 15+ng/ml. 1483 "true" smokers 45+ years of age with self-reported smoking and serum cotinine data from the Mobile Examination Center were identified in the third National Health and Nutrition Examination Survey. Invalid non-smoking was defined as "true" smokers self-reporting non-smoking. To assess predictors of invalid self-reported non-smoking, odds ratios (OR) and 95% confidence intervals (CI) were calculated for age, race/ethnicity-gender categories, education, income, diabetes, hypertension, and myocardial infarction. Multiple logistic regression modeling took into account the complex survey design and sample weights.

Results

Among smokers with diabetes, invalid non-smoking status was 15%, ranging from 0% for Mexican-American (MA) males to 22%–25% for Non-Hispanic White (NHW) males and Non-Hispanic Black (NHB) females. Among smokers without diabetes, invalid non-smoking status was 5%, ranging from 3% for MA females to 10% for NHB females. After simultaneously taking into account diabetes, education, race/ethnicity and gender, smokers with diabetes (OR_Adj = 3.15; 95% CI: 1.35–7.34), who did not graduate from high school (OR_Adj = 2.05; 95% CI: 1.30–3.22) and who were NHB females (OR_Adj = 5.12; 95% CI: 1.41–18.58) were more likely to self-report as non-smokers than smokers without diabetes, who were high school graduates, and MA females, respectively. Having a history of myocardial infarction or hypertension did not predict invalid reporting of non-smoking.

Conclusion

Validity of self-reported non-smoking may be related to the relatively slowly progressing chronic nature of diabetes, in contrast with the acute event of myocardial infarction which could be considered a more serious, major life changing event. These data also raise questions regarding the possible role of societal desirability in the validity of self-reported non-smoking, especially among smokers with diabetes, who did not graduate from high school, and who were NHB females.