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Cardiorespiratory Fitness in Metabolic Healthy Overweight Youth
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Abstracts / Can J Diabetes 36 (2012) S2eS22
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Linoleic Acid Augments Oxidative Damage and Initiates Fibrosis in Cardiomyocytes and Fibroblasts JULIANNE C. BEAM*, AMY M. BOTTA, JESSE OLSON, SANJOY GHOSH, REBEKAH S.A. BARENDREGT Kelowna, BC; Vancouver, BC
Healthy BuddiesÓ Manitoba: A Clustered Randomized Controlled Trial of Peer-Based Healthy Living Lessons Plans on Body Weight and Physical Activity in Early Years Students ROB SANTOS, ANITA DURKSEN, JEAN PIERRE CHANOINE, ANDREA LAMBOO MILN, THERESA MAYER, JONATHAN MCGAVOCK* Winnipeg, MB; Vancouver, BC
Cardiac fibrosis following the demise of cardiomyocytes is pivotal to cardiac remodeling and heart failure. Considering the rising rates of cardiovascular disease (CVD) and the preponderance of linoleic acid (LA) in the Canadian diet, we hypothesized that excess LA could initiate cell death and fibrosis in the heart. Four-month-old female C57/Bl6 mice were fed a high LA diet (HLA; corn oil rich) for 5 weeks, and a separate low LA diet group (LLA, canola oil rich) was kept as the isocaloric, isonitrogenous control. HLA feeding increased cardiac TUNEL positivity as a marker of cell death, protein expression of matrix metalloproteases (MMP-2 and -9) and downregulated tissue inhibitor of metalloproteases (TIMP-1 and -2). Sirius red and Masson's Trichrome staining of heart sections demonstrated augmented collagen deposition. Oxidative stress biomarkers such as nitrotyrosine and 4-hydroxynonenal also increased, whereas antioxidants including glutathione and superoxide dismutase were downregulated. To confirm that LA specifically plays a causative role, NIH-3T3 fibroblasts and differentiated H9c2 cardiomyoblasts were incubated with oleic, palmitic, or linoleic acid at concentrations from 0.1 to 1.0 mM over 24 hours. Mitochondrial redox potential in H9c2 cardiomyocytes was decreased with both palmitic acid and LA, but not oleic acid. Only incubation with LA demonstrated a dose-dependent reduction in cell viability in H9c2 cardiomyocytes. These results suggest that excess LA, a common dietary omega-6 PUFA, can augment cell death, oxidative damage, and loss of mitochondrial membrane potential in the heart and can contribute to current CVD rates in Canada.
Objective: To assess the effectiveness of a novel peer-led program called Healthy BuddiesÓ on weight gain and its determinants when disseminated at the provincial level to early years students in grades 1-6. Methods: We performed a cluster randomized controlled trial in 20 elementary schools in the province of Manitoba, Canada. Schools were randomized to receive regular curriculum or the Healthy BuddiesÓ curriculum. 21 lesson plans were delivered by older (9-12yrs) students to younger (6-8yrs) peers that focused on physical activity, healthy eating and self-esteem. The primary outcome measures were the change in waist circumference and body mass index z-score. Secondary outcome measures were objectively measured physical activity (steps/day), selfefficacy, healthy living knowledge and self-reported dietary intake. Results: Among the 647 students studied, 48% were girls, 36% were overweight or obese and 11% achieved the recommended 13,500 steps/day. Using intention to treat analyses, waist circumference declined significantly in the intervention group, relative to the controls, -1.42 (-2.68 to -0.17, p ¼ 0.026). BMI Z score was not changed, 0.03 (-0.06 to 0.11, p ¼ 0.54). Knowledge of healthy living, self efficacy and dietary intake were all significantly improved in the younger cohort that received the intervention, (p < 0.001). No differences were observed in daily step counts or fitness. Conclusions: The implementation of Healthy BuddiesÓ lesson plans in an elementary school setting is an effective method for attenuating central weight gain and improving diet quality, selfefficacy and knowledge of healthy living in younger students. 68
66 Cardiorespiratory Fitness in Metabolic Healthy Overweight Youth MARTIN SENECHAL, BRANDY A. WICKLOW, KRISTY WITTMEIER, JACQUELINE HAY, PINAR ESKICIOGLU, JONATHAN M. MCGAVOCK Winnipeg, MB Background: Metabolically Healthy Overweight (MHO) adolescents represent a subset of youth who are considered overweight but lack any obesity-related cardiometabolic risk factors (CMRF). The factors that protect overweight youth from CMRF clustering are not well established. We hypothesized that an elevated cardiorespiratory fitness (CRF) would increase the likelihood of being metabolically healthy if they are overweight or obese. Methods: Overweight adolescents, 12-18 yrs, were classified as MHO (n¼27; 0 risk factor) or non-MHO; (n¼81; 1 risk factor) based on age and sex-specific cut-points for the following CMRFs; fasting glucose, HDL-chol, triglycerides, systolic blood pressure, and hepatic triglyceride. CRF was assessed using a graded exercise test to exhaustion on a cycle ergometer. Results: MHO was associated with a lower waist circumference (99.7 13.2 cm vs. 106.1 13.7 cm) and body mass index Z-score, compared to non-MHO (P< 0.05). CRF was not associated with CMRF clustering or the presence of MHO. CRF was independently associated with two CMRF's, HDL-chol (r ¼0.22) and liver transaminases (r ¼ -0.24; all P< 0.05). Compared to the highest quartile of CRF, the odd of hepatic steatosis increased 4.5 fold (95% CI: 1.119.5; P¼0.04) compared to the lowest quartile of CRF. Conclusion: The MHO phenotype was present in w25% of overweight adolescents and is strongly associated with lower adiposity but not with higher CRF among adolescents. CRF is independently associated with hepatic steatosis, which is known to increase risk of type 2 diabetes.
Estimation of the Prevalence of Type 1 and Type 2 Diabetes Among Canadian Adults SULAN DAI, ASAKO BIENEK, CATHERINE PELLETIER, JAY ONYSKO, HOWARD MORRISON Ottawa, ON Objective: This study aims to estimate the prevalence of type 1 and type 2 diabetes among Canadian adults. Methods: Data from the 2011 Survey on Living with Chronic Diseases in Canada were analysed with SAS EG. Study sample included 2,903 (57.2% male) respondents aged 20+. Prevalence of type 1 and type 2 diabetes were estimated using three algorithms. Type 1 diabetes was defined as individuals using insulin at the time of survey, with insulin use initiated <1 year after diagnosis, and age at diagnosis: 1) <31 years; 2) <41 years; and 3) without specifying age. Rates were weighted to represent the Canadian population. Results: Only 2,528 respondents (89.2%) reported a diabetes type, with 202 (8.4%) type 1 and 2,326 (80.8%) type 2, and an additional 375 (10.8%) unknown/other. Overall, 683/2,528 (24.7%) of diabetics were using insulin. Prevalence were estimated using the three algorithms: 1) Type 1: 4.0% (95% CI: 2.7%-5.3%); type 2: 96.0% (95% CI: 94.7%97.3%) when age at diagnosis <31 years. 2) Type 1: 6.1% (95% CI: 4.5%-7.8%); type 2: 93.9% (95% CI: 92.2%95.5%) when age at diagnosis <41 years. 3) Type 1: 8.8% (95% CI: 6.8%-10.9%); type 2: 91.2% (95% CI: 89.1%93.2%) without specifying age. Conclusion: The estimated prevalence of type 1 diabetes varied from 4.0% to 8.8% among Canadian adults based on different criteria. Age at diagnosis played a significant role in estimating the prevalence for type 1 and type 2 diabetes. Further study should explore whether incident cases of type 1 diabetes occur in older Canadians.
Abstracts / Can J Diabetes 36 (2012) S2eS22
65
67
Linoleic Acid Augments Oxidative Damage and Initiates Fibrosis in Cardiomyocytes and Fibroblasts JULIANNE C. BEAM*, AMY M. BOTTA, JESSE OLSON, SANJOY GHOSH, REBEKAH S.A. BARENDREGT Kelowna, BC; Vancouver, BC
Healthy BuddiesÓ Manitoba: A Clustered Randomized Controlled Trial of Peer-Based Healthy Living Lessons Plans on Body Weight and Physical Activity in Early Years Students ROB SANTOS, ANITA DURKSEN, JEAN PIERRE CHANOINE, ANDREA LAMBOO MILN, THERESA MAYER, JONATHAN MCGAVOCK* Winnipeg, MB; Vancouver, BC
Cardiac fibrosis following the demise of cardiomyocytes is pivotal to cardiac remodeling and heart failure. Considering the rising rates of cardiovascular disease (CVD) and the preponderance of linoleic acid (LA) in the Canadian diet, we hypothesized that excess LA could initiate cell death and fibrosis in the heart. Four-month-old female C57/Bl6 mice were fed a high LA diet (HLA; corn oil rich) for 5 weeks, and a separate low LA diet group (LLA, canola oil rich) was kept as the isocaloric, isonitrogenous control. HLA feeding increased cardiac TUNEL positivity as a marker of cell death, protein expression of matrix metalloproteases (MMP-2 and -9) and downregulated tissue inhibitor of metalloproteases (TIMP-1 and -2). Sirius red and Masson's Trichrome staining of heart sections demonstrated augmented collagen deposition. Oxidative stress biomarkers such as nitrotyrosine and 4-hydroxynonenal also increased, whereas antioxidants including glutathione and superoxide dismutase were downregulated. To confirm that LA specifically plays a causative role, NIH-3T3 fibroblasts and differentiated H9c2 cardiomyoblasts were incubated with oleic, palmitic, or linoleic acid at concentrations from 0.1 to 1.0 mM over 24 hours. Mitochondrial redox potential in H9c2 cardiomyocytes was decreased with both palmitic acid and LA, but not oleic acid. Only incubation with LA demonstrated a dose-dependent reduction in cell viability in H9c2 cardiomyocytes. These results suggest that excess LA, a common dietary omega-6 PUFA, can augment cell death, oxidative damage, and loss of mitochondrial membrane potential in the heart and can contribute to current CVD rates in Canada.
Objective: To assess the effectiveness of a novel peer-led program called Healthy BuddiesÓ on weight gain and its determinants when disseminated at the provincial level to early years students in grades 1-6. Methods: We performed a cluster randomized controlled trial in 20 elementary schools in the province of Manitoba, Canada. Schools were randomized to receive regular curriculum or the Healthy BuddiesÓ curriculum. 21 lesson plans were delivered by older (9-12yrs) students to younger (6-8yrs) peers that focused on physical activity, healthy eating and self-esteem. The primary outcome measures were the change in waist circumference and body mass index z-score. Secondary outcome measures were objectively measured physical activity (steps/day), selfefficacy, healthy living knowledge and self-reported dietary intake. Results: Among the 647 students studied, 48% were girls, 36% were overweight or obese and 11% achieved the recommended 13,500 steps/day. Using intention to treat analyses, waist circumference declined significantly in the intervention group, relative to the controls, -1.42 (-2.68 to -0.17, p ¼ 0.026). BMI Z score was not changed, 0.03 (-0.06 to 0.11, p ¼ 0.54). Knowledge of healthy living, self efficacy and dietary intake were all significantly improved in the younger cohort that received the intervention, (p < 0.001). No differences were observed in daily step counts or fitness. Conclusions: The implementation of Healthy BuddiesÓ lesson plans in an elementary school setting is an effective method for attenuating central weight gain and improving diet quality, selfefficacy and knowledge of healthy living in younger students. 68
66 Cardiorespiratory Fitness in Metabolic Healthy Overweight Youth MARTIN SENECHAL, BRANDY A. WICKLOW, KRISTY WITTMEIER, JACQUELINE HAY, PINAR ESKICIOGLU, JONATHAN M. MCGAVOCK Winnipeg, MB Background: Metabolically Healthy Overweight (MHO) adolescents represent a subset of youth who are considered overweight but lack any obesity-related cardiometabolic risk factors (CMRF). The factors that protect overweight youth from CMRF clustering are not well established. We hypothesized that an elevated cardiorespiratory fitness (CRF) would increase the likelihood of being metabolically healthy if they are overweight or obese. Methods: Overweight adolescents, 12-18 yrs, were classified as MHO (n¼27; 0 risk factor) or non-MHO; (n¼81; 1 risk factor) based on age and sex-specific cut-points for the following CMRFs; fasting glucose, HDL-chol, triglycerides, systolic blood pressure, and hepatic triglyceride. CRF was assessed using a graded exercise test to exhaustion on a cycle ergometer. Results: MHO was associated with a lower waist circumference (99.7 13.2 cm vs. 106.1 13.7 cm) and body mass index Z-score, compared to non-MHO (P< 0.05). CRF was not associated with CMRF clustering or the presence of MHO. CRF was independently associated with two CMRF's, HDL-chol (r ¼0.22) and liver transaminases (r ¼ -0.24; all P< 0.05). Compared to the highest quartile of CRF, the odd of hepatic steatosis increased 4.5 fold (95% CI: 1.119.5; P¼0.04) compared to the lowest quartile of CRF. Conclusion: The MHO phenotype was present in w25% of overweight adolescents and is strongly associated with lower adiposity but not with higher CRF among adolescents. CRF is independently associated with hepatic steatosis, which is known to increase risk of type 2 diabetes.
Estimation of the Prevalence of Type 1 and Type 2 Diabetes Among Canadian Adults SULAN DAI, ASAKO BIENEK, CATHERINE PELLETIER, JAY ONYSKO, HOWARD MORRISON Ottawa, ON Objective: This study aims to estimate the prevalence of type 1 and type 2 diabetes among Canadian adults. Methods: Data from the 2011 Survey on Living with Chronic Diseases in Canada were analysed with SAS EG. Study sample included 2,903 (57.2% male) respondents aged 20+. Prevalence of type 1 and type 2 diabetes were estimated using three algorithms. Type 1 diabetes was defined as individuals using insulin at the time of survey, with insulin use initiated <1 year after diagnosis, and age at diagnosis: 1) <31 years; 2) <41 years; and 3) without specifying age. Rates were weighted to represent the Canadian population. Results: Only 2,528 respondents (89.2%) reported a diabetes type, with 202 (8.4%) type 1 and 2,326 (80.8%) type 2, and an additional 375 (10.8%) unknown/other. Overall, 683/2,528 (24.7%) of diabetics were using insulin. Prevalence were estimated using the three algorithms: 1) Type 1: 4.0% (95% CI: 2.7%-5.3%); type 2: 96.0% (95% CI: 94.7%97.3%) when age at diagnosis <31 years. 2) Type 1: 6.1% (95% CI: 4.5%-7.8%); type 2: 93.9% (95% CI: 92.2%95.5%) when age at diagnosis <41 years. 3) Type 1: 8.8% (95% CI: 6.8%-10.9%); type 2: 91.2% (95% CI: 89.1%93.2%) without specifying age. Conclusion: The estimated prevalence of type 1 diabetes varied from 4.0% to 8.8% among Canadian adults based on different criteria. Age at diagnosis played a significant role in estimating the prevalence for type 1 and type 2 diabetes. Further study should explore whether incident cases of type 1 diabetes occur in older Canadians.