Normal-weight Volunteers Research Articles

Gastric microbiome composition in obese patients and normal weight subjects with functional dyspepsia.

Despite the numerous studies demonstrating gut microbiota dysbiosis in obese subjects, there is no data on the association between obesity and gastric microbiota. The aim of this study was to address this gap in literature by comparing the composition of gastric microbiota in obese patients and a control group which included normal weight volunteers diagnosed with functional dyspepsia (FD). A total of 19 obese patients, and 18 normal weight subjects with FD and normal endoscopy results were included in the study. The gastric tissue samples were collected from participants in both groups by bariatric surgery and endoscopy, respectively, and profiled using 16S ribosomal RNA gene sequencing. There was no significant difference in the α-diversity scores, while distinct gastric microbial compositions were detected in both groups. Significantly lower levels of Bacteroidetes and Fusobacteria, and higher Firmicutes/Bacteroidetes ratio were recorded in the obese patients. A total of 15 bacterial genera exhibited significant difference in gastric abundance with Prevotella_7, Veillonella, Cupriavidus, and Acinetobacter, present in frequencies higher than 3% in at least one subject group. Our study suggests a significant association between obesity and gastric microbiome composition. Future studies with larger sample size and gastric samples from subjects without any gastrointestinal complications are required to confirm our conclusions.

Insulin regulation of regional lipolysis in upper-body obese and lean humans.

Upper-body obesity (UBO) results in insulin resistance with regards to free fatty acid (FFA) release; how this differs by fat depot and sex between adults with UBO and lean adults is unknown. We tested the hypothesis that insulin suppression of FFA release from the splanchnic bed, leg fat, and upper-body nonsplanchnic (UBNS) adipose tissue would be impaired in UBO. Fourteen volunteers with UBO (7 men and 7 women) and 14 healthy volunteers with normal weight (7 men and 7 women) participated in studies that included femoral artery, femoral vein, and hepatic vein catheterization. We then measured leg and splanchnic plasma flow as well as FFA kinetics (using isotopic tracers) under overnight fasting as well as low- and high-dose insulin infusion using the insulin clamp technique. We found the expected insulin resistance in UBO; the most quantitatively important difference between adults with UBO and lean adults was greater FFA release from UBNS adipose tissue when plasma insulin concentrations were in the postprandial, physiological range. There were obesity, but not sex, differences in the regulation of splanchnic FFA release and sex differences in the regulation of leg FFA release. Reversing the defects in insulin-regulated UBNS adipose tissue FFA release would have the greatest effect on systemic FFA abnormalities in UBO. These studies were supported by the US Public Health Service (grants DK45343 and DK40484), the Novo Nordic Foundation (grant NNF18OC0031804 and NNF16OC0021406), and the Independent Research Fund Denmark (grant 8020-00420B).

Assessment of steroid enzymes action in children and adolescents with obesity

Rising prevalence of obesity has become an important impulse to investigate basic mechanisms involved in regulating the energy balance. It is widely accepted that steroids are potent factors affecting glucose, fat, and protein metabolism. Our study was aimed to analyze differences in the total amount of selected enzymes implicated in steroid metabolism in a group of children suffering from obesity and those with normal weight, further subdivided according to sex and pubertal stage. Data were obtained from 187 Caucasian children and adolescents, including 113 patients (63 girls, 50 boys) with obesity and 74 (34 girls, 40 boys) normal weight volunteers. Standard clinical examinations were performed in both groups. To evaluate the impact of puberty, preadolescent children and those with advanced puberty were assessed separately. Urine steroid excretion profiles were analyzed using gas chromatography/mass spectrometry method. Children with obesity revealed several changes in in the total amount of steroid enzymes as assessed by the relevant metabolite proportions, compared to their norm weight peers. Girls showed a significant increase in the activity of 11βHSD1, while boys demonstrated a relevant elevation in 20αHSD action. Regardless of sex, children with obesity showed an increase in the activity of 5β-reductase + 3αHSD complex and a decrease in the involvement of 11βOH-lase. The effect is attenuated when consider pre- and pubertal subgroups. We hypothesize that changes in the activity levels of selected enzymes may be a compensatory mechanism to limit the glucocorticoid exposure of key target tissues as well as to improve metabolic control and reduce long-term complications of obesity.

Increased meso-striatal connectivity mediates trait impulsivity in FTO variant carriers.

While variations in the first intron of the fat mass and obesity-associated gene (FTO, rs9939609 T/A variant) have long been identified as a major contributor to polygenic obesity, the mechanisms underlying weight gain in risk allele carriers still remain elusive. On a behavioral level, FTO variants have been robustly linked to trait impulsivity. The regulation of dopaminergic signaling in the meso-striatal neurocircuitry by these FTO variants might represent one mechanism for this behavioral alteration. Notably, recent evidence indicates that variants of FTO also modulate several genes involved in cell proliferation and neuronal development. Hence, FTO polymorphisms might establish a predisposition to heightened trait impulsivity during neurodevelopment by altering structural meso-striatal connectivity. We here explored whether the greater impulsivity of FTO variant carriers was mediated by structural differences in the connectivity between the dopaminergic midbrain and the ventral striatum. Eighty-seven healthy normal-weight volunteers participated in the study; 42 FTO risk allele carriers (rs9939609 T/A variant, FTO + group: AT, AA) and 39 non-carriers (FTO - group: TT) were matched for age, sex and body mass index (BMI). Trait impulsivity was assessed via the Barratt Impulsiveness Scale (BIS-11) and structural connectivity between the ventral tegmental area/substantia nigra (VTA/SN) and the nucleus accumbens (NAc) was measured via diffusion weighted MRI and probabilistic tractography. We found that FTO risk allele carriers compared to non-carriers, demonstrated greater motor impulsivity (p = 0.04) and increased structural connectivity between VTA/SN and the NAc (p< 0.05). Increased connectivity partially mediated the effect of FTO genetic status on motor impulsivity. We report altered structural connectivity as one mechanism by which FTO variants contribute to increased impulsivity, indicating that FTO variants may exert their effect on obesity-promoting behavioral traits at least partially through neuroplastic alterations in humans.

The Influence of Cola Nitida on Testosterone and Progesterone Concentrations in the Normal Weight Humans under Resting Condition in Ambrose Alli University

In quest of a stimulant to cope with rather challenging activities, some individuals take to the consumption of Cola nitida. The most active ingredient, caffeine, could be responsible for the physiological or clinical effects of Cola nitida in humans. Such a practice could culminate in the abuse of the said substance. Caffeine might alter hormonal profiles and thereby affect menstrual function, which might have a direct bearing on fertility. Amongst other factors, testosterone and progesterone are important to the chances of fertility in the humans. Besides, it has been well documented that the probability of pregnancy is reduced by 5% per unit of body mass index exceeding 29 kg/m2 . From some published evidences of the high prevalence of infertility nowadays, the need for this study was thereby necessitated. Here we report the influence of Cola nitida on testosterone and progesterone concentrations in the normal weight humans under resting condition in Ambrose Alli University. Twenty (20) normal weight volunteers (10 males and 10 females) and non-habitual Cola nitida chewers, aged 18-28 years were used for the study. 0.5g/kg body weight of Cola nitida was administered to each subject to be chewed as a bolus. After ingestion, 50ml of water was given to each volunteer to flush the masticated Cola nitida down the gut. The subject was allowed to rest for 90 minutes. Blood sample was collected from the medial cubital vein using vacutainer syringe. The radio-immunoassay principle was used for the estimation of testosterone and progesterone levels. The results showed that Cola nitida consumption by the normal weight male and female subjects significantly (P&lt;0.05) reduced serum level of progesterone in the females (from 16.47±039 ng/ml to 4.690±0.592 ng/ml) and serum testosterone level in the males (from 7.392±0.479 to 4.727±0.466 ng/ml). We show that Cola nitida, at the specific dosage, could reduce the chances of fertility in both the male and female normal weight subjects.

Availability of Central α4β2* Nicotinic Acetylcholine Receptors in Human Obesity.

Obesity is thought to arise, in part, from deficits in the inhibitory control over appetitive behavior. Such motivational processes are regulated by neuromodulators, specifically acetylcholine (ACh), via α4β2* nicotinic ACh receptors (nAChR). These nAChR are highly enriched in the thalamus and contribute to the thalamic gating of cortico-striatal signaling, but also act on the mesoaccumbal reward system. The changes in α4β2* nAChR availability, however, have not been demonstrated in human obesity thus far. The aim of our study was, thus, to investigate whether there is altered brain α4β2* nAChR availability in individuals with obesity compared to normal-weight healthy controls. We studied 15 non-smoking individuals with obesity (body mass index, BMI: 37.8 ± 3.1 kg/m2; age: 39 ± 14 years, 9 females) and 16 normal-weight controls (non-smokers, BMI: 21.9 ± 1.7 kg/m2; age: 28 ± 7 years, 13 females) by using PET and the α4β2* nAChR selective (-)-[18F]flubatine, which was applied within a bolus-infusion protocol (294 ± 16 MBq). Volume-of-interest (VOI) analysis was performed in order to calculate the regional total distribution volume (VT). No overall significant difference in VT between the individuals with obesity and the normal-weight volunteers was found, while the VT in the nucleus basalis of Meynert tended to be lower in the individuals with obesity (10.1 ± 2.1 versus 11.9 ± 2.2; p = 0.10), and the VT in the thalamus showed a tendency towards higher values in the individuals with obesity (26.5 ± 2.5 versus 25.9 ± 4.2; p = 0.09). While these first data do not show greater brain α4β2* nAChR availability in human obesity overall, the findings of potentially aberrant α4β2* nAChR availability in the key brain regions that regulate feeding behavior merit further exploration.

The National Institute for Occupational Safety and Health (NIOSH) Recommended Weight Generates Different Spine Loads in Load-Handling Activity Performed Using Stoop, Semi-squat and Full-Squat Techniques; a Full-Body Musculoskeletal Model Study.

Adequacy of the Revised NIOSH Lifting Equation (RNLE) in maintaining lumbosacral (L5-S1) loads below their recommended action limits in stoop, full-squat, and semi-squat load-handling activities was investigated using a full-body musculoskeletal model. The NIOSH committee did not consider the lifting technique adapted by workers when estimating the recommended weight limit (RWL). It is currently unknown whether the lifting technique adapted by workers would affect the competence of the RNLE in keeping spine loads below their recommended limits. A full-body subject-specific musculoskeletal model (Anybody Modeling System, AMS) driven by a 10-camera Vicon motion capture system (Vicon Motion Systems Inc., Oxford, UK) was used to simulate different static stoop, semi-squat, and full-squat load-handling activities of ten normal-weight volunteers (mean of ∼70kg corresponding to the 15th percentile of adult American males) with the task-specific NIOSH RWL held in hands. Two-way repeated measures ANOVA revealed a significant effect of lifting technique on both the L5-S1 compression (p = 0.003) and shear (p = 0.004) loads with semi-squat technique resulting in significantly larger loads than both stoop and full-squat techniques (p < 0.05). While mean of L5-S1 loads remained smaller than their recommended limits, it is much expected that they pass these limits for heavier individuals, that is, for the 50th percentile of adult American males. Spinal loads are expected to pass their recommended limits for heavier individuals especially during semi-squat lifting as the most frequently adapted technique by workers. Caution is required for the assessment of semi-squat lifting activities by the RNLE.

Sex difference in human olfactory sensitivity is associated with plasma adiponectin

Energy deprivation as well as hormones that regulate appetite and eating can influence olfactory function. This study investigated olfactory sensitivity for a food-related and a non-food odour prior to and after a meal, and its relationship to the energy-regulating hormones ghrelin and adiponectin.The olfactory sensitivity for orange and rose (PEA) odour in healthy, normal-weight volunteers (19 women, 45 men, 1 undisclosed individual) was not affected by the consumption of a meal. Olfactory sensitivity was not associated with concentrations of circulating ghrelin. However, olfactory sensitivity was higher for women than for men, indicating better olfactory performance. This difference between women and men was related to concentrations of plasma adiponectin, an adipose-specific hormone.Adiponectin may thus explain why sex differences in olfactory sensitivity emerge, and may also account for some of the inconsistencies in previous findings on sex differences. Our findings add to the limited literature on the impact of stomach and adipose tissue-derived hormones on olfactory sensitivity. Further studies are needed to establish a causal link between circulating adiponectin and a sex difference in olfactory sensitivity.

Appetite ratings and ghrelin concentrations in young adults after administration of a balanced meal. Does sex matter?

BackgroundSex-based differences in appetite ratings have been observed previously. Ghrelin is the only known orexigenic peptide hormone. Sex differences in postprandial ghrelin responses may underlie different perceptions of hunger and satiety, but results are conflicting. We conducted a parallel study to evaluate sex differences in postprandial appetite ratings and ghrelin concentration after administration of a physiological meal among students of University of Milan.MethodsTwenty-four healthy, normal weight volunteers (12 men and 12 women) aged 18–35 years were recruited. A balanced mixed meal meeting 40% of the estimated daily energy expenditure and providing 60% of calories from carbohydrates, 25% from lipids and 15% from protein was administrated. Sex differences in appetite ratings (satiety, hunger, fullness and desire to eat) and magnitude of ghrelin suppression during postprandial period (up to 180 min) were determined.ResultsIn the fasting state, men and women did not differ in appetite ratings and ghrelin concentrations. After feeding, women tended to reach peak of satiety earlier than men, who in turn reached the nadir of hunger later than women (median: 30 min, interquartile range (IQR): 1; 120 vs. 1 min, IQR 1; 1, p = 0.007). Ghrelin suppression was greater in women (median decremental AUC − 95, IQR − 122; − 66) than in men (median decremental AUC − 47, IQR − 87; − 31, p = 0.041).ConclusionsThese findings suggest sex differences in the postprandial appetite regulation that might be important for nutritional strategy to prevent and treat obesity and eating disorders.

Immunomodulatory effect of a very-low-calorie ketogenic diet compared with bariatric surgery and a low-calorie diet in patients with excessive body weight

<h2>Summary</h2><h3>Background & aim</h3> Inflammation and oxidative stress are the most probable mechanistic link between obesity and its co-diseases with cancer among them. The aim of this study was to evaluate whether the nutritional ketosis and weight loss induced by a very-low-calorie ketogenic diet (VLCKD) modulates the inflammatory and oxidative stress profile, compared with a standard, balanced hypocaloric diet (LCD) or bariatric surgery (BS) in patients with obesity. <h3>Methods</h3> The study was performed in 79 patients with overweight or obesity and 32 normal-weight volunteers as the control group. Patients with obesity underwent a weight reduction therapy based on VLCKD, LCD or BS. The quantification of the circulating levels of a multiplexing test of cytokines and carcinogenesis/aging biomarkers, as well as of lipid peroxides and total antioxidant power, was carried out. <h3>Results</h3> First, we observed that pro-inflammatory cytokines increase, while anti-inflammatory cytokines decrease under excessive body weight. Relevantly, when patients underwent weight loss strategies, it was shown that energy-restricted and surgical strategies of weight loss induced changes in circulating cytokine and lipid peroxides. This effect was more notable in patients following the VLCKD than the LCD or BS and it was observed mainly in the ketosis phase of the intervention. Particularly, IL-11, IL-12, IL-2, INF-γ, INF-β, Pentraxin-3 or MMP1 changed after VLCKD. Whereas, APRIL, TWEAK, osteocalcin and IL-28A increased after BS. <h3>Conclusion</h3> As far as we know, this is the first study that evaluate the time-course of cytokines and oxidative stress markers after a VLCKD as compared with a standard LCD and BS. The observed results support the immunomodulatory effect of nutritional ketosis induced by a VLCKD synergistically with weight loss as a strategy to improve innate-immunity and to prevent infections and carcinogenesis in patients with obesity.

TAS1R3 and TAS2R38 Polymorphisms Affect Sweet Taste Perception: An Observational Study on Healthy and Obese Subjects.

Background: The inter-individual differences in taste perception find a possible rationale in genetic variations. We verified whether the presence of four different single nucleotide polymorphisms (SNPs) in genes encoding for bitter (TAS2R38; 145G > C; 785T > C) and sweet (TAS1R3; −1572C > T; −1266C > T) taste receptors influenced the recognition of the basic tastes. Furthermore, we tested if the allelic distribution of such SNPs varied according to BMI and whether the associations between SNPs and taste recognition were influenced by the presence of overweight/obesity. Methods: DNA of 85 overweight/obese patients and 57 normal weight volunteers was used to investigate the SNPs. For the taste test, filter paper strips were applied. Each of the basic tastes (sweet, sour, salty, bitter) plus pure rapeseed oil, and water were tested. Results: Individuals carrying the AV/AV diplotype of the TAS2R38 gene (A49P G/G and V262 T/T) were less sensitive to sweet taste recognition. These alterations remained significant after adjustment for gender and BMI. Moreover, a significant decrease in overall taste recognition associated with BMI and age was found. There was no significant difference in allelic distribution for the investigated polymorphisms between normal and overweight/obese patients. Conclusions: Our findings suggest that overall taste recognition depends on age and BMI. In the total population, the inter-individual ability to identify the sweet taste at different concentrations was related to the presence of at least one genetic variant for the bitter receptor gene but not to the BMI.

Altered Brain Structural Reorganization and Hierarchical Integrated Processing in Obesity.

The brain receives sensory information about food, evaluates its desirability and value, and responds with approach or withdrawal. The evaluation process of food in the brain with obesity may involve a variety of neurocircuit abnormalities in the integration of internal and external information processing. There is a lack of consistency of the results extant reported for aberrant changes in the brain with obesity that prohibits key brain alterations to be identified. Moreover, most studies focus on the observation of neural plasticity of function or structure, and the evidence for functional and structural correlations in the neuronal plasticity process of obesity is still insufficient. The aims of this article are to explore the key neural structural regions and the hierarchical activity pattern of key structural nodes and evaluate the correlation between changes in functional modulation and eating behavior. Forty-two participants with obesity and 33 normal-weight volunteers were recruited. Gray matter volume (GMV) and Granger causality analysis (GCA) were performed using the DPARSF, CAT12, and DynamicBC toolbox. Compared with the normal weight group, the obesity group exhibited significantly increased GMV in the left parahippocampal gyrus (PG). The obesity group showed decreased causal inflow to the left PG from the left orbitofrontal cortex (OFC), right calcarine, and bilateral supplementary motor area (SMA). Decreased causal outflow to the left OFC, right precuneus, and right SMA from the left PG, as well as increased causal outflow to the left middle occipital gyrus (MOG) were observed in the obesity group. Negative correlations were found between DEBQ-External scores and causal outflow from the left PG to the left OFC, and DEBQ-Restraint scores and causal inflow from the left OFC to the left PG in the obesity group. Positive correlation was found between DEBQ-External scores and causal outflow from the left PG to the left MOG. These results show that the increased GMV in the PG may play an important role in obesity, which may be related to devalued reward system, altered behavioral inhibition, and the disengagement of attentional and visual function for external signals. These findings have important implications for understanding neural mechanisms in obesity and developing individual-tailored strategies for obesity prevention.

Influence of Raspberry and Its Dietary Fractions on the In vitro Activity of the Colonic Microbiota from Normal and Overweight Subjects

Raspberry is a source of dietary fibre and phenolic compounds, which are metabolised by the gut microbiota, resulting in the production of short chain fatty acids (SCFAs) and phenolic catabolites; but the formation of these compounds depends on the microbiota composition. The aim of this study was to investigate whether the raspberry and its fractions (phenolic extract, total and insoluble dietary fibre) affect the microbial activity depending on the body weight condition. For this, in vitro fermentations of raspberry fractions were carried out using faeces from normal-weight (NW) and overweight volunteers (OW) during 48 h, and phenolic catabolites and SCFAs were analysed at 0, 6, 24 and 48 h. The whole raspberry and the phenolic extract produced greater quantities of urolithins and total SCFAs when compared with fibre fractions, reaching the highest amount between 24 and 48 h. The body weight condition was an important factor, since faeces from NW led to greater production of urolithins from non-extractable phenolic compounds bound to fibre fractions, whereas in OW the urolithins production was higher from the fractions with more extractable polyphenols. In summary, the whole raspberry has been shown to have a prebiotic effect, mainly due to its phenolic compounds content rather than its fibre content.

Glycemic Control and Metabolic Adaptation in Response to High-Fat versus High-Carbohydrate Diets-Data from a Randomized Cross-Over Study in Healthy Subjects.

Granular study of metabolic responses to alterations in the ratio of dietary macro-nutrients can enhance our understanding of how dietary modifications influence patients with impaired glycemic control. In order to study the effect of diets enriched in fat or carbohydrates, fifteen healthy, normal-weight volunteers received, in a cross-over design, and in a randomized unblinded order, two weeks of an iso-caloric high-fat diet (HFD: 60E% from fat) and a high-carbohydrate diet (HCD: 60E% from carbohydrates). A mixed meal test (MMT) was performed at the end of each dietary period to examine glucose clearance kinetics and insulin and incretin hormone levels, as well as plasma metabolomic profiles. The MMT induced almost identical glycemia and insulinemia following the HFD or HCD. GLP-1 levels were higher after the HFD vs. HCD, whereas GIP did not differ. The HFD, compared to the HCD, increased the levels of several metabolomic markers of risk for the development of insulin resistance, e.g., branched-chain amino acid (valine and leucine), creatine and α-hydroxybutyric acid levels. In normal-weight, healthy volunteers, two weeks of the HFD vs. HCD showed similar profiles of meal-induced glycemia and insulinemia. Despite this, the HFD showed a metabolomic pattern implying a risk for a metabolic shift towards impaired insulin sensitivity in the long run.

Epigenetic landscape in blood leukocytes following ketosis and weight loss induced by a very low calorie ketogenic diet (VLCKD) in patients with obesity

The molecular mechanisms underlying the potential health benefits of a ketogenic diet are unknown and could be mediated by epigenetic mechanisms. To identify the changes in the obesity-related methylome that are mediated by the induced weight loss or are dependent on ketosis in subjects with obesity underwent a very-low calorie ketogenic diet (VLCKD). Twenty-one patients with obesity (n=12 women, 47.9±1.02yr, 33.0±0.2kg/m2) after 6 months on a VLCKD and 12 normal weight volunteers (n=6 women, 50.3±6.2yrs, 22.7±1.5kg/m2) were studied. Data from the Infinium MethylationEPIC BeadChip methylomes of blood leukocytes were obtained at time points of ketotic phases (basal, maximum ketosis, and out of ketosis) during VLCKD (n=10) and at baseline in volunteers (n=12). Results were further validated by pyrosequencing in representative cohort of patients on a VLCKD (n=18) and correlated with gene expression. After weight reduction by VLCKD, differences were found at 988 CpG sites (786 unique genes). The VLCKD altered methylation levels in patients with obesity had high resemblance with those from normal weight volunteers and was concomitant with a downregulation of DNA methyltransferases (DNMT)1, 3a and 3b. Most of the encoded genes were involved in metabolic processes, protein metabolism, and muscle, organ, and skeletal system development. Novel genes representing the top scoring associated events were identified, including ZNF331, FGFRL1 (VLCKD-induced weight loss) and CBFA2T3, C3orf38, JSRP1, and LRFN4 (VLCKD-induced ketosis). Interestingly, ZNF331 and FGFRL1 were validated in an independent cohort and inversely correlated with gene expression. The beneficial effects of VLCKD therapy on obesity involve a methylome more suggestive of normal weight that could be mainly mediated by the VLCKD-induced ketosis rather than weight loss.

Leptin G-2548A and Leptin Receptor Q223R Gene Polymorphisms are Differently Associated with Oxidative Process in Mexican Mestizo and Indigenous with Obesity.

The aim of this study was to examine whether plasma lipid peroxidation, antioxidant capability, leptin levels are associate selected LEP -2548 A/G and LEPR Q223R polymorphisms in mestizo and indigenous obesity Mexican population. We identified and characterized 50 overweight or obese subjects and 50 healthy, normal- weight volunteers with indigenous Tepehuana or Mexican mestizo ethnicity from Durango, Mexico. LEP -2548 A/G and LEPR Q223R polymorphisms were determined by genotyping. Concentrations of leptin, antioxidant capacity (CA) and lipoperoxidation (LIPX) were determined in fast conditions on plasma with Enzyme-Linked ImmunoSorbent Assay (ELISA) in all participants. The highest genotype frequency was the heterozygous LEPR, which was associated with lipid peroxidation levels in normal-weight Tepehuan populations. A positive correlation was observed (r = 0.5; p <0.01) between LEP polymorphism and lipoperoxidation in normal weight Tepehuan subjects. On the other hand, the LEPR polymorphism was associated with the level of lipoperoxidation (r = 0.13; P <0.05) in mestizo populations of normal weight. It is probable that there is a synergistic effect for obesity, where the presence of oxidative stress and single nucleotide polymorphisms (SNP) of leptin and its receptor contributes to the generation of pathological subcutaneous fat of obesity, together with the environmental conditions of the populations.

The correlation between dietary fat quality indices and lipid profile with Atherogenic index of plasma in obese and non-obese volunteers: a cross-sectional descriptive-analytic case-control study

Background and aimAbnormalities in lipid metabolism are commonly observed in patients who were obese. Alongside dyslipidemia, one of the markers in predicting the risk of cardiovascular disease is the Atherogenic Index of Plasma (AIP), which is related to dietary intake. Healthy fat quality indices might affect on AIP. The purpose of this study is to find the possible relationship between dietary fat quality, and AIP and comparison of these indices among obese and non-obese volunteers.MethodsThis study was a cross-sectional descriptive-analytic case-control study with 157 normal and overweight and obese volunteers (n = 71 normal, Age: 38.90 ± 10.976 vs n = 86 overweight/obese, Age: 38.60 ± 9.394) in the age range of 18–65 years. Food intake was measured using FFQ, anthropometric indices (weight, height, body mass index and waist to hip ratio), body composition (visceral fat level, total body water, body fat mass), and lipid profile were measured.ResultsBased on the present results, comparable biochemical parameters including TC (P = 0.580), TG (P = 0.362), LDL (P = 0.687) and HDL (P = 0.151) among overweight/obese volunteers as compared to normal ones were noticed. Effects of dietary fat quality, including Atherogenicity (AI) and Thrombogenicity (TI) hypo/hypercholesterolemic ratio (h/H), the Cholesterol-Saturated Fat Index (CSI) showed significantly higher AI (P = 0.012) in the overweight/obese group as compared to the normal group. Whereas, h/H (P = 0.034) and ω-6/ω-3 ratio (P = 0.004) were significantly higher in normal-weight volunteers. There was a positive correlation between AI, TI, CSI, SFA, MUFA, PUFA and ω-6/ω-3 ratio with AIP and negative correlation between h/H with AIP in both groups. Despite the significances of these correlations no strong relation was observed by doing multiple regression among normal and overweight/obese groups (R2 = 0.210, R2 = 0.387).ConclusionsIn summary, the present work proposes a direct relationship between dietary fat quality, increased BMI, and lipid abnormalities with AIP. Nevertheless, further large-scale studies are required to sustain a clear conclusion in this wish.

Approach bias modification training to increase physical activity: A pilot randomized controlled trial in healthy volunteers

Regular physical activity is associated with better physical and mental health outcomes as well as higher quality of life. This pilot randomized controlled trial examined whether approach bias modification, an economical and easily accessible computerized cognitive training, could increase objectively and subjectively measured physical activity in individuals aiming for more physical activity. Forty healthy volunteers of normal weight were randomly allocated to six sessions of approach bias modification or no treatment. The approach bias modification adopted an implicit learning paradigm that trained participants to show approach behavior in response to visual cues of physical activity. Approach bias modification did not increase objectively and subjectively measured physical activity.

Differential Expression of Human N-Alpha-Acetyltransferase 40 (hNAA40), Nicotinamide Phosphoribosyltransferase (NAMPT) and Sirtuin-1 (SIRT-1) Pathway in Obesity and T2DM: Modulation by Metformin and Macronutrient Intake.

BackgroundInteractions between environmental factors, such as diet and lifestyle, and metabolic pathways are pivotal in understanding aging mechanisms. hNAA40, Nicotinamide phosphoribosyltransferase (NAMPT), and NAD-dependent protein deacetylase sirtuin-1 (SIRT-1) have been shown to exert important biological processes, including stress response and aging.MethodshNAA40, NAMPT, and SIRT-1 mRNA expression in peripheral blood mononuclear cells (PBMC) were quantitated in 30 lean adult volunteers of normal weight, 30 obese, 20 drug-naïve obese Type 2 diabetes mellitus (T2DM), and 30 obese T2DM on Metformin. Similarly, hNAA40, NAMPT, and SIRT-1 expression in PBMC were quantitated in 36 normal healthy adults randomly assigned to three different groups (Glucose or Whey proteins or lipids; 300 kcal). Blood samples were obtained at 1, 2, and 3 hrs after the macronutrient intake.ResultsThere was an increase in hNAA40 and a decrease in NAMPT and SIRT-1 expression in PBMC from T2DM. Metformin treatment reverted hNAA40, NAMPT, and SIRT-1 expression levels to normal levels. Glucose intake resulted in a significant increase in expression of hNAA40 at 1 hr and decreased significantly at 3 hrs post intake. Lipid intake resulted in an increase in expression of hNAA40 at 2 hr post intake and returned to normal levels at 3 hrs. Neither glucose nor lipid intake resulted in a significant change in NAMPT or SIRT-1 expression. Whey proteins resulted in significantly lower expression of NAMPT at 3 hrs and did not alter the expression levels of SIRT-1 significantly.ConclusionhNAA40, NAMPT, and SIRT-1 pathway could play a role in the determination of the healthy life-span. Metformin modulates this pathway.

External loading alters lower extremity kinetics, kinematics, and muscle activity in a distribution-specific manner during the transition from stair descent to level walking

BackgroundExcess body mass is thought to be a major cause of altered biomechanics in obesity, but the effects of body mass distribution in biomechanics during daily living tasks are unknown. The purpose of this study was to determine how increasing body mass centrally and peripherally affects lower extremity kinematics, kinetics, and muscle activation when transitioning from stair descent to level gait. MethodsFifteen normal weight volunteers descended a staircase at a self-selected pace under unloaded, centrally loaded, and peripherally loaded conditions. Spatial-temporal gait characteristics and lower extremity joint kinematics, kinetics, and mean electromyography amplitude were calculated using 3D motion analysis. FindingsBoth central and peripheral loading reduced gait velocity. Peripheral loading increased time spent in stance phase, increased step width, and reduced step length. At the hip joint, peripheral loading reduced peak hip extension and adduction angle. Conversely, central loading reduced peak hip flexor moment. Both central and peripheral loading increased peak knee flexion angle, but only peripheral loading increased peak knee extensor moment. Central and peripheral loading increased mean electromyography amplitude of the medial gastrocnemius, but only peripheral loading increased mean electromyography amplitude of the semitendinosus and the vastus medialis. InterpretationIncreasing mass centrally and peripherally differently affects spatial-temporal gait characteristics and lower extremity joint kinematics, kinetics, and electromyography when transitioning from stair descent to level gait. Body mass distribution may be an important factor for obesity-induced biomechanical alterations and should be considered when developing biomechanical models of obesity.