Canadian Health Measures Survey Cycles Research Articles

Percentile curves for skinfold thickness for Canadian children and youth.

Background. Skinfold thickness (SFT) measurements are a reliable and feasible method for assessing body fat in children but their use and interpretation is hindered by the scarcity of reference values in representative populations of children. The objective of the present study was to develop age- and sex-specific percentile curves for five SFT measures (biceps, triceps, subscapular, suprailiac, medial calf) in a representative population of Canadian children and youth.Methods. We analyzed data from 3,938 children and adolescents between 6 and 19 years of age who participated in the Canadian Health Measures Survey cycles 1 (2007/2009) and 2 (2009/2011). Standardized procedures were used to measure SFT. Age- and sex-specific centiles for SFT were calculated using the GAMLSS method.Results. Percentile curves were materially different in absolute value and shape for boys and girls. Percentile girls in girls steadily increased with age whereas percentile curves in boys were characterized by a pubertal centered peak.Conclusions. The current study has presented for the first time percentile curves for five SFT measures in a representative sample of Canadian children and youth.

Urinary bisphenol A concentrations positively associated with glycated hemoglobin and other indicators of diabetes in Canadian men

BackgroundBisphenol A (BPA), an endocrine disrupting chemical (EDC), may pose a risk to human health, including diabetes. However, epidemiological studies from the U.S., China and South Korea showed inconsistent results. ObjectiveTo examine the associations between BPA and indicators of diabetes in the general Canadian population. MethodsThe analysis was based on cross-sectional data from the Canadian Health Measures Survey (CHMS) Cycle 2 (2009–2011). We included 1915 participants with glycated hemoglobin (HbA1c) measurement and 2405 participants with serum glucose (SG) measurement aged 3–79 years, respectively. Multiple linear regression analyses were performed to model HbA1c and log-transformed SG levels associated with quartiles of urinary BPA concentrations controlling for potential confounders. Further, in adults (age≥18 years), logistic regression analysis was conducted to evaluate the association between BPA and physician-diagnosed diabetes mellitus (DM). Bootstrap weights were applied to all the analyses to account for the complex survey design. ResultsThe geometric mean of urinary BPA was 1.21 (±0.05)µg/L. Overall, a positive association was observed between urinary BPA quartiles and HbA1c levels in men after controlling for potential confounders (P<0.05), but not in women and children. Similar patterns were found for the associations of BPA with log-transformed SG levels and doctor-diagnosed DM. ConclusionsHigher urinary BPA levels were associated with adverse glucose homeostasis in Canadian men, independent of major covariates. Prospective studies with longitudinal design are needed to further investigate the causality.

Prevalence of metabolic syndrome and its risk factors in Canadian children and adolescents: Canadian Health Measures Survey Cycle 1 (2007-2009) and Cycle 2 (2009-2011).

We investigated the prevalence of metabolic syndrome (MetS) and its risk factors, and the influence of socioeconomic status, in Canadian children and adolescents. Canadian Health Measures Survey cycle 1 (2007-2009) and cycle 2 (2009-2011) respondents aged 10 to 18 years who provided fasting blood samples were included (n = 1228). The International Diabetes Federation (IDF) consensus definition for children and adolescents (10-15 years) and worldwide adult definition (≥ 16 years) were used to diagnose MetS. Prevalence of MetS and its risk factors were calculated and differences by socioeconomic status were examined using χ2 tests. The prevalence of MetS was 2.1%. One-third (37.7%) of participants had at least one risk factor, with the most prevalent being abdominal obesity (21.6%), low HDL-C (19.1%) and elevated triglyceride levels (7.9%). This combination of abdominal obesity, low HDL-C and elevated triglyceride levels accounted for 61.5% of MetS cases. Participants from households with the highest income adequacy and educational attainment levels had the lowest prevalence of one or more MetS risk factors, abdominal obesity and low HDL-C. The prevalence of MetS (2.1%) was lower than previously reported in Canada (3.5%) and the USA (4.2%¬-9.2%), potentially due to the strict application of the IDF criteria for studying MetS. One-third of Canadian children and adolescents have at least one risk factor for MetS. Given that the risk for MetS increases with age, these prevalence estimates, coupled with a national obesity prevalence of almost 10% among youth, point to a growing risk of MetS and other chronic diseases for Canadian youth.

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

BackgroundInsulin 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.MethodsData 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.ResultsThe 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.ConclusionsThis 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.

Urinary Dialkyl Phosphate Concentrations and Lung Function Parameters in Adolescents and Adults: Results from the Canadian Health Measures Survey.

Background:Epidemiological studies have reported associations between lung function parameters and organophosphate (OP) pesticide exposures in agricultural occupations, but to our knowledge associations have not been evaluated in general populations.Objectives:We examined associations between OP metabolite dialkyl phosphates (DAPs) and lung function using data from the Canadian Health Measures Survey (CHMS) Cycle 1.Methods:Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1/FVC ratio, and forced expiratory flow between 25% and 75% of FVC (FEF25%–75%) were measured for 4,446 CHMS participants. Urinary concentrations of six DAP metabolites (DMP, DMTP, DMDTP, DEP, DETP, and DEDTP), smoking status, and other predictors of lung function were also measured in the CHMS-Cycle 1. Multiple linear regression analyses were used to examine the relationship between total DAP concentrations (ΣDAPs) and lung function in adolescents (12–19 years) and adults (20–79 years).Results:In adults, estimates from multiple regression analyses suggested that a 1-unit increase on natural logarithmic scale (171% increase on the original scale) in the creatinine-corrected urinary concentration (nanomoles per gram creatinine) of ΣDAP was associated with a 32.6-mL (95% CI: –57.2, –8.1) reduction in FVC, 32.6-mL (95% CI: –59.0, –6.3) reduction in FEV1, 0.2% (95% CI: –0.6, 0.2) reduction in FEV1/FVC ratio, and 53.1-mL/sec (95% CI: –113.9, 7.7) reduction in FEF25%–75%. In adolescents, associations between ΣDAP and FEV1 were closer to the null and positive for FVC, whereas associations with FEV1/FVC and FEF25%–75% were negative, as in adults. However, none of the associations were significant in adolescents.Conclusions:The negative association between ΣDAP and lung function in adult participants suggests a detrimental effect of OP pesticides on lung function in the adult general population. Further studies using prospective designs are warranted to confirm the findings reported in this study.Citation:Ye M, Beach J, Martin JW, Senthilselvan A. 2016. Urinary dialkyl phosphate concentrations and lung function parameters in adolescents and adults: results from the Canadian Health Measures Survey. Environ Health Perspect 124:491–497; http://dx.doi.org/10.1289/ehp.1509745

Percentile Curves for Anthropometric Measures for Canadian Children and Youth.

Body mass index (BMI) is commonly used to assess a child's weight status but it does not provide information about the distribution of body fat. Since the disease risks associated with obesity are related to the amount and distribution of body fat, measures that assess visceral or subcutaneous fat, such as waist circumference (WC), waist-to-height ratio (WHtR), or skinfolds thickness may be more suitable. The objective of this study was to develop percentile curves for BMI, WC, WHtR, and sum of 5 skinfolds (SF5) in a representative sample of Canadian children and youth. The analysis used data from 4115 children and adolescents between 6 and 19 years of age that participated in the Canadian Health Measures Survey Cycles 1 (2007/2009) and 2 (2009/2011). BMI, WC, WHtR, and SF5 were measured using standardized procedures. Age- and sex-specific centiles were calculated using the LMS method and the percentiles that intersect the adult cutpoints for BMI, WC, and WHtR at age 18 years were determined. Percentile curves for all measures showed an upward shift compared to curves from the pre-obesity epidemic era. The adult cutoffs for overweight and obesity corresponded to the 72nd and 91st percentile, respectively, for both sexes. The current study has presented for the first time percentile curves for BMI, WC, WHtR, and SF5 in a representative sample of Canadian children and youth. The percentile curves presented are meant to be descriptive rather than prescriptive as associations with cardiovascular disease markers or outcomes were not assessed.

Review of the state of the art of human biomonitoring for chemical substances and its application to human exposure assessment for food safety

Review of the state of the art of human biomonitoring for chemical substances and its application to human exposure assessment for food safety

BMI-specific waist circumference is better than skinfolds for health-risk determination in the general population.

Distribution of fat is important when considering health risk; however, the value added from skinfold measurements (SKF) when using body mass index (BMI) refined by waist circumference (WC) is not well understood. The purpose of this study was to assess the utility of SKF compared with WC in determination of health risk in the general population. Data from the Canadian Health Measures Survey (cycles 1 and 2; N = 5217) were used. Health outcomes included directly measured blood pressure, cholesterol, glycated haemoglobin, lung function, self-reported health, and chronic conditions. Technical errors of measurements (TEM), sensitivity, and specificity analysis and linear regressions were conducted. Data indicated that TEM for SKF was above the acceptable 5% in most age and sex categories. Sensitivity and specificity of chronic conditions was not improved with the inclusion of SKF in models containing WC (in those aged 45-69 years) and SKF did not explain any additional variance in regression models containing WC. Health outcomes for those in the normal weight and overweight BMI category were significantly worse in those classified as high risk based on WC, whereas SKF did not consistently discriminate risk. In conclusion, evidence-based WC cut-points were shown to identify health risk, particularly in normal weight and overweight individuals. Thus, BMI refined by WC appears to be more appropriate than SKF for assessment of body composition when determining health risk in the general population.

Baseline levels of selected environmental chemicals in Canadians: Results from Canadian Health Measures Survey

Background: The Canadian Health Measures Survey (CHMS) is an on-going nationally representative direct health measures survey launched in 2007. This survey collects new and important data to fill knowledge gaps on health status of Canadians. The biomonitoring component of CHMS, supported by Canada’s Chemicals Management Plan, collects and analyzes blood and urine samples for several classes of environmental chemicals. Method: Each CHMS cycle spans approximately two years in which about 5500-6500 individuals are selected representing about 96% of the general population in Canada. Respondents aged 6-79 years were selected for CHMS (2007-2009) while the subsequent CHMS cycles (CHMS 2009-2011; CHMS 2012-2013) include 3-5 years olds. The respondents completed a household interview and visited a mobile examination centre where the physical health measurements were performed and blood and urine samples were collected. Biomarkers for about 90 environmental chemicals were analyzed in the respondent’s bio-specimens. Results: Descriptive statistics (arithmetic and geometric means, and selected percentiles) were computed on the levels of individual biomarkers in Canadians. Baseline levels of selected group of environmental chemicals (including heavy metals, pesticides and emerging contaminants) from CHMS 2007-2009 and 2009-2011 (to be released in April 2013) will be presented. These biomarker levels in Canadians will be compared with similar findings reported in other population surveys. Preliminary analysis on the temporal trends in the biomarker levels will be highlighted. Conclusion: Nationally representative data on the levels of biomarkers from CHMS provides valuable information for current and future human health risk assessments and for assessing potential links between chemical exposures and health outcomes. Moreover, it allows comparison of similar data from other countries and helps in monitoring temporal and geospatial trends in biomarker levels.

Blood total mercury concentrations in the Canadian population: Canadian Health Measures Survey cycle 1, 2007-2009.

We present total mercury (THg) in blood of Canadians 6-79 years of age from the first to-date nationally-representative survey, the Canadian Health Measures Survey (CHMS). This analysis is particularly relevant in the context of recent changes to Health Canada's blood Hg guidance values. We used data from cycle 1 (2007-2009) of the CHMS, in particular focussing on 5,319 respondents aged 6-79 years for whom blood THg data were available. We calculated descriptive statistics of blood Hg levels and analyzed the associations between blood THg levels and relevant variables. We also compared blood THg levels to existing Health Canada blood Hg guidance values. The geometric mean blood THg level of the Canadian population was 0.69 µg/L (95% CI 0.56-0.86 µg/L). The majority (97.8%) of Canadian women aged 16-49 years, including pregnant women, had blood Hg values below the provisional HC blood guidance value of 8 µg/L. Mean blood THg levels were significantly higher in the "other or mixed" (1.14 µg/L, p=0.0003) and Asian (1.41 µg/L, p=0.0476) groups compared to those who self-identified as solely Caucasian (0.62 µg/L). There was however no significant difference between participants self-identified as Aboriginal Canadians versus Caucasians (0.56 µg/L vs 0.62 µg/L, p=0.2902).Fish and shellfish consumption significantly influenced blood Hg levels, as did alcohol consumption and the presence of dental amalgams. This paper presents the first description of blood THg levels in the general Canadian population. These findings will serve as a national baseline for monitoring future changes should they arise.

Do perfluoroalkyl substances affect metabolic function and plasma lipids?—Analysis of the 2007–2009, Canadian Health Measures Survey (CHMS) Cycle 1

BackgroundPerfluorinated compounds (PFCs) are man-made chemicals that are heat stable, non-flammable and able to repel both water and oils. Biomonitoring research shows global distribution in human, animal and aquatic environments of these chemicals. PFCs have been shown to activate the peroxisome proliferator-activated receptors which play a large role in metabolism and the regulation of energy homeostasis. Previous epidemiological research has also suggested a potential role of PFCs on lipid and glucose metabolism. ObjectivesThe objectives of this study were to examine the association between the levels of perfluorinated compounds perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonate (PFHxS) in plasma and metabolic function and plasma lipid levels. MethodsUsing cross-sectional data from the Canadian Health Measures Survey (Cycle 1 2007–2009) we examined the association in adults between plasma levels of PFOA, PFOS and PFHxS (n=2700) on cholesterol outcomes, metabolic syndrome and glucose homeostasis using multivariate linear and logistic regression models. ResultsWe found some evidence of a significant association between perfluoroalkyl substances, notably PFHxS, with total cholesterol (TC), low-density lipoprotein cholesterol (LDL), total cholesterol/high density lipoprotein cholesterol ratio (TC/HDL) and non-HDL cholesterol as well as an elevated odds of high cholesterol. We found some associations with PFOA and PFOS in our unweighted models but these results did not remain significant after weighting for sampling strategy. We found no association with metabolic syndrome, or glucose homeostasis parameters. ConclusionsThis study showed lower levels of PFOA and PFOS and slightly higher levels of PFHxS than other published population studies. Our results did not give significant evidence to support the association with cholesterol outcomes with PFOS and PFOA. However, we did observe several significant associations with the PFHxS and cholesterol outcomes (LDL, TC, NON-HDL, TC/HDL ratio).

Human biomonitoring of environmental chemicals—Early results of the 2007–2009 Canadian Health Measures Survey for males and females

Human biomonitoring is an important indicator and measure of exposure to environmental chemicals and provides information to support health protection policies and programs. Cycle 1 (2007-2009) of the Canadian Health Measures Survey (CHMS) collected and analyzed biological samples from over 5600 males and females aged 6-79 years, which established national representative blood and urine concentrations for a number of environmental chemicals including metals, organophosphate insecticide metabolites, polychlorinated biphenyls (PCBs), organochlorines (OCs), perfluorinated compounds (PFCs), bisphenol A (BPA), and cotinine. The results of CHMS Cycle 1 indicate that while some organophosphate insecticide metabolites were below limits of detection for most participants, metals, PCBs, OCs, PFCs and BPA were detected in almost all blood or urine samples. Significant differences (p<0.05) in blood concentrations between males and females were also determined for several metals (e.g., lead for males and females was 15.1 and 11.8 μg/L, respectively), PFCs (e.g., PFOS for males and females was 11.13 and 7.07 μg/L, respectively), and OCs (e.g., p,p'-DDE for males and females was 134.43 and 172.07 μg/kg lipid, respectively) and in urine concentrations for BPA (1.29 and 1.04 μg/L for males and females, respectively). Future cycles of the CHMS will permit temporal trend analysis for a number of these chemicals.

The vitamin D status of Canadians relative to the 2011 Dietary Reference Intakes: an examination in children and adults with and without supplement use

The 2011 Dietary Reference Intakes (DRIs) for vitamin D use 25-hydroxyvitamin D [25(OH)D] concentrations to define vitamin D deficiency (<30 nmol/L), the Estimated Average Requirement (40 nmol/L), and the Recommended Dietary Allowance (RDA; 50 nmol/L). The Canadian population has not yet been assessed according to these recommendations. We determined the prevalence of meeting DRI recommendations and the role of vitamin D supplement use among Canadians aged 6-79 y. Plasma 25(OH)D from a representative sample of Canadians in the Canadian Health Measures Survey-Cycle 1 (n = 5306) were used. Supplement use was assessed by household interview. Concentrations of 25(OH)D were compared in supplement users and nonusers by season and race. Overall, 5.4%, 12.7%, and 25.7% of the participants had 25(OH)D concentrations below the 30-, 40-, and 50-nmol/L cutoffs, respectively. In white Canadians, plasma 25(OH)D concentrations ranged from an undetectable percentage with concentrations <30 nmol/L in summer to 24.5% with concentrations <50 nmol/L in winter; the corresponding values ranged from 12.5% to 53.1% in nonwhite Canadians. Supplement users had significantly higher 25(OH)D concentrations than did nonusers, and no seasonal differences were found. In nonsupplement users, the prevalence of 25(OH)D concentrations <50 nmol/L in winter was 37.2% overall and was 60.7% in nonwhites. One-quarter of Canadians did not meet the RDA, but the use of vitamin D supplements contributed to a better 25(OH)D status. Nonwhite Canadians had the highest risk of not achieving DRI recommendations. More than one-third of Canadians not using supplements did not meet the RDA in winter. This suggests that current food choices alone are insufficient to maintain 25(OH)D concentrations of 50 nmol/L in many Canadians, especially in winter.