German Origin Clusters for High Cardiovascular Risk in an Italian Enclave

The ROVIGO study (risk of vascular complications: impact of genetics in old people): protocol, study design, and preliminary results of the initial survey : cardiovascular epidemiology in the elderly

BACKGROUND

The epidemiology of cardiovascular risk (CV) in the elderly is far from being defined, and the reasons why some subjects retain a healthy body while growing old while others are affected by different diseases or die prematurely are still unknown.

AIMS

To compare the CV risk pattern in two elderly cohorts living in North-East Italy.

MATERIALS AND METHODS

The Risk Of Vascular complications: Impact of Genetics in Old people (ROVIGO) study is a population-based study including 580 unrelated elderly subjects representative of general population living in Rovigo in the Veneto region. They were compared to a cohort of 580 age-gender-matched unrelated subjects from the CArdiovascular STudy in the Elderly (CASTEL) living in the same region in Castelfranco Veneto and Chioggia.

RESULTS

Blood pressure (BP), heart rate (HR), low-density-lipoprotein cholesterol, and prevalence of coronary heart disease, heart failure and chronic pulmonary disease were lower in the ROVIGO than in the CASTEL cohort, while high-density-lipoprotein cholesterol and the prevalence of diabetes were higher in the former than in the latter. In the ROVIGO cohort, diabetes, left ventricular hypertrophy, coronary and cerebrovascular diseases were more represented in men. In the CASTEL cohort, systolic BP was higher in women. In both cohorts, the lipid pattern was less favourable and HR higher in women, chronic pulmonary disease more represented in men.

CONCLUSIONS

People living in Rovigo were at lower CV risk than those in Castelfranco Veneto and Chioggia, mainly due to lower BP values, better lipid pattern and lower prevalence of CV and pulmonary disease.

Cognitive Functions across the GNB3 C825T Polymorphism in an Elderly Italian Population

To verify whether the C825T polymorphism of the GNB3 influences the response to neuropsychological tests, mini-mental state examination, digit span (DS), immediate and delayed prose memory, memory with interference at 10 and 30 seconds (MI 10 and 30), trail making tests (TMTs) A and B, abstraction task, verbal fluency (VF) test, figure drawing and copying, overlapping figures test and clock test were performed in 220 elderly men and women free from clinical dementia and from neurological and psychiatric diseases randomly taken from the Italian general population and analysed across the C825T polymorphism. The performance of DS, immediate and delayed prose memory, VF, and TMTs was worse in subjects who were TT for the polymorphism in comparison to the C-carriers. The performance of all tests declined with age. In the case of DS, immediate and delayed prose memory, MI 10 and VF, this trend was maintained in the C-carriers but not in TT. In the case of prose memory, of memory with interference, and of VF, schooling reduced the detrimental interaction between age and genotype. The C825T polymorphism of GNB3 gene therefore influences memory and verbal fluency, being additive to the effects of age and partially mitigated by schooling.

Genetics of mineralocorticoid excess: an update for clinicians

Aldosterone plays a major role in the regulation of sodium and potassium homeostasis and blood pressure. More recently, aldosterone has emerged as a key hormone mediating end organ damage. In extreme cases, dysregulated aldosterone production leads to primary aldosteronism (PA), the most common form of secondary hypertension. However, even within the physiological range, high levels of aldosterone are associated with an increased risk of developing hypertension over time. PA represents the most common and curable form of hypertension, with a prevalence that increases with the severity of hypertension. Although genetic causes underlying glucocorticoid-remediable aldosteronism, one of the three Mendelian forms of PA, were established some time ago, somatic and inherited mutations in the potassium channel GIRK4 have only recently been implicated in the formation of aldosterone-producing adenoma (APA) and in familial hyperaldosteronism type 3. Moreover, recent findings have shown somatic mutations in two additional genes, involved in maintaining intracellular ionic homeostasis and cell membrane potential, in a subset of APAs. This review summarizes our current knowledge on the genetic determinants that contribute to variations in plasma aldosterone and renin levels in the general population and the genetics of familial and sporadic PA. Various animal models that have significantly improved our understanding of the pathophysiology of excess aldosterone production are also discussed. Finally, we outline the cardiovascular, renal, and metabolic consequences of mineralocorticoid excess beyond blood pressure regulation.

Cognitive functions and cognitive reserve in relation to blood pressure components in a population-based cohort aged 53 to 94 years

In 288 men and women from general population in a cross-sectional survey, all neuropsychological tests were negatively associated with age; memory and executive function were also positively related with education. The hypertensives (HT) were less efficient than the normotensives (NT) in the test of memory with interference at 10 sec (MI-10) (−33%, P = 0.03), clock drawing test (CLOX) (−28%, P < 0.01), and mini-mental state examination (MMSE) (−6%, P = 0.02). Lower MMSE, MI-10, and CLOX were predicted by higher systolic (odds ratio, OR, 0.97, P = 0.02; OR 0.98, P < 0.005; OR 0.95, P < 0.001) and higher pulse blood pressure (BP) (OR 0.97, P = 0.02; OR 0.97, P < 0.01; and 0.95, P < 0.0001). The cognitive reserve index (CRI) was 6% lower in the HT (P = 0.03) and was predicted by higher pulse BP (OR 0.82, P < 0.001). The BP vectors of lower MMSE, MI-10, and CLOX were directed towards higher values of systolic and diastolic BP, that of low CRI towards higher systolic and lower diastolic. The label of hypertension and higher values of systolic or pulse BP are associated to worse memory and executive functions. Higher diastolic BP, although insufficient to impair cognition, strengthens this association. CRI is predicted by higher systolic BP associated to lower diastolic BP.

The C825T GNB3 polymorphism, independent of blood pressure, predicts cerebrovascular risk at a population level

BACKGROUND

The role of C825T polymorphism of the candidate GNB3 gene in predicting cerebrovascular outcome has been poorly explored in longitudinal setting at a population level.

METHODS

In an epidemiological setting, 1,678 men and women from general population were genotyped for C825T polymorphism of GNB3 gene and follow-up for 10 years to detect nonfatal and fatal cerebrovascular events (CE). Established cerebrovascular risk factors were used to adjust the multivariate Cox analysis for confounders.

RESULTS

Seventy-three nonfatal and 30 fatal CE were recorded. Incidence of CE was higher in TT than in C-carriers (fatal: 2.6 vs. 1.7%, P < 0.03; nonfatal: 7.8 vs. 3.9%, P < 0.03; fatal recurrences: 1.6 vs. 0.6%, P < 0.03). In Cox analysis, the TT genotype predicted nonfatal (hazard ratio 1.99, 95% confidence interval 1.05-3.79, P = 0.03), fatal (2.91, 1.05-8.12, P = 0.04), and fatal recurrent CE (6.82, 1.50-31.1, P = 0.02) also after adjustment for age, gender, systolic and diastolic blood pressure, body adiposity, atherogenetic blood lipids, serum uric acid, diabetes, calories, caffeine and ethanol intake, and coronary events at baseline. Further adjustment for historical CE made the association between TT genotype and incident fatal CE nonsignificant (hazard ratio 2.72, 95% confidence interval 0.96-7.22, P = 0.06).

CONCLUSIONS

The TT genotype of GNB3 gene predicts incident CE independent of blood pressure and other established risk factors at a population level. Further studies are needed to clarify the nature and pathways of this association.

Hypertension in the elderly and the very old

High systolic blood pressure represents a challenge for the modern world. Epidemiologists are in the best position to appreciate the importance of systolic hypertension and its cardiovascular consequences. Although the label of hypertension seems to have lower importance in the elderly, and above all in the very old, than in younger people, high systolic and high pulse pressure are risk factors for cardiovascular events and necessitates treatment. Unfortunately, due to indolence and lack of aggressiveness, only a limited fraction of elderly hypertensive patients receives adequate therapy.

Prognostic value of ambulatory heart rate revisited in 6928 subjects from 6 populations

The evidence relating mortality and morbidity to heart rate remains inconsistent. We performed 24-hour ambulatory blood pressure monitoring in 6928 subjects (not on beta-blockers; mean age: 56.2 years; 46.5% women) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden, Uruguay, and China. We computed standardized hazard ratios for heart rate, while stratifying for cohort, and adjusting for blood pressure and other cardiovascular risk factors. Over 9.6 years (median), 850, 325, and 493 deaths accrued for total, cardiovascular, and noncardiovascular mortality, respectively. The incidence of fatal combined with nonfatal end points was 805, 363, 439, and 324 for cardiovascular, stroke, cardiac, and coronary events, respectively. Twenty-four-hour heart rate predicted total (hazard ratio: 1.15) and noncardiovascular (hazard ratio: 1.18) mortality but not cardiovascular mortality (hazard ratio: 1.11) or any of the fatal combined with nonfatal events (hazard ratio: < or =1.02). Daytime heart rate did not predict mortality (hazard ratio: < or =1.11) or any fatal combined with nonfatal event (hazard ratio: < or =0.96). Nighttime heart rate predicted all of the mortality outcomes (hazard ratio: > or =1.15) but none of the fatal combined with nonfatal events (hazard ratio: < or =1.11). The night:day heart rate ratio predicted total (hazard ratio: 1.14) and noncardiovascular mortality (hazard ratio: 1.12) and all of the fatal combined with nonfatal events (hazard ratio: > or =1.15) with the exception of stroke (hazard ratio: 1.06). Sensitivity analyses, in which we stratified by risk factors or from which we excluded 1 cohort at a time or the events occurring within 2 years of enrollment, showed consistent results. In the general population, heart rate predicts total and noncardiovascular mortality. With the exception of the night:day heart rate ratio, heart rate did not add to the risk stratification for fatal combined with nonfatal cardiovascular events. Thus, heart rate adds little to the prediction of cardiovascular risk.

Electrocardiographic criteria of left ventricular hypertrophy in general population

The question on whether the electrocardiographic criteria are reliable for detection of left ventricular hypertrophy (LVH) and play a role in predicting outcome is open. Answer can only proceed from population-based studies over unselected people followed up for years. In this study, 1,699 subjects from general population underwent echocardiogram and standard electrocardiogram (ECG) codified for LVH with Minnesota code and with other five methods. Other items were also recorded and used as covariables. Left ventricular mass index (LVMI) was 127.6 +/- 44.9 g m(-2) in men and 120.8 +/- 41.2 g m(-2 )in women, and correlated directly with age in both genders. Prevalence of echocardiographic LVH was 36.6% in men and 53.4% in women. LVMI correlated directly with the Sokolow-Lyon score in both genders at any age, with the Romhilt-Estes, Cornell and R(aVL) scores in all subjects but elderly men, and with the Lewis score in men and women aged < or =69 years. Sensitivity and the predictive value of electrocardiographic tests, as well as the prevalence of LVH diagnosed with electrocardiographic criteria, were always low. Specificity was high for all the tests, and in particular for the Cornell index. Only when diagnosed with echocardiogram or with the Sokolow-Lyon criterion, LVH was an independent predictor of mortality. We conclude that electrocardiographic tests cannot be used as a surrogate of echocardiogram in detecting LVH in the general population because their positive predictive value (PPV) is unacceptably low. On the contrary, they could replace echocardiography in the follow up and for prediction of outcome, when LVH has previously been correctly diagnosed with other methods.

Skinfold thickness and blood pressure across C-344T polymorphism of CYP11B2 gene

OBJECTIVE

To ascertain whether body adiposity is associated with the C-344T polymorphism of the CYP11B2 gene codifying for aldosterone synthase.

DESIGN

A cross-sectional epidemiological evaluation of a highly homogeneous unselected general population of Caucasians.

METHODS

Lifestyle, medical history, anthropometrics, subscapular, triceps and suprailiac skinfold thickness, lying blood pressure and biochemical measures were recorded in a population-based study among 1386 unselected subjects (56.5% women) living in a secluded valley. All were genotyped for C-344T allele status. Continuous variables were compared across genotypes with analysis of covariance and correlations evaluated using the Pearson method. Odds ratios (OR) were calculated for the TT and CT genotype versus the CC homozygotes and compared with the T-carriers with a logistic model.

RESULTS

The C-344T genotypic frequency did not deviate from Hardy-Weinberg equilibrium. In women, higher values of triceps and subscapular skinfold thickness were found in the CC homozygotes than in the T-carriers. In this sex, skinfold thickness also directly correlated with both systolic and diastolic blood pressure in the T-carriers only. The logistic regression for the dependent variable arterial hypertension showed an influence of triceps [OR 1.07, 95% confidence interval (CI) 1.02-1.12, P=0.006], subscapular (OR 1.13, 95% CI 1.06-1.20, P<0.0001) and suprailiac (OR 1.08, 95% CI 1.01-1.15, P=0.03) skinfold in T-carrier women only. These relationships were not detectable in men. The aldosterone-to-renin ratios were comparable across genotypes and sexes.

CONCLUSION

The C-344T polymorphism of the CYP11B2 gene seems to exert a sex-specific influence on body adiposity, independent of adrenal aldosterone.

Prognostic accuracy of day versus night ambulatory blood pressure: a cohort study

BACKGROUND

Few studies have formally compared the predictive value of the blood pressure at night over and beyond the daytime value. We investigated the prognostic significance of the ambulatory blood pressure during night and day and of the night-to-day blood pressure ratio.

METHODS

We did 24-h blood pressure monitoring in 7458 people (mean age 56.8 years [SD 13.9]) enrolled in prospective population studies in Denmark, Belgium, Japan, Sweden, Uruguay, and China. We calculated multivariate-adjusted hazard ratios for daytime and night-time blood pressure and the systolic night-to-day ratio, while adjusting for cohort and cardiovascular risk factors.

FINDINGS

Median follow-up was 9.6 years (5th to 95th percentile 2.5-13.7). Adjusted for daytime blood pressure, night-time blood pressure predicted total (n=983; p<0.0001), cardiovascular (n=387; p<0.01), and non-cardiovascular (n=560; p<0.001) mortality. Conversely, adjusted for night-time blood pressure, daytime blood pressure predicted only non-cardiovascular mortality (p<0.05), with lower blood pressure levels being associated with increased risk. Both daytime and night-time blood pressure consistently predicted all cardiovascular events (n=943; p<0.05) and stroke (n=420; p<0.01). Adjusted for night-time blood pressure, daytime blood pressure lost prognostic significance only for cardiac events (n=525; p> or =0.07). Adjusted for the 24-h blood pressure, night-to-day ratio predicted mortality, but not fatal combined with non-fatal events. Antihypertensive drug treatment removed the significant association between cardiovascular events and the daytime blood pressure. Participants with systolic night-to-day ratio value of 1 or more were older, at higher risk of death, and died at an older age than those whose night-to-day ratio was normal (> or =0.80 to <0.90).

INTERPRETATION

In contrast to commonly held views, daytime blood pressure adjusted for night-time blood pressure predicts fatal combined with non-fatal cardiovascular events, except in treated patients, in whom antihypertensive drugs might reduce blood pressure during the day, but not at night. The increased mortality in patients with higher night-time than daytime blood pressure probably indicates reverse causality. Our findings support recording the ambulatory blood pressure during the whole day.

Prognostic superiority of daytime ambulatory over conventional blood pressure in four populations: a meta-analysis of 7,030 individuals

OBJECTIVE

To investigate the multivariate-adjusted predictive value of systolic and diastolic blood pressures on conventional (CBP) and daytime (10-20 h) ambulatory (ABP) measurement.

METHODS

We randomly recruited 7,030 subjects (mean age 56.2 years; 44.8% women) from populations in Belgium, Denmark, Japan and Sweden. We constructed the International Database on Ambulatory blood pressure and Cardiovascular Outcomes.

RESULTS

During follow-up (median = 9.5 years), 932 subjects died. Neither CBP nor ABP predicted total mortality, of which 60.9% was due to noncardiovascular causes. The incidence of fatal combined with nonfatal cardiovascular events amounted to 863 (228 deaths, 326 strokes and 309 cardiac events). In multivariate-adjusted continuous analyses, both CBP and ABP predicted cardiovascular, cerebrovascular, cardiac and coronary events. However, in fully-adjusted models, including both CBP and ABP, CBP lost its predictive value (P >or= 0.052), whereas systolic and diastolic ABP retained their prognostic significance (P <or= 0.007) with the exception of diastolic ABP as predictor of cardiac and coronary events (P >or= 0.21). In adjusted categorical analyses, normotension was the referent group (CBP < 140/90 mmHg and ABP < 135/85 mmHg). Adjusted hazard ratios for all cardiovascular events were 1.22 [95% confidence interval (CI) = 0.96-1.53; P = 0.09] for white-coat hypertension (>or= 140/90 and < 135/85 mmHg); 1.62 (95% CI = 1.35-1.96; P < 0.0001) for masked hypertension (< 140/90 and >or= 135/85 mmHg); and 1.80 (95% CI = 1.59-2.03; P < 0.0001) for sustained hypertension (>or= 140/90 and >or= 135/85 mmHg).

CONCLUSIONS

ABP is superior to CBP in predicting cardiovascular events, but not total and noncardiovascular mortality. Cardiovascular risk gradually increases from normotension over white-coat and masked hypertension to sustained hypertension.

The International Database of Ambulatory Blood Pressure in relation to Cardiovascular Outcome (IDACO): protocol and research perspectives

OBJECTIVES

The International Database on Ambulatory Blood Pressure Monitoring (1993-1994) lacked a prospective dimension. We are constructing a new resource of longitudinal population studies to investigate with great precision to what extent the ambulatory blood pressure improves risk stratification.

METHODS

The acronym IDACO refers to the new International Database of Ambulatory blood pressure in relation to Cardiovascular Outcome. Eligible studies are population based, have fatal as well as nonfatal outcomes available for analysis, comply with ethical standards, and have been previously published in peer-reviewed journals. In a meta-analysis based on individual patient data, composite and cause-specific cardiovascular events will be related to various indexes derived by ambulatory blood pressure monitoring. The analyses will be stratified by cohort and adjusted for the conventional blood pressure and other cardiovascular risk factors.

RESULTS

To date, the international database includes 7609 patients from four cohorts recruited in Copenhagen, Denmark (n=2311), Noorderkempen, Belgium (n=2542), Ohasama, Japan (n=1535), and Uppsala, Sweden (n=1221). In these four cohorts, during a total of 69,295 person-years of follow-up (median 9.3 years), 1026 patients died and 929 participants experienced a fatal or nonfatal cardiovascular event. Follow-up in five other eligible cohorts, involving a total of 4027 participants, is still in progress. We expect that this follow-up will be completed by the end of 2007.

CONCLUSION

The international database of ambulatory blood pressure in relation to cardiovascular outcome will provide a shared resource to investigate risk stratification by ambulatory blood pressure monitoring to an extent not possible in any earlier individual study.

Reduction of cardiovascular risk and mortality: a population-based approach

The purpose of this study was to evaluate risk pattern and mortality in a general population epidemiologic study performed by a staff of hypertension specialists working as the "good father of a family," with lifestyle and therapeutic advice and instrumental measurements. Mortality among the study population (n=856) during the 4-y study was compared with that recorded in the general population during the 4-y period before the study; those who refused to participate in the study were also recorded (n=280). Among study subjects, blood pressure decreased by 3.6/3.5 mm Hg (P<.01/P<.0001), serum total cholesterol by 3.8% (P<.0001), and low-density lipoprotein cholesterol by 10.9% (P<.01); awareness of hypertension increased by 87% (P<.0001); 20% of hypercholesterolemic patients (P<.01) and 28% of diabetic patients (P<.001) were identified; and 40% of hypertensive patients (P<.0001) were treated. Overall 4-y mortality was 12.5% in study subjects, 36.6% in renitent subjects (P<.0001 vs enrolled), and 19.9% during the period preceding the study (P<.0001 vs enrolled); cardiovascular mortality rates were 5.8%, 18.6% (P<.0001), and 11.4% (P<.0001), respectively. In particular, the frequency of fatal stroke was 0.06%, 3.8% (P<.0001), and 2.5% (P<.0001), respectively, and that of fatal coronary events was 3.4%, 7.5% (P<.0001), and 4.6% (P<.0001), respectively. In conclusion, when an epidemiologic professional staff member approaches patients in a manner similar to that of the "good father of a family," a better risk pattern and lower mortality rates (particularly cerebrovascular and coronary) are seen in those who are receptive to the care provided; those who decide not to participate in health care opportunities do not benefit.