Chris I. Ardern

Physical inactivity, excess adiposity and premature mortality

The purpose of this report is to review the evidence that physical inactivity and excess adiposity are related to an increased risk of all‐cause mortality, and to better identify the independent contributions of each to all‐cause mortality rates. A variance‐based method of meta‐analysis was used to summarize the relationships from available studies. The summary relative risk of all‐cause mortality for physical activity from the 55 analyses (31 studies) that included an index of adiposity as a covariate was 0.80 [95% confidence interval (CI) 0.78–0.82], whereas it was 0.82 [95% CI 0.80–0.84] for the 44 analyses (26 studies) that did not include an index of adiposity. Thus, physically active individuals have a lower risk of mortality by comparison to physically inactive peers, independent of level of adiposity. The summary relative risk of all‐cause mortality for an elevated body mass index (BMI) from the 25 analyses (13 studies) that included physical activity as a covariate was 1.23 [95% CI 1.18–1.29], and it was 1.24 [95% CI 1.21–1.28] for the 81 analyses (36 studies) that did not include physical activity as a covariate. Studies that used a measure of adiposity other than the BMI show similar relationships with mortality, and stratified analyses indicate that both physical inactivity and adiposity are important determinants of mortality risk.

Are metabolically normal but obese individuals at lower risk for all-cause mortality?

OBJECTIVE The clinical relevance of the metabolically normal but obese phenotype for mortality risk is unclear. This study examines the risk for all-cause mortality in metabolically normal and abnormal obese (MNOB and MAOB, respectively) individuals. RESEARCH DESIGN AND METHODS The sample included 6,011 men and women from the Third National Health and Nutrition Examination Survey (NHANES III) with public-access mortality data linkage (follow-up = 8.7 ± 0.2 years; 292 deaths). Metabolically abnormal was defined as insulin resistance (IR) or two or more metabolic syndrome (MetSyn) criteria (excluding waist). RESULTS A total of 30% of obese subjects had IR, and 38.4% had two or more MetSyn factors, whereas only 6.0% (or 1.6% of the whole population) were free from both IR and all MetSyn factors. By MetSyn factors or IR alone, MNOB subjects (hazard ratio [HR]MetSyn 2.80 [1.18–6.65]; HRIR 2.58 [1.00–6.65]) and MAOB subjects (HRMetSyn 2.74 [1.46–5.15]; HRIR 3.09 [1.55–6.15]) had similar elevations in mortality risk compared with metabolically normal, normal weight subjects. CONCLUSIONS Although a rare phenotype, obesity, even in the absence of overt metabolic aberrations, is associated with increased all-cause mortality risk.

Prognostic value of the Quebec Classification of Whiplash-Associated Disorders

Study Design. Retrospective cohort. Objectives. 1) Evaluate the utility of the Québec Classification of Whiplash-Associated Disorders as an initial assessment tool; 2) assess its ability to predict persistence of symptoms at 6, 12, 18, and 24 months postcollision; 3) examine one potential modification to the Classification. Summary of Background Data. In 1995, a task force from Québec, Canada, developed the Québec Classification of Whiplash-Associated Disorders to assist health care workers in making therapeutic decisions. The Classification was applied to an inception cohort of patients presenting for emergency medical care following their involvement in a rear-end motor vehicle collision. Methods. All patients (n = 446) presenting to the only two emergency departments serving Kingston, Ontario, between October 1, 1995 and March 31, 1998 were considered for inclusion in the study. Eligible patients (n = 380) were categorized according to the Classification based on signs and symptoms documented in their emergency medical chart. Attempts were made to interview all patients shortly following and again 6 months after their collision. Patients were contacted at 12, 18, and 24 months postinjury only if sufficient time had elapsed between recruitment into and cessation of the study. Data were gathered regarding symptoms, treatments received, effects on usual activities, crash circumstances, and personal factors. Associations between initial Classification grade and the frequency/intensity of follow-up symptoms were quantified via multivariable analyses. Results. The Classification was prognostic in that risk for Whiplash-Associated Disorders at 6, 12, 18, and 24 months increased with increasing grade. Analyses supported modification of the Classification to distinguish between Grade II cases of Whiplash-Associated Disorders with normal or limited range of motion. The greatest risk for long-term symptoms was seen among the group of patients with both point tenderness and limited range of motion. Conclusion. The analyses of this study support the use of the Québec Classification of Whiplash-Associated Disorders as a prognostic tool for emergency department settings, and the authors propose a modification of the Classification using a subdivision of the Grade II category.

Edmonton Obesity Staging System: association with weight history and mortality risk

We sought to determine whether the Edmonton Obesity Staging System (EOSS), a newly proposed tool using obesity-related comorbidities, can help identify obese individuals who are at greater mortality risk. Data from the Aerobics Center Longitudinal Study (n = 29 533) were used to assess mortality risk in obese individuals by EOSS stage (follow-up (SD), 16.2 (7.5) years). The effect of weight history and lifestyle factors on EOSS classification was explored. Obese participants were categorized, using a modified EOSS definition, as stages 0 to 3, based on the severity of their risk profile and conditions (stage 0, no risk factors or comorbidities; stage 1, mild conditions; and stages 2 and 3, moderate to severe conditions). Compared with normal-weight individuals, obese individuals in stage 2 or 3 had a greater risk of all-cause mortality (stage 2 hazards ratio (HR) (95% CI), 1.6 (1.3-2.0); stage 3 HR, 1.7 (1.4-2.0)) and cardiovascular-related mortality (stage 2 HR, 2.1 (1.6-2.8); stage 3 HR. 2.1 (1.6-2.8)). Stage 0/1 was not associated with higher mortality risk. Lower self-ascribed preferred weight, weight at age 21, cardiorespiratory fitness, reported dieting, and fruit and vegetable intake were each associated with an elevated risk for stage 2 or 3. Thus, EOSS offers clinicians a useful approach to identify obese individuals at elevated risk of mortality who may benefit from more attention to weight management. Further research is necessary to determine what EOSS factors are most predictive of mortality risk, and whether these findings can be generalized to other obese populations.

Influence of Age on the Association Between Various Measures of Obesity and All‐Cause Mortality

OBJECTIVES: To determine whether the association between various simple measures of obesity and risk for all‐cause mortality differs between younger and older men and women.

Age and Sex Differences in the Clustering of Metabolic Syndrome Factors Association with mortality risk

OBJECTIVE The metabolic syndrome is a general term given to a clustering of cardiometabolic risk factors that may consist of different phenotype combinations. The purpose of this study was to determine the prevalence of the different combinations of factors that make up the metabolic syndrome as defined by the National Cholesterol Education Program and to examine their association with all-cause mortality in younger and older men and women. RESEARCH DESIGN AND METHODS A total of 2,784 men and 3,240 women from the Third National Health and Nutrition Examination Survey with public-access mortality data linkage (follow-up = 14.2 ± 0.2 years) were studied. RESULTS Metabolic syndrome was present in 26% of younger (aged ≤65 years) and 55.0% of older (aged >65 years) participants. The most prevalent metabolic syndrome combination was the clustering of high triglycerides, low HDL cholesterol, and elevated blood pressure in younger men (4.8%) and triglycerides, HDL cholesterol, and elevated waist circumference in younger women (4.2%). The presence of all five metabolic syndrome factors was the most common metabolic syndrome combination in both older men (8.0%) and women (9.2%). Variation existed in how metabolic syndrome combinations were associated with mortality. In younger adults, having all five metabolic syndrome factors was most strongly associated with mortality risk, whereas in older men, none of metabolic syndrome combinations were associated with mortality. In older women, having elevated glucose or low HDL as one of the metabolic syndrome components was most strongly associated with mortality risk. CONCLUSIONS Metabolic syndrome is a heterogeneous entity with age and sex variation in component clusters that may have important implications for interpreting the association between metabolic syndrome and mortality risk. Thus, metabolic syndrome used as a whole may mask important differences in assessing health and mortality risk.

Variation in mode of physical activity by ethnicity and time since immigration: a cross-sectional analysis.

BackgroundPhysical activity (PA) levels are known to be significantly lower in ethnic minority and immigrant groups living in North America and Europe compared to the general population. While there has been an increase in the number of interventions targeting these groups, little is known about their preferred modes of PA.MethodsUsing three cycles of the Canadian Community Health Survey (cycles 1.1, 2.1, 3.1; 2000-2005, n = 400,055) this investigation determined PA preferences by self-ascribed ethnicity (White, South Asian, South-East Asian, Blacks, Latin American, West Asian, Aboriginal persons and Other) and explored variation in PA preference across time since immigration categories (non-immigrant, established immigrant [> 10 years], and recent immigrant [≤ 10 years]). PA preferences over the past three months were collapsed into eight categories: walking, endurance, recreation, sports, conventional exercise, active commuting, and no PA. Logistic regression models were used to estimate the odds of participating in each PA across ethnicity and time since immigration compared to Whites and non-immigrants, respectively.ResultsCompared to Whites, all other ethnic groups were more likely to report no PA and were less likely to engage in walking, with the exception of Aboriginal persons (OR: 1.25, CI: 1.16-1.34). Further, all ethnic groups including Aboriginal persons were less likely to engage in endurance, recreation, and sport activities, but more likely to have an active commute compared to Whites. Recent and established immigrants were more likely to have an active commute and no PA, but a lower likelihood of walking, sports, endurance, and recreation activities than non-immigrants.ConclusionEthnic minority groups and immigrants in Canada tend to participate in conventional forms of exercise compared to Whites and non-immigrants and are less likely to engage in endurance exercise, recreation activities, and sports. Health promotion initiatives targeting ethnic and immigrant groups at high-risk for physical inactivity and chronic disease should consider mode of PA preference in intervention development.

Degree and correlates of cardiac knowledge and awareness among cardiac inpatients

OBJECTIVE To investigate the degree of CHD awareness as well as symptom, risk factor, and treatment knowledge in a broad sample of cardiac inpatients, and to examine its sociodemographic, clinical and psychosocial correlates. METHODS 1308 CHD inpatients (351 [27.0%] female), recruited from 11 acute care sites in Ontario, participated in this cross-sectional study. Participants were provided with a survey which included a knowledge questionnaire among other measures, and clinical data were extracted from medical charts. RESULTS 855 (68.8%) respondents cited heart disease as the leading cause of death in men, versus only 458 (37.0%) in women. Participants with less than high school education (p<.001), an annual family income less than

Age at menarche in Canada: results from the National Longitudinal Survey of Children & Youth

50,000CAD (p=.022), low functional capacity (p=.042), who were currently smoking (p=.022), who had no family history of heart disease (p<.001), and who had a perception of low personal control (p=.033) had significantly lower CHD knowledge. CONCLUSIONS Awareness of CHD is not optimal, especially among women, South Asians, and those of low socioeconomic status. CHD patients have a moderate level of disease knowledge overall, but greater education is needed. PRACTICE IMPLICATIONS Tailored educational approaches may be necessary for those of low socioeconomic status, particularly with regard to the nature of CHD, tests and treatments.

Relation of physical activity to cardiovascular disease mortality and the influence of cardiometabolic risk factors.

BackgroundGiven the downward trend in age at menarche and its implications for the reproductive health and wellbeing of women, little is known about menarcheal age in Canada. Most Canadian studies are only representative of specific populations. The present study, therefore, aims to assess the distribution of age at menarche for Canadian girls and explore its variation across socio-economic and demographic factors.MethodsThe analysis of the study was based on all female respondents aged 14 to 17 years during Cycle 4 (2000/2001) of the National Longitudinal Survey of Children & Youth (NLSCY). The main outcome was age at menarche assessed as the month and year of the occurrence of the first menstrual cycle. Kaplan Meier was used to estimate the mean and median of age at menarche. Chi-square test was used to assess the differences in early, average and later maturers across the different levels of socio-economic and demographic variables. Bootstrapping was performed to account for the complex sampling design.ResultsThe total number of girls analyzed in this study was 1,403 weighted to represent 601,911 Canadian girls. The estimated mean and median of age at menarche was 12.72 years (standard deviation = 1.05) and 12.67 years, respectively. The proportions of early (< 11.53 years), average (≥11.53 years and ≤13.91 years) and late maturers (> 13.91 years) were 14.6% (95% confidence interval (CI): 11.92-17.35), 68.0% (95% CI: 63.82-72.17) and 17.4% (95% CI: 14.10-20.63), respectively. Variations across the menarcheal groups were statistically significant for the province of residence, household income and family type.ConclusionThe findings of the study pave the way for future Canadian research. More studies are warranted to understand menarcheal age in terms of its variation across the provinces, the secular trend over time and its potential predictors.