Multicollinearity in associations between multiple environmental features and body weight and abdominal fat: using matching techniques to assess whether the associations are separable.

Because of the strong correlations among neighborhoods' characteristics, it is not clear whether the associations of specific environmental exposures (e.g., densities of physical features and services) with obesity can be disentangled. Using data from the RECORD (Residential Environment and Coronary Heart Disease) Cohort Study (Paris, France, 2007-2008), the authors investigated whether neighborhood characteristics related to the sociodemographic, physical, service-related, and social-interactional environments were associated with body mass index and waist circumference. The authors developed an original neighborhood characteristic-matching technique (analyses within pairs of participants similarly exposed to an environmental variable) to assess whether or not these associations could be disentangled. After adjustment for individual/neighborhood socioeconomic variables, body mass index/waist circumference was negatively associated with characteristics of the physical/service environments reflecting higher densities (e.g., proportion of built surface, densities of shops selling fruits/vegetables, and restaurants). Multiple adjustment models and the neighborhood characteristic-matching technique were unable to identify which of these neighborhood variables were driving the associations because of high correlations between the environmental variables. Overall, beyond the socioeconomic environment, the physical and service environments may be associated with weight status, but it is difficult to disentangle the effects of strongly correlated environmental dimensions, even if they imply different causal mechanisms and interventions.

Multiple dimensions of residential environments, neighborhood experiences, and jogging behavior in the RECORD Study.

OBJECTIVE: The purpose of this study was to examine the associations between a broad range of environmental characteristics and jogging behavior while taking into account different complementary outcomes to describe the behavior. METHODS: Using the RECORD Cohort Study (7290 participants, 2007-2008, Paris region, France), multilevel models were used to investigate individual/neighborhood variables associated with the probability of jogging; the time spent jogging; and the location of the practice. RESULTS: The presence and quality of green and open spaces was associated both with a greater probability of jogging [risk ratio (RR) for the first vs. the fourth quartile=1.22, 95% credible interval (CrI): 1.03-1.44] and with the practice of jogging within rather than outside the neighborhood (RR=1.29; 95% CrI: 1.10-1.53). Moreover, a high social cohesion and the presence of enjoyable places were associated with a higher probability of jogging (RR=1.15; 95% CrI: 1.00-1.31; RR=1.22; 95% CrI: 1.03-1.44) while the presence of parks or a lake increased the probability of jogging inside rather than outside the neighborhood (RR=1.29; 95% CrI: 1.10-1.53; RR=1.14; 95% CrI: 1.03-1.26). CONCLUSIONS: Paying attention to physical and social environments, related neighborhood experiences, and attitudes toward health may be an effective approach to promote outdoor physical activity.

Are associations between neighborhood socioeconomic characteristics and body mass index or waist circumference based on model extrapolations?

BACKGROUND: We investigated whether neighborhood socioeconomic characteristics, measured within person-centered areas (ie, centered on individuals' residences) are associated with body mass index (BMI [kg/m²]) and waist circumference. We used propensity-score matching as a diagnostic and validation tool to examine whether socio-spatial segregation (and related structural confounding) allowed us to estimate neighborhood socioeconomic effects adjusted for individual socioeconomic characteristics without excessive model extrapolations. METHODS: Using the RECORD (Residential Environment and CORonary heart Disease) Cohort Study, we conducted cross-sectional analyses of 7230 adults from the Paris region. We first estimated the relationships of 3 neighborhood socioeconomic indicators (education, income, real estate prices) with BMI and waist circumference using traditional multilevel regression models adjusted for individual covariates. Second, we examined whether these associations persisted when estimated among participants exchangeable based on their probability of living in low-socioeconomic-status neighborhoods (propensity-score matched samples). RESULTS: After adjustment for covariates, BMI/waist circumference increased with decreasing neighborhood socioeconomic status, especially with neighborhood education measured within 500-m radius buffers around residences; associations were stronger for women. With propensity-score matching techniques, there was some overlap in the odds of exposure between exposed and unexposed populations. As a function of socio-spatial segregation and an indicator of whether the data support inferences, sample size decreased by 17%-59% from the initial to the propensity-score matched samples. Propensity-score matched models confirmed relationships obtained from models in the entire sample. CONCLUSIONS: Overall, adjusted associations between neighborhood socioeconomic variables and BMI/waist circumference were empirically estimable in the French context, without excessive model extrapolations, despite the extent of socio-spatial segregation.

Neighborhood effects on health: correcting bias from neighborhood effects on participation.

BACKGROUND: Studies of neighborhood effects on health that are based on cohort data are subject to bias induced by neighborhood-related selective study participation. METHODS: We used data from the RECORD Cohort Study (REsidential Environment and CORonary heart Disease) carried out in the Paris metropolitan area, France (n = 7233). We performed separate and joint modeling of neighborhood determinants of study participation and type-2 diabetes. We sought to identify selective participation related to neighborhood, and account for any biasing effect on the associations with diabetes. RESULTS: After controlling for individual characteristics, study participation was higher for people residing close to the health centers and in neighborhoods with high income, high property values, high proportion of the population looking for work, and low built surface and low building height (contextual effects adjusted for each other). After individual-level adjustment, the prevalence of diabetes was elevated in neighborhoods with the lowest levels of educational attainment (prevalence odds ratio = 1.56 [95% credible interval = 1.06-2.31]). Neighborhood effects on participation did not bias the association between neighborhood education and diabetes. However, residual geographic variations in participation weakly biased the neighborhood education-diabetes association. Bias correction through the joint modeling of neighborhood determinants of participation and diabetes resulted in an 18% decrease in the log prevalence odds ratio for low versus high neighborhood education. CONCLUSIONS: Researchers should develop a comprehensive, theory-based model of neighborhood determinants of participation in their study, investigate resulting biases for the environment-health associations, and check that unexplained geographic variations in participation do not bias these environment-health relationships.

Paris Prospective Study III: a study of novel heart rate parameters, baroreflex sensitivity and risk of sudden death.

Resting heart rate has been related to the risk of cardiovascular disease and sudden death in several large prospective studies. To investigate prospectively the association of novel heart rate parameters and of carotid artery stiffness with sudden death and other cardiovascular disease. The Paris Prospective Study III (PPS3) is a new, ongoing French prospective study. From June 2008 to December 2011, 10,000 men and women aged 50-75 years who will have a preventive medical check-up at the Centre d'Investigations Préventives et Cliniques in Paris (France), will be enrolled in the study, after signing an informed consent. In addition to the general health examination, each subject's heart rhythm will be recorded during the course of the health check-up (approximately 2(1/2) h) and an echo-tracking of the right carotid bulb will be performed by trained technicians. A bio bank and DNA bank will be established for further biomarker and genetic analyses. The occurrence of cardiovascular disease including acute coronary syndrome, stroke, peripheral artery disease and sudden death, and of mortality, of the participants will be followed up during 20 years. With an estimated mean annual rate of sudden death of 0.1% and its increasing incidence rate with age, between 250 and 300 sudden deaths are expected. This unique study should provide new insights into the regulation of heart rate and blood pressure and should enable to identify novel heart rate parameters that are associated with sudden death.

Social inequalities in residential exposure to road traffic noise: an environmental justice analysis based on the RECORD Cohort Study.

OBJECTIVES: To explore social inequalities in residential exposure to road traffic noise in an urban area. METHODS: Environmental injustice in road traffic noise exposure was investigated in Paris, France, using the RECORD Cohort Study (n = 2130) and modelled noise data. Associations were assessed by estimating noise exposure within the local area around participants' residence, considering various socioeconomic variables defined at both individual and neighbourhood level, and comparing different regression models attempting or not to control for spatial autocorrelation in noise levels. RESULTS: After individual-level adjustment, participants' noise exposure increased with neighbourhood educational level and dwelling value but also with proportion of non-French citizens, suggesting seemingly contradictory findings. However, when country of citizenship was defined according to its human development level, noise exposure in fact increased and decreased with the proportions of citizens from advantaged and disadvantaged countries, respectively. These findings were consistent with those reported for the other socioeconomic characteristics, suggesting higher road traffic noise exposure in advantaged neighbourhoods. Substantial collinearity between neighbourhood explanatory variables and spatial random effects caused identifiability problems that prevented successful control for spatial autocorrelation. CONCLUSIONS: Contrary to previous literature, this study shows that people living in advantaged neighbourhoods were more exposed to road traffic noise in their residential environment than their deprived counterparts. This case study demonstrates the need to systematically perform sensitivity analyses with multiple socioeconomic characteristics to avoid incorrect inferences about an environmental injustice situation and the complexity of effectively controlling for spatial autocorrelation when fixed and random components of the model are correlated.

Lung function impairment and metabolic syndrome: the critical role of abdominal obesity.

RATIONALE: Increased risk for cardiovascular morbidity and mortality has been related to both lung function impairment and metabolic syndrome. Data on the relationship between lung function and metabolic syndrome are sparse. OBJECTIVES: To investigate risk for lung function impairment according to metabolic syndrome traits. METHODS: This cross-sectional population-based study included 121,965 men and women examined at the Paris Investigations Préventives et Cliniques Center between 1999 and 2006. The lower limit of normal was used to define lung function impairment (FEV(1) or FVC < lower limit of normal). Metabolic syndrome was assessed according to the American Heart Association/National Heart, Lung, and Blood Institute statement. MEASUREMENTS AND MAIN RESULTS: We used a logistic regression model and principal component analysis to investigate the differential associations between lung function impairment and specific components of metabolic syndrome. Lung function impairment was associated with metabolic syndrome (prevalence = 15.0%) independently of age, sex, smoking status, alcohol consumption, educational level, body mass index, leisure-time physical activity, and cardiovascular disease history (odds ratio [OR] [95% confidence interval], 1.28 [1.20-1.37] and OR, 1.41 [1.31-1.51] for FEV(1) and FVC, respectively). Three factors were identified from factor analysis: "lipids" (low high-density lipoprotein cholesterol, high triglycerides), "glucose-blood pressure" (high fasting glycemia, high blood pressure), and "abdominal obesity" (large waist circumference). All factors were inversely related to lung function, but abdominal obesity was the strongest predictor of lung function impairment (OR, 1.94 [1.80-2.09] and OR, 2.11 [1.95-2.29], for FEV(1) and FVC, respectively). Similar results were obtained for women and men. CONCLUSIONS: We found a positive independent relationship between lung function impairment and metabolic syndrome in both sexes, predominantly due to abdominal obesity. Further studies are required to clarify the underlying mechanisms.

The metabolic syndrome: similar deleterious impact on all-cause mortality in hypertensive and normotensive subjects.

OBJECTIVES: Few data are available on the impact of the metabolic syndrome on all-cause mortality risk according to the presence of hypertension. Our aim was to evaluate the 5-year impact of the metabolic syndrome, according to blood pressure status, on all-cause mortality risk in a large French population. METHODS: The study population included 39 998 men and 20 756 women with no personal history of cardiovascular disease, who had a health check-up at the IPC Center (Paris, France) between 1999 and 2002, and who were followed up for 4.7 +/- 1.2 years. The metabolic syndrome was defined according to the National Cholesterol Educational Program classification (2001). Cox regression models were used to evaluate risk of all-cause mortality after adjustment for age, sex, classical risk factors and socioeconomic categories. Subjects were classified according to blood pressure status: hypertensive subject (systolic blood pressure > or =140 mmHg and/or diastolic blood pressure > or =90 mmHg or treatment) and normotensive subject. RESULTS: The risk of all-cause mortality associated with the metabolic syndrome was 1.50 (1.24-1.82) [hazard ratio (HR) (95% confidence interval)]. The risk of all-cause mortality associated with the presence of hypertension was 1.60 (1.38-1.85). During the 4.7 years of follow-up, the impact of the metabolic syndrome was similar among normotensive and hypertensive subjects [HR: 1.09 (0.68-1.75) and 1.40 (1.13-1.74), respectively, P for interaction = 0.35]. CONCLUSION: The findings from this study show that, in a large middle-aged French population, the metabolic syndrome has the same deleterious impact on all-cause mortality in hypertensive subjects and normotensive subjects.

All-cause and cardiovascular mortality using the different definitions of metabolic syndrome.

The aim of the present study was to assess the risk of all-cause and cardiovascular disease (CVD) mortality in subjects identified as having metabolic syndrome (MS) using either the recent International Diabetes Federation (IDF) definition or the revised National Cholesterol Educational Program (NCEP-R) definition, but not the original NCEP (2001) definition. The study population was composed of 84,730 men and women without CVD aged > or =40 years who had a health checkup at the IPC Center. Follow-up for mortality was 4.7 +/-1.7 years. Prevalences of MS were 9.6%, 21.6%, and 16.5% according to the NCEP, IDF, and NCEP-R definitions, respectively. Compared with subjects without MS, risks of all-cause mortality associated with MS were 1.63 (95% confidence interval [CI] 1.38 to 1.93) with the NCEP, 1.25 (95% CI 1.09 to 1.45) with the IDF, and 1.32 (95% CI 1.13 to 1.53) with the NCEP-R, and risks of CVD mortality were 2.05 (95% CI 1.28 to 3.28), 1.77 (95% CI 1.18 to 2.64), and 1.64 (95% CI 1.08 to 2.50), respectively. In subjects with MS detected using the IDF and NCEP-R definitions, but not the NCEP definition, risks of all-cause mortality were 1.07 (95% CI 0.89 to 1.28) and 0.92 (95% CI 0.73 to 1.18) and 1.42 (95% CI 0.86 to 2.34) and 1.07 (95% CI 0.55 to 2.09) for CVD mortality, respectively. In conclusion, in a large French population, the recent definitions of MS almost double the prevalence compared with the original definition. Subjects identified as having MS using only the recent definitions and not the original definition did not have higher rates of all-cause and CVD mortality compared with subjects without MS during follow-up.

[Diabetes and socio-economic deprivation. A study in a large French population]. / Diabète et précarité. Etude d'une vaste population française.

Socio-economically deprived subjects are reported to have an increased risk of diabetes and related complications. The aim of this study was to confirm this relation in a large French population. The study subjects consisted of 32,435 men and 16,378 women aged from 35 to 80 years who had a free health checkup at the IPC Center (Investigations Preventives et Cliniques, Paris-Ile de France) between January 2003 and December 2006. Socio-economic deprivation was evaluated by using the EPICES approach (Evaluation de la Précarité et des Inégalités de santé dans les Centres d'Examens de Santé de France). Socio-economically deprived subjects were defined as those with scores in the 5th quintile. The prevalence of diabetes among deprived men and women was respectively 6% and 7% at age 35-59 years, and 18% and 15% at age 60-80 years. The prevalence of diabetes increased with level of deprivation. Compared to the 1st quintile of the EPICES score distribution, diabetes was three to eight times more frequent in the 5th quintile. After taking into account age, the body mass index, waist circumference, and anxiety and depression, the risk that deprived subjects would be diabetic (odds ratio) was respectively 4.2 and 5.2 for men and women aged 35-39 years, and 3.5 and 2.2 for those aged 60-80 years. The following cardiovascular risk markers were significantly higher or more frequent among deprived subjects: body mass, abdominal obesity, high blood pressure and the metabolic syndrome in women; and lower HDL cholesterol, higher triglyceride levels, proteinuria, a higher heart rate and additional ECG abnormalities in both men and women. Other indicators of poor health were also more frequent among deprived subjects, including anxiety and depression, smoking (among men), elevated gamma-GT and alkaline phosphatase levels, lung vital capacity, visual disorders, and dental plaque. Finally, deprived subjects also had more limited access to health care. Thus, socio-economic status markedly influences the risk of diabetes, independently of confounding factors. Several markers of cardiovascular risk and poor health were significantly more frequent among socio-economically deprived subjects, who also had more limited access to health care.

Prevalence and determinants of hypertension in the Algerian Sahara.

BACKGROUND: In-Salah is a city-oasis located in the middle of the Algerian Sahara, a desert area whose drinking water has a high sodium content. No cardiovascular epidemiological studies have ever been conducted in this region. METHODS: A randomized sample of 635 men and 711 women, aged 40-99 years, was studied. Blood pressure measurements, combined with a clinical questionnaire that included educational and socio-economic data, and standard blood samples for the detection of dyslipidemia and diabetes mellitus, were collected. RESULTS: The mean age was 55 +/- 12 years. The prevalence of hypertension was 44% and was highly influenced by age, sex, skin colour, educational status, obesity and metabolic parameters. The higher prevalence of hypertension among black individuals was independent of socio-economic and educational levels, and of metabolic parameters. The presence of antihypertensive treatment was three times more frequent in women than in men, and there was no difference according to skin colour. Among treated subjects, 25% were well controlled, and this percentage was similar among both black and white individuals. CONCLUSION: Epidemiological studies in such an emergent population indicate that hypertension is a major public health problem. The high sodium content in drinking water in this region could play a major role in the development of hypertension.

[Atrial fibrillation: prevalence, risk factors and mortality in a large French population with 15 years of follow-up]. / Fibrillation atriale: prévalence, facteurs de risque et mortalité dans une vaste population française suivie 15 ans.

We examined the prevalence of atrial fibrillation (AF) in a large French population according to age, risk factors, all-cause mortality, and cardiovascular and cerebrovascular mortality. The study population was composed of 98,961 men and 55,109 women over 30 years of age who had a free medical checkup at the IPC Center (Centre d'Investigations Préventives et Cliniques). Routine electrocardiograms revealed the presence of AF in 235 men (mean age 60.2 +/- 10.3 years) and 63 women (mean age 62.5 +/- 9.1 years). Mean follow-up was 15.2 years. The relative risk of death [Hazard Ratio (95% CI)] was determined with a Cox regression model. The prevalence of AF increased strongly with age in both genders and was higher among men. Before 50 years of age, AF was present in 0.05% of men and 0.01% of women, compared to 6.5% and 5.2%, respectively, in over-80s. After adjustment for age, factors significantly associated with AF were cardiopathy [Odds Ratio (OR) = 3.2 (2.3-4.5) among men and 4.9 (2.5-9.5) among women], hypertension [OR = 1.4 (1.1-1.9) in men and 2.2 (1.2-3.9) in women], overweight [OR = 2.2 (1.4-3.2) in men and 2.3 (1.0-5. 1) in women], ventilatory failure [OR = 1.4 (0.9-2.2) in men and 4.9 (2.4-10) in women], diabetes [OR = 1.7 (1.1-2.5) in men] and alcohol consumption [OR = 1.7 (1.2-2.4) in men]. The relative risk of death was then adjusted for age, cardiopathy, left venticular hypertrophy, blood pressure, cholesterol, glycemia, body mass index, smoking, alcohol, and vital capacity. The HR of all-cause mortality was 1.5 (1.0-2.0) in men and 1.8 (1.0-3.3) in women. The HR of cardiovascular mortality was 2.2 (1.2-3.1) in men and 3.4 (1.5-7. 7) in women, while for stroke-related mortality it was 2.0 (0.7-4.3) in men and 4.5 (1.3-16) in women. No association was found between AF and non-cardiovascular mortality in either men or women. The risk of death among men without cardiopathy or hypertension, after adjustment for the other risk factors, was not significantly increased (overall mortality 1.1 (0.5-2.0), cardiovascular mortality 1.4 (0.6-2.9)). In contrast, men with cardiopathy or hypertension had an adjusted HR of 1.7 (1.1-2.8) for overall mortality and 2.6 (1.3-5.3) for cardiovascular mortality. In conclusion, after adjustment for all risk factors, the AF-related relative risk of overall mortality and of cardiovascular mortality was higher among women than among men, especially for cerebrovascular mortality. AF was not an independent risk factor for death among men free of cardiopathy and hypertension.

[Metabolic syndrome: prevalence, risk factors and mortality in a French population of 62 000 subjects]. / Syndrome métabolique: prévalence, marqueurs de risque associés et mortalité dans une population française de 62 000 sujets.

We evaluated the prevalence, risk factors and impact on all-cause mortality of the metabolic syndrome (MetS) and its components in a large French population. The study population consisted of subjects aged 40 years or more who volunteered for a free health check-up at the IPC Center (Investigations Préventives et Cliniques, Paris) between 1999 and 2002. There were 40 977 men (53.2 +/- 9.1 years) and 21 277 women (55.9 +/- 10.3 years). The cutoff date for mortality data was March 2004. The mean follow-up period was 3.57 +/- 1.12 years. During this period, 271 men and 87 women died. MetS was defined according to NCEP-ATP III criteria. Cox regression models were used to evaluate the risk of death [hazards ratio (95% CI)]. MetS was present at baseline in 11.8% of men and 7.6% of women. The prevalence of MetS increased from 9% in men aged 40 to 49 years to 12.5% in men aged 70 years. In women, the prevalence rose from 4.9% to 11.3%, respectively. From 1999 to 2002, the prevalence of MetS increased from 11.0% to 12.8% in men and from 7.2% to 8.8% in women. The following clinical and biological parameters were significantly associated with MetS in men and women, after adjustment for age: lower physical activity, lower vital capacity ratio, higher pulse pressure and heart rate, higher gamma-glutamyl transpeptidase, ASA and ALA transaminase and alkaline phosphatase levels, higher uricemia, leukocyte and globulin levels, dental and gingival inflammation, and higher stress and depression scores. After adjustment for age, the excess risk of all-cause mortality in subjects with MetS compared to subjects without MetS was 1.82 (1.35-2.43) in men and 1.80 (1.01-3.19) in women. After adjustment for age, gender, smoking, cholesterol, physical activity, socioeconomic status and prior cardiovascular disease, the risk of all-cause mortality was 1.69 (1.28-2.22) in the entire population. In order to evaluate the impact of each Mets component, and combinations of three MetS components, on all-cause mortality, a control group of subjects with no MetS components was used. After adjustment for age and gender, the risk of death associated with each MetS component was 2.36 (1.65-3.37) for high waist circumference, 2.08 (1.44-3.01) for elevated triglyceride levels, 1.71 (1.07-2.72) for low HDL-cholesterol levels, 1.75 (1.29-2.38) for elevated arterial pressure, and 2.93 (2.04-4.22) for elevated glucose levels. Waist circumference + elevated triglycerides + elevated glucose was the three-component combination with the strongest impact [HR = 4.95 (2.92-8.37)]. In this large French population, in which MetS was moderate, MetS was associated with other hemodynamic, hepatic, inflammatory and psychological risk factors, and with a 70% increase in all-cause mortality. The three-component combination most strongly associated with mortality was high waist circumference + elevated glucose + elevated triglycerides.

An exploratory investigation of quality of life in adult liver transplant recipients.

Quality of life is an important outcome indicator of experiences associated with liver transplantation. Unfortunately, quality of life has been defined in many different ways, causing confusion and misconceptions among practitioners, researchers, policy makers, and patients. This exploratory qualitative study was initiated to gain greater understanding regarding the adult transplant recipients' experiences with liver transplantation in order to direct future studies with this population and to assist in selection of a relevant quality of life survey tool for quantitative investigation. Twelve informants (7 women, 5 men) shared their experiences in face-to-face interviews conducted by the researcher. Analysis of these interviews reveals the importance of physiologic, psychological, social, spiritual, family, and socioeconomic aspects of quality of life for liver transplant recipients.

Clinical results with bisoprolol 2.5 mg/hydrochlorothiazide 6.25 mg combination in systolic hypertension in the elderly.

Hypertension in the elderly, especially systolic hypertension, has been recognized as a major cardiovascular risk factor. Several international studies, using primarily diuretics and/or beta-blockers, have shown the benefits of antihypertensive treatment in elderly patients in terms of cardiovascular morbidity and mortality reduction. However, because the risk of side-effects is a major concern when treating the elderly, the use of low-dose combination treatments may be of particular interest. A randomized, multicentre, double-blind, parallel group study was conducted to compare the efficacy and safety of bisoprolol 2.5 mg/hydrochlorothiazide 6.25 mg (biso 2.5/HCTZ 6.25) (n = 84) versus amlodipine 5 mg (n = 80) in subjects over 60years of age with isolated systolic hypertension. The effects of these two treatment strategies on patients' quality of life were also assessed. After a two- to four-week placebo washout period, both drugs were administered once daily and taken for 12 weeks. Blood pressure was measured 24 h after treatment administration. Systolic blood pressure/diastolic blood pressure changes from baseline to week 12 were similar for both biso 2.5/HCTZ6.25 and amlodipine (-20.0/-4.5 mmHg and -19.6/-2.4 mmHg, respectively). Overall adverse events for biso 2.5/HCTZ 6.25 and amlodipine were 39% and 40%, respectively. Both treatments improved quality of life scores in the same way. This study demonstrates comparable efficacy and tolerability of biso 2.5/HCTZ 6.25 and amlodipine. Low-dose combination of bisoprolol and hydrochlorothiazide may be an appropriate alternative for elderly patients with systolic hypertension.

Inflammatory mediators in saliva associated with arterial stiffness and subclinical atherosclerosis.

OBJECTIVE: Whereas circulating levels of C-reactive protein (CRP) have been associated with, for example, arterial stiffness, subclinical atherosclerosis and metabolic syndrome, other inflammatory biomarkers with potential interest for these conditions may not be measurable systemically. The predictive value of salivary biomarkers in these contexts has remained largely unexplored. The aim of the present study was to establish the association of different salivary biomarkers of inflammation with subclinical cardiovascular disease. METHODS: Two hundred and fifty-nine individuals were included in the study. Saliva and plasma samples were collected, and each individual underwent carotid ultrasound and measures of pulse wave velocity and blood pressure. Medical history of previous cardiovascular disease, current medications and smoking were collected by questionnaire. RESULTS: Salivary levels of CRP, leukotriene B4 (LTB4), prostaglandin E2 (PGE2), matrix metalloproteinase 9 (MMP-9), creatinine and lysozyme were measured. Salivary levels of CRP were significantly correlated with plasma levels (r = 0.73, P < 0.0001). In an age-adjusted and sex-adjusted analysis, salivary CRP was significantly and positively correlated with mean arterial blood pressure, pulse pressure, pulse wave velocity, BMI, metabolic syndrome, waist-to-hip ratio and intima-media thickness. Increasing age and sex-adjusted salivary CRP tertiles were in addition associated with carotid plaques. In a multivariate analysis, CRP and MMP-9 were associated with intima-media thickness, LTB4 and PGE2 with arterial stiffness, and lysozyme with hypertension. CONCLUSION: Saliva may represent an alternative mean for evaluation of cardiovascular risk.

Influence of the AGTR1 A1166C genotype on the progression of arterial stiffness: A 16-year longitudinal study.

BACKGROUND: We examined the influence of the AGTR1 A1166C genotype on the 16-year evolution of pulse wave velocity (PWV) in a middle-aged population. In a cross-sectional study, we reported that the presence of the AGTR1 1166C allele was associated with higher aortic stiffness compared with the AGTR1 1166AA genotype. METHODS: The study was conducted in 259 subjects who underwent 3 health check-ups over 16 years at the Centre IPC-Paris: an initial visit in 1992-1993, an intermediate visit in 1998-1999, and a final visit in 2007-2008. Aortic stiffness was assessed during the 3 visits by measuring carotid-femoral PWV. AGTR1 A1166C polymorphism was assayed by allele-specific oligonucleotide hybridization. RESULTS: AGTR1 1166C allele carriers (AC + CC genotypes) had a 35% more pronounced increase in PWV over this 16-year period when compared with the AGTR1 1166AA subjects (3.01 ± 0.32 vs. 1.92 ± 0.23 m/s; P < 0.001). This increase remained significant after adjustment for age, sex, initial PWV values, and changes in blood pressure (+37%; P < 0.05). The genotype-related differences in PWV were only observed at the last visit (i.e., later in life, after the age of 55 years). The effects of this genotype on PWV were not related to the presence of antihypertensive treatment. CONCLUSIONS: This is the first long-term longitudinal study indicating that AT1 1166C carriers are at increased risk of pronounced arterial stiffening during aging especially after the age of 55.

Occupational status moderates the association between current perceived stress and high blood pressure: evidence from the IPC cohort study.

Although lay beliefs commonly relate high blood pressure (BP) to psychological stress exposure, research findings are conflicting. This study examined the association between current perceived stress and high BP, and explored the potential impact of occupational status on this association. Resting BP was measured in 122 816 adults (84 994 men), aged ≥30 years (mean age±standard deviation: 46.8±9.9 years), without history of cardiovascular and renal disease and not on either psychotropic or antihypertensive drugs. High BP was defined as systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg. Perceived stress in the past month was measured with the 4-item perceived stress scale. A total of 33 154 participants (27.0%) had high BP (151±14/90±9 mm Hg). After adjustment for all variables except occupational status, perceived stress was associated with high BP (odds ratio [OR] for a 5-point increase: 1.06; 95% confidence interval [CI]: 1.03-1.09). This association was no longer significant after additional adjustment for occupational status (OR: 1.01; 95% CI: 0.99-1.04). There was a significant interaction (P<0.001) between perceived stress and occupational status in relation to BP: perceived stress was negatively associated with high BP among individuals of high occupational status (OR: 0.91; 95% CI: 0.87-0.96), but positively associated among those of low status (OR: 1.10; 95% CI: 1.03-1.17) or unemployed (OR: 1.13; 95% CI: 1.03-1.24). Sensitivity analyses yielded similar results. The association between current perceived stress and BP depends on occupational status. This interaction may account for previous conflicting results and warrants further studies to explore its underlying mechanisms.

Associations of supermarket characteristics with weight status and body fat: a multilevel analysis of individuals within supermarkets (RECORD study).

PURPOSE: Previous research on the influence of the food environment on weight status has often used impersonal measures of the food environment defined for residential neighborhoods, which ignore whether people actually use the food outlets near their residence. To assess whether supermarkets are relevant contexts for interventions, the present study explored between-residential neighborhood and between-supermarket variations in body mass index (BMI) and waist circumference (WC), and investigated associations between brands and characteristics of supermarkets and BMI or WC, after adjustment for individual and residential neighborhood characteristics. METHODS: Participants in the RECORD Cohort Study (Paris Region, France, 2007-2008) were surveyed on the supermarket (brand and exact location) where they conducted their food shopping. Overall, 7 131 participants shopped in 1 097 different supermarkets. Cross-classified multilevel linear models were estimated for BMI and WC. RESULTS: Just 11.4% of participants shopped for food primarily within their residential neighborhood. After accounting for participants' residential neighborhood, people shopping in the same supermarket had a more comparable BMI and WC than participants shopping in different supermarkets. After adjustment for individual and residential neighborhood characteristics, participants shopping in specific supermarket brands, in hard discount supermarkets (especially if they had a low education), and in supermarkets whose catchment area comprised low educated residents had a higher BMI/WC. CONCLUSION: A public health strategy to reduce excess weight may be to intervene on specific supermarkets to change food purchasing behavior, as supermarkets are where dietary preferences are materialized into definite purchased foods.

Why socially deprived populations have a faster resting heart rate: impact of behaviour, life course anthropometry, and biology--the RECORD Cohort Study.

Although studies have shown that resting heart rate (RHR) is predictive of cardiovascular morbidity/mortality, few studies focused on the epidemiology and social aetiology of RHR. Using the RECORD Cohort Study (7158 participants, 2007-2008, Paris region, France), we investigated individual/neighbourhood socioeconomic variables associated with resting heart rate, and assessed which of a number of psychological factors (depression and stress), behaviour (sport-related energy expenditure, medication use, and alcohol, coffee, and tobacco consumption), life course anthropometric factors (body mass index, waist circumference, and leg length as a marker of childhood environmental exposures), and biologic factors (alkaline phosphatase and gamma-glutamyltransferase) contributed to the socioeconomic disadvantage-RHR relationship. Combining individual/neighbourhood socioeconomic factors in a socioeconomic score, RHR increased with socioeconomic disadvantage: +0.9 [95% credible interval (CrI): +0.2, +1.6], +1.8 (95% CrI: +1.0, +2.5), and +3.6 (95% CrI: +2.9, +4.4) bpm for the 3 categories reflecting increasing disadvantage, compared with the lowest disadvantage category. Twenty-one percent of the socioeconomic disadvantage-RHR relationship was explained by sport practise variables, 9% by waist circumference, 7% by gamma-glutamyltransferase, 5% by alkaline phosphatase, and 3% by leg length. Future research should further clarify the mechanisms through which socioeconomic disadvantage influences resting heart rate, as a pathway to social disparities in cardiovascular morbidity/mortality.