Search

We undertook a population-based cohort study in Pizarra (Spain). Anthropometric and nutritional variables were recorded for 613 persons. The type of fat used was determined by measurement of the fatty acids contained in cooking oil. Serum fatty acid was used as a biological marker of the type of fat consumed. Obesity incidence in persons who were not obese at baseline was greater in those who consumed sunflower oil (Group 1: 41.5 (95% CI, 25.4-67.8) cases per 1000 person-years) than in those who consumed olive oil or a mixture of oils (Group 2: 17.3 (95% CI, 11.6-25.8) cases per 1000 person-years). The risk of developing obesity over 6 years, adjusted for age, sex, physical activity, smoking, instruction level, energy intake and baseline BMI, was 2.3 (95% CI, 1.06-5.02) in group 1 compared with that in group 2. The increase in the prevalence of obesity in the free-living population is associated with the type of fatty acids in the diet. Keywords: olive oil; obesity incidence; population-based cohort study doi: 10.1038/ejcn.2009.65; published online 22 July 2009, Two of the most important factors contributing to the increased prevalence of obesity in the world are the reduction in physical exercise and an increased intake of energy. The importance [...]

Objective: Few epidemiological studies have examined the relationship of dietary fatty acids, especially MUFA, with the interrelation between insulin secretion and insulin resistance. We assessed the relation of dietary fatty acids with insulin secretion in a free-living population. Design and setting: This cross-sectional, population-based study was undertaken in Pizarra, a small town in Spain. Subjects and methods: Anthropometrical data were collected for 1226 persons selected randomly from the municipal census, 538 of whom (randomly chosen) were given a prospective, quantitative, 7-day nutritional questionnaire. The fatty acid composition of the serum phospholipids was used as a biological marker of the type of fat consumed. Beta-cell function ([beta]CFI) and insulin-resistance index (IRI) were estimated by the Homeostasis Model Assessment. Results: To determine which factors influence the variability of the [beta]CFI, we analyzed the variance of the [beta]CFI according to sex, the presence of carbohydrate metabolism disorders and the different components of the diet, adjusting the models for age, body mass index (BMI) and IRI. The dietary MUFA and polyunsaturated fatty acids (PUFA) contributed to the variability of the [beta]CFI, whereas only the proportion of serum phospholipid MUFA, but neither the saturated fatty acids nor the PUFA accounted for part of the variability of the [beta]CFI in a multiple regression analysis. Conclusion: The results of this population-based study corroborate the results of other clinical and experimental studies suggesting a favorable relationship of MUFA with [beta]-cell insulin secretion. Sponsorship: Fondo de Investigaci#243;n Sanitaria, Junta de Andaluc#237;a and the Asociaci#243;n Maim#243;nides. European Journal of Clinical Nutrition (2006) 60, 1195-1200. doi: 10.1038/sj.ejcn.1602437; published online 26 April 2006 Keywords: beta-cell function, homeostasis model assessment, monounsaturated fatty acids, Author(s): G Rojo-Martinez [1]; I Esteva [1]; M S Ruiz de Adana [1]; J M Garcia-Almeida [1]; F Tinahones [1]; F Cardona [1]; S Morcillo [1]; E Garcia-Escobar [1]; E [...]

The adipokine resistin is an insulin-antagonizing factor that also plays a regulatory role in inflammation, immunity, food intake, and gonadal function and also regulates growth hormone (GH) secretion in rat adenopituitary cells cultures with the adipokine. Although adipose tissue is the primary source of resistin, it is also expressed in other tissues, including the pituitary. The aim of this study is to investigate the possible action of resistin on the lipid metabolism in the pituitary gland in vivo (rats in two different nutritional status, fed and fast, treated with resistin on acute and a chronic way) and in vitro (adenopituitary cell cultures treated with the adipokine).Here, by a combination of in vivo and in vitro experimental models, we demonstrated that central acute and chronic administration of resistin enhance mRNA levels of the lipid metabolic enzymes which participated on lipolysis and moreover inhibiting mRNA levels of the lipid metabolic enzymes involved in lipogenesis. Taken together, our results demonstrate for the first time that resistin has a regulatory role on lipid metabolism in the pituitary gland providing a novel insight in relation to the mechanism by which this adipokine can participate in the integrated control of lipid metabolism. [ABSTRACT FROM AUTHOR]

Objective: It has been proposed that a mild form of acquired resistance to thyroid hormone may occur in the general population. Its clinical significance remains largely unknown. The objective of the study was to explore whether a newly described thyroid hormone resistance index is associated with the risk of mortality in a sample of community-dwelling euthyroid subjects representative of the adult population of Spain., Design: Longitudinal observational study including 3750 individuals, free of thyroid disease, TPO antibodies-negative (<50 IU/mL) and with TSH levels within the euthyroid range (≥0.5 and ≤5.0 mUI/mL) participating in the nationwide study Di@bet.es (2008-2010)., Methods: We used the Thyroid Feedback Quantile-based Index (TFQI) as a marker of resistance to thyroid hormone. The study population was grouped into categories according to their TFQI values at baseline. Fatal events were ascertained from the national death registry (end of follow-up December 2016)., Results: A total of 231 deaths were recorded during an average follow-up of 7.3 years. Compared with the category with the highest sensitivity to free thyroxine (TFQI ≤ p5) (reference), the relative risk of mortality in the categories with TFQI > p5 and ≤p25; >p25 and ≤p50; >p50 and ≤p75; >p75 and ≤p95 and >p95 were 1.01, (0.47-2.19), 1.42 (0.68-2.97), 1.54 (0.74-3.22), 1.47 (0.70-3.11) and 2.61 (1.16-5.89), respectively (P for trend 0.003). The association remained significant after multivariate adjustment of the data (P for trend 0.017)., Conclusions: A thyroid hormone resistance index focused on deviations of the average pituitary response to thyroid hormones may be associated with all-cause mortality independently of other conventional risk factors and comorbidities.

Objective: The effects of C-peptide on adipose tissue, an organ involved in the development of obesity and insulin resistance, are not yet well known. The aim of this study was to determine whether C-peptide could be involved in the regulation of the adipocytokine synthesis in human visceral adipose tissue., Methods: The association between C-peptide and different serum adipocytokines, with an intravenous glucose tolerance test (IVGTT), and in an in vitro study in subjects without obesity and in subjects with morbid obesity were analyzed., Results: In different multiple regression analysis models, C-peptide and C-peptide increase above basal levels during total IVGTT and between 0 and 10 min were associated positively with leptin and negatively with visfatin. Rhodamine-labeled C-peptide binds to human adipocytes, and this binding was blocked with excess of unlabeled C-peptide. Exposure of human visceral explants and adipocytes from subjects with morbid obesity to C-peptide at 1 and 10 nM induced a significant increase in leptin and a decrease in visfatin secretion. In subjects without obesity, these C-peptide effects were found mainly at 10 nM. These effects can be inhibited by phosphatidylinositol 3-kinase (PI3K) or protein kinase B (PKB) inhibitors., Conclusions: C-peptide may be involved in the regulation of leptin and visfatin secretion, molecules intimately involved in energy homeostasis processes, through PI3K or PKB pathways., (© 2015 The Obesity Society.)

Introduction: Irisin activates the thermogenic function in adipose tissues. However, little is known on the association between human irisin and different cardiometabolic risk factors. We analyse the influence of morbid obesity on irisin levels and its relation with leptin and different cardiovascular risk factors., Material and Methods: We measured the serum irisin level and the fibronectin type III domain containing 5 (FNDC5) expression in adipose tissue from 33 morbidly obese subjects and 12 nonobese subjects. We also studied the effect of leptin on FNDC5 expression., Results: Serum irisin was higher in the nonobese subjects than in morbidly obese subjects, both before (P = 0·043) and after bariatric surgery (P = 0·042). The variable that best explained the serum irisin levels in a multiple linear regression model was the waist-to-hip ratio (WHR) (R(2) = 0·201) (Beta = -0·357, P = 0·046). Those morbidly obese subjects with android-type obesity had lower serum irisin levels than those with gynecoid-type obesity, both before (P = 0·027) and after bariatric surgery (P = 0·006). Only the percentage change in WHR was associated with serum irisin levels after bariatric surgery (r = -0·529, P = 0·005). FNDC5 expression levels in subcutaneous adipose tissue (SAT) were higher in the nonobese than in the morbidly obese subjects (P = 0·042). In SAT explants from nonobese subjects, leptin (20 and 150 ng/mL) produced a decrease in FNDC5 expression (P = 0·009 and P = 0·037, respectively)., Conclusions: We showed decreased serum irisin levels in morbidly obese subjects, related mainly to WHR. FNDC5 expression could be regulated by leptin., (© 2014 Stichting European Society for Clinical Investigation Journal Foundation.)

Scope: The effects that fatty acids (FAs) exert on G protein-coupled receptor-120 (GPR120) levels, a receptor for FAs, are still unknown. We analyzed the association between GPR120 and obesity, and the FA effects on its expression., Methods and Results: GPR120 levels were analyzed in visceral adipose tissue (VAT) from nonobese and morbidly obese subject. VAT GPR120 mRNA and protein levels were lower in morbidly obese subjects (p = 0.004). After, these subjects underwent a high-fat meal. GPR120 mRNA expression in peripheral blood mononuclear cells in the fasting state was lower in morbidly obese subjects (p = 0.04), with a decrease 3 h after a high-fat meal only in morbidly obese subjects (p = 0.043). Also, incubations of visceral adipocytes from these subjects were made with different FAs. In nonobese subjects, palmitic, oleic, linoleic, and docosahexaenoic acids produced an increase in GPR120 mRNA and protein levels (p < 0.05). In morbidly obese subjects, only linoleic acid produced an increase in GPR120 mRNA and protein levels (p < 0.05)., Conclusion: Morbidly obese subjects had lower GPR120 mRNA and protein levels in VAT and a lower mRNA expression after a high-fat meal in peripheral blood mononuclear cells. The FAs effect on GPR120 mRNA and protein levels in visceral adipocytes was lower in morbidly obese subjects., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Little is known about the association between iodine and human milk composition. In this study, we investigated the association between iodine and different markers of oxidative stress and obesity-related hormones in human breast milk. This work is composed of two cross-sectional studies (in lactating women and in the general population), one prospective and one in vitro. In the cross-sectional study in lactating women, the breast milk iodine correlated negatively with superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px) activities, and with adiponectin levels. An in vitro culture of human adipocytes with 1 μM potassium iodide (KI, dose similar to the human breast milk iodine concentration) produced a significant decrease in adiponectin, GSH-Px, SOD1, and SOD2 mRNA expression. However, after 2 months of treatment with KI in the prospective study, a positive correlation was found between 24-h urinary iodine and serum adiponectin. Our observations lead to the hypothesis that iodine may be a factor directly involved in the regulation of oxidative stress and adiponectin levels in human breast milk.

Background: Childhood obesity has grown very fast over recent decades and now it represents a serious public health problem. The number of adipocytes is set in childhood and adolescence and then, an effective understanding of the development of adipose tissue during these periods will help in the prevention of this pathology., Objectives: The current study aimed to determine which adipose tissue characteristics are related to a high weight Z-score in childhood., Patients and Methods: The current study included 82 children aged 5-130 months who underwent inguinal hernia surgery. Anthropometric variables were measured, and a nutritional and physical activity questionnaire was completed. Subcutaneous adipose tissue samples, taken during the operation, were analyzed for preadipocyte number, adipocyte volume, fatty acid composition (gas chromatography of FAME), and relative gene expression of various genes (real time PCR)., Results: The results showed that children with a higher weight Z-score spend more time in sedentary activities and less time running or involved in active games. SCD-1 activity index, arachidonic/linoleic index, and adipocyte volume were significantly higher in children with a weight Z-score greater than 0. The preadipocyte number and the genetic expression of the studied genes did not differ between the groups. A multiple regression analysis was done to determine which variables were related to the weight Z-score. R2 values indicated that the model which included adipocyte volume, SREBP-1c, SCD-1 expression, and activity index, predicted 59% of the variability in the weight Z-score among the children. The main variables associated with adipocyte volume were PPARγ, Adiponectin, CB1R expressions, as well as the SCD-1 activity and normalized weight., Conclusions: It was concluded that in childhood, the weight Z-score is related to adipocyte volume and adipose tissue gene expression.

Objective: To identify different markers in order to validate the assessment of dietary intake in adults with cystic fibrosis (CF)., Design: Cross-sectional survey., Setting: Tertiary care., Subjects: We assessed 37 adults with CF whose nutritional and respiratory condition was stable and 37 healthy adults, matched for age, sex, and nutritional status., Interventions: A consecutive, 7-day, prospective dietary survey was given to all the participants. Anthropometric variables were measured and a fasting blood sample was drawn to measure the composition of the serum phospholipid fatty acids by gas chromatography. We also measured fecal fat and nitrogen at 72 hours and 24-hour urine nitrogen., Results: The ratio of energy intake to basal metabolic rate expenditure was significantly greater in the patients (2.1+/-0.4) than the controls (1.79+/-0.4) and the percentage of patients with the ratio of energy intake to basal metabolic rate lower than 1.55 was 24% in the controls (n=9) vs 8% in the patients (n=3). Fecal nitrogen correlated significantly with total energy and the intake of carbohydrates, lipids, and proteins. In the patients, total dietary energy and fat and protein intake correlated positively with fecal fat. The protein and fat intake and fecal nitrogen and fat correlated significantly with urine nitrogen. In the controls, significant correlations were seen between different parameters of intake and the percentage of certain serum phospholipid fatty acids. These correlations in the patients were either absent or less marked., Conclusions: Use in persons with CF of the energy intake to basal metabolic rate ratio, measurement of fecal fat and nitrogen at 72 hours and of urine nitrogen may be useful to validate dietary surveys. The serum phospholipid fatty acid profile, however, may be less useful for this purpose in these patients.