Validation of continuous clinical indices of cardiometabolic risk in a cohort of Australian adults

BACKGROUND

Indicators of cardiometabolic risk typically include non-clinical factors (e.g., smoking). While the incorporation of non-clinical factors can improve absolute risk prediction, it is impossible to study the contribution of non-clinical factors when they are both predictors and part of the outcome measure. Metabolic syndrome, incorporating only clinical measures, seems a solution yet provides no information on risk severity. The aims of this study were: 1) to construct two continuous clinical indices of cardiometabolic risk (cCICRs), and assess their accuracy in predicting 10-year incident cardiovascular disease and/or type 2 diabetes; and 2) to compare the predictive accuracies of these cCICRs with existing risk indicators that incorporate non-clinical factors (Framingham Risk Scores).

METHODS

Data from a population-based biomedical cohort (n = 4056) were used to construct two cCICRs from waist circumference, mean arteriole pressure, fasting glucose, triglycerides and high density lipoprotein: 1) the mean of standardised risk factors (cCICR-Z); and 2) the weighted mean of the two first principal components from principal component analysis (cCICR-PCA). The predictive accuracies of the two cCICRs and the Framingham Risk Scores were assessed and compared using ROC curves.

RESULTS

Both cCICRs demonstrated moderate accuracy (AUCs 0.72 - 0.76) in predicting incident cardiovascular disease and/or type 2 diabetes, among men and women. There were no significant differences between the predictive accuracies of the cCICRs and the Framingham Risk Scores.

CONCLUSIONS

cCICRs may be useful in research investigating associations between non-clinical factors and health by providing suitable alternatives to current risk indicators which include non-clinical factors.

Characterising the smoking status and quit smoking behaviour of aboriginal health workers in South Australia

The study objectives were to characterise the smoking status and quit smoking behaviour of Aboriginal Health Workers (AHWs) in South Australia (SA), Australia; and identify the psychosocial, socio-demographic, and household smoking characteristics that distinguish smokers from quitters and never smokers. A self-reported cross-sectional survey was completed by AHWs in SA. Non-parametric statistics were used for inferential analyses. Eighty-five AHWs completed surveys representing a response rate of 63.0%. The prevalence of current smokers was 50.6%. Non-smokers (49.5%) included quitters (22.4%) and never smokers (27.1%). Smoking status did not differ by gender or geographic location. Of current smokers, 69.0% demonstrated a readiness to quit and 50.0% had made at least one quit attempt in the last 12 months. Compared to quitters and never smokers, current smokers expressed lower emotional wellbeing, and three times as many resided with another smoker. Quitters had the highest levels of perceived social support and part-time employment. A high proportion of AHWs who smoke desire, and are ready to quit. Individual, social and household factors differentiated smokers from non-smokers and quitters. Social support, and relationships and structures that favour social support, are implicated as necessary to enable AHWs who smoke to act on their desire to quit smoking.

Area-level socioeconomic characteristics and incidence of metabolic syndrome: a prospective cohort study

BACKGROUND

The evidence linking socioeconomic environments and metabolic syndrome (MetS) has primarily been based on cross-sectional studies. This study prospectively examined the relationships between area-level socioeconomic position (SEP) and the incidence of MetS.

METHODS

A prospective cohort study design was employed involving 1,877 men and women aged 18+ living in metropolitan Adelaide, Australia, all free of MetS at baseline. Area-level SEP measures, derived from Census data, included proportion of residents completing a university education, and median household weekly income. MetS, defined according to International Diabetes Federation, was ascertained after an average of 3.6 years follow up. Associations between each area-level SEP measure and incident MetS were examined by Poisson regression Generalised Estimating Equations models. Interaction between area- and individual-level SEP variables was also tested.

RESULTS

A total of 156 men (18.7%) and 153 women (13.1%) developed MetS. Each percentage increase in the proportion of residents with a university education corresponded to a 2% lower risk of developing MetS (age and sex-adjusted incidence risk ratio (RR)=0.98; 95% confidence interval (CI) =0.97-0.99). This association persisted after adjustment for individual-level income, education, and health behaviours. There was no significant association between area-level income and incident MetS overall. For the high income participants, however, a one standard deviation increase in median household weekly income was associated with a 29% higher risk of developing MetS (Adjusted RR=1.29; 95%CI=1.04-1.60).

CONCLUSIONS

While area-level education was independently and inversely associated with the risk of developing MetS, the association between area-level income and the MetS incidence was modified by individual-level income.

Hypertriglyceridemic waist and newly-diagnosed diabetes among remote-dwelling Indigenous Australians

AIMS

Hypertriglyceridemic waist (HTgW) is predictive of cardiovascular disease. The HTgW relationship with diabetes is little studied.

METHODS

This study analysed data from diabetes and cardiovascular risk factor screening programmes in remote Indigenous Australian settlements. Elevated waist girth (EW) was defined as ≥90 cm for men (n = 1134) or ≥80 cm for women (n = 1313). Hypertriglyceridemia (ETg) was defined as ≥1.7 mmol/L. Diabetes was defined as fasting plasma glucose ≥7.0 mmol/L. Body mass index (BMI) was categorised as <22, 22-24.9 and >25.0 kg/m(2). Logistic regression was used to analyse the odds of newly-diagnosed diabetes for individuals with either HTgW, ETg or EW, relative to individuals with values below cut-offs.

RESULTS

The prevalence of HTgW was 33.2% for men and 34.8% for women. Accounting for age-group and gender, newly-diagnosed diabetes was associated (odds ratio (OR) (95% confidence interval)) with HTgW: 9.6 (6.6, 13.8). The relationship remained strong after accounting for the covariates BMI and smoking (OR = 4.9 (2.7, 8.8)). In BMI-stratified analyses the strongest odds were observed for the lowest category (<22 kg/m(2): OR = 12.9 (4.0, 41.7)).

CONCLUSIONS

HTgW has a high prevalence and is associated with newly-diagnosed diabetes in Indigenous people, particularly those with BMI <22 kg/m(2), whom clinicians might not normally consider for screening.

Is walkability associated with a lower cardiometabolic risk?

Walkability of residential environments has been associated with more walking. Given the health benefits of walking, it is expected that people living in locations with higher measured walkability should have a lower risk of cardiometabolic diseases. This study tested the hypothesis that higher walkability was associated with a lower cardiometabolic risk (CMR) for two administrative spatial units and three road buffers. Data were from the North West Adelaide Health Study first wave of data collected between 2000 and 2003. CMR was expressed as a cumulative sum of six clinical risk markers, selected to reflect components of the metabolic syndrome. Walkability was based on an established methodology and operationalised as dwelling density, intersection density, land-use mix and retail footprint. Walkability was associated with lower CMR for the three road buffer representations of the built environment but not for the two administrative spatial units. This may indicate a limitation in the use of administrative spatial units for analyses of walkability and health outcomes.

High frequency of potentially pathogenic SORL1 mutations in autosomal dominant early-onset Alzheimer disease

Performing exome sequencing in 14 autosomal dominant early-onset Alzheimer disease (ADEOAD) index cases without mutation on known genes (amyloid precursor protein (APP), presenilin1 (PSEN1) and presenilin2 (PSEN2)), we found that in five patients, the SORL1 gene harbored unknown nonsense (n=1) or missense (n=4) mutations. These mutations were not retrieved in 1500 controls of same ethnic origin. In a replication sample, including 15 ADEOAD cases, 2 unknown non-synonymous mutations (1 missense, 1 nonsense) were retrieved, thus yielding to a total of 7/29 unknown mutations in the combined sample. Using in silico predictions, we conclude that these seven private mutations are likely to have a pathogenic effect. SORL1 encodes the Sortilin-related receptor LR11/SorLA, a protein involved in the control of amyloid beta peptide production. Our results suggest that besides the involvement of the APP and PSEN genes, further genetic heterogeneity, involving another gene of the same pathway is present in ADEOAD.

Evaluation of food quality in geriatric institutions

PURPOSE

The aim was to develop a strategy for evaluating food sensory quality in an institutional setting, the Parameter Specific Sensory Quality (PSSQ) approach, and to compare the inter-evaluator judgement concordance (IEC) using the PSSQ tool versus a traditional tool (TT).

METHODS

Inter-evaluator judgement concordance was assessed before and after participants underwent 12 (Study 1) or eight hours of training (Study 2). In Study 1, the IEC was determined before training using the traditional tool only (29 food items) and after training using both the traditional tool and the PSSQ (28 food items). In Study 2, the IEC was determined before and after training using the PSSQ (19 food items). Intraclass correlation coefficients (ICCs) were used to measure the IEC, and data were compared using Fisher's transformation.

RESULTS

Study 1 highlighted the poor IEC for the traditional tool in general (ICC(pre)=0.41 vs. ICC(post)=0.43; p>0.1), especially in comparison with that for the PSSQ (ICC(PSSQ)=0.88 vs. ICC(TT)=0.43; p<0.01). Study 2 corroborated the excellent performance of the PSSQ, even when participants had as few as eight hours of training (ICC(post)=0.93).

CONCLUSIONS

The inter-evaluator judgement concordance in the evaluation of food sensory quality is fundamental to the generation of valid and useful information. Study results suggest that the food sensory IEC could be improved in hospital settings through the use of a parameter-specific approach, and that this improvement could help ensure the provision of foods of consistent quality.

[Migration, health and access to care in Mayotte Island in 2007: lessons learned from a representative survey]

BACKGROUND

Mayotte Island, located in the Indian Ocean, is a French overseas departmental community with certain specificities: recent development of sanitary institutions, significant immigration, free access to care for legal residents but with co-payments for irregular residents, the absence of many of the social benefits which exist in mainland France and poor or non-existent health information systems. We report here the first population-based survey describing the links between health, migration and healthcare utilization in this territory.

METHODS

Cross sectional population-based study using a three-stage random sample (geographic areas, households, individuals). In all, 2105 individuals were interviewed either in French, Shimaore or Kibushi (response rate=96%), using a questionnaire adapted to the context of Mayotte Island after a preliminary qualitative survey. Descriptive analyses and logistic regression models were performed.

RESULTS

Foreigners make up 40% of the Mayotte population (total 186,452 inhabitants), of which one-quarter are children born in Mayotte and 80% have no regular residence status. The median length of residence of migrant foreigners is 10 years. Foreigners represent a majority of the female population, of the 20 to 35 years old population and of the urban areas. Main determinants for migration were economical (50%) or family-related (26%). Health was stated as a cause of migration by 11% of migrants. The social situation of foreigners is more precarious and their perceived health poorer than those of the French. Their access to care is also perceived as more difficult. We did not observe any notable difference in terms of frequency of healthcare attendance over the last 12 months between the two groups, but foreigners have consulted less often private GPs and more often traditional practitioners than French.

CONCLUSION

In this overseas French island, the migrant population is numerous and resident for a long time. Their main motivations to immigrate are economic and family-related. They report hurdles to healthcare related with their precarious living conditions, including their illegal residence status.

Interactive effects of reward sensitivity and residential fast-food restaurant exposure on fast-food consumption

BACKGROUND

Local fast-food environments have been increasingly linked to obesity and related outcomes. Individuals who are more sensitive to reward-related cues might be more responsive to such environments.

OBJECTIVE

This study aimed to assess the moderating role of sensitivity to reward on the relation between residential fast-food restaurant exposure and fast-food consumption.

DESIGN

Four hundred fifteen individuals (49.6% men; mean age: 34.7 y) were sampled from 7 Montreal census tracts stratified by socioeconomic status and French/English language. The frequency of fast-food restaurant visits in the previous week was self-reported. Sensitivity to reward was self-reported by using the Behavioral Activation System (BAS) scale. Fast-food restaurant exposure within 500 m of the participants' residence was determined by using a Geographic Information System. Main and interactive effects of the BAS and fast-food restaurant exposure on fast-food consumption were tested with logistic regression models that accounted for clustering of observations and participants' age, sex, education, and household income.

RESULTS

Regression results showed a significant interaction between BAS and fast-food restaurant exposure (P < 0.001). Analysis of BAS tertiles indicated that the association between neighborhood fast-food restaurant exposure and consumption was positive for the highest tertile (odds ratio: 1.49; 95% CI: 1.20, 1.84; P < 0.001) but null for the intermediate (odds ratio: 1.03; 95% CI: 0.80, 1.34; P = 0.81) and lowest (odds ratio: 0.84; 95% CI: 0.51, 1.37; P = 0.49) tertiles.

CONCLUSION

Reward-sensitive individuals may be more responsive to unhealthful cues in their immediate environment.

Associations between area-level unemployment, body mass index, and risk factors for cardiovascular disease in an urban area

INTRODUCTION

Cardiovascular Disease (CVD) has been linked to "neighbourhood" socioeconomic status (nSES), often operationalized as a composite index of aggregate income, occupation and education within predefined administrative boundaries. The role of specific, non-composite socioeconomic markers has not been clearly explained. It is also unclear whether the relationship between nSES and CVD varies according to sex. We sought to determine whether area-level unemployment (ALU) was associated with CVD risk, and whether this association differed by sex.

METHODS

342 individuals from the Montreal Neighbourhood Survey of Lifestyle and Health provided self-reported behavioural and socioeconomic information. A nurse collected biochemical and anthropometric data. ALU, a weighted average of the proportion of persons 15-years and older available for but without work, was measured using a Geographic Information System for a 250 m buffer centred on individual residence. Generalized Estimating Equations were used to estimate the associations between ALU, body mass index (BMI) and a cumulative score for total cardiometabolic risk (TCR).

RESULTS

After confounder adjustments, the mean 4(th) minus 1(st) quartile difference in BMI was 3.19 kg/m(2) (95% CI: 2.39, 3.99), while the prevalence ratio for the 4(th) relative to 1(st) quartile for TCR was 2.20 (95 % CI: 1.53, 3.17). Sex interacted with ALU; women relative to men had greater mean 3.97 kg/m(2) (95% CI: 2.08, 5.85) BMI and greater mean TCR 1.51 (95% CI: 0.78, 2.90), contrasted at mean ALU.

CONCLUSIONS

Area-level unemployment is associated with greater CVD risk, and this association is stronger for women.

Association of individual network social capital with abdominal adiposity, overweight and obesity

BACKGROUND

Limited research has examined the association of individual trust, participation and social capital with obesity using objective measures of waist circumference (WC), body mass index (BMI) and network measures of social capital.

METHODS

Data were obtained from a representative sample of Montreal residents. Participants completed questionnaires that included a position generator for collecting network social capital data. Measures of WC, height and weight were collected by registered nurses. To estimate associations with cardiometabolic risk, data on WC for individuals with BMI between 18.5 and 34.9 were extracted for analysis (n = 291). Using a proportional odds model with clustered robust standard errors, we evaluated the association of three different measures of individual social capital with elevated and substantially elevated WC and overweight and obesity categories of BMI. These measures were then evaluated in their associations with elevated WC and BMI, adjusting for socio-demographic and behavioral covariates.

RESULTS

Network social capital was inversely associated with the likelihood of being in an elevated WC risk category (odds ratio (OR) = 0.81, 95% confidence intervals (CI: 0.69, 0.96) and higher BMI category (OR = 0.81, 95% CI: 0.71, 0.92).

CONCLUSION

Higher individual network social capital is associated with a lower likelihood of elevated WC risk and overweight and obesity.

Field validation of listings of food stores and commercial physical activity establishments from secondary data

BACKGROUND

Food- and activity-related establishments are increasingly viewed as neighbourhood resources that potentially condition health-related behaviour. The primary objective of the current study was to establish, using ground truthing (on-site verification), the validity of measures of availability of food stores and physical activity establishments that were obtained from commercial database and Internet searches. A secondary objective was to examine differences in validity results according to neighbourhood characteristics and commercial establishment categories.

METHODS

Lists of food stores and physical activity-related establishments in 12 census tracts within the Montreal metropolitan region were compiled using a commercial database (n = 171 establishments) and Internet search engines (n = 123 establishments). Ground truthing through field observations was performed to assess the presence of listed establishments and identify those absent. Percentage agreement, sensitivity (proportion of establishments found in the field that were listed), and positive predictive value (proportion of listed establishments found in the field) were calculated and contrasted according to data sources, census tracts characteristics, and establishment categories.

RESULTS

Agreement with field observations was good (0.73) for the commercial list, and moderate (0.60) for the Internet-based list. The commercial list was superior to the Internet-based list for correctly listing establishments present in the field (sensitivity), but slightly inferior in terms of the likelihood that a listed establishment was present in the field (positive predictive value). Agreement was higher for food stores than for activity-related establishments.

CONCLUSION

Commercial data sources may provide a valid alternative to field observations and could prove a valuable tool in the evaluation of commercial environments relevant to eating behaviour. In contrast, this study did not find strong evidence in support of commercial and Internet data sources to represent neighbourhood opportunities for active lifestyle.