Aerobic exercise attenuates the effects of ovariectomy and sedentarism on body composition and food intake in female rats / Exercício aeróbico atenua os efeitos da ovariectomia e do sedentarismo na composição corporal e no consumo alimentar em ratas

ABSTRACT Objective To evaluate the impact of low to moderate aerobic exercise and ovariectomy on body composition and food consumption in female rats. Methods Forty adult Wistar female rats (age: 23 weeks; body weight: 275.2±3.6g; mean±SEM) were divided into 4 groups (n=10): laparotomy-sedentary; laparotomy-exercised; ovariectomy-sedentary; and ovariectomy-exercised. The exercised groups were submitted to a treadmill running program (16m/min; 30min/day, 5 days/week), for 8 weeks. Body weight and food consumption were monitored during the experiment. Visceral fat and carcass water, protein, ash, fat and carbohydrate fractions were analyzed. Two-way ANOVA plus the Tukey's post hoc test was used for comparisons and p<0.05 was considered significant. Results The ovariectomized (ovariectomy-sedentary+ovariectomy-exercised) and sedentary (laparotomy-sedentary+ovariectomy-sedentary) animals showed higher (p<0.05) weight gain, food consumption, food efficiency ratio and weight gain/body weight ratio than laparotomy animals (laparotomy-sedentary+laparotomy-exercised) and exercised (exercised laparotomy+exercised ovariectomy), respectively. The ovariectomized and sedentary animals showed higher (p<0.05) carcass weight, fat percentage and visceral fat than laparotomy and exercised rats, respectively. Conclusion Ovariectomy and physical inactivity increase obesogenic indicators, whereas regular aerobic exercise of low to moderate intensity attenuates these unfavorable effects in female rats.

RESUMO Objetivo Avaliar o impacto do exercício aeróbico de intensidade baixa a moderada e da ovariectomia na composição corporal e no consumo alimentar em ratas. Métodos Quarenta ratas Wistar adultas (idade: 23 semanas; peso corporal: 275, 2±3, 6g; média±EPM) foram divididas em 4 grupos (n=10): laparotomia-sedentária, laparotomia-exercitada, ovariectomia-sedentária e ovariectomia-exercitada. Os grupos laparotomia-exercitada e ovariectomia-exercitada foram submetidos a um programa de corrida em esteira (16m/mim; 30min/dia, 5 dias/semana) durante 8 semanas. Foram monitorados o peso corporal e o consumo alimentar das ratas durante o experimento. Analisaram-se as frações de água, proteínas, cinzas, gordura e carboidrato da carcaça, bem como a gordura visceral. Empregou-se ANOVA Two-Way, seguida do teste post hoc de Tukey para as análises estatísticas. Adotou-se o nível de significância de p<0,05. Resultados As ratas ovariectomizadas (ovariectomia-sedentária+ovariectomia-exercitada) e sedentárias (laparotomia-sedentária+ ovariectomia-sedentária) exibiram maior (p<0,05) ganho de peso, consumo alimentar, coeficiente de eficácia alimentar e taxa de ganho de peso/peso corporal do que as ratas laparotomizadas (laparotomia-sedentária+laparotomia-exercitada) e exercitadas (laparotomia-exercitada+ovariectomia-exercitada), respectivamente. A carcaça das ratas ovariectomizadas e sedentárias apresentaram maior (p<0,05) peso, percentual de gordura e gordura visceral do que as ratas laparotomizadas e exercitadas, respectivamente. Conclusão A ovariectomia e o sedentarismo elevam indicadores obesogênicos, enquanto que o exercício aeróbico regular de intensidade baixa a moderada atenua esses efeitos desfavoráveis em ratas.

Waist circumference is an effect modifier of the association between bone mineral density and glucose metabolism

ABSTRACT Objective: The role of bone markers on insulin resistance (IR) remains controversial. The objective of this study is to evaluate the association between bone mineral density (BMD) and glucose metabolism and investigate if visceral hyperadiposity, evaluated by waist circumference (WC), is an effect modifier of this association. Subjects and methods: Cross-sectional analysis with 468 young adults from the fourth follow-up of the 1978/79 Ribeirão Preto prospective birth cohort, Brazil. BMD, total osteocalcin (OC), fasting plasma glucose and insulin concentrations were assessed. IR, sensitivity (S) and secretion (β) were estimated by homeostasis model assessment (HOMA) indexes. Multiple linear regression models were constructed to estimate the association between BMD and glucose metabolism. Beta coefficient, R2 and p-values were provided. WC was tested as an effect modifier and OC as a confounder. The covariates were selected based on Direct Acyclic Graph. Results: Significant interaction between BMD (femoral neck and proximal femur areas) and WC on glucose metabolism was observed in the adjusted models. Subjects with increased WC presented a positive association between BMD and log HOMA1-IR while an inverse association was found in those with normal WC (femoral neck R2 = 0.17, p = 0.036; proximal femur R2 = 0.16, p = 0.086). BMD was negatively associated with log HOMA2-S in individuals with increased WC and positively in those with normal WC (femoral neck R2 = 0.16, p = 0.042; proximal femur R2 = 0.15, p = 0.097). No significant associations between BMD, log HOMA2-β and OC and glucose metabolism markers were observed. Conclusions: BMD was associated with glucose metabolism, independently of OC, and WC modifies this association.

Application of alternative anthropometric measurements to predict metabolic syndrome

OBJECTIVE: The association between rarely used anthropometric measurements (e.g., mid-upper arm, forearm, and calf circumference) and metabolic syndrome has not been proven. The aim of this study was to assess whether mid-upper arm, forearm, calf, and waist circumferences, as well as waist/height ratio and waist-to-hip ratio, were associated with metabolic syndrome. METHODS: We enrolled 387 subjects (340 women, 47 men) who were admitted to the obesity outpatient department of Istanbul Medeniyet University Goztepe Training and Research Hospital between September 2010 and December 2010. The following measurements were recorded: waist circumference, hip circumference, waist/height ratio, waist-to-hip ratio, mid-upper arm circumference, forearm circumference, calf circumference, and body composition. Fasting blood samples were collected to measure plasma glucose, lipids, uric acid, insulin, and HbA1c. RESULTS: The odds ratios for visceral fat (measured via bioelectric impedance), hip circumference, forearm circumference, and waist circumference/hip circumference were 2.19 (95% CI, 1.30-3.71), 1.89 (95% CI, 1.07-3.35), 2.47 (95% CI, 1.24-4.95), and 2.11(95% CI, 1.26-3.53), respectively. The bioelectric impedance-measured body fat percentage correlated with waist circumference only in subjects without metabolic syndrome; the body fat percentage was negatively correlated with waist circumference/hip circumference in the metabolic syndrome group. All measurements except for forearm circumference were equally well correlated with the bioelectric impedance-measured body fat percentages in both groups. Hip circumference was moderately correlated with bioelectric impedance-measured visceral fat in subjects without metabolic syndrome. Muscle mass (measured via bioelectric impedance) was weakly correlated with waist and forearm circumference in subjects with metabolic syndrome and with calf circumference in subjects without metabolic syndrome. ...

Abdominal adiposity, insulin and bone quality in young male rats fed a high-fat diet containing soybean or canola oil

OBJECTIVES: A low ratio of omega-6/omega-3 polyunsaturated fatty acids is associated with healthy bone properties. However, fatty diets can induce obesity. Our objective was to evaluate intra-abdominal adiposity, insulin, and bone growth in rats fed a high-fat diet containing low ratios of omega-6/omega-3 provided in canola oil. METHODS: After weaning, rats were grouped and fed either a control diet (7S), a high-fat diet containing soybean oil (19S) or a high-fat diet of canola oil (19C) until they were 60 days old. Differences were considered to be significant if p<0.05. RESULTS: After 60 days, the 19S and 19C groups showed more energy intake, body density growth and intraabdominal fat mass. However, the 19S group had a higher area (200 percent) and a lower number (44 percent) of adipocytes, while the 7S and 19C groups did not differ. The serum concentrations of glucose and insulin and the insulin resistance index were significantly increased in the 19C group (15 percent, 56 percent, and 78 percent, respectively) compared to the 7S group. Bone measurements of the 19S and 19C groups showed a higher femur mass (25 percent) and a higher lumbar vertebrae mass (11 percent) and length (5 percent). Computed tomography analysis revealed more radiodensity in the proximal femoral epiphysis and lumbar vertebrae of 19C group compared to the 7S and 19S groups. CONCLUSIONS: Our results suggest that the amount and source of fat used in the diet after weaning increase body growth and fat depots and affect insulin resistance and, consequently, bone health.

Association of Visceral Fat and Risk Factors for Metabolic Syndrome in Children and Adolescents

PURPOSE: Visceral fat (VF) is closely associated with many metabolic risk factors and is also known to be a strong predictive factor for severe metabolic complications in adults. But there are only a few studies concerning the association of VF and risk factors for metabolic syndrome (MS) in children and adolescents. In our study, we emphasized the association of VF [measured by VF computed tomography (VFCT)] and risk factors for metabolic syndrome in children and adolescents. MATERIALS AND METHODS: The subjects were outpatients aged 6 to 18 years who underwent VFCT in the family medicine of The Catholic University of Korea from January 2005 to August 2009. There were 82 patients in total (42 children, 40 adolescents). Height, weight, blood pressure (BP), blood tests, body composition analysis and VF were measured. The three groups were also classified by metabolic score. RESULTS: In children, only high density lipoprotein cholesterol (HDL-C) showed a statistically significant difference, while in adolescents, triglyceride, HDL-C, BP, body mass index (BMI), waist circumference (WC) and VFA showed statistically significant differences. In terms of VFA, fasting glucose, BP, BMI, basal metabolic rate (BMR) and WC showed statistically significant differences. BMI showed a statistically significant difference in terms of BP, BMR, WC, VFA and HDL-C. CONCLUSION: There is a need to acknowledge the statistically significant associations of VF and risk factors for MS in children and adolescents. Screening tests for BP, cholesterol, fasting glucose and WC should be given in clinics for children and adolescents so that MS can be detected and its risk factors treated early.

Distribuição centrípeta da gordura corporal, sobrepeso e aptidão cardiorrespiratória: associação com sensibilidade insulínica e alterações metabólicas / Centripetal distribution of body fat, overweight and cardiorespiratory fitness: association with insulin sensitivity and metabolic alterations / Centripetal distribution of body fat, overweight and cardiorespiratory fitness: association with insulin sensitivity and metabolic alterations

O objetivo do presente estudo foi investigar associações entre a distribuição centrípeta da gordura corporal e lipídios-lipoproteínas séricos, pressão arterial e índice Homa-IR de resistência insulínica, mediante ajuste estatístico de indicadores quanto ao sobrepeso e à aptidão cardiorrespiratória. Foram analisados 89 voluntários (44 homens e 45 mulheres). A distribuição centrípeta da gordura foi analisada através de circunferência da cintura (CC) e o sobrepeso pelo índice de massa corporal (IMC). A aptidão cardiorrespiratória foi acompanhada pelo VO2máx estimado por teste de caminhada. Após ajuste pelos valores de IMC verificamos coeficientes de correlação significativos entre CC e níveis de pressão arterial e ApoB em homens, e entre CC e índice Homa-IR e triglicerídios em mulheres. Após ajuste pelos valores de VO2máx observamos correlações significativas entre CC e ApoB e índice Homa-IR em homens, e entre CC e índice Homa-IR em mulheres. Conclui-se que, dependendo do sexo, a quantidade e a distribuição da gordura corporal podem apresentar ações distintas na resistência insulínica e nas disfunções associadas. A aptidão cardiorrespiratória per se parece não contribuir na minimização da associação entre a distribuição centrípeta da gordura e o índice Homa-IR; porém, apresenta considerável impacto na associação entre a distribuição centrípeta da gordura e o metabolismo lipídico e os níveis de pressão arterial, sobretudo nos homens.

The purpose of this paper was to investigate associations between the centripetal distribution of the body fat and serum lipid-lipoproteins, blood pressure and the index Homa-IR of insulin resistance, adjusting for indicators of overweight and cardiorespiratory fitness. Eighty-nine voluntaries were analyzed (44 men and 45 women). The centripetal distribution of the body fat was analyzed through waist circumference (CC) and the overweight by the body mass index (BMI). The cardiorespiratory fitness was followed by the estimate VO2max by test of walking. After adjusted for BMI values were found significant coefficient of correlation between CC and levels of blood pressure and ApoB in men, and between CC and index Homa-IR and triglycerides in women. After adjusted for VO2max values were verified significant correlations between CC and ApoB and index Homa-IR in men, and between CC and index Homa-IR in women. In conclusion, depending on the sex, the quantity and distribution of the body fat can present different actions in the insulin resistance and associated dysfunctions. The cardiorespiratory fitness per se seems not to contribute on the minimization of the association between the centripetal distribution of the body fat and the index Homa-IR; but presents a considerable impact on the association between the centripetal distribution of the body fat and the lipid metabolism and the levels of blood pressure, mainly in men.