Barriers to oral care: a cross-sectional analysis of the Canadian longitudinal study on aging (CLSA)

BACKGROUND

Oral health plays a role in overall health, indicating the need to identify barriers to accessing oral care. The objective of this study was to identify barriers to accessing oral health care and examine the association between socioeconomic, psychosocial, and physical measures with access to oral health care among older Canadians.

METHODS

A cross-sectional study was conducted using data from the Canadian Longitudinal Study on Aging (CLSA) follow-up 1 survey to analyze dental insurance and last oral health care visit. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between socioeconomic, psychosocial, and physical measures with access to oral care, measured by dental insurance and last oral health visit.

RESULTS

Among the 44,011 adults included in the study, 40% reported not having dental insurance while 15% had not visited an oral health professional in the previous 12 months. Several factors were identified as barriers to accessing oral health care including, no dental insurance, low household income, rural residence, and having no natural teeth. People with an annual income of <$50,000 were four times more likely to not have dental insurance (adjusted OR: 4.09; 95% CI: 3.80-4.39) and three times more likely to report not visiting an oral health professional in the previous 12 months (adjusted OR: 3.07; 95% CI: 2.74-3.44) compared to those with annual income greater than $100,000.

CONCLUSIONS

Identifying barriers to oral health care is important when developing public health strategies to improve access, however, further research is needed to identify the mechanisms as to why these barriers exist.

Oral Health Problems among Canadians Aged 45 to 85: Data from the Canadian Longitudinal Study on Aging Baseline Survey (2011-2015)

Oral health is a critical component of overall health. The objective of this study was to describe oral health problems among 47,581 adults aged 45 to 85 in the Canadian Longitudinal Study on Aging (CLSA) among those who have at least one natural tooth (92%) and those without natural teeth across various demographic categories. Among the 47,581 participants in the study, 92% reported having at least one natural tooth (dentate). Among those without teeth, 63% reported an income less than CAD 50,000 versus 39% among those with teeth. Whether they had teeth or not, over 30% of people reported two or more oral health problems. Older adults appear to be retaining their natural teeth (28.9%), but still report experiencing oral health problems. As the population ages, loss of all teeth may not be the most useful proxy for poor oral health, and a population-level understanding of oral health problems may help to better define poor oral health.

Technical note: Investigating the suitability of existing facilities for a new Lu-177 prostate-specific membrane antigen therapy program

BACKGROUND

¹⁷⁷ Lu prostate-specific membrane antigen (PSMA) therapy prolongs survival for some prostate cancer patients. To adopt this technique, institutions may need to evaluate the suitability of existing infrastructure.

PURPOSE

Develop a methodology to determine whether existing facilities can accommodate a ¹⁷⁷ Lu-PSMA therapy program.

METHODS

Room suitability is defined by both the ability to accommodate ¹⁷⁷ Lu-PSMA therapy workflow and to provide appropriate radiation shielding. Two methods of shielding calculation were performed: (1) National Council on Radiation Protection and Measurements report 151 (NCRP-151), with workload defined in terms of the activity of ¹⁷⁷ Lu administered, and (2) using the RadPro shielding calculator. This methodology was applied to ¹³¹ I therapy, PET-CT uptake, PET-SPECT injection, and orthovoltage therapy rooms.

RESULTS

¹³¹ I therapy rooms were found to meet both shielding and workflow requirements. The shielding was found to be adequate for orthovoltage and PET-SPECT facilities, neglecting patient transit between external washrooms. The workflow was the limiting factor for these rooms due to the requirement of dedicated washrooms that shield the patient and contain possible contamination. The PET-CT facility did not meet either criteria. The NCRP-151 method generally predicted a higher dose rate on the other side of shielding than did the RadPro calculator. The dose rate on the other side of concrete shielding as predicted by the NCRP-151 method increased relative to the dose rate predicted by the RadPro calculator as shielding thickness increased. For lead shielding, the dose rate predicted by the NCRP-151 method decreased relative to the result predicted by the RadPro calculator with increasing material thickness.

CONCLUSIONS

¹³¹ I therapy, PET-CT uptake, PET-SPECT injection, and orthovoltage therapy rooms were considered. The ¹³¹ I treatment rooms were the best candidate for ¹⁷⁷ Lu-PSMA therapy, due to their shielding and capability to accommodate the necessary workflow.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Changes in symptoms, sleep, oxidative stress, and inflammatory markers among community-dwelling stroke survivors after a tai chi exercise intervention

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Laurence B. Emmons Research Award

Background

Depression is prevalent among one-third to two-thirds of stroke survivors. Despite the availability of pharmacotherapies and/or psychotherapies, depression persists, even 5-10 years post-stroke, reflecting limited treatment responses and/or adherence to this conventional care. Mind-body interventions are commonly used among adults to ameliorate depressive symptoms, thus we investigated the feasibility of Tai Chi, alongside conventional care, to manage post-stroke depression.

Purpose

Describe changes in symptoms of depression, anxiety and stress, sleep, oxidative stress, and inflammatory markers post-intervention among community-dwelling stroke survivors with depressive symptoms.

Methods

In this feasibility study, a single-group pre-post intervention design was used. Due to COVID-19, participants attended a 1-hour Tai Chi exercise class three times per week for 8 weeks, instead of the planned 12-weeks. Symptoms of depression, anxiety and stress were assessed using standardized questionnaires (Center for Epidemiological Studies Depression scale, CESD; Generalized Anxiety Disorder Assessment; Perceived Stress Scale), objective sleep was assessed via a research-grade triaxial accelerometer (ActiGraph GT9X), and blood samples were taken to assess oxidative stress (plasma superoxide dismutase, SOD)  and inflammatory markers (serum tumor necrosis factor-alpha, interleukin-6, interleukin-10). Pre-post intervention changes were assessed using paired t-tests.

Results

Community-dwelling stroke survivors (N = 11) on average 69.7 ± 9.3 years old, mainly retired (73%, n = 8), married men (55%, n = 6) with &gt;13 years education (91%, n = 10), reporting depression symptoms (CESD = 17.3 ± 11.4) and 55% taking anti-depressant medications, enrolled. The majority of participants reported having an ischemic stroke (82%, n = 9) with hemiparesis (55%, n = 6), but were able to walk 15 feet without assistance (91%, n = 10). After the Tai Chi intervention, we observed significant reductions in symptoms of depression (-5.3 ± 5.9, p = 0.01), anxiety (-2.2 ± 2.4, p = 0.01) and stress (-4.6 ± 4.8, p = 0.01); along with better sleep efficiency (+1.8 ± 1.8, p = 0.01), less wakefulness after sleep onset (-9.3 ± 11.6, p = 0.04), and less time awake (-9.3 ± 11.6, p = 0.04). In addition, there was a 36% decrease in SOD activity (p = 0.02) indicative of a decreased oxidative environment post-intervention; though no significant changes in any of the inflammatory markers were found (all p-values &gt;0.05).

Conclusion

Symptoms of depression, anxiety and stress were observed in these community-dwelling stroke survivors along with sub-optimal sleep. Among community-dwelling stroke survivors, Tai Chi exercise is a feasible intervention that can be used alongside conventional care to manage post-stroke depression and may also aid in reducing symptoms of anxiety and stress, and improve sleep.  Further research is needed with rigorous study designs and larger samples, before widespread recommendations can be made.

Longitudinal associations between bullying and alcohol use and binge drinking among grade 9 and 10 students in the COMPASS study

OBJECTIVES

Adolescents involved in bullying are at increased risk for alcohol use; however, much of this research has been cross-sectional. The aim of this work was to therefore examine the longitudinal associations between bullying and future alcohol use.

METHODS

Data were drawn from the COMPASS study. The current study used a 2-year linked sample of grade 9 and 10 students from 2015 to 2017 (n = 6005). Students were asked to report their involvement with bullying as well as alcohol use and binge drinking behaviours. Generalized estimating equations regression analyses were used to examine the relationship between bullying involvement at baseline and alcohol use and binge drinking at follow-up.

RESULTS

Overall, 20% of students in grades 9 and 10 reported involvement in bullying. There was evidence of a modest longitudinal association between bullying and binge drinking. Being a bully or bully-victim at baseline was associated with increased odds of initiating future binge drinking.

CONCLUSIONS

Being a bully or bully-victim in grade 9 or 10 was associated with initiating binge drinking within the following 2 years. Targeted alcohol use prevention programming may benefit these groups.

At-a-glance - Supervised Injection Services: a community-based response to the opioid crisis in the City of Ottawa, Canada

In response to the current opioid crisis in Canada, establishing safe injection services (SIS) in high risk communities has become more prevalent. In November 2017, The Trailer opened in Ottawa, Canada and tracks client use, overdose treatment and overdoses reversed. We analyzed data collected between November 2017 and August 2018. During peak hours, demand for services consistently exceeded The Trailer's capacity. Overdoses treated and reversed in this facility increased substantially during this period. Results suggest The Trailer provided an important though not optimal (due to space restrictions) harm reduction service to this high-risk community.

Merlin modulates process outgrowth and synaptogenesis in the cerebellum

Neurofibromatosis type 2 (NF2) patients are prone to develop glial-derived tumors in the peripheral and central nervous system (CNS). The Nf2 gene product -Merlin is not only expressed in glia, but also in neurons of the CNS, where its function still remains elusive. Here, we show that cerebellar Purkinje cells (PCs) of isoform-specific Merlin-deficient mice were innervated by smaller vGluT2-positive clusters at presynaptic terminals than those of wild-type mice. This was paralleled by a reduction in frequency and amplitude of miniature excitatory postsynaptic currents (mEPSC). On the contrary, in conditional transgenic mice in which Merlin expression was specifically ablated in PCs (L7Cre;Nf2^fl/fl), we found enlarged vGluT2-positive clusters in their presynaptic buttons together with increased amplitudes of miniature postsynaptic currents. The presynaptic terminals of these PCs innervating neurons of the deep cerebellar nuclei were also enlarged. When exploring mice with Merlin-deficient granule cells (GCs) (Math1Cre;Nf2^fl/fl), we found cerebellar extracts to contain higher amounts of vGluT1 present in parallel fiber terminals. In parallel, mEPSC frequency was increased in Math1Cre;Nf2^fl/fl mice. On the contrary, VGluT2 clusters in cerebellar glomeruli composed of NF2-deficient presynaptic Mossy fiber terminals and NF2-deficient postsynaptic GC were reduced in size as shown for isoform-specific knockout mice. These changes in Math1Cre;Nf2^fl/fl-deficient mice were paralleled by an increased activation of Rac1-Cofilin signaling which is known to impact on cytoskeletal reorganization and synapse formation. Consistent with the observed synaptic alterations in these transgenic mice, we observed altered ultrasonic vocalization, which is known to rely on proper cerebellar function. No gross morphological changes or motor coordination deficits were observed in any of these transgenic mice. We therefore conclude that Merlin does not regulate overall cerebellar development, but impacts on pre- and post-synaptic terminal organization.

The Impact of Rimed Ice Hydrometeors on Global and Regional Climate

Rimed hydrometeors (graupel or hail) are added to a stratiform cloud scheme for global models and tested in a variety of configurations. Off-line tests compare well to other cloud microphysics schemes with rimed ice used in mesoscale models. Tests in single column and climate mode show expected production of small amounts of rimed ice in the middle troposphere and at high latitudes. The overall climate impacts of rimed ice (hail or graupel) at 100-km horizontal grid spacing are small. There are some changes to partitioning between cloud ice and snow that affect upper troposphere water budgets and clouds. High-resolution simulations are conducted with a global but regionally refined grid at 14 km over the Contiguous United States. High-resolution simulations show local production of graupel with realistic size and number concentrations. The maximum graupel frequency at high resolution is over Western U.S. mountain ranges. Differences in total precipitation with the addition of rimed ice in 8-year simulations are statistically significant only for orographic precipitation over the Cascade and Rocky mountains, reducing model biases when rimed ice is included. Rimed ice slightly improves summer precipitation intensity relative to observations. Thus, while the global climate impact of rimed ice in stratiform clouds may be negligible, there are potentially important and systematic regional effects, particularly for orographic precipitation. Rimed ice in cumulus clouds is not yet treated but is an important next step.

Childhood cancer incidence in Canada: demographic and geographic variation of temporal trends (1992-2010)

INTRODUCTION

Surveillance of childhood cancer incidence trends can inform etiologic research, policy and programs. This study presents the first population-based report on demographic and geographic variations in incidence trends of detailed pediatric diagnostic groups in Canada.

METHODS

The Canadian Cancer Registry data were used to calculate annual age-standardized incidence rates (ASIRs) from 1992 to 2010 among children less than 15 years of age by sex, age and region for the 12 main diagnostic groups and selected subgroups of the International Classification of Childhood Cancer (ICCC), 3rd edition. Temporal trends were examined by annual percent changes (APCs) using Joinpoint regression.

RESULTS

The ASIRs of childhood cancer among males increased by 0.5% (95% confidence interval (CI) = 0.2-0.9) annually from 1992 to 2010, whereas incidence among females increased by 3.2% (CI = 0.4-6.2) annually since 2004 after an initial stabilization. The largest overall increase was observed in children aged 1-4 years (APC = 0.9%, CI = 0.4-1.3). By region, the overall rates increased the most in Ontario from 2006 to 2010 (APC = 5.9%, CI = 1.9-10.1), and increased non-significantly in the other regions from 1992 to 2010. Average annual ASIRs for all cancers combined from 2006 to 2010 were lower in the Prairies (149.4 per million) and higher in Ontario (170.1 per million). The ASIRs increased for leukemias, melanoma, carcinoma, thyroid cancer, ependymomas and hepatoblastoma for all ages, and neuroblastoma in 1-4 year olds. Astrocytoma decreased in 10-14 year olds (APC = -2.1%, CI = -3.7 to -0.5), and among males (APC = -2.4%, CI = -4.6 to -0.2) and females (APC = -3.7%, CI = -5.8 to -1.6) in Ontario over the study period.

CONCLUSION

Increasing incidence trends for all cancers and selected malignancies are consistent with those reported in other developed countries, and may reflect the changes in demographics and etiological exposures, and artefacts of changes in cancer coding, diagnosis and reporting. Significant decreasing trend for astrocytoma in late childhood was observed for the first time.

Effectiveness of the CANRISK tool in the identification of dysglycemia in a Canadian South Asian Population

INTRODUCTION

South Asians have a higher than average risk of developing type 2 diabetes. We ascertained the effectiveness of CANRISK, an existing diabetes risk assessment tool, examining its sensitivity and specificity at two different predetermined scoring cut-off points comparing those participants under the age of 40 and those 40 and over. We examined the predictive ability of a model based on CANRISK variables, comparing ethno-specific body mass index (BMI) and waist circumference (WC) cut-off points with the original BMI and WC cut-off points to see if predictive ability could be improved for this population.

METHODS

Canadian South Asians of unknown diabetes status, age 18 to 78, were recruited across seven provinces from various community or health centers. CANRISK variables were collected followed by oral glucose tolerance testing. Descriptive analysis, logistic regression including alternative ethno-specific BMI and WC cut-off points, and sensitivity and specificity analyses were performed.

RESULTS

832 participants were recruited (584 under age 40). Using the entire study sample, logistic regression models including CANRISK variables predicted dysglycemia effectively (AUC of 0.80). However, by using alternative BMI/WC cut-off points with the scoring algorithm, predictive power via AUC was not improved. Sensitivity and specificity of CANRISK using the original pre-determined "high risk" cut-off point of 33 points in individuals age 40 years or over were 93% and 35%, respectively; in individuals under 40, these were 33% and 92%, respectively. Using the lower pre-determined "moderate risk" cut-off point of 21 points improved the sensitivity to 77% and specificity to 53% in the younger age group.

CONCLUSION

The existing CANRISK is an adequate risk assessment tool for dysglycemia in Canadian South Asians for those age 40 years and over; however, the tool does not work as well for individuals under 40. The lower cut-off of 21 points may be warranted for younger individuals to minimize false negatives. Ethno-specific BMI/WC cutoff points did not improve predictive ability of the CANRISK scoring algorithm as measured by AUC.

Canadian trends in opioid-related mortality and disability from opioid use disorder from 1990 to 2014 through the lens of the Global Burden of Disease Study

Introduction:

Several regions in Canada have recently experienced sharp increases in opioid overdoses and related hospitalizations and deaths. This paper describes opioidrelated mortality and disability from opioid use disorder in Canada from 1990 to 2014 using data from the Global Burden of Disease (GBD) study.

Methods:

We used data from the GBD study to describe temporal trends (1990–2014) in opioid-related mortality and disability from opioid use disorder using common metrics: disability-adjusted life years (DALY), deaths, years of life lost (YLL) and years lived with disability (YLD). We also compared age-standardized YLL and DALY rates per 100 000 population between Canada, the USA and other regions.

Results:

The age-standardized opioid-related DALY rate in Canada was 355.5 per 100 000 population in 2014, which was higher than the global rate of 193.2, but lower than the rate of 767.9 in the United States. Between 1990 and 2014, the age-standardized opioid-related YLL rate in Canada increased by 142.2%, while globally this rate decreased by 10.1%. In comparison with YLL, YLD accounted for a larger proportion of the overall opioid-related burden across all age groups. Health loss was greater for males than females, and highest among those aged 25 to 29 years.

Conclusion:

The health burden associated with opioid-related mortality and disability from opioid use disorder in Canada is significant and has increased dramatically from 1990 to 2014. These data point to a need for public health action including enhanced monitoring of a range of opioid-related harms.

Effectiveness of the CANRISK tool in the identification of dysglycemia in First Nations and Métis in Canada

INTRODUCTION

First Nations/Métis populations develop diabetes earlier and at higher rates than other Canadians. The Canadian diabetes risk questionnaire (CANRISK) was developed as a diabetes screening tool for Canadians aged 40 years or over. The primary aim of this paper is to assess the effectiveness of the existing CANRISK tool and risk scores in detecting dysglycemia in First Nations/Métis participants, including among those under the age of 40. A secondary aim was to determine whether alternative waist circumference (WC) and body mass index (BMI) cut-off points improved the predictive ability of logistic regression models using CANRISK variables to predict dysglycemia.

METHODS

Information from a self-administered CANRISK questionnaire, anthropometric measurements, and results of a standard oral glucose tolerance test (OGTT) were collected from First Nations and Métis participants (n = 1479). Sensitivity and specificity of CANRISK scores using published risk score cut-off points were calculated. Logistic regression was conducted with alternative ethnicity-specific BMI and WC cut-off points to predict dysglycemia using CANRISK variables.

RESULTS

Compared with OGTT results, using a CANRISK score cut-off point of 33, the sensitivity and specificity of CANRISK was 68% and 63% among individuals aged 40 or over; it was 27% and 87%, respectively among those under 40. Using a lower cut-off point of 21, the sensitivity for individuals under 40 improved to 77% with a specificity of 44%. Though specificity at this threshold was low, the higher level of sensitivity reflects the importance of the identification of high risk individuals in this population. Despite altered cut-off points of BMI and WC, logistic regression models demonstrated similar predictive ability.

CONCLUSION

CANRISK functioned well as a preliminary step for diabetes screening in a broad age range of First Nations and Métis in Canada, with an adjusted CANRISK cutoff point for individuals under 40, and with no incremental improvement from using alternative BMI/WC cut-off points.

Ethnic dependent differences in diagnostic accuracy of glycated hemoglobin (HbA1c) in Canadian adults

AIM

Previous studies have shown varying sensitivity and specificity of hemoglobin A1c (HbA1c) to identify diabetes and prediabetes, compared to 2-h oral glucose tolerance testing (OGTT) and fasting plasma glucose (FPG), in different ethnic groups. Within the Canadian population, the ability of HbA1c to identify prediabetes and diabetes in First Nations, Métis and Inuit, East and South Asian ethnic groups has yet to be determined.

METHODS

We collected demographic, lifestyle information, biochemical results of glycemic status (FPG, OGTT, and HbA1c) from an ethnically diverse Canadian population sample, which included a purposeful sampling of First Nations, Métis, Inuit, South Asian and East Asian participants.

RESULTS

Sensitivity and specificity using Canadian Diabetes Association (CDA) recommended cut-points varied between ethnic groups, with greater variability for identification of prediabetes than diabetes. Dysglycemia (prediabetes and diabetes) was identified with a sensitivity and specificity ranging from 47.1% to 87.5%, respectively in Caucasians to 24.1% and 88.8% in Inuit. Optimal HbA1c ethnic-specific cut-points for dysglycemia and diabetes were determined by receiver operating characteristic (ROC) curve analysis.

CONCLUSIONS

Our sample showed broad differences in the ability of HbA1c to identify dysglycemia or diabetes in different ethnic groups. Optimal cut-points for dysglycemia or diabetes in all ethnic groups were substantially lower than CDA recommendations. Utilization of HbA1c as the sole biochemical diagnostic marker may produce varying degrees of false negative results depending on the ethnicity of screened individuals. Further research is necessary to identify and validate optimal ethnic specific cut-points used for diabetic screening in the Canadian population.

Assessment of dysglycemia risk in the Kitikmeot region of Nunavut: using the CANRISK tool

INTRODUCTION

The Public Health Agency of Canada adapted a Finnish diabetes screening tool (FINDRISC) to create a tool (CANRISK) tailored to Canada's multi-ethnic population. CANRISK was developed using data collected in seven Canadian provinces. In an effort to extend the applicability of CANRISK to northern territorial populations, we completed a study with the mainly Inuit population in the Kitikmeot region of Nunavut.

METHODS

We obtained CANRISK questionnaires, physical measures and blood samples from participants in five Nunavut communities in Kitikmeot. We used logistic regression to test model fit using the original CANRISK risk factors for dysglycemia (prediabetes and diabetes). Dysglycemia was assessed using fasting plasma glucose (FPG) alone and/or oral glucose tolerance test. We generated participants' CANRISK scores to test the functioning of this tool in the Inuit population.

RESULTS

A total of 303 individuals participated in the study. Half were aged less than 45 years, two-thirds were female and 84% were Inuit. A total of 18% had prediabetes, and an additional 4% had undiagnosed diabetes. The odds of having dysglycemia rose exponentially with age, while the relationship with BMI was U-shaped. Compared with lab test results, using a cut-off point of 32 the CANRISK tool achieved a sensitivity of 61%, a specificity of 66%, a positive predictive value of 34% and an accuracy rate of 65%.

CONCLUSION

The CANRISK tool achieved a similar accuracy in detecting dysglycemia in this mainly Inuit population as it did in a multi-ethnic sample of Canadians. We found the CANRISK tool to be adaptable to the Kitikmeot region, and more generally to Nunavut.

Relation of insulin resistance with social-demographics, adiposity and behavioral factors in non-diabetic adult Canadians

BACKGROUND

Insulin resistance is a pathogenic factor for type II diabetes and has been associated with metabolic abnormalities and adverse clinical outcomes. The purpose of this study was to examine the relationship between insulin resistance and socio-demographics, adiposity and behavioral factors in the general, non-diabetic adult Canadian population.

METHODS

Data for 3515 non-diabetic adults aged 18 to 79 years from the Canadian Health Measures Survey (cycles 1 and 2, 2007-2011) were analyzed. Insulin resistance index was measured by the homeostasis model assessment of insulin resistance (HOMA-IR), and insulin resistance (IR) was defined as individuals in the highest quartile of the HOMA-IR index. Logistic regression models were used to examine the effect of demographics, lifestyle factors and adiposity measurements on HOMA-IR.

RESULTS

The risk of IR increased with age, particularly in men. Individuals had adjusted odds ratio (OR) (with corresponding 95 % confidence interval) of 5.97 (2.90-8.52) and 25.12 (15.20-41.51) associated with a body-mass-index (BMI) between 25.0 and < 30.0, or ≥30.0, of 9.23 (6.52-13.07) with abdominal obesity (waist circumstance ≥102 cm for men and ≥ 88 cm for women), of 8.72 (6.13-12.39) with a high waist-to-height ratio (>0.57), and of 6.30 (4.33-9.16) with a high waist-to-hip ratio (>0.90 for men and >0.85 for women). Physically inactive people and non-alcohol consumer also had a significantly higher odd of IR.

CONCLUSIONS

This study found that men and older, obese and physically inactive people were at increased risk for IR. Adiposity indices including BMI, waist circumstance, waist-to-height ratio and waist-to-hip ratio were highly associated with IR with similar magnitude of association.

Optical projection tomography permits efficient assessment of infarct volume in the murine heart postmyocardial infarction

Optical projection tomography permits rapid high-resolution imaging of intact murine heart in vitro and identification of tissue heterogeneity within individual optical slices of postmyocardial infarction hearts. Infarct volume derived from >400 slices correlates with in vivo magnetic resonance imaging and avoids the need for histological staining of multiple physical sections.

The extent of infarct injury is a key determinant of structural and functional remodeling following myocardial infarction (MI). Infarct volume in experimental models of MI can be determined accurately by in vivo magnetic resonance imaging (MRI), but this is costly and not widely available. Experimental studies therefore commonly assess injury by histological analysis of sections sampled from the infarcted heart, an approach that is labor intensive, can be subjective, and does not fully assess the extent of injury. The present study aimed to assess the suitability of optical projection tomography (OPT) for identification of injured myocardium and for accurate and efficient assessment of infarct volume. Intact, perfusion-fixed, optically cleared hearts, collected from mice 7 days after induction of MI by coronary artery occlusion, were scanned by a tomograph for autofluorescence emission after UV excitation, generating >400 transaxial sections for reconstruction. Differential autofluorescence permitted discrimination between viable and injured myocardium and highlighted the heterogeneity within the infarct zone. Two-dimensional infarct areas derived from OPT imaging and Masson's trichrome staining of slices from the same heart were highly correlated (r² = 0.99, P < 0.0001). Infarct volume derived from reconstructed OPT sections correlated with volume derived from in vivo late gadolinium enhancement MRI (r² = 0.7608, P < 0.005). Tissue processing for OPT did not compromise subsequent immunohistochemical detection of endothelial cell and inflammatory cell markers. OPT is thus a nondestructive, efficient, and accurate approach for routine in vitro assessment of murine myocardial infarct volume.

Status Report--Retracing the history of the early development of national chronic disease surveillance in Canada and the major role of the Laboratory Centre for Disease Control (LCDC) from 1972 to 2000

Health surveillance is the ongoing, systematic use of routinely collected health data to guide public health action in a timely fashion. This paper describes the creation and growth of national surveillance systems in Canada and their impact on chronic disease and injury prevention. In 2008, the authors started a review process to retrace the history of the early development of national chronic disease surveillance in Canada from 1960 to 2000. A 1967 publication describes the history of the development of the Laboratory of Hygiene from 1921 to 1967. This review is a sequel to that paper and describes the history of the development of national chronic disease surveillance in Canada before and after the formation of the Laboratory Centre for Disease Control (LCDC).

Macronutrient intake and stomach cancer

PURPOSE

This study examines the association between intake of selected macronutrients and the risk of stomach cancer in a Northern American population.

METHODS

Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces by 1,181 incident, histologically confirmed cases of stomach cancer and 5,039 population controls. Information on nutrient intake was obtained using a food frequency questionnaire. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were derived through unconditional logistic regression to adjust for potential confounders, including an estimate of total energy intake.

RESULTS

Intakes of total fat, saturated fat, and cholesterol were significantly associated with the risk of stomach cancer: The ORs for the highest versus the lowest quartile were 1.58 (95% CI 1.13-2.20), 1.86 (95% CI 1.37-2.52), and 1.75 (95% CI 1.36-2.25), respectively. Total fiber was inversely associated with stomach cancer (p = 0.03). The positive associations with intake of total fat and saturated fat were apparently stronger in women, overweight or obese subjects, and ever smokers. Saturated fat was specifically associated with increased risk of gastric cardia cancer, with an OR of 3.31 (95% CI 1.48-7.43).

CONCLUSIONS

A diet high in saturated fat appears to increase the risk of stomach cancer, particularly among obese subjects and for gastric cardia cancer.

Association of urinary sodium and potassium excretion with blood pressure

BACKGROUND

Higher levels of sodium intake are reported to be associated with higher blood pressure. Whether this relationship varies according to levels of sodium or potassium intake and in different populations is unknown.

METHODS

We studied 102,216 adults from 18 countries. Estimates of 24-hour sodium and potassium excretion were made from a single fasting morning urine specimen and were used as surrogates for intake. We assessed the relationship between electrolyte excretion and blood pressure, as measured with an automated device.

RESULTS

Regression analyses showed increments of 2.11 mm Hg in systolic blood pressure and 0.78 mm Hg in diastolic blood pressure for each 1-g increment in estimated sodium excretion. The slope of this association was steeper with higher sodium intake (an increment of 2.58 mm Hg in systolic blood pressure per gram for sodium excretion >5 g per day, 1.74 mm Hg per gram for 3 to 5 g per day, and 0.74 mm Hg per gram for <3 g per day; P<0.001 for interaction). The slope of association was steeper for persons with hypertension (2.49 mm Hg per gram) than for those without hypertension (1.30 mm Hg per gram, P<0.001 for interaction) and was steeper with increased age (2.97 mm Hg per gram at >55 years of age, 2.43 mm Hg per gram at 45 to 55 years of age, and 1.96 mm Hg per gram at <45 years of age; P<0.001 for interaction). Potassium excretion was inversely associated with systolic blood pressure, with a steeper slope of association for persons with hypertension than for those without it (P<0.001) and a steeper slope with increased age (P<0.001).

CONCLUSIONS

In this study, the association of estimated intake of sodium and potassium, as determined from measurements of excretion of these cations, with blood pressure was nonlinear and was most pronounced in persons consuming high-sodium diets, persons with hypertension, and older persons. (Funded by the Heart and Stroke Foundation of Ontario and others.).

Erectile dysfunction and fruit/vegetable consumption among diabetic Canadian men

OBJECTIVE

To evaluate the association between fruit/vegetable consumption and erectile dysfunction (ED) among Canadian men with diabetes.

METHODS

Data from the 2011 Survey on Living with Chronic Diseases in Canada - Diabetes Component were analyzed using Statistical Analysis System Enterprise Guide (SAS EG). Respondents were asked a series questions related to their sociodemographics, lifestyle, and chronic health conditions. The association between fruit/vegetable consumption and ED was examined using logistic regression after controlling for potential confounding factors. Bootstrap procedure was used to estimate sample distribution and calculate confidence intervals.

RESULTS

Overall, 26.2% of respondents reported having ED. The prevalence increased with age and duration of diabetes. Compared with respondents without ED, those with ED were more likely to be obese, smokers, physically inactive, and either divorced, widowed, or separated. Diabetes complications such as nerve damage, circulation problems, and kidney failure or kidney disease were also significantly associated with ED. After controlling for potential confounding factors, a 10% risk reduction of ED was found with each additional daily serving of fruit/vegetable consumed.

CONCLUSION

ED is common among Canadian men with diabetes. ED was highly associated with age, duration of diabetes, obesity, smoking, and the presence of other diabetes-related complications. Fruit and vegetable consumption might have a protective effect against ED.

Association between mental health and fall injury in Canadian immigrants and non-immigrants

The study was to determine the association between mental health and the incidence of injury among Canadian immigrants and non-immigrants. We used data from 15,405 individuals aged 12 years or more, who were living in British Columbia, Canada, and participated in the 2007-2008 Canadian Community Health Survey (CCHS). We calculated a 12-month cumulative incidence of fall injury based on self-reporting. Logistic regression model was used to examine the association of the 12-month cumulative incidence of fall injury with immigration status and mental health before and after adjustment for covariates. The results show that self-reported mood and anxiety disorders were significantly associated with an increased incidence of fall injury. The adjusted odds ratios were 1.81 (95% CI: 1.37, 2.38) for mood disorder and 1.55 (95% CI: 1.12, 2.13) for anxiety disorder. Immigrant status was a significant effect modifier for the association between mental health and fall injury, with stronger associations in immigrants than in non-immigrants especially in elderly people. People with poor self perceived health were more likely to have a fall injury. Both mental health and general health were related to fall injury. There was a stronger association between mental health and fall injury in immigrants compared with non-immigrants in the elderly. More attention should be paid to mental health in immigrants associated with fall injury.

Long-term follow-up of kidney transplant recipients: comparison of hospitalization rates to the general population

Background

Kidney transplant recipients are recognized as a vulnerable population that is at increased risk of adverse health outcomes. However, there have been few studies that have compared hospital-related morbidity of these patients to the general population, and how this differs with respect to time since transplantation. Such analyses are useful in estimating the health burden in this patient population.

Methods

We assembled a population-based Canadian cohort (excluding Quebec) of 6,116 kidney transplant recipients who underwent transplantation between 1 April 2001 and 31 December 2008. Record linkage was used to identify hospital discharge records of these patients from 1 April 2001 through 31 March 2009. Hospital discharges were tabulated across the main disease chapters of the ICD10, and person-years of follow-up were calculated across age and sex strata. Comparisons of hospital-related morbidity to the general population were made by using a standardized hospitalization ratio (SHR). For those who underwent transplantation in 2004, stratified analyses were performed to explore differences in hospital discharge rates both before and after transplantation.

Results

After excluding hospitalizations due to complications from transplantation, when compared to the general population, transplant recipients were approximately 6.4 (95% CI: 6.3, 6.5) times more likely to be hospitalized during follow-up. The SHRs were highest during the time periods proximate to transplantation, and then decreased to approximately a five-fold increase from 3 years post transplantation onwards. The largest disease-specific excesses were observed with infectious diseases and diseases of the endocrine system. Among those who underwent transplantation in 2004, the SHR decreased from 11.2 to 5.0 in the periods before and after surgery, respectively.

Conclusions

Our results indicate that, even more than 5-years post transplantation, there remains a more than six-fold difference in hospitalization rates relative to the general population. Additional work is needed to confirm these findings, and to develop strategies to reduce long-term morbidity in this patient population.

The prevalence of human papillomavirus and its impact on cervical dysplasia in Northern Canada

Introduction

Certain types of the Human Papillomavirus (HPV) are sexually transmitted and highly associated with development of cervical dysplasia and cervical cancer but the distribution of HPV infection in the North, particularly amongst First Nations, Metis, and Inuit peoples, is little known. The purposes of the study are to identify the prevalence of type-specific HPV infections and the association of different HPV types with cervical dysplasia among women in Northern Canada.

Methods

This was a cross-sectional study with attendants of the routine or scheduled Pap testing program in the Northwest Territories (NWT), Nunavut, Labrador and Yukon, Canada. Approximately half of each sample was used for Pap test and the remaining was used for HPV genotyping using a Luminex-based method. Pap test results, HPV types, and demographic information were linked for analyses.

Results

Results from 14,598 specimens showed that HPV infection was approximately 50% higher among the Aboriginal than the non-Aboriginal population (27.6% vs. 18.5%). Although the most common HPV type detected was HPV 16 across region, the prevalence of other high risk HPV types was different. The age-specific HPV prevalence among Aboriginal showed a ‘U’ shape which contrasted to non-Aboriginal. The association of HPV infection with cervical dysplasia was similar in both Aboriginal and non-Aboriginal populations.

Conclusions

The HPV prevalence was higher in Northern Canada than in other Areas in Canada. The prevalence showed a higher rate of other high risk HPV infections but no difference of HPV 16/18 infections among Aboriginal in comparison with non-Aboriginal women. This study provides baseline information on HPV prevalence that may assist in surveillance and evaluation systems to track and assess HPV vaccine programs.

Prevalence estimates of chronic kidney disease in Canada: results of a nationally representative survey

BACKGROUND

Chronic kidney disease is an important risk factor for death and cardiovascular-related morbidity, but estimates to date of its prevalence in Canada have generally been extrapolated from the prevalence of end-stage renal disease. We used direct measures of kidney function collected from a nationally representative survey population to estimate the prevalence of chronic kidney disease among Canadian adults.

METHODS

We examined data for 3689 adult participants of cycle 1 of the Canadian Health Measures Survey (2007-2009) for the presence of chronic kidney disease. We also calculated the age-standardized prevalence of cardiovascular risk factors by chronic kidney disease group. We cross-tabulated the estimated glomerular filtration rate (eGFR) with albuminuria status.

RESULTS

The prevalence of chronic kidney disease during the period 2007-2009 was 12.5%, representing about 3 million Canadian adults. The estimated prevalence of stage 3-5 disease was 3.1% (0.73 million adults) and albuminuria 10.3% (2.4 million adults). The prevalence of diabetes, hypertension and hypertriglyceridemia were all significantly higher among adults with chronic kidney disease than among those without it. The prevalence of albuminuria was high, even among those whose eGFR was 90 mL/min per 1.73 m(2) or greater (10.1%) and those without diabetes or hypertension (9.3%). Awareness of kidney dysfunction among adults with stage 3-5 chronic kidney disease was low (12.0%).

INTERPRETATION

The prevalence of kidney dysfunction was substantial in the survey population, including individuals without hypertension or diabetes, conditions most likely to prompt screening for kidney dysfunction. These findings highlight the potential for missed opportunities for early intervention and secondary prevention of chronic kidney disease.

Breast cancer detection and survival among women with cosmetic breast implants: systematic review and meta-analysis of observational studies

OBJECTIVES

To evaluate whether the stage distribution among women diagnosed as having breast cancer differs between those who have received breast implants for cosmetic purposes and those with no implants and to evaluate whether cosmetic breast augmentation before the detection of breast cancer is a predictor of post-diagnosis survival.

DESIGN

Systematic review of observational studies with two meta-analyses.

DATA SOURCES

Systematic search of the literature published before September 2012 conducted in Medline, Embase, Global health, CINAHL, IPAB, and PsycINFO.

STUDY SELECTION

Eligible publications were those that included women diagnosed as having breast cancer and who had had augmentation mammaplasty for cosmetic purposes.

RESULTS

The overall odds ratio of the first meta-analysis based on 12 studies was 1.26 (95% confidence interval 0.99 to 1.60; P=0.058; I(2)=35.6%) for a non-localized stage of breast cancer at diagnosis comparing women with implants who had breast cancer and women without implants who had breast cancer. The second meta-analysis, based on five studies, evaluated the relation between cosmetic breast implantation and survival. This meta-analysis showed reduced survival after breast cancer among women who had implants compared with those who did not (overall hazard ratio for breast cancer specific mortality 1.38, 95% confidence interval 1.08 to 1.75).

CONCLUSIONS

The research published to date suggests that cosmetic breast augmentation adversely affects the survival of women who are subsequently diagnosed as having breast cancer. These findings should be interpreted with caution, as some studies included in the meta-analysis on survival did not adjust for potential confounders. Further investigations are warranted regarding diagnosis and prognosis of breast cancer among women with breast implants.

A cohort study for the impact of activity-limiting injuries based on the Canadian National Population Health Survey 1994-2006

OBJECTIVE

To examine the prevalence and factors affecting activity-limiting injuries (ALI) in individuals and in the Canadian population; to estimate the short and long term impact on health status and well-being because of ALI in Canada from 1994 to 2006 using the Canadian National Population Health Survey (NPHS).

DESIGN

The NPHS is a randomised longitudinal cohort study with biennial interviews, with information on age, sex, education, marital status, income, residence, height and weight to self-perceived health status, healthcare utilisation and medication use in addition to ALI.

SETTING

The study population was a random sample of male and female participants 20 years and older from 10 provinces and three territories in Canada.

PRIMARY AND SECONDARY OUTCOME MEASURES

Logistic regression models were used to assess the potential impact of ALI on individuals and on the Canadian population. The interviews 2 years before and 2 years after the ALI were compared to examine long-term effects, and the McNemar test option in SAS was used for the matched analysis.

RESULTS

The immediate impacts of ALI were pain, disability and disruption of regular life. Long-term effects in patients were chronic pain and increased medical doctor visits. Population impact included a considerable increase in healthcare access and cost. The odds ratios (OR) for the 20-39 age group compared with those 60+ was 2.2; 95% CI 1.8 to 2.7, while the OR associated with male participants was 1.4; 95% CI 1.1 to 1.6. Individuals consuming nine or more alcoholic drinks per week were also significantly more likely to report an ALI (OR, 1.5; 95% CI 1.3 to 1.8).

CONCLUSIONS

The findings from this study illustrated the immediate and long-term impact of individuals and population level injuries in Canada. Injury control policies should aim to prevent the number of injuries, fatalities as well as the consequences among survivors.

Type-specific prevalence of human papillomavirus in women screened for cervical cancer in Labrador, Canada

Background

A higher incidence of cervical cancer and human papillomavirus (HPV) infection has been reported in northern Canada and in First Nation, Métis and Inuit women, with some evidence to suggest that the HPV type distribution in these populations may be different from the rest of Canada.

Objective

The objective of this study was to measure the HPV type prevalence in Labrador women to determine if significant differences in HPV types could reduce the effectiveness of HPV vaccination.

Design

The prevalence of HPV types was determined in 1,370 women presenting for routine pap screening in Labrador between February and November 2010. Cervical cytology and HPV genotyping were performed on the same liquid-based cytology specimens.

Results

The overall prevalence of HPV was 21.4%; cytological abnormalities were found in 8.8% of the participants. HPV 16 and 18 were the most common high-risk HPV types. These two types were found in 52.4% of high-grade lesions. The prevalence in HPV infections was comparable across the Labrador regions.

Conclusions

The present results support the potential effectiveness of the HPV immunization program in Labrador.

Perinatal and early childhood factors for overweight and obesity in young Canadian children

BACKGROUND

This study assessed potential early-life factors and their interrelationships with obesity among young Canadian children.

METHODS

Data from a nationally representative sample of children aged 6 to 11 years in the Canadian Health Measures Survey were analyzed. The associations of perinatal and early childhood behaviours and socio-economic factors with overweight or obesity were evaluated using multivariate logistic regression models. Adjusted population attributable risk fractions (PARFs) were calculated using multivariate logistic regression models.

RESULTS

Of 968 term-born children, 21% were overweight and another 13% were obese. Maternal smoking during pregnancy (adjusted odds ratio, 2.26; 95% confidence interval, 1.23-4.15) was positively associated with obesity. This association was mediated by birth weight (suppression effect); once controlled, the strength of the association between smoking and child obesity increased by 12%. Birth weight per 100 g (1.05; 1.005-1.09) was significantly associated with obesity. Exclusive breastfeeding for 6 months (0.44; 0.31-0.61), adequate sleep hours (0.39; 0.16-0.94) and being physically active (0.50; 0.26-0.93) were found to be protective. Breastfeeding, whether exclusive or not, significantly reduced obesity risk among children whose mothers never smoked in pregnancy. PARFs indicated that 24.4%, 11.5%, 11.3% and 6.0% prevalent cases of child obesity might be prevented by exclusive breastfeeding, smoking cessation during pregnancy, adequate sleep during childhood, and avoiding high birth weight, respectively.

CONCLUSIONS

This study identified multiple perinatal and childhood factors associated with obesity in young Canadian children. Effective prevention strategies targeting four modifiable maternal and child risk factors may reduce childhood obesity by up to 54% in Canada.

Long-term association between leisure-time physical activity and changes in happiness: analysis of the Prospective National Population Health Survey

Happiness is among the most fundamental of all human goals. Although the short-term association between physical activity and happiness is well known, the long-term associations are not. Data from the National Population Health Survey cycles conducted between 1994/1995 and 2008/2009 (cycles 1 through 8) were analyzed. Happy respondents were classified as physically active or inactive at baseline and then were followed up in subsequent cycles to examine their likelihood of becoming unhappy. Individuals who changed their activity level also were examined. After controlling for potential confounding factors, the authors found that leisure-time physical activity (LTPA) was associated with reduced odds of unhappiness after 2 years and 4 years. People who were inactive in 2 consecutive cycles were more than twice as likely to be unhappy as those who remained active in both cycles after 2 years. Compared with those who became active, inactive participants who remained inactive were also more likely to become unhappy. A change in LTPA from active to inactive was associated with increased odds of becoming unhappy 2 years later. This study suggests that LTPA has a long-term association with happiness. Changes in LTPA are associated with subsequent mood status.

Glycemic index, glycemic load and cancer risk

BACKGROUND

Dietary glycemic index (GI) and glycemic load (GL) have been related to the risk of selected cancers, but the issue remains open.

PATIENTS AND METHODS

Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces for incident, histologically confirmed cases of the stomach (n=1182), colon (n=1727), rectum (n=1447), liver (n=309), pancreas (n=628), lung (n=3341), breast (n=2362), ovary (n=442), prostate (n=1799), testis (n=686), kidney (n=1345), bladder (n=1029), brain (n=1009), non-Hodgkin's lymphomas (NHL, n=1666), leukemias (n=1069), multiple myelomas (n=343), and 5039 population controls. Dietary information on eating habits 2 years before participants' enrollment in the study was obtained using a validated food frequency questionnaire (FFQ). Odds ratios (ORs) and 95% confidence intervals (CI) were derived by unconditional logistic regression including recognized confounding factors.

RESULTS

Dietary GI was positively associated with the risk of prostate cancer (OR, 1.26 for the highest versus the lowest quartile). A higher dietary GL significantly increased the risk of colorectal (OR, 1.28), rectal (OR, 1.44) and pancreatic (OR, 1.41) cancers. No other significant associations were found.

CONCLUSIONS

Our findings suggest that a diet high in GI and GL is associated with increased risk of selected cancers.

Factors associated with human papillomavirus infection among women in the Northwest Territories

BACKGROUND

In some regions, Aboriginal women have higher rates of cervical cancer compared to other Canadian women. However, little data are available regarding the co-factors of HPV infection in the Aboriginal population of Canada. We examined factors associated with high-risk human papillomavirus (HR-HPV) infection in a population of women (both Aboriginal and non-Aboriginal) in the Northwest Territories (NWT).

METHODS

We used a cross-sectional design using a convenience sample of all women aged 14 years or older presenting for Papanicolaou (Pap) testing across all regions of the NWT from March 2009 to March 2010. Women answered a questionnaire on demographic characteristics, sexual behaviour, and gynaecological and obstetrical events. We used multiple regression analysis to explore factors associated with HR-HPV infection according to age and cultural background. HPV typing was done using the Luminex assay.

RESULTS

Of the total 1,279 participants, 178 had missing HPV results. We obtained data on 1,101 women and overall HR-HPV prevalence was 14.2%. Younger age, single marital status, Aboriginal background, current smoking, lifetime deliveries, use of hormonal contraceptives, and the numbers of sexual partners in the last year were associated with prevalent HR-HPV.

DISCUSSION

Our findings tend to indicate that Aboriginal women have different predictors of HR-HPV than non-Aboriginal women that may affect HPV progression to cervical cancer. These findings can help to better target public health practices for the women at higher risk of HPV infection and cervical cancer.

Increasing blood pressure and its associated factors in Canadian children and adolescents from the Canadian Health Measures Survey

BACKGROUND

Canada is facing a childhood obesity epidemic. Elevated blood pressure (BP) is a major complication of obesity. Reports on the impact of excess adiposity on BP in children and adolescents have varied significantly across studies. We evaluated the independent effects of obesity, physical activity, family history of hypertension, and socioeconomic status on BP in a nationally representative sample of children and adolescents.

METHODS

We analysed cross-sectional data for 1850 children aged 6 to 17 years who participated in the Canadian Health Measures Survey, Cycle 1, 2007-2009. Systolic BP (SBP) and diastolic BP (DBP) were age-, sex-, and height-adjusted to z-scores (SBPZ and DBPZ). Body mass index (BMI) z-scores were calculated based on World Health Organization growth standards. Multivariate linear regression was used to evaluate the independent effects of relevant variables on SBPZ and DBPZ.

RESULTS

For most age/sex groups, obesity was positively associated with SBP. Being obese was associated with higher DBP in adolescent boys only. The BP effect of obesity showed earlier in young girls than boys. Obese adolescents were estimated to have an average 7.6 mmHg higher SBP than normal weight adolescents. BMI had the strongest effect on BP among obese children and adolescents. Moderately active adolescent boys had higher SBP (3.9 mmHg) and DBP (4.9 mmHg) than physically active boys. Family history of hypertension showed effects on SBP and DBP in younger girls and adolescent boys. Both family income and parent education demonstrated independent associations with BP in young children.

CONCLUSIONS

Our findings demonstrate the early impact of excess adiposity, insufficient physical activity, family history of hypertension, and socioeconomic inequalities on BP. Early interventions to reduce childhood obesity can, among other things, reduce exposure to prolonged BP elevation and the future risk of cardiovascular disease.

Canadian breast implant cohort: extended follow-up of cancer incidence

Cosmetic breast implants are not associated with increased breast cancer incidence, but variations of risk according to implant characteristics are still poorly understood. As well, the assessment of cancer risk for sites other than breast needs to be clarified. The purpose of this study was to fill these research gaps. This study presents an extended analysis of 10 more years of follow-up of a large Canadian cohort of women who received either cosmetic breast implants (n = 24,558) or other cosmetic surgery (15,893). Over 70% of the implant cohort was followed for over 20 years. Cancer incidence among implant women was compared to those of controls using multivariate Poisson models and the general female population using the standardized incidence ratios (SIRs). Women with breast implants had reduced rates of breast and endometrial cancers compared to other surgery women. Subglandular implants were associated to a reduced rate of breast cancer compared to submuscular implants [incidence rate ratio (IRR) = 0.78, 95% confidence interval (CI) = 0.63-0.96] and this reduction persisted over time. We observed a sevenfold increased rate (IRR = 7.36, 95% CI = 1.86-29.12) of breast cancer in the first 5 years after the date of surgery for polyurethane-coated subglandular implant women but this IRR decreased progressively over time (p value for trend = 0.02). We also observed no increased risk of rarer forms of cancer among augmented women. A reduction in breast cancer incidence was observed for women with subglandular implants relative to women with submuscular implants. Possible increase of breast cancer incidence shortly after breast augmentation with polyurethane implants needs to be verified.

Migration and diabetes in British Columbia and Quebec: prevalence and health service utilization

OBJECTIVES

This study describes prevalence of diabetes among immigrants and health service utilization among diabetic immigrants in British Columbia (BC) and Quebec (QC).

METHODS

Immigrants to BC and QC between 1985 and 1999 were identified. Using age-standardized rate ratios, they were compared with a matched comparison group with respect to their diabetes prevalence and, among those with diabetes, physician service utilization.

RESULTS

Immigrant women in both provinces and men in BC had higher rates of diabetes compared to the matched comparison group. Rates varied by region of birth and language ability. Diabetes prevalence rate ratios increased with length of stay in BC. Diabetic immigrants had lower rates of physician visits than diabetic comparisons. This gap decreased commensurate with immigrants' length of stay in BC. Diabetic immigrants who spoke neither official language had similar or higher rates of physician visits compared with immigrants who spoke one or both official languages.

CONCLUSIONS

Genetic predisposition, lifestyle changes, acculturation, resettlement stress and differential health care access may explain increased prevalence of diabetes among many immigrants. These results can inform diabetes prevention and management programs tailored to the needs of specific immigrant groups. The gap in health service use between diabetic immigrants and comparisons does not appear to be related to language ability. Further studies are required to identify reasons.

Plasma vitamin D levels and risk of metabolic syndrome in Canadians

Purpose: Vitamin D deficiency has been implicated in susceptibility to the development of metabolic syndrome, obesity and type 2 diabetes mellitus. The present study aimed to quantify the association between vitamin D plasma level, the number of metabolic syndrome components and insulin resistance in Canadians. Methods: Vitamin D plasma level and clinical data were determined from 1,818 subjects from the Canadian Health Measures Survey; a representative health survey of the general population of Canada conducted from 2007 to 2009. The definition of metabolic syndrome was based on the National Cholesterol Education Program, Adult Treatment Panel III criteria. Adjusted general linear models were used to estimate the association between vitamin D level and probability of having metabolic syndrome, as well as the association between plasma vitamin D and insulin resistance (homeostasis model assessment for insulin resistance, or HOMA-IR). Results: The prevalence of metabolic syndrome in the study population was 8.9%. The number of metabolic syndrome components was inversely correlated with plasma vitamin D level (ρ= -0.1, p < 0.0001). Subjects in the highest vitamin D quartile had lower odds ratio of metabolic syndrome compared with their counterparts in the lowest vitamin D quartile (0.50, 95% CI= 0.24-1.06). Increasing plasma vitamin D level (by 10 nmol/L) was inversely associated with HOMA-IR score (β= -0.08, p=0.006) in a model adjusted for physical activity, smoking status, month of interview, age, sex and ethnicity. Conclusion: Vitamin D plasma levels are associated with the occurrence of metabolic syndrome components and insulin resistance among Canadians and are linked to increased level of insulin resistance.