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1.
Pharmacol Rev ; 75(6): 1140-1166, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37328294

ABSTRACT

Pharmacological agents used to treat or manage diseases can modify the level of heat strain experienced by chronically ill and elderly patients via different mechanistic pathways. Human thermoregulation is a crucial homeostatic process that maintains body temperature within a narrow range during heat stress through dry (i.e., increasing skin blood flow) and evaporative (i.e., sweating) heat loss, as well as active inhibition of thermogenesis, which is crucial to avoid overheating. Medications can independently and synergistically interact with aging and chronic disease to alter homeostatic responses to rising body temperature during heat stress. This review focuses on the physiologic changes, with specific emphasis on thermolytic processes, associated with medication use during heat stress. The review begins by providing readers with a background of the global chronic disease burden. Human thermoregulation and aging effects are then summarized to give an understanding of the unique physiologic changes faced by older adults. The effects of common chronic diseases on temperature regulation are outlined in the main sections. Physiologic impacts of common medications used to treat these diseases are reviewed in detail, with emphasis on the mechanisms by which these medications alter thermolysis during heat stress. The review concludes by providing perspectives on the need to understand the effects of medication use in hot environments, as well as a summary table of all clinical considerations and research needs of the medications included in this review. SIGNIFICANCE STATEMENT: Long-term medications modulate thermoregulatory function, resulting in excess physiological strain and predisposing patients to adverse health outcomes during prolonged exposures to extreme heat during rest and physical work (e.g., exercise). Understanding the medication-specific mechanisms of altered thermoregulation has importance in both clinical and research settings, paving the way for work toward refining current medication prescription recommendations and formulating mitigation strategies for adverse drug effects in the heat in chronically ill patients.


Subject(s)
Global Warming , Hot Temperature , Humans , Aged , Body Temperature Regulation/physiology , Body Temperature/physiology , Chronic Disease
2.
Arterioscler Thromb Vasc Biol ; 43(3): 427-442, 2023 03.
Article in English | MEDLINE | ID: mdl-36700429

ABSTRACT

BACKGROUND: Considerable evidence links dietary salt intake with the development of hypertension, left ventricular hypertrophy, and increased risk of stroke and coronary heart disease. Despite extensive epidemiological and basic science interrogation of the relationship between high salt (HS) intake and blood pressure, it remains unclear how HS impacts endothelial cell (EC) and vascular structure in vivo. This study aims to elucidate HS-induced vascular pathology using a differential systemic decellularization in vivo approach. METHODS: We performed systematic molecular characterization of the endothelial glycocalyx and EC proteomes in mice with HS (8%) diet-induced hypertension versus healthy control animals. Isolation of eGC and EC compartments was achieved using differential systemic decellularization in vivo methodology. Altered protein expression in hypertensive compared to normal mice was characterized by liquid chromatography tandem mass spectrometry. Proteomic results were validated using functional assays, microscopic imaging, and histopathologic evaluation. RESULTS: Proteomic analysis revealed a significant downregulation of eGC and associated proteins in HS diet-induced hypertensive mice (among 1696 proteins identified in this group, 723 were markedly decreased in abundance, while only 168 were increased in abundance. Bioinformatic analysis indicated substantial derangement of the eGC layer, which was subsequently confirmed by fluorescent and electron microscopy assessment of vessel damage ex vivo. In the EC fraction, HS-induced hypertension significantly altered protein mediators of contractility, metabolism, mechanotransduction, renal function, and the coagulation cascade. In particular, we observed dysregulation of integrin subunits α2, α2b, and α5, which was associated with arterial wall inflammation and substantial infiltration of CD68+ monocyte-macrophages. Consequently, HS-induced hypertensive mice also displayed reduced vascular integrity of multiple organs including lungs, kidneys, and heart. CONCLUSIONS: These findings provide novel molecular insight into HS-induced structural changes in eGC and EC composition that may increase cardiovascular risk and potentially guide the development of new diagnostics and therapeutic interventions.


Subject(s)
Hypertension , Sodium Chloride, Dietary , Mice , Animals , Sodium Chloride, Dietary/adverse effects , Proteomics , Mechanotransduction, Cellular , Blood Pressure/physiology
3.
Am J Physiol Endocrinol Metab ; 320(1): E139-E150, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33236920

ABSTRACT

The current COVID-19 pandemic is probably the worst the world has ever faced since the start of the new millennium. Although the respiratory system is the most prominent target of SARS-CoV-2 (the contagion of COVID-19), extrapulmonary involvement are emerging as important contributors of its morbidity and lethality. This article summarizes the impact of SARS-CoV and SARS-CoV-2 on the endocrine system to facilitate our understanding of the nature of coronavirus-associated endocrinopathy. Although new data are rapidly accumulating on this novel infection, many of the endocrine manifestations of COVID-19 remain incompletely elucidated. We, hereby, summarize various endocrine dysfunctions including coronavirus-induced new onset diabetes mellitus, hypocortisolism, thyroid hormone, and reproductive system aberrations so that clinicians armed with such insights can potentially benefit patients with COVID-19 at the bedside.


Subject(s)
COVID-19/complications , Endocrine System Diseases/virology , Angiotensin-Converting Enzyme 2 , Humans , Neuropilin-1 , Pandemics , Severe acute respiratory syndrome-related coronavirus , SARS-CoV-2 , Serine Endopeptidases , Severe Acute Respiratory Syndrome
4.
Small ; 16(31): e2002872, 2020 08.
Article in English | MEDLINE | ID: mdl-32603020

ABSTRACT

Obesity is a serious epidemic health problem that can cause many other diseases including type 2 diabetes and cardiovascular diseases. Current approaches to combat obesity suffer from low effectiveness and adverse side effects. Here, a new self-administrable and minimally invasive transdermal drug delivery strategy for home-based long-term treatment of obesity and other diseases is developed. Specifically, ultrathin, core-shelled, and lance-shaped polymeric drug reservoirs (micro-lances [MLs]) are readily fabricated by a thermal pressing molding method and totally implanted into subcutaneous fat by lancing through the skin. Using a diet-induced obese mouse model, it is shown that the development of obesity and associated metabolic disorders is effectively inhibited by applying therapeutic core-shelled MLs once every 2 weeks. The outstanding therapeutic effects are attributable to highly localized and biphasic drug release, as well as combination therapy based on browning transformation of white fat and enhanced insulin sensitivity.


Subject(s)
Diabetes Mellitus, Type 2 , Pharmaceutical Preparations , Animals , Mice , Obesity , Subcutaneous Fat
5.
Magn Reson Med ; 84(1): 384-395, 2020 07.
Article in English | MEDLINE | ID: mdl-31799761

ABSTRACT

PURPOSE: The vascular blood flow in brown adipose tissue (BAT) is important for handling triglyceride clearance, increased blood flow and oxygenation. We used dynamic contrast-enhanced (DCE)-MRI and fat fraction (FF) imaging for investigating vascular perfusion kinetics in brown and beige adipose tissues with cold exposure or treatment with ß3-adrenergic agonist. METHODS: FF imaging and DCE-MRI using gadolinium-diethylenetriaminepentaacetic acid were performed in interscapular BAT (iBAT) and beige tissues using male Wister rats (n = 38). Imaging was performed at thermoneutral condition and with either cold exposure, treatment with pharmacological agent CL-316,243, or saline. DCE-MRI and FF data were co-registered to enhance the understanding of metabolic activity. RESULTS: Uptake of contrast agent in activated iBAT and beige tissues were significantly (P < .05) higher than nonactivated iBAT. The Ktrans and kep increased significantly in iBAT and beige tissues after treatment with either cold exposure or ß3-adrenergic agonist. The FF decreased in activated iBAT and beige tissues. The Ktrans and FF from iBAT and beige tissues were inversely correlated (r = 0.97; r = 0.94). Significant increase in vascular endothelial growth factor expression and Ktrans in activated iBAT and beige tissues were in agreement with the increased vasculature and vascular perfusion kinetics. The iBAT and beige tissues were validated by measuring molecular markers. CONCLUSION: Increased Ktrans and decreased FF in iBAT and beige tissues were in agreement with the vascular perfusion kinetics facilitating the clearance of free fatty acids. The methodology can be extended for the screening of browning agents.


Subject(s)
Adipose Tissue, Beige , Adipose Tissue, White , Adipose Tissue, Brown/diagnostic imaging , Animals , Magnetic Resonance Imaging , Male , Rats , Vascular Endothelial Growth Factor A
6.
Int J Mol Sci ; 21(5)2020 Mar 04.
Article in English | MEDLINE | ID: mdl-32143325

ABSTRACT

Daily activities expose muscles to innumerable impacts, causing accumulated tissue damage and inflammation that impairs muscle recovery and function, yet the mechanism modulating the inflammatory response in muscles remains unclear. Our study suggests that Forkhead box A2 (FoxA2), a pioneer transcription factor, has a predominant role in the inflammatory response during skeletal muscle injury. FoxA2 expression in skeletal muscle is upregulated by fatty acids and peroxisome proliferator-activated receptors (PPARs) but is refractory to insulin and glucocorticoids. Using PPARß/δ agonist GW501516 upregulates FoxA2, which in turn, attenuates the production of proinflammatory cytokines and reduces the infiltration of CD45+ immune cells in two mouse models of muscle inflammation, systemic LPS and intramuscular injection of carrageenan, which mimic localized exercise-induced inflammation. This reduced local inflammatory response limits tissue damage and restores muscle tetanic contraction. In line with these results, a deficiency in either PPARß/δ or FoxA2 diminishes the action of the PPARß/δ agonist GW501516 to suppress an aggravated inflammatory response. Our study suggests that FoxA2 in skeletal muscle helps maintain homeostasis, acting as a gatekeeper to maintain key inflammation parameters at the desired level upon injury. Therefore, it is conceivable that certain myositis disorders or other forms of painful musculoskeletal diseases may benefit from approaches that increase FoxA2 activity in skeletal muscle.


Subject(s)
Hepatocyte Nuclear Factor 3-beta/metabolism , Muscle, Skeletal/metabolism , Myoblasts/metabolism , PPAR delta/agonists , PPAR-beta/agonists , Animals , Cytokines/metabolism , Gene Expression Regulation , Glucocorticoids/metabolism , HEK293 Cells , Homeostasis , Humans , Inflammation , Male , Mice , Mice, Inbred C57BL , Signal Transduction , Thiazoles/pharmacology , Transcriptional Activation , Up-Regulation
7.
Biochem Biophys Res Commun ; 516(1): 144-148, 2019 08 13.
Article in English | MEDLINE | ID: mdl-31200959

ABSTRACT

Abnormal adhesion of red blood cells (RBC) to the endothelium has been linked to the pathophysiology of several diseases associated with vascular disorders. Various biochemical changes on the outer membrane of RBC, as well as plasma protein levels, have been identified as possibly playing key roles, but the detailed interplay between plasma factors and cellular factors often remains unclear. In this work, we identified an alternative pathway by demonstrating that non-adsorbing macromolecules can also have a marked impact on the adhesion efficiency of RBC from patients with type 2 Diabetes (T2DM) to endothelial cells (EC). RBC isolated from blood samples of T2DM patients were suspended in isotonic solutions of dextran in order to mimic the impact of non-adsorbing macromolecules. Static and continuous flow adhesion assays were used to determine the adhesion behavior of T2DM RBC with EC and the results compared with those of normal controls. We found that the presence of non-adsorbing molecules promotes an increase in T2DM RBC - EC adhesion and that these RBC exhibit much greater adhesion than normal red cells. Our results thus suggest that the depletion mechanism might be an alternative phenomenon through which plasma proteins could cause enhanced RBC-EC adhesion in diabetes mellitus. These findings contribute towards the comprehensive understanding of pathophysiological mechanisms of vascular complications in diabetes and other diseases with similar vascular sequelae.


Subject(s)
Diabetes Mellitus, Type 2/pathology , Endothelial Cells/pathology , Erythrocytes/pathology , Adult , Cell Adhesion , Cell Communication , Endothelial Cells/cytology , Erythrocytes/cytology , Human Umbilical Vein Endothelial Cells , Humans , Middle Aged
8.
Eur J Nutr ; 58(1): 301-313, 2019 Feb.
Article in English | MEDLINE | ID: mdl-29236165

ABSTRACT

PURPOSE: To investigate acute effects of two doses of a polyphenol-rich curry made with seven different spices and four base vegetables, eaten with white rice, on 24 h glucose response, postprandial insulinemia, triglyceridemia and 24 h urinary total polyphenol excretion (TPE). METHODS: Randomized, controlled, dose-response crossover trial in healthy, Chinese men [n = 20, mean ± standard deviation (SD) age 23.7 ± 2.30 years, BMI 23.0 ± 2.31 kg/m2] who consumed test meals matched for calories, macronutrients and total vegetables content, consisting either Dose 0 Control (D0C) or Dose 1 Curry (D1C) or Dose 2 Curry (D2C) meal. 24 h glucose concentration was measured using continuous glucose monitoring (CGM), together with postprandial plasma insulin and triglyceride for up to 7 h. Total polyphenol content (TPC) of test meals and urinary TPE were measured using the Folin-Ciocalteu assay. RESULTS: TPC for D0C, D1C and D2C were 130 ± 18, 556 ± 19.7 and 1113 ± 211.6 mg gallic acid equivalent (GAE) per portion served, respectively (p < 0.0001). Compared with D0C meal, we found significant linear dose-response reductions in the 3-h postprandial incremental AUC (iAUC) for CGM glucose of 19% and 32% during D1C and D2C meals respectively (p < 0.05) and non-significant linear dose response reductions in iAUC of insulin (p = 0.089). Notably, we found significant dose-dependent increases in postprandial triglyceride with increasing curry doses (p < 0.01). Significant increases in TPE with increasing curry doses were also observed (p < 0.01). CONCLUSION: Polyphenol-rich curry intake can improve postprandial glucose homeostasis. The longer term effects remain to be established.


Subject(s)
Blood Glucose/metabolism , Homeostasis/drug effects , Polyphenols/pharmacology , Spices/statistics & numerical data , Vegetables/metabolism , Adult , Blood Glucose/drug effects , China , Cross-Over Studies , Dose-Response Relationship, Drug , Humans , Insulin/urine , Male , Polyphenols/metabolism , Postprandial Period , Triglycerides/blood , Young Adult
9.
J Theor Biol ; 419: 333-342, 2017 04 21.
Article in English | MEDLINE | ID: mdl-28039012

ABSTRACT

Glucose plasma measurements for diabetes patients are generally presented as a glucose concentration-time profile with 15-60min time scale intervals. This limited resolution obscures detailed dynamic events of glucose appearance and metabolism. Measurement intervals of 15min or more could contribute to imperfections in present diabetes treatment. High resolution data from mixed meal tolerance tests (MMTT) for 24 type 1 and type 2 diabetes patients were used in our present modeling. We introduce a model based on the physiological properties of transport, storage and utilization. This logistic approach follows the principles of electrical network analysis and signal processing theory. The method mimics the physiological equivalent of the glucose homeostasis comprising the meal ingestion, absorption via the gastrointestinal tract (GIT) to the endocrine nexus between the liver, pancreatic alpha and beta cells. This model demystifies the metabolic 'black box' by enabling in silico simulations and fitting of individual responses to clinical data. Five-minute intervals MMTT data measured from diabetic subjects result in two independent model parameters that characterize the complete glucose system response at a personalized level. From the individual data measurements, we obtain a model which can be analyzed with a standard electrical network simulator for diagnostics and treatment optimization. The insulin dosing time scale can be accurately adjusted to match the individual requirements of characterized diabetic patients without the physical burden of treatment.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Insulin/administration & dosage , Models, Biological , Precision Medicine/methods , Algorithms , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Glucose/metabolism , Homeostasis , Humans , Hypoglycemic Agents/administration & dosage
10.
Eur J Nutr ; 56(1): 77-87, 2017 Feb.
Article in English | MEDLINE | ID: mdl-26439722

ABSTRACT

PURPOSE: Milk protein ingestion reduces post-meal glycemia when consumed either before or together with carbohydrate foods. The aim of this study was to compare the effects of dairy and soy milk consumed either before (preload) or together with (co-ingestion) a carbohydrate (bread), on postprandial blood glucose, insulin and gastric emptying in healthy participants. METHODS: Twelve healthy Chinese male participants were studied on five separate occasions using a randomized crossover design. White wheat bread consumed with water was used as a reference meal. Capillary and venous bloods were sampled pretest and 3.5 h post-test meal for glucose and insulin measurement. Gastric emptying was measured using real-time ultrasonography. RESULTS: Co-ingestion of dairy milk or soy milk with bread lowered postprandial blood glucose response and glycemic index. Co-ingesting soy milk with bread increased insulin response and insulinemic index significantly compared to co-ingestion of dairy milk and preload treatments. Preloads (30 min prior to bread) significantly lowered postprandial glycemia and insulinemia compared to co-ingestion. Gastric emptying was slower after co-ingesting dairy milk with bread than after reference meal. CONCLUSIONS: Preloading either soy milk or dairy milk results in greater reduction in glycemic response compared to co-ingestion alone. This dietary practice may have therapeutic advantage in communities consuming high GI diets. Optimal glucose control may have the potential for increasing the time of transition from prediabetes to type 2 diabetes in Asian communities. CLINICAL TRIAL REGISTRATION: This trial was registered at clinicaltrials.gov as NCT 02151188.


Subject(s)
Blood Glucose/metabolism , Gastric Emptying , Insulin/blood , Milk/chemistry , Postprandial Period , Soy Milk/administration & dosage , Adult , Animals , Asian People , Bread , Cross-Over Studies , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/prevention & control , Diet , Dietary Carbohydrates/administration & dosage , Humans , Male , Meals , Prediabetic State/blood , Prediabetic State/diet therapy , Treatment Outcome , Young Adult
11.
Int J Med Sci ; 14(7): 639-647, 2017.
Article in English | MEDLINE | ID: mdl-28824295

ABSTRACT

Background: Modern medicine recognizes that salient, inherent variations between Caucasians and Asians exist. Radical changes are occurring in the health scene with increasing emphasis centered on the recognition of inter-individual variations unique to Asians that impact on medical management and outcomes. Aim: This review analyzes distinct features or outcomes in terms of epidemiology, disease thresholds, diagnostic cutoffs and treatment responses of Asian people compared with non-Asians. Methods: This review is based on a literature search via PubMed and MEDLINE for relevant articles related to the Asian phenotype and its impact on health and disease. Results: An 'Asian phenotype' could be characterized across the spectrum of biomedical disciplines and underscores the major challenges clinicians must face in their daily management of a cosmopolitan population and their extrapolation of research outcomes. Conclusion: Interventions for various ailments that have traditionally ignored population differences have now entered the age of personalized, stratified or precision medicine requiring an individualized approach being adopted as a new standard of care. Factoring in Asian phenotypes is essential for the medical research community and the development of improved clinical practice guidelines across a continuum of disciplines that will ultimately translate to better human health round the world.


Subject(s)
Asian People/genetics , Molecular Epidemiology , White People/genetics , Humans , Phenotype , Precision Medicine
13.
J Biol Syst ; 25(1): 119-143, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28989211

ABSTRACT

The effects of a single oral dose of liothyronine (L-T3) on thyroid stimulating hormone (TSH) and other related thyroid system parameters are partly understood despite therapeutic use of this hormone over many decades. We characterize individualized responses of the hypothalamus-pituitary-thyroid (HPT) axis and its related temporal hormonal profile using an electrical network model. Based on thyroid hormone responses from blood samples using a single 50 µg oral dose of liothyronine in healthy persons with a normal operating euthyroid feedback HPT system, we derived an equivalent electrical circuit model for the system's responses. The mathematical model was tested with a circuit simulator and validated with individualized clinical data. This signal processing technique makes the evaluation of bioequivalence and bioavailability of various preparations of liothyronine at an individualized level a feasible endeavor for clinical application.

14.
J Biol Chem ; 290(23): 14679-91, 2015 Jun 05.
Article in English | MEDLINE | ID: mdl-25931124

ABSTRACT

Brown adipose tissue expends energy in the form of heat via the mitochondrial uncoupling protein UCP1. Recent studies showed that brown adipose tissue is present in adult humans and may be exploited for its anti-obesity and anti-diabetes actions. Apelin is an adipocyte-derived hormone that plays important roles in energy metabolism. Here, we report that apelin-APJ signaling promotes brown adipocyte differentiation by increasing the expressions of brown adipogenic and thermogenic transcriptional factors via the PI3K/Akt and AMPK signaling pathways. It is also found that apelin relieves the TNFα inhibition on brown adipogenesis. In addition, apelin increases the basal activity of brown adipocytes, as evidenced by the increased PGC1α and UCP1 expressions, mitochondrial biogenesis, and oxygen consumption. Finally, we provide both in vitro and in vivo evidence that apelin is able to increase the brown-like characteristics in white adipocytes. This study, for the first time, reveals the brown adipogenic and browning effects of apelin and suggests a potential therapeutic route to combat obesity and related metabolic disorders.


Subject(s)
Adipocytes, Brown/cytology , Adipocytes, White/cytology , Adipogenesis , Intercellular Signaling Peptides and Proteins/metabolism , Adipocytes, Brown/metabolism , Adipocytes, White/metabolism , Adipokines , Animals , Apelin , Apelin Receptors , Cell Line , Cells, Cultured , Humans , Intercellular Signaling Peptides and Proteins/analysis , Ion Channels/metabolism , Male , Mice , Mice, Inbred C57BL , Mitochondrial Proteins/metabolism , Rats , Receptors, G-Protein-Coupled/analysis , Receptors, G-Protein-Coupled/metabolism , Signal Transduction , Uncoupling Protein 1
15.
Br J Nutr ; 115(12): 2130-7, 2016 06.
Article in English | MEDLINE | ID: mdl-27185412

ABSTRACT

The short-term effect of soya protein, polydextrose and their combination on energy intake (EI) was investigated in Chinese. In total, twenty-seven healthy, normotensive and lean Chinese men aged 21-40 years were given four different soyabean curd preloads with or without polydextrose. The study was a repeated-measure, randomised, cross-over design. The consumption of high-protein soyabean curd alone or in addition with polydextrose as a preload led to greater reduction in EI at a subsequent meal. A similar observation was also found after intake of low-protein soyabean curd with polydextrose. The gut hormone responses mirrored the reduction in food intake. It appears that incorporation of polydextrose either with low- or high-protein soyabean curd could be a potential strategy to reduce EI and assist with weight management. The popular consumption of soyabean curd in Chinese makes it an ideal vehicle for incorporation of polydextrose. This evidence-based dietary approach can serve as a guideline for developing functional foods for weight reduction and weight maintenance.


Subject(s)
Blood Glucose/metabolism , Eating/drug effects , Energy Intake/drug effects , Gastric Emptying/drug effects , Gastrointestinal Hormones/metabolism , Glucans/pharmacology , Soybean Proteins/pharmacology , Adult , Appetite/drug effects , China , Cross-Over Studies , Dietary Carbohydrates/pharmacology , Dietary Proteins/pharmacology , Functional Food , Ghrelin/metabolism , Glucagon-Like Peptide 1/metabolism , Glycemic Index , Humans , Male , Meals , Obesity/diet therapy , Obesity/metabolism , Weight Loss , Young Adult
16.
Nutr J ; 15: 27, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-26979583

ABSTRACT

BACKGROUND: Cardio-Metabolic Disease (CMD) is the leading cause of death globally and particularly in Asia. Postprandial elevation of glycaemia, insulinaemia, triglyceridaemia are associated with an increased risk of CMD. While studies have shown that higher protein intake or increased meal frequency may benefit postprandial metabolism, their combined effect has rarely been investigated using composite mixed meals. We therefore examined the combined effects of increasing meal frequency (2-large vs 6-smaller meals), with high or low-protein (40 % vs 10 % energy from protein respectively) isocaloric mixed meals on a range of postprandial CMD risk markers. METHODS: In a randomized crossover study, 10 healthy Chinese males (Age: 29 ± 7 years; BMI: 21.9 ± 1.7 kg/m(2)) underwent 4 dietary treatments: CON-2 (2 large Low-Protein meals), CON-6 (6 Small Low-Protein meals), PRO-2 (2 Large High-Protein meals) and PRO-6 (6 Small High-Protein meals). Subjects wore a continuous glucose monitor (CGM) and venous blood samples were obtained at baseline and at regular intervals for 8.5 h to monitor postprandial changes in glucose, insulin, triglycerides and high sensitivity C-reactive protein (hsCRP). Blood pressure was measured at regular intervals pre- and post- meal consumption. Urine was collected to measure excretion of creatinine and F2-isoprostanes and its metabolites over the 8.5 h postprandial period. RESULTS: The high-protein meals, irrespective of meal frequency were beneficial for glycaemic health since glucose incremental area under the curve (iAUC) for PRO-2 (185 ± 166 mmol.min.L(-1)) and PRO-6 (214 ± 188 mmol.min.L(-1)) were 66 and 60 % lower respectively (both p < 0.05), compared with CON-2 (536 ± 290 mmol.min.L(-1)). The iAUC for insulin was the lowest for PRO-6 (13.7 ± 7.1 U.min.L(-1)) as compared with CON-2 (28.4 ± 15.6 U.min.L(-)1), p < 0.001. There were no significant differences in postprandial responses in other measurements between the dietary treatments. CONCLUSIONS: The consumption of composite meals with higher protein content, irrespective of meal frequency appears to be beneficial for postprandial glycemic and insulinemic responses in young, healthy Chinese males. Implications of this study may be useful in the Asian context where the consumption of high glycemic index, carbohydrate meals is prevalent. TRIAL REGISTRATION: NCT02529228 .


Subject(s)
Cardiovascular Diseases/blood , Diet, Protein-Restricted , Dietary Proteins/administration & dosage , Metabolic Syndrome/blood , Postprandial Period/physiology , Adult , Asian People , Blood Glucose/metabolism , Blood Pressure , Body Mass Index , C-Reactive Protein/metabolism , Creatinine/urine , Cross-Over Studies , Diet , Energy Intake , F2-Isoprostanes/urine , Glycemic Index , Humans , Insulin/blood , Male , Meals , Risk Factors , Triglycerides/blood , Young Adult
17.
MAGMA ; 29(2): 277-86, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26747282

ABSTRACT

OBJECTIVE: The aim was to auto-segment and characterize brown adipose, white adipose and muscle tissues in rats by multi-parametric magnetic resonance imaging with validation by histology and UCP1. MATERIALS AND METHODS: Male Wistar rats were randomized into two groups for thermoneutral (n = 8) and cold exposure (n = 8) interventions, and quantitative MRI was performed longitudinally at 7 and 11 weeks. Prior to imaging, rats were maintained at either thermoneutral body temperature (36 ± 0.5 °C), or short term cold exposure (26 ± 0.5 °C). Neural network based automatic segmentation was performed on multi-parametric images including fat fraction, T2 and T2* maps. Isolated tissues were subjected to histology and UCP1 analysis. RESULTS: Multi-parametric approach showed precise delineation of the interscapular brown adipose tissue (iBAT), white adipose tissue (WAT) and muscle regions. Neural network based segmentation results were compared with manually drawn regions of interest, and showed 96.6 and 97.1% accuracy for WAT and BAT respectively. Longitudinal assessment of the iBAT volumes showed a reduction at 11 weeks of age compared to 7 weeks. The cold exposed group showed increased iBAT volume compared to thermoneutral group at both 7 and 11 weeks. Histology and UCP1 expression analysis supported our imaging results. CONCLUSION: Multi-parametric MR based neural network auto-segmentation provides accurate separation of BAT, WAT and muscle tissues in the interscapular region. The cold exposure improves the classification and quantification of heterogeneous BAT.


Subject(s)
Adipose Tissue, Brown/diagnostic imaging , Cold Temperature , Image Interpretation, Computer-Assisted/methods , Multimodal Imaging/methods , Scapula/diagnostic imaging , Shoulder Joint/diagnostic imaging , Adipose Tissue, Brown/anatomy & histology , Animals , Male , Rats , Rats, Wistar , Reproducibility of Results , Scapula/anatomy & histology , Sensitivity and Specificity , Shoulder Joint/anatomy & histology
18.
Appetite ; 101: 119-24, 2016 Jun 01.
Article in English | MEDLINE | ID: mdl-26946279

ABSTRACT

OBJECTIVES: Previous studies reveal that the Three-Factor Eating Questionnaire (TFEQ), which assesses eating behaviour, performs differently across population groups and cultures. We aimed to identify the factor structure that is most appropriate to capture eating behaviour in an overweight and obese Chinese population in Singapore. METHODS: TFEQ-51 was administered to 444 Chinese subjects pooled from four separate studies and scored according to various alternative versions of the TFEQ. Confirmatory factor analyses and goodness of fit indices were used to determine the most appropriate factor structure. Known-group validity analyses were conducted. RESULTS: Niemeier's Disinhibition Factors and the TFEQ-R18 factor structures were found to be the most applicable in our population based on goodness of fit indices, with a x(2)/df ratio of <3, RMSEA of ≤ 0.6 and a CFI value of >0.9 for both. Only two of three factors (Emotional Eating and Uncontrolled Eating) of the TFEQ-R18 showed good internal consistency, while none of Niemeier's Disinhibition Factors showed good internal consistency. Known-group validity showed that Emotional Eating and Internal Disinhibition were significantly associated with higher BMI. CONCLUSION: We found that the TFEQ-R18 factor structure is the most appropriate and practical for use in measuring eating behaviour in an overweight and obese Chinese population in Singapore.


Subject(s)
Eating/psychology , Obesity/psychology , Overweight/psychology , Psychometrics/methods , Surveys and Questionnaires , Adult , Asian People , Body Mass Index , Cross-Sectional Studies , Emotions , Female , Humans , Male , Singapore
19.
J Biol Chem ; 289(6): 3763-74, 2014 Feb 07.
Article in English | MEDLINE | ID: mdl-24362107

ABSTRACT

It has been recently recognized that the increased oxidative stress (ROS overproduction) in obese condition is a key contributor to the pathogenesis of obesity-associated metabolic diseases. Apelin is an adipocytokine secreted by adipocytes, and known for its anti-obesity and anti-diabetic properties. In obesity, both oxidative stress and plasma level of apelin are increased. However, the regulatory roles of apelin on oxidative stress in adipocytes remain unknown. In the present study, we provide evidence that apelin, through its interaction with apelin receptor (APJ), suppresses production and release of reactive oxygen species (ROS) in adipocytes. This is further supported by the observations that apelin promotes the expression of anti-oxidant enzymes via MAPK kinase/ERK and AMPK pathways, and suppresses the expression of pro-oxidant enzyme via AMPK pathway. We further demonstrate that apelin is able to relieve oxidative stress-induced dysregulations of the expression of anti- and pro-oxidant enzymes, mitochondrial biogenesis and function, as well as release of pro- and anti-inflammatory adipocytokines. This study, for the first time, reveals the antioxidant properties of apelin in adipocytes, and suggests its potential as a novel therapeutic target for metabolic diseases.


Subject(s)
Antioxidants/metabolism , Gene Expression Regulation, Enzymologic/physiology , Intercellular Signaling Peptides and Proteins/metabolism , MAP Kinase Signaling System/physiology , Oxidative Stress/physiology , Oxidoreductases/biosynthesis , Adipocytes , Apelin , Apelin Receptors , Cells, Cultured , Humans , Intercellular Signaling Peptides and Proteins/genetics , Male , Oxidoreductases/genetics , Reactive Oxygen Species/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism
20.
BMC Med ; 13: 106, 2015 May 06.
Article in English | MEDLINE | ID: mdl-25943590

ABSTRACT

BACKGROUND: Medical apps are widely available, increasingly used by patients and clinicians, and are being actively promoted for use in routine care. However, there is little systematic evidence exploring possible risks associated with apps intended for patient use. Because self-medication errors are a recognized source of avoidable harm, apps that affect medication use, such as dose calculators, deserve particular scrutiny. We explored the accuracy and clinical suitability of apps for calculating medication doses, focusing on insulin calculators for patients with diabetes as a representative use for a prevalent long-term condition. METHODS: We performed a systematic assessment of all English-language rapid/short-acting insulin dose calculators available for iOS and Android. RESULTS: Searches identified 46 calculators that performed simple mathematical operations using planned carbohydrate intake and measured blood glucose. While 59% (n = 27/46) of apps included a clinical disclaimer, only 30% (n = 14/46) documented the calculation formula. 91% (n = 42/46) lacked numeric input validation, 59% (n = 27/46) allowed calculation when one or more values were missing, 48% (n = 22/46) used ambiguous terminology, 9% (n = 4/46) did not use adequate numeric precision and 4% (n = 2/46) did not store parameters faithfully. 67% (n = 31/46) of apps carried a risk of inappropriate output dose recommendation that either violated basic clinical assumptions (48%, n = 22/46) or did not match a stated formula (14%, n = 3/21) or correctly update in response to changing user inputs (37%, n = 17/46). Only one app, for iOS, was issue-free according to our criteria. No significant differences were observed in issue prevalence by payment model or platform. CONCLUSIONS: The majority of insulin dose calculator apps provide no protection against, and may actively contribute to, incorrect or inappropriate dose recommendations that put current users at risk of both catastrophic overdose and more subtle harms resulting from suboptimal glucose control. Healthcare professionals should exercise substantial caution in recommending unregulated dose calculators to patients and address app safety as part of self-management education. The prevalence of errors attributable to incorrect interpretation of medical principles underlines the importance of clinical input during app design. Systemic issues affecting the safety and suitability of higher-risk apps may require coordinated surveillance and action at national and international levels involving regulators, health agencies and app stores.


Subject(s)
Blood Glucose/analysis , Cell Phone , Diabetes Mellitus/drug therapy , Insulins/administration & dosage , Mobile Applications , Self Care/methods , Diabetes Mellitus/blood , Humans
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