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Biomedical subjects

Natalie Alméras

Publications and source records attributed to Natalie Alméras.

10 recordsLinked to original sources
PubMed2007

The effect of topiramate on energy balance in obese men: a 6-month double-blind randomized placebo-controlled study with a 6-month open-label extension.

OBJECTIVE: Topiramate (TPM) has been reported to reduce body weight beyond a placebo in the treatment of obese participants, but the effect of this agent on components of energy balance has not yet been established in humans. Thus, the aim of this study was to study the impact of TPM on food preferences, measures of satiety, food intake, resting metabolic rate (RMR), and 24-h energy expenditure. METHODS: The study design consisted of a 6-month, single-center, randomized, double-blind, parallel group, placebo-controlled trial with a 6-month open-label extension. The study included 68 sedentary men with abdominal obesity (waist circumference > or = 100 cm), of between 25 and 55 years of age, with a dyslipidemic profile and a body mass index (BMI) > or = 27 and < or = 40 kg/m(2). RESULTS: Treatment with TPM produced significant changes in anthropometric variables and body composition compared with placebo. However, at the end of the 1-year study, the placebo/TPM group showed similar weight loss and reduction in body fatness compared with the TPM/TPM group. For instance, at the end of the 12-month intervention, mean percentage of body weight loss from baseline was about -5% in both groups (-4 kg fat loss). Topiramate treatment reduced energy intake, be it in the context of an ad libitum buffet-type meal or under free living conditions. The 24-h daily energy expenditure (DEE) assessed by whole-body indirect calorimetry adjusted for body weight and age was not altered by TPM treatment. CONCLUSION: Topiramate treatment produced significantly greater weight loss than placebo and the majority of this loss was explained by a decrease in body fat stores. Most of the weight loss effect produced by TPM therapy was observed within a period of 6 months. Finally, TPM treatment had an impact on energy balance through a reduction in food intake that appears to have created an energy deficit of about 30,000-40,000 kcal compared with treatment with the placebo over 6 months.

Adipose Tissue↗
PubMed2004

Adiponectinemia in visceral obesity: impact on glucose tolerance and plasma lipoprotein and lipid levels in men.

The present study examined the associations between a major adipokine, adiponectin, and adiposity indices as well as metabolic risk variables in a sample of 190 untreated asymptomatic men. Anthropometric measurements and a complete fasting plasma lipoprotein and lipid profile were obtained, and subjects underwent an oral glucose tolerance test. Fasting plasma adiponectin concentrations were determined by an ELISA. Although all adiposity and adipose tissue (AT) distribution indices were negatively correlated with plasma adiponectin levels (-0.14 </= r </= -0.32; P < 0.04), multiple regression analyses revealed that visceral AT accumulation was the only independent predictor of adiponectin levels, with 10% of its variance explained by visceral AT (P < 0.0001). Comparison of obese men with similar body mass index values (>/=30 kg/m(2)) but who markedly differed in their level of visceral AT (< vs. >/=130 cm(2); n = 15) revealed significant differences in adiponectin levels (7.0 +/- 3.0 vs. 11.1 +/- 4.9 microg/ml; P < 0.02 for men with high vs. low visceral AT, respectively). Finally, when men were stratified into tertiles of visceral AT and further classified on the basis of the 50th percentile of adiponectin levels (</= vs. >8.8 microg/ml), a 3 x 2 ANOVA revealed an independent contribution of adiponectin on the variation of high-density lipoprotein cholesterol levels (P < 0.002) and of the glucose area (P < 0.02). These results support the notion that adiponectin concentration is influenced to a greater extent by visceral than sc obesity. Furthermore, adiponectin predicts glucose tolerance and plasma high-density lipoprotein cholesterol levels in a manner that is partly independent from the contribution of visceral adiposity.

Adiponectin↗
PubMed2004

Associations between the fatty acid content of triglyceride, visceral adipose tissue accumulation, and components of the insulin resistance syndrome.

Many factors are involved in the development of the insulin resistance syndrome, such as visceral obesity and the type of dietary fat. The main purpose of this study was to investigate the relationships between fatty acid content of triglyceride (TG), visceral adipose tissue (AT) accumulation, and metabolic components of the insulin resistance syndrome in a group of 97 Caucasian men with a mean age of 45.1 +/- 7.2 years (29 to 63 years). To reach these objectives, Spearman correlations, group comparisons, and stepwise multiple regression analyses were performed. The proportion of palmitic acid (16:0) in the TG fraction was positively associated with plasma fasting insulin (r =.25, P =.03), diastolic (r =.45, P <.001), and systolic (r =.29, P =.003) blood pressure. On the other hand, the proportion of alpha-linolenic acid (18:3n-3) was associated negatively with apolipoprotein (apo) B (r = -.29, P =.005) and positively with low-density lipoprotein (LDL) diameter (r =.29, P =.007), while the proportion of gamma-linolenic acid (18:3n-6) was associated negatively with plasma TG (r = -.33, P =.003), diastolic (r = -.29, P =.01), and systolic (r = -.35, P =.002) blood pressure and plasma fasting insulin (r = -.37, P =.0005) and positively with high-density lipoprotein (HDL)(2)-cholesterol (r =.27, P =.01) and LDL diameter (r =.25, P =.02). Stepwise multiple regression analyses were conducted to determine the contribution of visceral AT, body fat mass, and the fatty acid content of TG to the variance of metabolic variables studied. It was found that visceral AT contributed significantly to the variance in plasma TG (R(2) = 20.7%, P <.0001), apo B (R(2) = 9.0%, P =.007), HDL(2)-cholesterol (R(2) = 17.9%, P <.0001), LDL diameter (R(2) = 4.9%, P =.02), and area under the glucose curve (AUC-glucose) (R(2) = 8.2%, P =.006). On the other hand, body fat mass contributed significantly to the variance in fasting insulin (R(2) = 19.7%, P <.0001) and diastolic (R(2) = 6.8%, P =.007) and systolic (R(2) = 10.5%, P =.01) blood pressure. At least one fatty acid made a significant contribution to the variance of each metabolic variable studied. In fact, the proportion of 18:3n-6 contributed significantly to the variance in both TG (R(2) = 8.9%, P = 0.007) and HDL(2)-cholesterol (R(2) = 6.0%, P =.01). Moreover, 18:3n-3 contributed to the variance of apo B (R(2) = 7.0%, P =.02), while 18:3n-6 made the largest contribution to the variance of LDL diameter (R(2) = 7.6%, P =.02). Finally, 16:0 significantly contributed to the variance of AUC-glucose (R(2) = 11.4%, P =.0003), diastolic (R(2) = 25.2%, P <.0001), and systolic (R(2) = 6.8%, P =.002) blood pressure. In summary, results of this study suggest that the fatty acid content of TG is associated with many metabolic variables of the insulin resistance syndrome independently of body fat mass or visceral AT accumulation.

Adipose Tissue↗
PubMed2004

Development of an atherogenic metabolic risk factor profile associated with the use of atypical antipsychotics.

BACKGROUND: It is important to assess cardiovascular risk factors to properly verify the potential consequences of atypical antipsychotic-related weight gain. The objective of the present study was to evaluate whether 2 atypical antipsychotics differ regarding their impact on the cardiovascular disease risk profile compared with a reference group. METHOD: We conducted a cross-sectional, multicenter study to assess anthropometric indices of obesity and to obtain a comprehensive fasting metabolic risk profile. Either risperidone or olanzapine had to be prescribed as the first and only antipsychotic for a minimum of 6 months. Patients were compared with a reference group of nondiabetic men. Data were collected from August 1999 to August 2001. RESULTS: Eighty-seven patients treated with olanzapine (N = 42) or risperidone (N = 45) were evaluated. Olanzapine-treated patients had significantly higher plasma triglyceride concentrations (2.01 +/-1.05 vs. 1.34 +/-0.65 mmol/L, p < or =.05), lower high-density lipoprotein (HDL)-cholesterol levels (0.92 +/-0.17 vs. 1.04 +/- 0.21 mmol/L, p < or =.05), higher cholesterol/HDL-cholesterol ratios (5.62 +/-1.70 vs. 4.50 +/- 1.44, p < or =.05), higher apolipoprotein B levels (1.07 +/- 0.35 vs. 0.92 +/- 0.27 g/L, p < or =.05), smaller low-density lipoprotein peak particle diameters (252.6 +/-4.1 vs. 255.2 +/-4.3 A, p <.01), and higher fasting insulin concentrations (103.9 +/- 67.6 vs. 87.5 +/- 56.1 pmol/L, p < or =.05) than risperidone-treated patients. Moreover, 33% of olanzapine-treated patients were carriers of 3 atherogenic features of the metabolic syndrome as opposed to a prevalence of only 11% of risperidone-treated patients. CONCLUSION: These results suggest that olanzapine-treated patients are characterized by a more deteriorated metabolic risk factor profile compared with risperidone-treated patients. These observations raise concerns about the potential differential long-term deleterious effects of some antipsychotics, such as olanzapine, on cardiovascular health.

Adult↗
PubMed2003

Relation between appetite ratings before and after a standard meal and estimates of daily energy intake in obese and reduced obese individuals.

The aim of the present study was to relate appetite ratings before and after a standard breakfast to estimates of daily energy intake, before and after weight loss obese men and women. Nineteen obese subjects (9 men and 10 women) took part in a 15-week drug-based weight-loss program coupled to energy intake restriction. Body weight and body composition were significantly decreased in men and women. Both before and after the weight loss program, desire to eat, hunger, fullness and prospective food consumption (PFC) were measured after an overnight fast and at 10-min intervals in the hour following the ingestion of a standardized breakfast. Energy intakes were also measured and reported before and after weight loss. Fasting desire to eat and postprandial area under the curve (AUC) for hunger were significantly increased (p<0.05) after the intervention. No association was observed between measured or reported energy intakes and appetite ratings before weight loss in either men or women. Reported energy intake was not associated with appetite sensations after weight loss either. In contrast, measured energy intake was significantly associated with postprandial AUC for fullness (r=-0.90, p<0.01) and PFC (r=0.80, p<0.01) in men at the end of the program. In stepwise multiple regression analysis, only postprandial AUC for PFC contributed independently to the variance of measured energy intake after weight loss (r(2)=0.60, p=0.01). This study did not show consistent associations between averaged appetite ratings after a meal and daily energy intake, either before or after weight loss.

Adult↗
PubMed2003

Greater than predicted decrease in energy expenditure during exercise after body weight loss in obese men.

This study was performed retrospectively to investigate whether exercise energy expenditure (EE) measured during a standardized treadmill protocol (4.5 km/h at 0% grade) falls below predicted values after body weight loss in obese men. A reference equation was established to predict net exercise EE in a control sample of 83 obese individuals (27 kg/m(2)< or = body mass index <45 kg/m(2)), using age, fat mass and fat-free mass as independent variables. This equation was then used to predict net exercise EE in another group of 11 obese men before and after a 15-week drug-based weight loss programme that was coupled with energy restriction [-2929 kJ/day (-700 kcal/day)]. Body weight and body composition were determined by hydrodensitometry. Net exercise EE, insulin, leptin, 3,3',5-tri-iodothyronine and free thyroxine were measured after an overnight fast at baseline and 2-4 weeks after the end of the programme, when subjects were weight stable. Body weight was significantly reduced (-11%; P <0.01) at the end of the weight loss programme. At baseline, measured net exercise EE was similar to that predicted from the regression equation [19.6 and 19.8 kJ/min (4.69 and 4.74 kcal/min) respectively; not significant]. However, after the end of the intervention, measured net exercise EE was significantly below the predicted value [15.5 and 17.3 kJ/min (3.71 and 4.14 kcal/min) respectively; P <0.01]. The difference between the predicted and the measured fall in net exercise EE was significantly associated with changes in leptin concentration ( r =0.79, P <0.01), even after correction for changes in fat mass and insulin. These observations suggest that net exercise EE falls below predicted values after body weight loss. In addition, this greater than predicted decrease in net exercise EE was associated with changes in leptin.

Adult↗
PubMed2003

Prevalence of metabolic alterations predictive of cardiovascular disease risk in the Québec population.

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.

Adolescent↗
PubMed2002

Evidence for impaired lipolysis in abdominally obese men: postprandial study of apolipoprotein B-48- and B-100-containing lipoproteins.

BACKGROUND: Abdominal obesity has been associated with postprandial hypertriglyceridemia. The contribution of intestinally and hepatically derived lipoproteins to this exaggerated postprandial lipemic response is not known. OBJECTIVE: We examined the associations between body fatness, fat distribution, and postprandial apolipoprotein (apo) B-48 and apo B-100 concentrations measured in triacylglycerol-rich lipoproteins (TRLs). DESIGN: Dietary fat tolerance was investigated in 50 men aged 28-67 y. The subjects were given a test meal containing 60 g fat/m(2) body surface area and providing 64% of energy from fat, 18% from carbohydrates, and 18% from protein. The meal provided 7524-9196 kJ, depending on body surface area. Blood samples were collected every 2 h over an 8-h period. RESULTS: The increase in plasma triacylglycerol after the meal resulted from increases in both apo B-48- and apo B-100-containing lipoproteins. The apo B-100 concentration was the strongest contributor (R(2) = 69.6%, P = 0.0001) to postprandial triacylglycerol in total TRLs; the postprandial increase in triacylglycerol was best predicted by the apo B-48 concentration (R(2) = 32.7%, P = 0.0001). Visceral abdominal fat was significantly associated with high postprandial TRL apo B-48 and apo B-100 concentrations (r = 0.30-0.44, P < 0.05). After the meal, the apo B-100 concentration in small TRLs decreased in 12 subjects. These men showed features of the insulin resistance-dyslipidemic syndrome, including more visceral fat (P = 0.07) and an altered fasting metabolic profile. CONCLUSION: A lower lipolytic capacity may contribute to the exaggerated and prolonged postprandial lipemia among abdominally obese men.

Adult↗
PubMed2002

Prevalence of 'hypertriglyceridemic waist' in men who participated in the Quebec Health Survey: association with atherogenic and diabetogenic metabolic risk factors.

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.

Abdomen↗