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Lean Subjects (lean + subject)
Selected AbstractsDPP-IV inhibition enhances the antilipolytic action of NPY in human adipose tissueDIABETES OBESITY & METABOLISM, Issue 4 2009K. Kos Context:, Dipeptidyl peptidase IV (DPP-IV) inactivates the incretin hormone glucagon-like peptide. It can also affect the orexigenic hormone neuropeptide Y (NPY1,36) which is truncated by DPP-IV to NPY3,36, as a consequence NPY's affinity changes from receptor Y1, which mediates the antilipolytic function of NPY, to other NPY receptors. Little is known whether DPP-IV inhibitors for the treatment of type 2 diabetic (T2DM) patients could influence these pathways. Aims:, To investigate the in vitro effects of NPY with DPP-IV inhibition in isolated abdominal subcutaneous (AbdSc) adipocytes on fat metabolism, and assessment of NPY receptor and DPP-IV expression in adipose tissue (AT). Methods:,Ex vivo human AT was taken from women undergoing elective surgery (body mass index: 27.5 (mean ± s.d.) ± 5 kg/m2, age: 43.7 ± 10 years, n = 36). Isolated AbdSc adipocytes were treated with human recombinant (rh)NPY (1,100 nM) with and without DPP-IV inhibitor (1 M); glycerol release and tissue distribution of DPP-IV, Y1 and Y5 messenger RNA (mRNA) were measured and compared between lean and obese subjects. Results and conclusion:, rhNPY reduced glycerol release, an effect that was further enhanced by co-incubation with a DPP-IV inhibitor [control: 224 (mean ± s.e.) ± 37 ,mol/l; NPY, 100 nM: 161 ± 27 ,mol/l**; NPY 100 nM/DPP-IV inhibitor, 1 M: 127 ± 14 ,mol/l**; **p < 0.01, n = 14]. DPP-IV was expressed in AbdSc AT and omental AT with relative DPP-IV mRNA expression lower in AbdSc AT taken from obese [77 ± 6 signal units (SU)] vs. lean subjects (186 ± 29 SU*, n = 10). Y1 was predominantly expressed in fat and present in all fat depots but higher in obese subjects, particularly the AbdSc AT-depot (obese: 1944 ± 111 SU vs. lean: 711 ± 112 SU**, n = 10). NPY appears to be regulated by AT-derived DPP-IV. DPP-IV inhibitors augment the antilipolytic effect of NPY in AT. Further studies are required to show whether this explains the lack of weight loss in T2DM patients treated with DPP-IV inhibitors. [source] Diurnal triglyceridaemia and insulin resistance in mildly obese subjects with normal fasting plasma lipidsJOURNAL OF INTERNAL MEDICINE, Issue 1 2004C. J. M. Halkes Abstract. Objective., A novel method has been developed to study diurnal triglyceride (TG) profiles using repeated capillary self-measurements in an ,out-of-hospital' situation. We assessed the diurnal capillary TG (TGc) profile in males with mild obesity and evaluated the use of plasma and capillary TG as markers of insulin resistance. Design., Cross-sectional study. Setting and Subjects., Fifty-four lean (body mass index, BMI < 25 kg m,2) and 27 mildly obese (25 < BMI < 30 kg m,2), normolipidaemic males measured capillary TG concentrations on six fixed time-points over a 3-day period in an ,out-of-hospital' situation. Main outcome measures., The total area under the TGc curve (TGc-AUC) and incremental area under the TGc curve (TGc-IAUC) were used as estimation of diurnal triglyceridaemia. Fasting blood samples were obtained once. Food intake was recorded by all participants. Results., Obese and lean subjects had comparable fasting capillary TG concentrations (1.37 ± 0.40 mmol L,1 and 1.32 ± 0.53 mmol L,1, respectively). However, during the day, obese subjects showed a greater TG increase, resulting in significantly higher TGc-AUC (27.1 ± 8.4 and 23.0 ± 6.3 mmol h,1 l,1, respectively; P < 0.05) and TGc-IAUC (7.9 ± 5.8 and 4.6 ± 6.6 mmolh,1 L,1, respectively; P < 0.05). The total group of 81 males was divided into quartiles based on fasting plasma TG, fasting capillary TG, TGc-AUC and TGc-IAUC. Amongst these variables, TGc-AUC was the only significant discriminator of subjects with high homeostasis model assessment (HOMA) (insulin resistance) compared with low HOMA (insulin sensitive). Overall, BMI was the strongest determinant of HOMA. Conclusions., Diurnal TG profiles can be used to investigate postprandial lipaemia in both lean and mildly obese subjects and may help to detect subjects with an underlying disposition for hypertriglyceridaemia related to insulin resistance, i.e. the metabolic syndrome. [source] Role of protein and carbohydrate sources on acute appetite responses in lean and overweight menNUTRITION & DIETETICS, Issue 2008Jane BOWEN Abstract Dietary protein induces greater satiety compared with carbohydrate in lean subjects, which may involve appetite-regulatory gut hormones. Little is known about the duration of effect, influence of protein and carbohydrate source and relevance to non-lean individuals. We compared the effect of various dietary proteins and carbohydrates on post-prandial appetite ratings, ad libitum energy intake (EI) and appetite hormones in lean and overweight men. Three randomised double-blinded cross-over studies examined appetite response (appetite ratings, ghrelin, glucagon-like peptide-1 (GLP-1) and cholecystokinin) to liquid preloads over three to four hours followed by a buffet meal to assess ad libitum EI. The 1-MJ preloads contained ,55 g of protein (whey, casein, soy and gluten), carbohydrate (glucose, lactose and fructose) or combined whey/fructose. EI was 10% higher following glucose preloads compared with protein preloads, observed at three hours but not four hours. Protein ingestion was followed by prolonged elevation of cholecystokinin and GLP-1 (two hours) and suppression of ghrelin (three to four hours) compared with glucose and independent of protein type. Replacing some whey with fructose attenuated the effect of protein on these hormones. Treatment effects on EI and appetite hormones were independent of bodyweight status, despite higher GLP-1 and lower ghrelin in overweight subjects. Protein-rich liquid preloads reduce EI over three hours in overweight men compared with glucose. These findings suggest a potential application for protein-rich drinks and/or foods to facilitate reduced EI. Future studies should explore additional dietary manipulations that may enhance this relationship, and confirm these effects within the context of energy-restricted dietary patterns. [source] p.Q223R leptin receptor polymorphism associated with obesity in Brazilian multiethnic subjectsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2006Stenio Fernando Pimentel Duarte Several genes play a major role in obese phenotypes, and studies suggest that genetic variations among individuals, as well as their lifestyles, may bring about different body compositions. Among these genes, LEP, which codifies leptin, and the LEPR gene encoding its receptor were extensively studied for variants that could explain the obese phenotype. The LEPR p.Q223R gene polymorphism was analyzed in a sample of obese and nonobese individuals from Brazil to evaluate the role of this polymorphism in the obese phenotype in the population. Two hundred obese patients (60 males, 140 females, body mass index (BMI) >30 kg/m2) were screened, together with 150 lean or normal healthy individuals (63 males, 87 females, BMI <24 kg/m2). Genomic DNA was extracted and amplified by polymerase chain reaction (PCR). PCR products were digested with the restriction of endonuclease MspI, and separated by electrophoresis through an 8% polyacrilamide gel stained with silver nitrate. There was a significant difference in LEPR p.Q223R polymorphism frequency when comparing obese and lean subjects, with an odds ratio of 1.92 and a 95% confidence interval of 1.15,3.22 (P = 0.013). There is a strong association of the LEPR p.Q223R gene polymorphism with obesity in Brazil. Am. J. Hum. Biol. 18:448,453, 2006. © 2006 Wiley-Liss, Inc. [source] Dynamics of GH secretion during incremental exercise in obesity, before and after a short period of training at different work-loadsCLINICAL ENDOCRINOLOGY, Issue 4 2010Alberto Salvadori Summary Background, Growth hormone (GH) secretion is normally sensitive to physical exercise. Intensity and duration of exercise, fitness and age can all influence the GH response to exercise. In obesity, GH secretion is decreased both in basal conditions and in response to exercise. Objective, To analyse the dynamics of GH response to a progressive cycloergometric test, conducted up to exhaustion, in adult normal subjects and obese patients, after a reconditioning program at different workloads. Design and methods, We studied eight lean subjects (four men, mean age 34·3 years, range 26,47 years, mean body mass index (BMI) 22·1 kg/m2). GH was sampled at baseline and during the last 30 s of each power output increase. Anaerobic threshold (AT) was detected by the V-slope method. The same test was carried out in 16 obese subjects (seven men, mean age 39·1 years, range 20,59 years, mean BMI 35·8 kg/m2) and repeated after a 4-week reconditioning program consisting of aerobic workout (Group A, eight subjects, three men, mean age 40·5 years, range 22,59 years, mean BMI 33·6 kg/m2), and aerobic plus anaerobic work (group B, eight subjects, four men, mean age 37·6 years, range 20,56 years, mean BMI 38·0 kg/m2) for 6 days/week, with no dietary restrictions. Results, Mean exercise peak occurred at higher intensity in controls (140 vs 110 W, P < 0·05), and AT exceeded at higher work outputs than in obese subjects (102 vs 74 W, P < 0·05). In controls, GH response to exercise was prompt and further sustained after AT; in obese subjects, GH increased slowly and insignificantly before AT, thereafter it increased to lower levels than in controls (P < 0·001). Following the reconditioning period, both Group A and Group B of obese subjects failed to improve exercise performance as well as GH response to exercise before AT; beyond AT, a greater GH response to exercise occurred in Group B than Group A (7·59 ± 0·32 ,g/l at peak of exercise) with significantly different Delta AUCs (Area Under the Curves) following AT: 30·5 ± 12 ,g.min/l in Group A vs 124·2 ± 38 ,g.min/l in Group B, P < 0·05. Conclusions Our results confirm the blunted GH response to exercise in obese adults when compared to lean counterparts. With obesity, aerobic training poorly increases the GH response beyond AT, while supplemental anaerobic workload appears to increase GH response beyond AT. These observations may have implications for the prescription of physical exercise, which is one of the recommendations in the management of obesity. [source] Abnormal expression of PPAR gamma isoforms in the subcutaneous adipose tissue of patients with Cushing's diseaseCLINICAL ENDOCRINOLOGY, Issue 1 2007Fausto Bogazzi Summary Background, Obesity is a clinical feature of patients with Cushing's disease. Peroxisome proliferators-activated receptor (PPAR), is the master regulator of adipogenesis; however, the expression of PPAR, isoforms in the subcutaneous adipose tissue (SAT) of patients with Cushing's disease is unknown. Aim and methods, The expression of PPAR,1 and PPAR,2 was evaluated by real-time reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence (PPAR,2 only) in SAT samples of 7 patients with untreated active Cushing's disease (CushingUNTR), 8 with Cushing's disease in remission (CushingREM) after pituitary adenomectomy, 15 normal lean subjects (ControlLEAN), and 15 obese patients (ControlOBE). Results, ControlLEAN had a higher degree of PPAR,1 than PPAR,2 (PPAR,2/PPAR,1 ratio, 0·55 ± 0·35). PPAR,2/PPAR,1 ratio decreased in CushingUNTR (0·10 ± 0·043, P < 0·03 vs. ControlLEAN and ControlOBE), because of either increased PPAR,1 or reduced PPAR,2 expression. PPAR,2/PPAR,1 ratio was 0·48 ± 0·07 in CushingREM patients (P < 0·04 vs. CushingUNTR, P < 0·03 vs. ControlOBE). PPAR,2/PPAR,1 ratio was higher in ControlOBE 0·90 ± 0·38 than in ControlLEAN (P < 0·005 vs. ControlLEAN, P < 0·03 vs. CushingREM, P < 0·009 vs. CushingUNTR). PPAR,2/PPAR,1 ratio was related to serum cortisol levels only in patients with Cushing'disease (r = 0·688, P < 0·02). Conclusions, CushingUNTR patients had an abnormal expression of PPAR, isoforms in SAT related to serum cortisol levels. Although further studies are necessary, it is conceivable that variations in the expression of PPAR, isoforms might have a role in the abnormal adipogenesis of patients with Cushing's disease. [source] Obese children show increased intimal wall thickness and decreased pulse wave velocityCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2008Frida Dangardt Summary Objective:, Childhood obesity confers an increased risk of vascular changes and adult cardiovascular disease. Using a high-resolution ultrasound technique that enables separation of intimal and medial layers, we examined the intimal thickness (IT) and intimal,medial thickness (IMT) of radial (RA) and dorsal pedal (DPA) arteries and the pulse wave velocity (PWV) in overweight/obese children and adolescents and in healthy subjects. Methods and results:, IT and IMT of RA and DPA and PWV were measured in 33 obese children and adolescents (13·9 ± 1·6 years) and in 18 matched lean controls (14·3 ± 2·2). Increased RA IT was found in the obese group, whereas no differences in RA IMT or medial thickness were observed. Obese females accounted for the entire difference in RA IT (P = 0·04). DPA IT was inversely correlated with HDL cholesterol in the obese group (,0·56, P = 0·0089). PWV was lower in the obese group than in the lean group (6·2 ± 0·8 versus 7·0 ± 0·9 m s,1, respectively; P = 0·001). Conclusions:, Obese children and adolescents, primarily females, present with increased RA IT. The decreased PWV in the obese versus lean subjects might reflect general vasodilatation. [source] | ||||||||||