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Background/objectives: This study examined the relationship between yogurt consumption, family history of obesity (FHO), and health determinants., Subjects/methods: Youth (n = 198; mean age: 20 ± 0.5 years) from the Québec Family Study were first classified based on their FHO, defined as the presence or absence of at least one obese (BMI ≥30 kg/m 2 ) parent [with FHO (FHO+; n = 112) or without FHO (FHO-; n = 86)] and then on their yogurt consumption [yogurt consumers (YC+) n = 61 or non-consumers (YC-) n = 137]. A two-factor mixed ANOVA was performed to evaluate the association between FHO, YC, and their interaction with health determinant such as weight and body composition, metabolic and behavioral profiles., Results: There was a main effect of FHO, but not YC, for weight and body composition, but no interaction between YC and FHO for these measures. However, a significant interaction between YC and FHO was observed for fasting insulin (P = 0.02), insulin area under the curve (AUC) (P = 0.02), and homeostatic model assessment of insulin resistance (HOMA-IR; P = 0.03) after adjustment for studied covariates. Specifically, lower fasting plasma insulin, insulin AUC, and HOMA-IR were observed in FHO+ and YC+ youth compared to YC- youth of the same group while no differences were found between the FHO- sub-groups., Conclusions: Consuming yogurt may protect against insulin resistance more specifically among youth at risk of obesity, and this relationship appears to be independent of body composition and lifestyle factors measured in this study.

The contribution of adiposopathy to glucose-insulin homeostasis remains unclear. This longitudinal study examined the potential relationship between the adiponectin/leptin ratio (A/L, a marker of adiposopathy) and insulin resistance (IR: homeostasis model assessment (HOMA)), insulin sensitivity (IS: Matsuda), and insulin response to an oral glucose tolerance test before and after a 16-week walking program, in 29 physically inactive pre- and postmenopausal women with obesity (BMI, 29-35 kg/m 2 ; age, 47-54 years). Anthropometry, body composition, VO 2 max, and fasting lipid-lipoprotein and inflammatory profiles were assessed. A/L was unchanged after training (p = 0.15), despite decreased leptin levels (p < 0.05). While the Matsuda index tended to increase (p = 0.07), HOMA decreased (p < 0.05) and fasting insulin was reduced (p < 0.01) but insulin area under the curve (AUC) remained unchanged (p = 0.18) after training. Body fatness and VO 2 max were improved (p < 0.05) while triacylglycerols increased and HDL-CHOL levels decreased after training (p < 0.05). At baseline, A/L was positively associated with VO 2 max, HDL-CHOL levels, and Matsuda (0.37 < ρ < 0.56; p < 0.05) but negatively with body fatness, HOMA, insulin AUC, IL-6, and hs-CRP levels (- 0.41 < ρ < - 0.66; p < 0.05). After training, associations with fitness, HOMA, and inflammation were lost. Multiple regression analysis revealed A/L as an independent predictor of IR and IS, before training (partial R 2  = 0.10 and 0.22), although A/L did not predict the insulin AUC pre- or post-intervention. A significant correlation was found between training-induced changes to A/L and IS (r = 0.38; p < 0.05) but not with IR or insulin AUC. Although changes in the A/L ratio could not explain improvements to glucose-insulin homeostasis indices following training, a relationship with insulin sensitivity was revealed in healthy women with obesity.

Purpose: The aim was to compare the anthropometric and metabolic profiles and lifestyle behaviours of yogurt consumers and non-consumers and to determine if the observed differences persisted after adjustment for diet quality and related variables., Methods: Using cross-sectional and follow-up data from the Québec Family Study, men and women were classified into yogurt consumers (n = 269; 96 men and 173 women) and non-consumers (n = 570; 279 men and 291 women), and their anthropometric measurements, metabolic profiles, and lifestyle factors were compared., Results: Men yogurt consumers had a lower body weight, BMI, % body fat, waist circumference and lower plasma insulin, and C-peptide concentrations in response to oral glucose, while women yogurt consumers had lower waist circumference, BMI, % body fat, plasma glucose, insulin, and C-peptide compared with non-consumers (P < 0.05). After adjustment for the Nutrient-Rich Foods (NRF) index, a marker of diet quality, these differences persisted in men and only for glycemic variables in women. Additional adjustment for physical activity participation and % body fat did not abolish the significant differences observed between yogurt consumers and non-consumers for plasma glucose, insulin, and C-peptide responses to oral glucose in women only (P < 0.05). Analyses of data after a 6-year follow-up reinforced these observations, since both men and women yogurt consumers maintained a better metabolic profile compared with non-consumers after adjustments for age and NRF (P < 0.05). In addition, an interaction between group and time for % body fat in men suggests a benefit of yogurt consumption over time on body composition., Conclusion: Yogurt consumption is associated with body composition and metabolic health benefits that are not entirely explained by a global effect of diet quality.

Background: Subclinical atherosclerosis identification remains challenging; abdominal visceral adiposity may improve risk stratification beyond traditional cardiovascular risk factors. Hypertriglyceridemic waist, a visceral adiposity marker combining elevated triglycerides (≥2 mmol/L) and waist circumference (≥90 cm), has been related to carotid atherosclerosis, although associations with high-risk features, including lipid-rich necrotic core (LRNC), remain unknown. We tested the hypothesis that hypertriglyceridemic waist is an independent marker of high-risk atherosclerosis features., Methods and Results: In this cross-sectional study including 467 white men (mean age, 45.9±14.8 years; range 19.4-77.6 years), carotid atherosclerosis characteristics were examined by magnetic resonance imaging and associations with hypertriglyceridemic waist and benefits beyond Framingham Risk Score (FRS) and Pathobiological Determinants of Atherosclerosis in Youth (PDAY) were determined. Subclinical carotid atherosclerosis was present in 61.9% of participants, whereas 50.1% had LRNC. Hypertriglyceridemic waist was associated with carotid maximum wall thickness ( P =0.014), wall volume ( P =0.025), normalized wall index ( P =0.004), and Carotid Atherosclerosis Score (derived from wall thickness and LRNC; P =0.049). Hypertriglyceridemic waist was associated with carotid LRNC volume beyond FRS ( P =0.037) or PDAY ( P =0.015), contrary to waist circumference alone (both P >0.05). Although 69.7% and 62.0% of participants with carotid atherosclerosis and/or LRNC were not high-risk by FRS or PDAY, respectively, hypertriglyceridemic waist correctly reclassified 9.7% and 4.5% of them, respectively. Combining hypertriglyceridemic waist with FRS (net reclassification improvement=0.17; P <0.001) or PDAY (net reclassification improvement=0.05; P =0.003) was superior to each score alone in identifying individuals with carotid atherosclerosis and/or LRNC., Conclusions: Hypertriglyceridemic waist is an independent marker of carotid high-risk atherosclerosis features in men, improving on FRS and PDAY risk score., (© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Waist circumference (WC) and body mass index (BMI) are clinically used to assess adiposity. The aim of the present study was to evaluate the association of WC with postoperative morbidity and mortality in patients who underwent isolated coronary artery bypass grafting (CABG) in relation to patients' BMI category., Methods: We analyzed the associations of WC and BMI with short-term postoperative outcomes in a cohort of 7446 patients who underwent isolated CABG. We performed univariate and adjusted analyses on main postoperative outcomes after CABG for WC and BMI., Results: Adverse events researched included postoperative mortality, intensive care unit and hospital length of stay, cardiovascular and cerebrovascular events, respiratory complications, infectious, hemostasis complications, and renal complications. WC was independently associated with all postoperative outcomes except prolonged intubation and mortality. Overall, patients in the upper WC quartile in each BMI category were at increased risk of adverse events compared with patients in the lower 3 WC quartiles, with a maximal incremental risk of 1.91 (95% confidence interval, 1.23-2.95) among patients with a BMI ≥ 35. This association was observed for men and women, across all overweight and obesity categories. Neither WC nor BMI was associated with short-term postoperative mortality., Conclusions: In our large cohort of patients who underwent isolated CABG, WC was significantly associated with clinical adverse events, independently of BMI. These findings provide further evidence on the added value of measuring WC as a simple and easy to measure anthropometric marker to refine risk assessment beyond BMI among patients who undergo CABG., (Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.)

Purpose: The prevalence of numerous chronic metabolic diseases is increasing worldwide with considerable personal and societal consequences. The aim of our study was to test the hypothesis that assessment of waist circumference (WC) and of cardiorespiratory fitness (CRF) could be relevant clinical targets of a simple preventive approach designed to improve cardiometabolic risk (CMR) profile at the workplace., Methods: A total of 787 employees participated in a pilot project of the "Grand Défi Entreprise." This challenge involved a 3-month in-house competition to favor peer support in the adoption of healthier lifestyle habits. For that purpose, the participating companies offered a comprehensive cardiometabolic/cardiorespiratory health assessment performed at the workplace with a mobile risk assessment unit before and after the contest (nutrition/physical activity (PA) questionnaires, resting blood pressure (BP), anthropometric measurements, lipid profile, and submaximal treadmill test)., Results: At baseline, more than 43% of workers were considered sedentary or moderately inactive (<3.5 h·wk of physical activity). Furthermore, the proportion of subjects in the high-risk category of nutritional quality index (NQI) was high (49%). After 3 mo, NQI and PA level improved. Reductions in WC (-4.2 ± 4.0 cm, P < 0.0001), in heart rate at a standardized submaximal workload (-4 ± 10 bpm, P < 0.0001) as well as in resting systolic (-6 ± 11 mm Hg) and diastolic (-4 ± 7 mm Hg) blood pressure were also observed. Improvements in WC and CRF were associated with improvements in the CMR profile., Conclusion: Results of this study show the added value of measuring/targeting WC and CRF as a relevant approach to reduce CMR at the workplace. Results also suggest that putting in place a permissive "in-house ecosystem" within the company is relevant to promote the adoption of healthier lifestyle habits.

Background/aim: Total fat intake has an important impact on the low-density lipoprotein (LDL) peak particle diameter (LDL-PPD) and may interact with nutrient-sensitive single nucleotide polymorphisms (SNPs). The objective was to examine whether there is suggestive evidence of SNP × dietary fat intake interaction effects influencing the LDL-PPD in the Quebec Family Study (QFS) in order to generate hypotheses to be tested in larger studies., Methods: SNPs from a genome-wide association study (GWAS) using Illumina Human610-Quad BeadChip, total fat intake derived from a 3-day weighted food record, and SNP × total fat intake interaction effects were examined on LDL-PPD in 541 QFS subjects., Results: The GWAS analyses 29 identified independent SNP × total fat intake interaction effects on the LDL-PPD at p < 10(-5), including SNPs in the following genes: ABCG2, CPA3, FNBP1, KCNQ3, NBAS, NCALD, OPRL1, NKAIN2, SH3BGRL2, SOX5, and SUSD4., Conclusions: This observational study suggests that multiple SNPs interact with dietary fat intake to influence variation in the LDL-PPD., (© 2015 S. Karger AG, Basel.)

Unlabelled: Inflammation is an important factor linking abdominal obesity with insulin resistance and related cardiometabolic risk. A genome-wide association study of adiposity-related traits performed in the Quebec Family Study (QFS) revealed that a single-nucleotide polymorphism (SNP) in the LRRFIP1 gene (rs11680012) was associated with abdominal adiposity (P = 4.6 × 10(-6))., Objective: The objective of this study was to assess the relationship between polymorphisms in LRRFIP1 gene and adiposity (BMI, fat mass (FM), waist circumference (WC), and computed tomography-derived areas of total, subcutaneous and visceral abdominal adipose tissue) and markers of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6))., Design and Methods: Using Sequenom, 16 tag SNPs in the LRRFIP1 gene, capturing 78% of the genetic variation, were genotyped in 926 participants of the QFS., Results: Eight SNPs (rs7575941, rs3769053, rs11689421, rs3820808, rs11680012, rs3806505, rs6739130, and rs11686141) showed evidence of association with at least two adiposity phenotypes and plasma levels of one marker of inflammation. The strongest evidence of association was observed with rs11680012, which explained 1.8-3.4% of the variance in areas of abdominal adiposity and 2.0% of the variation in CRP levels. Carriers of the rare allele of rs11680012 had ≈ 30% more abdominal adiposity (P values between 2.7 × 10(-4) and 3.8 × 10(-6)) and 75% higher CRP levels (P = 1.6 × 10(-4)) than the common allele in age and sex adjusted data. Rs11680012 is a G/C SNP converting an arginine into a threonine and this amino acid substitution may potentially alter exonic splicing., Conclusion: This gene may therefore represent a potential interesting target to investigate in further functional studies on adiposity and inflammation., (Copyright © 2012 The Obesity Society.)

Eating behaviour traits of rigid control and disinhibition have been associated with body weight in both adults and adolescents. Moreover, adults reporting a dieting history have increased levels of unhealthy eating behaviours. Against this background, the present study aimed to examine the relationship between dieting history and eating behaviour traits in adolescents. For the purpose of this research, a total of sixty adolescents (aged 15 (sem 2·4) years) from the Québec Family Study completed the Three-Factor Eating Questionnaire (TFEQ) and a questionnaire regarding eating habits. Self-reported current and past dieting were analysed against eating behaviour traits measured by the TFEQ, including all subscales. As the results revealed, few adolescents reported currently dieting (n 3). Adolescents who reported a dieting history (23·3 %) were older (16·9 v. 14·4 years, P < 0·001), were more likely to be female (78·6 v. 41·3 %, P < 0·05) but did not have a significantly higher BMI z-score (1·5 v. 0·9, P = 0·10), although they were more likely to be either overweight or obese (P < 0·01). After correcting for sex, BMI and age, adolescents who reported a dieting history had higher levels of rigid control and disinhibition (P < 0·05-0·0001) than those reporting no dieting history. A greater proportion of adolescents characterised by high rigid control and high disinhibition were past dieters, compared to those characterised by low levels of both behaviour traits (53 v. 4 %). The study arrived at the following conclusions: as observed in adults, adolescents with a history of dieting present unfavourable eating behaviour traits. These behavioural traits may represent an additional challenge to the long-term regulation of body weight.

The objective of this cross-sectional study was to examine the association between sleep duration and alcohol consumption in adults (301 men and 402 women aged 18-64years) from the greater Quebec City area. Sleep duration (self-reported), alcohol consumption (3-day food record and questions on drinking habits), and disinhibition eating behavior trait (score ≥ 6 on the Three-Factor Eating Questionnaire) were assessed. Participants were categorized as short- ( ≤ 6h), average- (7-8h) or long- ( ≥ 9h) duration sleepers. Overall, short-duration sleepers consumed significantly more alcohol than the two other sleep-duration groups. After adjusting for relevant covariates, short sleep duration was associated with an increase in the odds of exceeding the recommendations for sensible weekly alcohol intake of 14 drinks for men and 7 drinks for women compared to those sleeping between 7 and 8h (OR 1.87, 95%CI 1.03-3.54, both sexes combined). In both men and women, daily alcohol intake was significantly higher in short-duration sleepers having a high disinhibition eating behavior trait. However, the prevalence of a binge drinking occasion (i.e. ≥5 drinks on one occasion) was more common in men than women. Men sleeping less than 6h per night with a disinhibited eating behavior were more likely to report binge drinking (41% of them). In summary, the combination of short sleep duration with disinhibited eating behavior is associated with greater alcohol intake in adults., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Postoperative atrial fibrillation (POAF) is a frequent complication of coronary artery bypass grafting (CABG) surgery. The objective of this study was to determine the impact of POAF on both short- and long-term mortality following isolated CABG., Hypothesis: POAF is associated with a poorer short and long-term mortality following CABG., Methods: We retrospectively analyzed the preoperative and operative data of 6728 consecutive patients undergoing a first isolated CABG., Results: The incidence of POAF was 27.8%. Operative mortality was higher in patients with POAF compared to those without POAF (2.3% vs 0.9%, P < 0.001). On multivariate analysis, POAF remained an independent predictor of operative mortality (odds ratio [OR]: 1.78, P = 0.01). Patients with POAF also had reduced long-term survival (6-year survival: 85.3% vs 89.2%, P < 0.001). After adjusting for other predictors of mortality, POAF was significantly associated with increased long-term mortality (hazard ratio [HR]: 1.35, P = 0.04). Of note, after adjustment for potential confounders, statin treatment had a highly protective effect in POAF patients for both operative mortality (OR: 0.38, P = 0.003) and long-term mortality (HR: 0.62, P = 0.03), whereas it had no significant effect in patients without POAF., Conclusions: POAF is an independent predictor of both short- and long-term mortality following CABG. Moreover, statin therapy was independently associated with better survival in patients with POAF., (© 2012 Wiley Periodicals, Inc.)

Background: The natural history of intermittent claudication, from its risk factors to its cardiovascular prognosis, has been reported in few prospective studies., Objective: To assess incident intermittent claudication, as well as its risk factors and long-term prognosis in men., Methods: A random sample of 4376 men 35 to 64 years of age from Quebec City (Quebec), who were free of cardiovascular disease (CVD), was evaluated in 1974 for CVD risk factors and followed until 1998. To assess the prognosis, the event rates between 1985 and 1998 were computed among men with incident claudication without other CVD, incident survivors of a first myocardial infarction (MI) without other CVD and men free of CVD between 1974 and 1985., Results: From 1974 to 1998, 300 men developed intermittent claudication. Tobacco consumption, high systolic blood pressure and diabetes at least doubled the adjusted RR (aRR) of intermittent claudication. In 1985, there were 80 claudicants, 2868 men free of CVD and 68 survivors of a first MI. During the 13-year follow-up, a new CVD occurred in 48.8% of the claudicants, in 18.9% of men without CVD (aRR 2.08; 95% CI 1.48 to 2.90) and in 45.6% of MI survivors (aRR compared with claudicants 1.12; 95% CI 0.69 to 1.79). There was also no significant difference between claudicants and MI survivors for fatal CVD, nonfatal CVD and total mortality., Conclusions: Men with intermittent claudication are at high risk for CVD that may be equivalent to men with previous MI.

The aim of this study was to determine the independent contribution of previously reported risk factors for adult overweight and obesity. A cross-sectional (n=537) and a longitudinal (n=283; 6-year follow-up period) analysis was performed for nine risk factors for overweight and obesity assessed in adult participants (aged 18-64 years) of the Quebec Family Study (QFS). The main outcome measure was overweight/obesity, defined as a BMI>or=25 kg/m2. Using logistic regression analysis adjusted for age, sex, and socioeconomic status, short sleep duration, high disinhibition eating behavior, low dietary calcium intake, high susceptibility to hunger behavior, nonparticipation in high-intensity physical exercise, high dietary restraint behavior, nonconsumption of multivitamin and dietary supplements, high dietary lipid intake, and high alcohol intake were all significantly associated with overweight and obesity in the cross-sectional sample. The analysis of covariance adjusted for age, socioeconomic status, and all other risk factors revealed that only individuals characterized by short sleep duration, high disinhibition eating behavior, and low dietary calcium intake had significantly higher BMI compared to the reference category in both sexes. Over the 6-year follow-up period, short-duration sleepers, low calcium consumers, and those with a high disinhibition and restraint eating behavior score were significantly more likely to gain weight and develop obesity. These results show that excess body weight or weight gain results from a number of obesogenic behaviors that have received considerable attention over the past decade. They also indicate that the four factors, which have the best predictive potential of variations in BMI, be it in a cross-sectional or a longitudinal analytical design, do not have a "caloric value" per se.

Objective: To examine the long-term relationship between sleep duration and type 2 diabetes or impaired glucose tolerance (IGT)., Methods: Body composition measurements and self-reported sleep duration were determined in a longitudinal sample of 276 individuals aged 21 to 64 years followed for a mean of 6 years. Risk factors of type 2 diabetes/IGT over the follow-up were determined and relative risks (RRs) calculated for the development of type 2 diabetes/IGT by sleep duration group., Results: Independent risk factors of type 2 diabetes/IGT over the follow-up included age, obesity, sleep duration, and glucose/insulin homeostasis indicators. Using adults with 7-8h of sleep as a reference, the adjusted RR for the development of type 2 diabetes/IGT was 2.78 (1.61-4.12) for those with 6h of sleep and 2.54 (1.42-3.53) for those with 9h of sleep. These elevated RRs remained significant after adjustment for body mass index, waist circumference or percent body fat., Conclusion: Short and long sleeping times are associated with a higher risk of developing type 2 diabetes/IGT, independent of several covariates. These results suggest that sleep duration may represent a novel risk factor for type 2 diabetes/IGT.

Background: People with type 2 diabetes mellitus are at high risk for cardiovascular disease. In some studies, the mortality rate among people with this condition has been equivalent to that among people with cardiovascular disease. We compared cardiovascular mortality between incident cases of diabetes and cardiovascular disease., Methods: The study population was part of a random sample of 4376 men from Quebec, Canada, aged 35 to 64 years, who did not have cardiovascular disease in 1974 and who were followed until 1998. Three groups of incident cases were identified: diabetes without cardiovascular disease, first cardiovascular event (myocardial infarction, unstable angina or stroke) without diabetes, and both cardiovascular disease and diabetes. These cases were age-matched to a control group without diabetes or cardiovascular disease., Results: During the 24-year follow-up period, new diabetes without cardiovascular disease was documented in 137 men. A first cardiovascular event without diabetes was documented in 527 men. Relative to the 627 controls, men with 1 of the 2 diseases of interest had higher cardiovascular mortality (age-adjusted relative risk [RR] 3.11, 95% confidence interval [CI] 1.96-4.92) for those with diabetes and 4.46 (95% CI 3.15-6.30) for those with cardiovascular disease). However, within the first 5 years after diagnosis, men with cardiovascular disease had higher cardiovascular mortality than men with diabetes (age-adjusted RR 2.03, 95% CI 1.01-4.08)., Interpretation: Men with isolated type 2 diabetes and men with isolated cardiovascular disease had similar cardiovascular mortality rates several years after initial diagnosis of either condition. These findings reinforce the need to prevent and optimally manage diabetes and cardiovascular disease.

Adipose tissue synthesizes and secretes a wide range of biologically active molecules considered as inflammatory markers whose dysregulation in obesity plays a role in the development of insulin resistance and vascular disorders. Thus, finding genes that influence circulating levels of inflammatory biomarkers may provide insights into the genetic determinants of obesity-related metabolic diseases. We performed linkage analyses for fasting plasma levels of adiponectin, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor-necrosis factor-alpha (TNF-alpha) in 764 subjects enrolled in the Quebec family study (QFS). A maximum of 393 pairs of siblings from 211 nuclear families were available for analyses. A total of 443 markers spanning the 22 autosomal chromosomes with an average inter-marker distance of 6.24 Mb were genotyped. Linkage was tested using both allele-sharing (SIBPAL) and variance component linkage methods (MERLIN). We showed suggestive evidence of linkage for plasma adiponectin levels on chromosome 15q21.1 [D15S659; logarithm of the odds (LOD) score = 2.23], 3q13.33 (D3S3023; LOD = 2.09), 20q13.2 (D20S197; LOD = 1.96) and 14q32.2 (D14S1426; LOD = 1.79). Evidence of linkage (SIBPAL) was also found for CRP on 12p11.23 (P = 0.001) and 12q15 (P = 0.0005) and for IL-6 on 14q12 (P = 0.002). None of these linkages remained significant after adjustment for body mass index. No evidence of linkage was found for TNF-alpha plasma levels. These results suggest that several QTLs can influence plasma levels of adiponectin and CRP, partly via their effects on adiposity.

The Quebec Heart Institute was established in 1957 at the Laval Hospital in Sainte-Foy, Quebec. Since then, clinical and research activities have made this Institute one of the largest tertiary care cardiology centres in Canada. With its vast catchment area of more than 3,000,000 people, the Institute has developed a strong collaboration with referral physicians centred on clinical, teaching and research interests. The Institute pioneered several aspects of cardiac surgery, invasive cardiology, echocardiography, basic research and, more recently, a network of researchers and clinicians working in the field of 'metabolic cardiology'. The first 50 years of the Quebec Heart Institute are depicted in this overview, which will also introduce this special supplement to The Canadian Journal of Cardiology.

Objective: To explore cross-sectional associations between short sleep duration and variations in body fat indices and leptin levels during adulthood in a sample of men and women involved in the Québec Family Study., Research Methods and Procedures: Anthropometric measurements, plasma lipid-lipoprotein profile, plasma leptin concentrations, and total sleep duration were determined in a sample of 323 men and 417 women ages 21 to 64 years., Results: When compared with adults reporting 7 to 8 hours of sleep per day, the adjusted odds ratio for overweight/obesity was 1.38 (95% confidence interval, 0.89 to 2.10) for those with 9 to 10 hours of sleep and 1.69 (95% confidence interval, 1.15 to 2.39) for those with 5 to 6 hours of sleep, after adjustment for age, sex, and physical activity level. In each sex, we observed lower adiposity indices in the 7- to 8-hour sleeping group than in the 5- to 6-hour sleeping group. However, all of these significant differences disappeared after statistical adjustment for plasma leptin levels. Finally, the well-documented regression of plasma leptin levels over body fat mass was used to predict leptin levels of short-duration sleepers (5 and 6 hours of sleep), which were then compared with their measured values. As expected, the measured leptin values were significantly lower than predicted values., Discussion: There may be optimal sleeping hours at which body weight regulation is facilitated. Indeed, short sleep duration predicts an increased risk of being overweight/obese in adults and is related to a reduced circulating leptin level relative to what is predicted by fat mass. Because sleep duration is a potentially modifiable risk factor, these findings might have important clinical implications for the prevention and treatment of obesity.

Objectives: People of African descent may be at greater risk of metabolic syndrome (MS) compared with whites. We examined the associations among MS markers, body composition, and resting metabolic rate (RMR) in black Haitians and in white subjects living in Quebec, Canada., Research Methods and Procedures: Forty randomly selected Haitians were matched with 40 white subjects for age, sex, and BMI. Glycemic status and insulin resistance were assessed based on a 3-hour glucose tolerance test. Blood lipids, blood pressure, abdominal fat (computed tomography), and waist circumference (WC) were measured. RMR was estimated by indirect calorimetry., Results: Triglycerides were significantly correlated with blood pressure only in Haitians and with the area under the curve for insulin only in whites. Haitians had significantly (p < 0.05) lower triglycerides and higher high-density lipoprotein-cholesterol concentrations but higher blood pressure than whites at any given WC value. General linear models showed that Haitians had less visceral adipose tissue than whites for the same WC. RMR was lower among Haitians for any given value of BMI or WC than in whites. Also, WC was more strongly associated with glucose area under the curve and to log-homeostasis model assessment in white than in Haitian subjects., Discussion: The MS may be ethnospecific in its features and etiology. The standard anthropometric indices of obesity may not be as effective in populations of African descent compared with whites, unless appropriate cut-off values are defined.

Low-density lipoprotein (LDL) size, a coronary heart disease risk factor, is influenced by both genetic and environmental factors. Results from the Quebec Family Study (QFS) revealed that the LDL peak particle diameter (LDL-PPD) aggregates in families with a heritability coefficient above 50% and is affected by a major quantitative trait locus on chromosome 17q (LOD=6.8). Complex segregation analyses have consistently demonstrated a major gene effect influencing LDL size. In the present study, we report a similar analysis in the QFS cohort, which suggests that a major gene explains 23% of the variance in age-body mass index and triglyceride-adjusted LDL-PPD. The most intuitive positional candidate gene on chromosome 17q is the apolipoprotein H gene. Direct sequencing of the promoter, coding regions, and exon-intron splicing boundaries of this gene revealed the presence of three missense mutations and two polymorphisms in the untranslated regions. Using family-based association tests, none of these variants was individually associated with LDL-PPD. However, analysis of the haplotypes constructed from the three missense mutations, suggested that one particular haplotype (frequency=20.9%) was associated with a significant increase in LDL-PPD trait values (p=0.046). Taken together, these results suggest the presence of a major gene effect influencing LDL-PPD and a positive association with a positional candidate gene located on chromosome 17q. Replication of the association between apolipoprotein H gene haplotype and LDL-PPD is required before reaching firm conclusion.

We tested the hypothesis that elevated plasma interleukin-6 (IL-6), C-reactive protein (CRP) and fibrinogen concentrations are independent risk factors and interact in increasing the long-term risk of ischemic heart disease (IHD) in men. A total of 1982 IHD-free men from the Quebec Cardiovascular Study were followed over a period of 13 years during which 210 first fatal IHD events and non-fatal myocardial infarctions were recorded. Increased CRP levels (4th versus 1st quartile) were not associated with an increased risk of IHD after adjustment for non-lipid risk factors (age, body mass index, systolic blood pressure, diabetes, smoking and medication use at baseline), lipid risk factors (LDL and HDL cholesterol and triglyceride levels) and for IL-6 and fibrinogen (RR=0.70, 95% CI=0.43-1.13). High plasma IL-6 levels (4th versus 1st quartile) were associated with a 70% greater risk of IHD independent of confounding risk factors and of the other 2 inflammatory markers (RR=1.71, 95% CI=1.07-2.75). The relationship between high fibrinogen levels (4th versus 1st quartile) and IHD risk was borderline significant in multivariate analyses (RR=1.53, 95% CI=0.97-2.43). An inflammation score based on plasma IL-6 and fibrinogen levels improved the IHD risk predictive value of a multivariate model of traditional risk factors (p=0.03). Including plasma CRP levels into the inflammatory score provided no additional predictive value. In conclusion, elevated plasma IL-6 concentrations are more strongly related to IHD risk than CRP and fibrinogen. An inflammation score based on high plasma IL-6 and fibrinogen levels used in combination with traditional risk factors may improve our ability to adequately identify high risk individuals.

Objective: It is commonly recognized that genetic, environmental, behavioral, and social factors are involved in the development of obesity. The family environment may play a key role in shaping children's eating behaviors. The purpose of this study was to estimate the degree of familial resemblance in eating behavioral traits (cognitive dietary restraint, disinhibition, and susceptibility to hunger)., Research Methods and Procedures: Eating behavioral traits were assessed with the Three-Factor Eating Questionnaire in 282 men and 402 women (202 families) from the Quebec Family Study. Familial resemblance for each trait (adjusted for age, sex, and BMI) was investigated using a familial correlation model., Results: The pattern of familial correlation showed significant spouse correlation for the three eating behavior phenotypes, as well as significant parent-offspring and sibling correlations for disinhibition and susceptibility to hunger. According to the most parsimonious model, generalized heritability estimates (including genetic and shared familial environmental effects) reached 6%, 18%, and 28% for cognitive dietary restraint, disinhibition, and susceptibility to hunger, respectively., Discussion: These results suggest that there is a significant familial component to eating behavioral traits but that the additive genetic component appears to be small, with generalized heritability estimates ranging from 6% to 28%. Thus, non-familial environmental factors and gene-gene and gene-environmental interactions seem to be the major determinants of the eating/behavioral traits.

Objective: The objective of the present study was to investigate the association between large and small low-density lipoprotein (LDL) and long-term ischemic heart disease (IHD) risk in men of the Quebec Cardiovascular Study., Methods and Results: Cholesterol levels in the large and small LDL subfractions (termed LDL-C> or =260A and LDL-C<255A, respectively) were estimated from polyacrylamide gradient gel electrophoresis of whole plasma in the cohort of 2072 men of the population-based Quebec Cardiovascular Study. All men were free of IHD at the baseline examination and followed-up for a period of 13 years, during which 262 first IHD events (coronary death, nonfatal myocardial infarction, and unstable angina pectoris) were recorded. Our study confirmed the strong and independent association between LDL-C<255A levels as a proxy of the small dense LDL phenotype and the risk of IHD in men, particularly over the first 7 years of follow-up. However, elevated LDL-C> or =260A levels (third versus first tertile) were not associated with an increased risk of IHD over the 13-year follow-up (RR=0.76; P=0.07)., Conclusions: These results indicated that estimated cholesterol levels in the large LDL subfraction were not associated with an increased risk of IHD in men and that the cardiovascular risk attributable to variations in the LDL size phenotype was largely related to markers of a preferential accumulation of small dense LDL particles.

The purpose of the present cross-sectional study was to compare eating behaviours (cognitive dietary restraint, disinhibition and susceptibility to hunger), dietary profile and physiological variables according to the practice of dieting: current dieting; history of dieting in the 10-year period that preceded the study; no dieting during the same period. Dieting history, anthropometric markers of adiposity, RMR, dietary profile (3 d food record) and eating behaviours (three-factor eating questionnaire) were determined in a sample of 244 men and 352 women. A greater proportion of women (31.8 %) than men (16.8 %) reported that they had been on a diet over the past 10 years (P=0.0001). In both genders, current and past dieters had a higher BMI (P<0.05) than non-dieters and current dieters had lower reported energy intakes than past dieters and non-dieters (only in women) (P<0.05). Current and past dieters also had higher scores for all eating behaviours and their subscales (P<0.05; except for susceptibility to hunger in men) compared with non-dieters (adjusted for age, reported energy intake, percentage of dietary fat, BMI and RMR). Moreover, for each dieting-history category, women had significantly higher scores for cognitive dietary restraint than men (P<0.05). In conclusion, the present study showed that current and past dieters had higher scores for cognitive dietary restraint and disinhibition compared with non-dieters. As disinhibition has previously been associated with a greater risk of subsequent weight gain, interventions aimed at preventing an increase in disinhibition may be promising for long-term weight maintenance.

LDL size has been associated with the risk of coronary heart disease. The objective of the present study was to verify whether familial factors influence LDL peak particle diameter (LDL-PPD), a quantitative trait reflecting the size of the major LDL subclass. LDL-PPD was measured by 2-16% polyacrylamide gradient gel electrophoresis in 681 members of 236 nuclear families participating in the Quebec Family Study. LDL-PPD was adjusted for age (LDL-PPD1), age and body mass index (LDL-PPD2), or age, body mass index, and plasma triglyceride levels (LDL-PPD3) separately in men and women. The residual scores were used to test for familial aggregation, using an ANOVA and to compute maximum likelihood estimates of familial correlations. The ANOVA test revealed that family lines accounted for 47.4%, 46.7%, and 48.9% of the variance in the LDL-PPD1, LDL-PPD2, and LDL-PPD3 phenotypes, respectively. The pattern of familial correlations revealed no significant spouse correlations but significant parent-offspring and sibling correlations for the three LDL-PPD phenotypes, with maximal heritability estimates of 59%, 58%, and 52% for LDL-PPD1, LDL-PPD2, and LDL-PPD3, respectively. These results suggest that LDL-PPD strongly aggregates in families, and that the familial resemblance appears to be primarily attributable to genetic factors. Genes responsible for this genetic contribution remain to be identified., (Copyright 2003 Wiley-Liss, Inc.)

We compared the effects of ad libitum consumption of a defined high complex carbohydrate (CHO) diet (% of energy: CHO, 58.3; fat, 25.8) vs. a defined high monounsaturated fatty acid (MUFA) diet (% of energy: CHO, 44.7; fat, 40.1; MUFA, 22.5) on LDL electrophoretic characteristics. Healthy men [n = 65; age, 37.5 +/- 11.2 (mean +/- SD) y; BMI, 29.2 +/- 4.9 kg/m2] were randomly assigned to one of the two diets that they consumed for 6-7 wk. The high CHO diet significantly reduced body weight (-2%). The diet-induced reduction in plasma LDL cholesterol (C) levels in the high-CHO diet group was due mainly to concurrent reductions in the cholesterol content of small (<25.5 nm, P < 0.01) and medium-sized LDL (25.5-26.0 nm, P = 0.01). The high MUFA diet also reduced body weight, and LDL-C and LDL-apolipoprotein (apo)B levels, which were comparable to those in the high CHO group. The cholesterol levels of small LDL particles tended to be reduced (P = 0.24) in the high MUFA group (-12%), similar to changes in the high CHO group. These results suggest that, when associated with weight loss, ad libitum consumption of high CHO and high MUFA diets may be considered to be equally beneficial for the management of LDL-related atherogenic dyslipidemia. However, the high MUFA diet more favorably affected triglyceride levels, suggesting that it may be preferable to a high CHO diet in cardiovascular disease prevention.

Objective: To put into relationship the dietary and anthropometric profile of men and women with their eating behaviors (cognitive dietary restraint, disinhibition, and susceptibility to hunger) and to assess whether gender and obesity status influence these associations., Research Methods and Procedures: Anthropometric measurements (including visceral adipose tissue accumulation), dietary profile (3-day food record), and eating behaviors (Three-Factor Eating Questionnaire) were determined in a sample of 244 men and 352 women., Results: Women had significantly higher cognitive dietary restraint and disinhibition scores than men (p < 0.0001). In both genders, scores for disinhibition and susceptibility to hunger, but not for cognitive dietary restraint, were higher in obese subjects than in overweight and nonobese subjects (p < 0.05). Positive correlations were observed between rigid restraint and most of the anthropometric variables studied (0.12

The objective of the present study was to examine concordance/discordance among 4 atherogenic indexes of cardiovascular risk: plasma total cholesterol, low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (non-HDL) cholesterol, and apolipoprotein B-100 (apoB). Analyses were conducted in a cohort of 2,103 men without coronary artery disease (CAD) at the onset of the Quebec Cardiovascular Study. Although there were strong and highly significant correlations among the 4 risk indexes (0.78 < r < 0.97), only 50% of all subjects had concordant apoB and LDL cholesterol levels (i.e., values that fell into the same quintile of the population distribution). Moreover, concordance/discordance was not the same throughout the range of both variables; it was greater at the extremes of their respective distributions (65%), but significantly less in the midpoints (<40%). ApoB appeared to be more concordant with non-HDL cholesterol than with LDL cholesterol, although >1/3 of all subjects had discordant levels. Kappa analysis confirmed that there was only fair agreement between apoB and total or LDL cholesterol (0.38 and 0.36, respectively) and only moderate agreement between non-HDL cholesterol and apoB (0.47). Finally, a significant proportion of subjects (528 of 2,103) who had disproportionately higher apoB levels than would have been predicted based on their LDL cholesterol concentrations was more obese and manifested several features of the metabolic syndrome. They also had a significantly increased cardiovascular risk. In summary, plasma apoB and the various cholesterol indexes are complementary rather than competitive indexes of atherosclerotic risk and provide further evidence as to why measurement of apoB should be part of a standard lipoprotein assessment of CAD risk.

This purpose of this study was to investigate how plasma C-reactive protein (CRP), a nonspecific acute-phase reactant, modulates the risk of coronary heart disease (CHD) associated with the small, dense, low-density lipoprotein (LDL) phenotype. LDL particle size and plasma CRP were measured in the Quebec Cardiovascular Study cohort of 2,025 men free of CHD at baseline, among whom 103 had a first CHD event during a 5-year follow-up period. Plasma CRP levels were measured using the Behring Latex-Enhanced (highly sensitive) CRP assay. LDL particle size phenotype was characterized using 2% to 16% polyacrylamide gradient gel electrophoresis. There were weak but significant associations between plasma CRP levels and features of LDL size, such as the proportion of LDL with a diameter <255 A (r = 0.09, p <0.001) and LDL peak particle size (r = -0.09, p <0.001). Variations in plasma CRP levels modulated the risk of CHD associated with small LDL peak particle size (relative risk 4.3 vs 2.5 in men with high vs low plasma CRP levels, respectively) and with an elevated proportion of LDL <255 A (relative risk 6.6 vs 3.0). Thus, increased plasma CRP levels further elevate the risk of CHD associated with having small, dense LDL particles.

Background: It is well established that cardiovascular diseases (CVD) are the most important cause of morbidity and mortality in North America and in industrialized countries. Furthermore, the presence of CVD risk factors is widespread in Canada, and two-thirds of adult Canadians present at least one traditional risk factor for CVD., Objective: To quantify the prevalence of metabolic alterations predictive of an increased risk of CVD in a representative sample of the Québec population., Methods: A representative sample of the Québec population was obtained through the Québec Health Survey 1990. The cohort of 1844 subjects (907 men and 937 women), aged from 18 to 74 years, completed the evaluation, which consisted of interviews, validated questionnaires for personal and family history of CVD risk factors, and a physical examination. Anthropometric measurements, blood pressure, fasting plasma lipoprotein-lipid levels as well as fasting glucose and insulin concentrations were obtained., Results: Thirty one per cent of the Québec population had a normal body weight defined by body mass index (BMI) less than 25 kg/m2 with a healthy metabolic profile (glycemia less than 6.1 mmol/L, total cholesterol less than 5.2 mmol/L, low density lipoprotein-cholesterol less than 3.4 mmol/L, triglycerides less than 2.3 mmol/L and high density lipoprotein-cholesterol greater than 0.90 mmol/L). On the other hand, 28% of the population was treated for known metabolic chronic diseases (CVD, diabetes, dyslipidemias and hypertension), whereas the remaining 33% of the Québec population (BMI greater than 25 kg/m2) were characterized by an altered metabolic profile predictive of an increased CVD risk. Furthermore, 75% of men and 70% of women with an altered metabolic profile presented at least two CVD risk factors. Overall, women tended to display a significantly healthier metabolic risk profile than men (P<0.05)., Conclusions: According to our results, only 31% of the Québec population is nonobese without major alterations in their metabolic risk profile. Indeed, 61% of Quebecers are either characterized by chronic diseases or by an altered metabolic profile increasing their risk for the development of CVD and type 2 diabetes. Such a high prevalence should be a source of concern justifying the development of simple screening tools for early identification of the asymptomatic carriers of this cluster of metabolic abnormalities.

Background: A triad of metabolic markers (high insulin and apolipoprotein B levels, and small, dense, low density lipoprotein particles) is associated with a substantially increased risk of coronary artery disease (CAD) in men. Also, the simultaneous presence of an elevated waist circumference (90 cm or greater) and moderate hypertriglyceridemia (triglyceride concentration 2.0 mmol/L or higher) in men has been shown to be associated with this atherogenic metabolic triad, with a probability of more than 80%., Objectives: To quantify the prevalence of the 'hypertriglyceridemic waist' phenotype in a sample of adult men and to compare the metabolic risk profile of nondiabetic men with hypertriglyceridemic waist with the CAD risk profile of patients with type 2 diabetes., Methods: The sample of people who participated in the Quebec Health Survey was used to obtain representative data on the prevalence and distribution of cardiovascular disease risk factors in the Quebec population. Fasting plasma lipoprotein-lipid, insulin and glucose concentrations were measured, and anthropometric measurements were taken in a sample of 907 men., Results: Among men who participated in the Quebec Health Survey, 19% had an elevated waist circumference (90 cm or greater) plus elevated triglyceride levels (2.0 mmol/L or higher). Men with this hypertriglyceridemic waist phenotype were characterized by the highest values for fasting plasma insulin, and the highest total cholesterol to high density lipoprotein cholesterol ratios. They also displayed a metabolic risk profile that was deteriorated to the same extent as that of men with diabetes who had participated in the survey., Conclusions: The results of the the present study of men who participated in the Quebec Health Survey provide further evidence that the simultaneous measurement and interpretation of waist circumference and fasting triglyceride concentrations may improve the physician's ability to identify abdominally obese men with atherogenic and diabetogenic profiles. Furthermore, this high risk clinical phenotype is highly prevalent (about 20%) among adult men.

Fibrinogen has been prospectively found to correlate with coronary heart disease (CHD) but a similar association has not been well established for lipoprotein (a) (Lp(a)). Plasma lipids, Lp(a), and fibrinogen levels were measured in 2,125 men (aged 47 to 76 years) who were free of clinical CHD. During a 5-year follow-up period, 116 first CHD events were documented. Men with CHD were older, smoked more, had a higher prevalence of diabetes, and higher levels of systolic blood pressure, cholesterol, low-density lipoprotein cholesterol, Lp(a), and fibrinogen, and lower plasma high-density lipoprotein cholesterol levels. Only fibrinogen levels in the upper tertile of the distribution compared with the lower tertiles were associated with a significant risk of CHD (adjusted risk ratio 2.5; 95% confidence interval [CI] 1.4 to 4.2; p = 0.0010). Such an association was not observed with Lp(a). To assess a possible relation between fibrinogen and Lp(a) to the risk of CHD events, men were assigned to 1 of 4 groups according to fibrinogen median levels and a Lp(a) cut-off level of 300 mg/L: group 1: fibrinogen < 4.05 g/L and Lp(a) < 300 mg/L; group 2: fibrinogen < 4.05 g/L and Lp(a) > or =300 mg/L; group 3: fibrinogen > or =4.05 g/L and Lp(a) < 300 mg/L; and group 4: fibrinogen > or =4.05 g/L and Lp(a) > or =300 mg/L. Using group 1 as a reference, a significant risk ratio was only documented in group 4 (2.5; 95% CI 1.2 to 5.1; p = 0.0132). In this population, high fibrinogen levels associated with high Lp(a) levels significantly increased the risk of CHD.