ABSTRACT
AIMS: To examine the impact of impaired glycaemic regulation (IGR) and exercise training on hepatic lipid composition in men with metabolic dysfunction-associated steatotic liver disease (MASLD). MATERIALS AND METHODS: In Part A (cross-sectional design), 40 men with MASLD (liver proton density fat fraction [PDFF] ≥5.56%) were recruited to one of two groups: (1) normal glycaemic regulation (NGR) group (glycated haemoglobin [HbA1c] < 42 mmolâmol-1 [<6.0%]; n = 14) or (2) IGR group (HbA1c ≥ 42 mmolâmol-1 [≥6.0%]; n = 26). In Part B (randomized controlled trial design), participants in the IGR group were randomized to one of two 6-week interventions: (1) exercise training (EX; 70%-75% maximum heart rate; four sessions/week; n = 13) or (2) non-exercise control (CON; n = 13). Saturated (SI; primary outcome), unsaturated (UI) and polyunsaturated (PUI) hepatic lipid indices were determined using proton magnetic resonance spectroscopy. Additional secondary outcomes included liver PDFF, HbA1c, fasting plasma glucose (FPG), homeostatic model assessment of insulin resistance (HOMA-IR), peak oxygen uptake (VO2 peak), and plasma cytokeratin-18 (CK18) M65, among others. RESULTS: In Part A, hepatic SI was higher and hepatic UI was lower in the IGR versus the NGR group (p = 0.038), and this hepatic lipid profile was associated with higher HbA1c levels, FPG levels, HOMA-IR and plasma CK18 M65 levels (rs ≥0.320). In Part B, hepatic lipid composition and liver PDFF were unchanged after EX versus CON (p ≥ 0.257), while FPG was reduced and VO2 peak was increased (p ≤ 0.030). ΔVO2 peak was inversely associated with Δhepatic SI (r = -0.433) and positively associated with Δhepatic UI and Δhepatic PUI (r ≥ 0.433). CONCLUSIONS: Impaired glycaemic regulation in MASLD is characterized by greater hepatic lipid saturation; however, this composition is not altered by 6 weeks of moderate-intensity exercise training.
Subject(s)
Exercise , Liver , Humans , Male , Middle Aged , Liver/metabolism , Cross-Sectional Studies , Exercise/physiology , Glycated Hemoglobin/metabolism , Glycated Hemoglobin/analysis , Exercise Therapy/methods , Lipid Metabolism , Blood Glucose/metabolism , Glycemic Control , Aged , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/therapy , Non-alcoholic Fatty Liver Disease/complications , Adult , Insulin Resistance , Fatty Liver/metabolismABSTRACT
BACKGROUND: The updated European Working Group on Sarcopenia in Older People (EWGSOP2) recommends handgrip strength (HGS) and the chair stand test (CST) to assess muscle strength, with the CST being a convenient proxy for lower limb strength. However, adiposity may differentially influence these strength criteria and produce discrepant sarcopenia prevalence. OBJECTIVE: To determine the prevalence of sarcopenia using HGS or the CST, and to investigate the associations between these strength criteria and adiposity in adults with type 2 diabetes mellitus. METHODS: The EWGSOP2 definition was used to assess the prevalence of probable (low muscle strength), confirmed (plus low muscle mass) and severe (plus poor physical performance) sarcopenia. Linear regression models were used to study the association between different measures of muscle strength and adiposity. RESULTS: We used data from 732 adults with type 2 diabetes mellitus (35.7% female, aged 64 ± 8 years, body mass index 30.7 ± 5.0 kg/m2). Using the CST compared with HGS produced a higher prevalence of probable (31.7% vs. 7.1%), confirmed (5.6% vs. 1.6%) and severe (1.0% vs. 0.3%) sarcopenia, with poor agreement between strength criteria to identify probable sarcopenia. CST performance, but not HGS, was significantly associated with all measures of adiposity in unadjusted and adjusted models. CONCLUSIONS: Higher levels of adiposity may impact CST performance, but not HGS, resulting in a higher prevalence of sarcopenia in adults with type 2 diabetes mellitus. Consideration should be paid to the most appropriate measure of muscle function in this population.
Subject(s)
Adiposity , Diabetes Mellitus, Type 2 , Hand Strength , Sarcopenia , Humans , Sarcopenia/epidemiology , Sarcopenia/physiopathology , Sarcopenia/diagnosis , Female , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/physiopathology , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/complications , Male , Aged , Prevalence , Middle Aged , Cross-Sectional Studies , Geriatric Assessment/methods , Predictive Value of Tests , Age Factors , Linear ModelsABSTRACT
Glucagon-like peptide-1 receptor agonists (GLP-1RAs, incretin mimetics) and dipeptidyl peptidase-4 inhibitors (DPP-4is, incretin enhancers) are glucose-lowering therapies with proven cardiovascular safety, but their effect on microvascular disease is not fully understood. Both therapies increase GLP-1 receptor agonism, which is associated with attenuation of numerous pathological processes that may lead to microvascular benefits, including decreased reactive oxygen species (ROS) production, decreased inflammation and improved vascular function. DPP-4is also increase stromal cell-derived factor-1 (SDF-1), which is associated with neovascularisation and tissue repair. Rodent studies demonstrate several benefits of these agents in the prevention or reversal of nephropathy, retinopathy and neuropathy, but evidence from human populations is less clear. For nephropathy risk in human clinical trials, meta-analyses demonstrate that GLP-1RAs reduce the risk of a composite renal outcome (doubling of serum creatinine, eGFR reduction of 30%, end-stage renal disease or renal death), whereas the benefits of DPP-4is appear to be limited to reductions in the risk of albuminuria. The relationship between GLP-1RAs and retinopathy is less clear. Many large trials and meta-analyses show no effect, but an observed increase in the risk of retinopathy complications with semaglutide therapy (a GLP-1RA) in the SUSTAIN-6 trial warrants caution, particularly in individuals with baseline retinopathy. Similarly, DPP-4is are associated with increased retinopathy risk in both trials and meta-analysis. The association between GLP-1RAs and peripheral neuropathy is unclear due to little trial evidence. For DPP-4is, one trial and several observational studies show a reduced risk of peripheral neuropathy, with others reporting no effect. Evidence in other less-established microvascular outcomes, such as microvascular angina, cerebral small vessel disease, skeletal muscle microvascular disease and autonomic neuropathies (e.g. cardiac autonomic neuropathy, gastroparesis, erectile dysfunction), is sparse. In conclusion, GLP-1RAs are protective against nephropathy, whereas DPP-4is are protective against albuminuria and potentially peripheral neuropathy. Caution is advised with DPP-4is and semaglutide, particularly for patients with background retinopathy, due to increased risk of retinopathy. Well-designed trials powered for microvascular outcomes are needed to clarify associations of incretin therapies and microvascular diseases.
Subject(s)
Diabetes Mellitus , Diabetic Retinopathy , Kidney Diseases , Peripheral Nervous System Diseases , Retinal Diseases , Vascular Diseases , Humans , Male , Albuminuria , Incretins/therapeutic useABSTRACT
BACKGROUND/OBJECTIVES: Inadequate movement, excess adiposity, and insulin resistance augment cardiometabolic risk. This study examined the associations of objectively measured moderate-to-vigorous intensity physical activity (MVPA), sedentary time and cardiorespiratory fitness (CRF), with adipose tissue insulin resistance and ectopic fat. METHODS: Data were combined from two previous experimental studies with community volunteers (n = 141, male = 60%, median (interquartile range) age = 37 (19) years, body mass index (BMI) = 26.1 (6.3) kg·m-2). Adipose tissue insulin resistance was assessed using the adipose tissue insulin resistance index (Adipo-IR); whilst magnetic resonance imaging (MRI) was used to measure liver, visceral (VAT) and subcutaneous abdominal adipose tissue (ScAT). Sedentary time and MVPA were measured via an ActiGraph GT3X+ accelerometer. Generalized linear models examined the association of CRF, MVPA, and sedentary time with Adipo-IR and fat depots. Interaction terms explored the moderating influence of age, sex, BMI and CRF. RESULTS: After controlling for BMI and cardiometabolic variables, sedentary time was positively associated with Adipo-IR (ß = 0.68 AU [95%CI = 0.27 to 1.10], P < 0.001). The association between sedentary time and Adipo-IR was moderated by age, CRF and BMI; such that it was stronger in individuals who were older, had lower CRF and had a higher BMI. Sedentary time was also positively associated with VAT (ß = 0.05 L [95%CI = 0.01 to 0.08], P = 0.005) with the relationship being stronger in females than males. CRF was inversely associated with VAT (ß = -0.02 L [95%CI = -0.04 to -0.01], P = 0.003) and ScAT (ß = -0.10 L [95%CI = -0.13 to -0.06], P < 0.001); with sex and BMI moderating the strength of associations with VAT and ScAT, respectively. CONCLUSIONS: Sedentary time is positively associated with adipose tissue insulin resistance which regulates lipogenesis and lipolysis. CRF is independently related to central fat storage which is a key risk factor for cardiometabolic disease.
Subject(s)
Cardiorespiratory Fitness , Cardiovascular Diseases , Insulin Resistance , Female , Humans , Male , Adult , Cardiorespiratory Fitness/physiology , Sedentary Behavior , Exercise/physiology , Body Mass Index , Adipose Tissue , Physical FitnessABSTRACT
AIMS: We investigated evidence from randomised, placebo-controlled trials of novel glucose-lowering therapies; sodium-glucose co-transporter-2 inhibitors (SGLT2i), dipeptidyl peptidase-4 inhibitors (DPP4i) and glucagon-like peptide-1 receptor agonists (GLP-1RA), on physical function in people with type 2 diabetes (T2D). METHODS: PubMed, Medline, Embase and Cochrane library were searched from 1 April 2005 to 20 January 2022. The primary outcome was change in physical function in groups receiving a novel glucose-lowering therapy versus placebo at the trial end-point. RESULTS: Eleven studies met our criteria including nine for GLP-1RA and one each for SGLT2i and DPP4i. Eight studies included a self-reported measure of physical function, seven with GLP-1RA. Pooled meta-analysis showed an improvement of 0.12 (0.07, 017) points in favour of novel glucose-lowering therapies, mainly GLP-1RA. These findings were consistent when assessed individually for commonly used subjective assessments of physical function; namely the Short-Form 36 item-questionnaire (SF-36; all investigating GLP-1RA) and the Impact of Weight on Quality of Life-Lite (IWQOL-LITE; all, except one, exploring GLP-1RA) with estimated treatment differences (ETDs) of 0.86 (0.28, 1.45) and 3.72 (2.30, 5.15) respectively in favour of novel GLTs. For objective measures of physical function (VO2max and 6-minute walk test (6MWT)) no significant between-group differences between the intervention and the placebo were found. CONCLUSIONS: GLP-1RAs showed improvements in self-reported outcomes of physical function. However, there is limited evidence to draw definitive conclusions especially because of lack of studies exploring the impact of SGLT2i and DPP4i on physical function. There is a need for dedicated trials to establish the association between novel agents and physical function.
Subject(s)
Diabetes Mellitus, Type 2 , Dipeptidyl-Peptidase IV Inhibitors , Sodium-Glucose Transporter 2 Inhibitors , Humans , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Glucose , Quality of Life , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , Glucagon-Like Peptide-1 Receptor/agonists , Randomized Controlled Trials as TopicABSTRACT
Exercise is recommended for those with, or at risk of nonalcoholic fatty liver disease (NAFLD), owing to beneficial effects on hepatic steatosis and cardiometabolic risk. Whilst exercise training reduces total intrahepatic lipid in people with NAFLD, accumulating evidence indicates that exercise may also modulate hepatic lipid composition. This metabolic influence is important as the profile of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA) dramatically affect the metabolic consequences of hepatic lipid accumulation; with SFA being especially lipotoxic. Relatedly, obesity and NAFLD are associated with hepatic PUFA depletion and elevated SFA. This review summarizes the acute (single bout) and chronic (exercise training) effects of exercise on hepatic lipid composition in rodents (acute studies: n = 3, chronic studies: n = 13) and humans (acute studies: n = 1, chronic studies: n = 3). An increased proportion of hepatic PUFA after acute and chronic exercise is the most consistent finding of this review. Mechanistically, this may relate to an enhanced uptake of adipose-derived PUFA (reflecting habitual diet), particularly in rodents. A relative decrease in the proportion of hepatic MUFA after chronic exercise is also documented repeatedly, particularly in rodent models with elevated hepatic MUFA. This outcome is related to decreased hepatic stearoyl-CoA desaturase-1 activity in some studies. Findings regarding hepatic SFA are less consistent and limited by the absence of metabolic challenge in rodent models. These findings require confirmation in well-controlled interventions in people with NAFLD. These studies will be facilitated by recently validated magnetic resonance spectroscopy techniques, able to precisely quantify hepatic lipid composition in vivo.
Subject(s)
Non-alcoholic Fatty Liver Disease , Humans , Fatty Acids, Monounsaturated/metabolism , Fatty Acids, Unsaturated/metabolism , Obesity/metabolism , Exercise , Fatty Acids/metabolismABSTRACT
AIM: To assess the impact of the sodium-glucose co-transporter-2 (SGLT2) inhibitor empagliflozin (25 mg once-daily), dietary energy restriction, or both combined, on circulating appetite-regulatory peptides in people with type 2 diabetes (T2D) and overweight or obesity. MATERIALS AND METHODS: In a double-blind, placebo-controlled trial, 68 adults (aged 30-75 years) with T2D (drug naïve or on metformin monotherapy; HbA1c 6.0%-10.0% [42-86 mmol/mol]) and body mass index of 25 kg/m2 or higher were randomized to (a) placebo only, (b) placebo plus diet, (c) empagliflozin only or (d) empagliflozin plus diet for 24 weeks. Dietary energy restriction matched the estimated energy deficit elicited by SGLT2 inhibitor therapy through urinary glucose excretion (~360 kcal/day). The primary outcome was change in postprandial circulating total peptide-YY (PYY) during a 3-hour mixed-meal tolerance test from baseline to 24 weeks. Postprandial total glucagon-like peptide-1 (GLP-1), acylated ghrelin and subjective appetite perceptions formed secondary outcomes, along with other key components of energy balance. RESULTS: The mean weight loss in each group at 24 weeks was 0.44, 1.91, 2.22 and 5.74 kg, respectively. The change from baseline to 24 weeks in postprandial total PYY was similar between experimental groups and placebo only (mean difference [95% CI]: -8.6 [-28.6 to 11.4], 13.4 [-6.1 to 33.0] and 1.0 [-18.0 to 19.9] pg/ml in placebo-plus diet, empagliflozin-only and empagliflozin-plus-diet groups, respectively [all P ≥ .18]). Similarly, there was no consistent pattern of difference between groups for postprandial total GLP-1, acylated ghrelin and subjective appetite perceptions. CONCLUSIONS: In people with T2D and overweight or obesity, changes in postprandial appetite-regulatory gut peptides may not underpin the less than predicted weight loss observed with empagliflozin therapy. CLINICAL TRIALS REGISTRATION: NCT02798744, www. CLINICALTRIALS: gov; 2015-001594-40, www.EudraCT.ema.europa.eu; ISRCTN82062639, www.ISRCTN.org.
Subject(s)
Diabetes Mellitus, Type 2 , Sodium-Glucose Transporter 2 Inhibitors , Adult , Aged , Appetite , Benzhydryl Compounds , Diabetes Mellitus, Type 2/drug therapy , Double-Blind Method , Ghrelin/therapeutic use , Glucagon-Like Peptide 1/therapeutic use , Glucose/therapeutic use , Glucosides , Humans , Hypoglycemic Agents , Middle Aged , Obesity/complications , Obesity/drug therapy , Overweight/complications , Overweight/drug therapy , Peptide YY , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , Weight LossABSTRACT
BACKGROUND: The number of individuals recovering from severe COVID-19 is increasing rapidly. However, little is known about physical behaviours that make up the 24-h cycle within these individuals. This study aimed to describe physical behaviours following hospital admission for COVID-19 at eight months post-discharge including associations with acute illness severity and ongoing symptoms. METHODS: One thousand seventy-seven patients with COVID-19 discharged from hospital between March and November 2020 were recruited. Using a 14-day wear protocol, wrist-worn accelerometers were sent to participants after a five-month follow-up assessment. Acute illness severity was assessed by the WHO clinical progression scale, and the severity of ongoing symptoms was assessed using four previously reported data-driven clinical recovery clusters. Two existing control populations of office workers and individuals with type 2 diabetes were comparators. RESULTS: Valid accelerometer data from 253 women and 462 men were included. Women engaged in a mean ± SD of 14.9 ± 14.7 min/day of moderate-to-vigorous physical activity (MVPA), with 12.1 ± 1.7 h/day spent inactive and 7.2 ± 1.1 h/day asleep. The values for men were 21.0 ± 22.3 and 12.6 ± 1.7 h /day and 6.9 ± 1.1 h/day, respectively. Over 60% of women and men did not have any days containing a 30-min bout of MVPA. Variability in sleep timing was approximately 2 h in men and women. More severe acute illness was associated with lower total activity and MVPA in recovery. The very severe recovery cluster was associated with fewer days/week containing continuous bouts of MVPA, longer total sleep time, and higher variability in sleep timing. Patients post-hospitalisation with COVID-19 had lower levels of physical activity, greater sleep variability, and lower sleep efficiency than a similarly aged cohort of office workers or those with type 2 diabetes. CONCLUSIONS: Those recovering from a hospital admission for COVID-19 have low levels of physical activity and disrupted patterns of sleep several months after discharge. Our comparative cohorts indicate that the long-term impact of COVID-19 on physical behaviours is significant.
Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , Accelerometry/methods , Aftercare , Aged , Diabetes Mellitus, Type 2/therapy , Exercise , Female , Hospitalization , Hospitals , Humans , Male , Patient Discharge , SleepABSTRACT
Obesity is a primary antecedent to non-alcoholic fatty liver disease whose cardinal feature is excessive hepatic lipid accumulation. Although total hepatic lipid content closely associates with hepatic and systemic metabolic dysfunction, accumulating evidence suggests that the composition of hepatic lipids may be more discriminatory. This review summarises cross-sectional human studies using liver biopsy/lipidomics and proton magnetic resonance spectroscopy to characterise hepatic lipid composition in people with obesity and related metabolic disease. A comprehensive literature search identified 26 relevant studies published up to 31st March 2021 which were included in the review. The available evidence provides a consistent picture showing that people with hepatic steatosis possess elevated saturated and/or monounsaturated hepatic lipids and a reduced proportion of polyunsaturated hepatic lipids. This altered hepatic lipid profile associates more directly with metabolic derangements, such as insulin resistance, and may be exacerbated in non-alcoholic steatohepatitis. Further evidence from lipidomic studies suggests that these deleterious changes may be related to defects in lipid desaturation and elongation, and an augmentation of the de novo lipogenic pathway. These observations are consistent with mechanistic studies implicating saturated fatty acids and associated bioactive lipid intermediates (ceramides, lysophosphatidylcholines and diacylglycerol) in the development of hepatic lipotoxicity and wider metabolic dysfunction, whilst monounsaturated fatty acids and polyunsaturated fatty acids may exhibit a protective role. Future studies are needed to prospectively determine the relevance of hepatic lipid composition for hepatic and non-hepatic morbidity and mortality; and to further evaluate the impact of therapeutic interventions such as pharmacotherapy and lifestyle interventions.
Subject(s)
Insulin Resistance , Non-alcoholic Fatty Liver Disease , Cross-Sectional Studies , Fatty Acids/metabolism , Humans , Lipid Metabolism , Liver/pathology , Non-alcoholic Fatty Liver Disease/pathology , Obesity/metabolismABSTRACT
The mechanisms behind the beneficial cardiovascular effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) compared with dipeptidyl peptidase-4 inhibitors (DPP4is) remain largely unknown, despite both targeting the incretin pathway to improve glycaemic control. In these prespecified secondary analyses of the LYDIA trial, we examined the impact of the GLP-1RA liraglutide (1.8 mg once-daily) and the DPP4i sitagliptin (100 mg once-daily) on circulating cardiovascular biomarkers associated with atherosclerotic risk, including circulating progenitor cells (CPCs). LYDIA was a 26-week, randomized, active-comparator trial in 61 adults with type 2 diabetes and obesity (mean ± SD: age 43.8 ± 6.5 years, body mass index 35.3 ± 6.4 kg/m2 , HbA1c 7.5% ± 0.83% [58.5 ± 9.1 mmol/mol]). Vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1-alpha (SDF-1É), both of which are implicated in endothelial function, were higher at 26 weeks with liraglutide therapy compared with sitagliptin (mean between-group difference [95% CI]: 77.03 [18.29, 135.77] pg/mL, p = .010; and 996.25 [818.85, 1173.64] pg/mL, p < .001, respectively). There were no between-group differences in CPCs, nitric oxide, C-reactive protein, interleukin-6, tumour necrosis factor alpha and advanced glycation end-products. These analyses suggest a favourable impact of liraglutide on VEGF and SDF-1É levels compared with sitagliptin. These factors may therefore be implicated in the differential cardiovascular effects observed between these agents in large cardiovascular outcome trials. However, these are secondary analyses from a previous trial and thus hypothesis-generating. Purposive trials are required to examine these findings further.
Subject(s)
Diabetes Mellitus, Type 2 , Dipeptidyl-Peptidase IV Inhibitors , Adult , Biomarkers , Diabetes Mellitus, Type 2/drug therapy , Dipeptidyl-Peptidase IV Inhibitors/therapeutic use , Glucagon-Like Peptide 1 , Humans , Hypoglycemic Agents/therapeutic use , Liraglutide/therapeutic use , Middle Aged , Obesity/complications , Obesity/drug therapy , Sitagliptin Phosphate/therapeutic use , Stem Cells , Vascular Endothelial Growth Factor AABSTRACT
AIMS/HYPOTHESIS: Early-onset adult type 2 diabetes (diagnosed between ages 18 and 39 years) is increasingly prevalent and associated with poor long-term outcomes. We hypothesised that individuals with early-onset adult type 2 diabetes were underrepresented in the prominent research trials that underpin type 2 diabetes management guidelines. METHODS: We reviewed the mean age of the study populations recruited to 90 prominent trials in type 2 diabetes, including 37 cardio-renal outcomes trials across a range of pharmacological, non-pharmacological and multifactorial interventions, 28 trials from the phase III programmes of three representative glucose-lowering therapies used routinely in clinical practice (empagliflozin, liraglutide and sitagliptin) and 25 prominent trials of diabetes self-management education and support or intensive lifestyle interventions (diet or supervised exercise training). We then estimated the number of individuals within these trials who were aged between 18 and 39 years. RESULTS: Across all 90 trials, the mean age of 268,978 participants was 63 years (range 51-69 years in individual trials). In 73 trials (81%), <5% of participants were estimated to be aged 18-39 years, despite this age group representing ~15-20% of the adult type 2 diabetes population. Twenty-nine of these trials (32%; total 164,953 participants) excluded individuals below 40 years of age altogether. CONCLUSIONS/INTERPRETATION: Guidelines for early-onset adult type 2 diabetes are extrapolated predominantly from evidence in older individuals. Strategies to support the participation of individuals with early-onset adult type 2 diabetes in future research are imperative to ensure guidelines for these high-risk individuals are evidence-based.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Adolescent , Adult , Aged , Benzhydryl Compounds/therapeutic use , Blood Glucose/drug effects , Diabetes Mellitus, Type 2/blood , Female , Glucosides/therapeutic use , Glycated Hemoglobin/metabolism , Humans , Insulin/metabolism , Liraglutide/therapeutic use , Male , Middle Aged , Sitagliptin Phosphate/therapeutic use , Young AdultABSTRACT
To systematically review the current literature investigating associations between zinc-alpha2-glycoprotein (ZAG) and dysglycaemia (including type 2 diabetes (T2DM), poly-cystic-ovary syndrome (PCOS), pre-diabetes or insulin resistance). This included relationships between ZAG and continuous measures of insulin and glucose. Additionally, we performed a meta-analysis to estimate the extent that ZAG differs between individuals with or without dysglycaemia; whilst examining the potential influence of adiposity. A systematic search was performed on four databases for studies on circulating ZAG concentrations in adult human populations, comparing healthy controls to individuals with dysglycaemia. Key characteristics, including the mean ZAG concentrations (mgâL-1), and any correlational statistics between ZAG and continuous measures of glucose, glycated haemoglobin (HbA1c) or insulin were extracted. Meta-analyses were performed to compare metabolically healthy controls to cases, and on studies that compared controls and cases considered overweight or obese (body mass index (BMI) ≥25 kg.m2). 1575 papers were identified and 14 studies (16 cohorts) were considered eligible for inclusion. Circulating ZAG was lower in individuals with dysglycaemia compared to metabolically healthy controls (-4.14 [-8.17, -0.11] mg.L-1; I2 = 98.5%; p < 0.001). When using data from only studies with overweight or obese groups with or without dysglycaemia (three studies (four cohorts); pooled n = 332), the difference in circulating ZAG was no longer significant (-0.30 [-3.67, 3.07] mg. L-1; I2 = 28.0%; p = 0.225). These data suggest that ZAG may be implicated in dysglycaemia, although there was significant heterogeneity across different studies and the mediating effect of adiposity cannot be excluded. Therefore, more research is needed before robust conclusions can be drawn.
Subject(s)
Adipokines/metabolism , Diabetes Mellitus, Type 2/metabolism , Insulin Resistance , Overweight/metabolism , Polycystic Ovary Syndrome/metabolism , Prediabetic State/metabolism , Female , HumansABSTRACT
BACKGROUND: Hepatokines such as fibroblast growth factor 21 (FGF21), leukocyte cell-derived chemotaxin 2 (LECT2), fetuin-A, fetuin-B, and selenoprotein P (SeP) are liver-derived proteins that are modulated by chronic energy status and metabolic disease. Emerging data from rodent and cell models indicate that hepatokines may be sensitive to acute nutritional manipulation; however, data in humans are lacking. OBJECTIVE: The aim was to investigate the influence of hyperenergetic, high-fat feeding on circulating hepatokine concentrations, including the time course of responses. METHODS: In a randomized, crossover design, 12 healthy men [mean ± SD: age, 24 ± 4 y; BMI (kg/m2), 24.1 ± 1.5] consumed a 7-d hyperenergetic, high-fat diet [HE-HFD; +50% energy, 65% total energy as fat (32% saturated, 26% monounsaturated, 8% polyunsaturated)] and control diet (36% total energy as fat), separated by 3 wk. Whole-body insulin sensitivity was assessed before and after each diet using oral-glucose-tolerance tests. Fasting plasma concentrations of FGF21 (primary outcome), LECT2, fetuin-A, fetuin-B, SeP, and related metabolites were measured after 1, 3, and 7 d of each diet. Hepatokine responses were analyzed using 2-factor repeated-measures ANOVA and subsequent pairwise comparisons. RESULTS: Compared with the control, the HE-HFD increased circulating FGF21 at 1 d (105%) and 3 d (121%; P ≤ 0.040), LECT2 at 3 d (17%) and 7 d (32%; P ≤ 0.004), and fetuin-A at 7 d (7%; P = 0.028). Plasma fetuin-B and SeP did not respond to the HE-HFD. Whole-body insulin sensitivity was reduced after the HE-HFD by 31% (P = 0.021). CONCLUSIONS: Acute high-fat overfeeding augments circulating concentrations of FGF21, LECT2, and fetuin-A in healthy men. Notably, the time course of response varies between proteins and is transient for FGF21. These findings provide further insight into the nutritional regulation of hepatokines in humans and their interaction with metabolic homeostasis. This study was registered at clinicaltrials.gov as NCT03369145.
Subject(s)
Diet, High-Fat , Energy Intake , Fibroblast Growth Factors/blood , Intercellular Signaling Peptides and Proteins/blood , alpha-2-HS-Glycoprotein/metabolism , Adult , Blood Glucose/drug effects , Cross-Over Studies , Fibroblast Growth Factors/genetics , Fibroblast Growth Factors/metabolism , Gene Expression Regulation/drug effects , Humans , Insulin/blood , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Liver/drug effects , Liver/metabolism , Male , Young Adult , alpha-2-HS-Glycoprotein/geneticsABSTRACT
AIM: To compare the effects of a glucagon-like peptide-1 receptor agonist and a dipeptidyl peptidase-4 inhibitor on magnetic resonance imaging-derived measures of cardiovascular function. MATERIALS AND METHODS: In a prospective, randomized, open-label, blinded endpoint trial liraglutide (1.8 mg) and sitagliptin (100 mg) were compared in asymptomatic, non-insulin treated young (aged 18-50 years) adults with obesity and type 2 diabetes. The primary outcome was difference in circumferential peak early diastolic strain rate change (PEDSR), a biomarker of cardiac diastolic dysfunction 26 weeks after randomization. Secondary outcomes included other indices of cardiac structure and function, HbA1c and body weight. RESULTS: Seventy-six participants were randomized (54% female, mean ± SD age 44 ± 6 years, diabetes duration 4.4 years, body mass index 35.3 ± 6.1 kg m-2 ), of whom 65% had ≥1 cardiovascular risk factor. Sixty-one participants had primary outcome data available. There were no statistically significant between-group differences (intention-to-treat; mean [95% confidence interval]) in PEDSR change (-0.01 [-0.07, +0.06] s-1 ), left ventricular ejection fraction (-1.98 [-4.90, +0.94]%), left ventricular mass (+1.14 [-5.23, +7.50] g) or aortic distensibility (-0.35 [-0.98, +0.28] mmHg-1 × 10-3 ) after 26 weeks. Reductions in HbA1c (-4.57 [-9.10, -0.37] mmol mol-1 ) and body weight (-3.88 [-5.74, -2.01] kg) were greater with liraglutide. CONCLUSION: There were no differences in cardiovascular structure or function after short-term use of liraglutide and sitagliptin in younger adults with obesity and type 2 diabetes. Longer studies in patients with more severe cardiac dysfunction may be necessary before definitive conclusions can be made about putative pleiotropic properties of incretin-based therapies.
Subject(s)
Diabetes Mellitus, Type 2 , Liraglutide , Adult , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Female , Glycated Hemoglobin , Humans , Hypoglycemic Agents/therapeutic use , Liraglutide/therapeutic use , Male , Middle Aged , Obesity/complications , Obesity/drug therapy , Prospective Studies , Sitagliptin Phosphate/therapeutic use , Stroke Volume , Treatment Outcome , Ventricular Function, LeftABSTRACT
Single bouts of land-based exercise (for example, walking, running, cycling) do not typically alter post-exercise energy intake on the day of exercise. However, anecdotal and preliminary empirical evidence suggests that swimming may increase appetite and energy intake. This study compared the acute effects of swimming on appetite, energy intake, and food preference and reward, versus exertion-matched cycling and a resting control. Thirty-two men (n = 17; mean ± SD age 24 ± 2 years, body mass index [BMI] 25.0 ± 2.6 kg/m2) and women (n = 15; age 22 ± 3 years, BMI 22.8 ± 2.3 kg/m2) completed three experimental trials (swimming, cycling, control) in a randomised, crossover design. The exercise trials involved 60-min of 'hard' exercise (self-selected rating of perceived exertion: 15) performed 90-min after a standardised breakfast. Food preference and reward were assessed via the Leeds Food Preference Questionnaire 15-min after exercise, whilst ad libitum energy intake was determined 30-min after exercise. The control trial involved identical procedures except no exercise was performed. Compared with control (3259 ± 1265 kJ), swimming increased ad libitum energy intake (3857 ± 1611 kJ; ES = 0.47, 95% CI of the mean difference between trials 185, 1010 kJ, P = 0.005); the magnitude of increase was smaller after cycling (3652 ± 1619 kJ; ES = 0.31, 95% CI -21, 805 kJ, P = 0.062). Ad libitum energy intake was similar between swimming and cycling (ES = 0.16, 95% CI -207, 618 kJ, P = 0.324). This effect was consistent across sexes and unrelated to food preference and reward which were similar after swimming and cycling compared with control. This study has identified an orexigenic effect of swimming. Further research is needed to identify the responsible mechanism(s), including the relevance of water immersion and water temperature per se.
Subject(s)
Energy Metabolism , Swimming , Adult , Appetite , Breakfast , Cross-Over Studies , Energy Intake , Female , Humans , Male , Young AdultABSTRACT
Intermittent energy restriction (IER) involves short periods of severe energy restriction interspersed with periods of adequate energy intake, and can induce weight loss. Insulin sensitivity is impaired by short-term, complete energy restriction, but the effects of IER are not well known. In randomised order, fourteen lean men (age: 25 (sd 4) years; BMI: 24 (sd 2) kg/m2; body fat: 17 (4) %) consumed 24-h diets providing 100 % (10 441 (sd 812) kJ; energy balance (EB)) or 25 % (2622 (sd 204) kJ; energy restriction (ER)) of estimated energy requirements, followed by an oral glucose tolerance test (OGTT; 75 g of glucose drink) after fasting overnight. Plasma/serum glucose, insulin, NEFA, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and fibroblast growth factor 21 (FGF21) were assessed before and after (0 h) each 24-h dietary intervention, and throughout the 2-h OGTT. Homoeostatic model assessment of insulin resistance (HOMA2-IR) assessed the fasted response and incremental AUC (iAUC) or total AUC (tAUC) were calculated during the OGTT. At 0 h, HOMA2-IR was 23 % lower after ER compared with EB (P<0·05). During the OGTT, serum glucose iAUC (P<0·001), serum insulin iAUC (P<0·05) and plasma NEFA tAUC (P<0·01) were greater during ER, but GLP-1 (P=0·161), GIP (P=0·473) and FGF21 (P=0·497) tAUC were similar between trials. These results demonstrate that severe energy restriction acutely impairs postprandial glycaemic control in lean men, despite reducing HOMA2-IR. Chronic intervention studies are required to elucidate the long-term effects of IER on indices of insulin sensitivity, particularly in the absence of weight loss.
Subject(s)
Blood Glucose/analysis , Energy Intake , Fasting , Glucose Tolerance Test , Insulin/blood , Adult , Area Under Curve , Caloric Restriction/methods , Energy Metabolism , Fibroblast Growth Factors/metabolism , Gastric Inhibitory Polypeptide , Glucagon-Like Peptide 1/blood , Glucose/metabolism , Healthy Volunteers , Humans , Insulin Resistance , Male , Obesity/metabolism , Postprandial Period , Weight Loss , Young AdultABSTRACT
PURPOSE: This study examined the feasibility of sprint interval exercise training (SIT) for men with non-alcoholic fatty liver disease (NAFLD) and its effects on intrahepatic triglyceride (IHTG), insulin sensitivity (hepatic and peripheral), visceral (VAT) and subcutaneous adipose tissue (ScAT). METHODS: Nine men with NAFLD (age 41 ± 8 years; BMI 31.7 ± 3.1 kg m-2; IHTG 15.6 ± 8.3%) were assessed at: (1) baseline (2) after a control phase of no intervention (pre-training) and (3) after 6 weeks of SIT (4-6 maximal 30 s cycling intervals, three times per week). IHTG, VAT and ScAT were measured using magnetic resonance spectroscopy or imaging and insulin sensitivity was assessed via dual-step hyperinsulinaemic-euglycaemic clamp with [6,6-D2] glucose tracer. RESULTS: Participants adhered to SIT, completing ≥ 96.7% of prescribed intervals. SIT increased peak oxygen uptake [[Formula: see text] peak: + 13.6% (95% CI 8.8-18.2%)] and elicited a relative reduction in IHTG [- 12.4% (- 31.6 to 6.7%)] and VAT [- 16.9% (- 24.4 to - 9.4%); n = 8], with no change in body weight or ScAT. Peripheral insulin sensitivity increased throughout the study (n = 8; significant main effect of phase) but changes from pre- to post-training were highly variable (range - 18.5 to + 58.7%) and not significant (P = 0.09), despite a moderate effect size (g* = 0.63). Hepatic insulin sensitivity was not influenced by SIT. CONCLUSIONS: SIT is feasible for men with NAFLD in a controlled laboratory setting and is able to reduce IHTG and VAT in the absence of weight loss.
Subject(s)
Lipid Metabolism/physiology , Liver/metabolism , Non-alcoholic Fatty Liver Disease/physiopathology , Obesity/physiopathology , Adult , Exercise/physiology , Humans , Insulin Resistance/physiology , Lipids , Liver/physiopathology , Male , Middle Aged , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathologyABSTRACT
AIM: To investigate the relationship between age at diagnosis of type 2 diabetes and the risk of macrovascular disease, heart failure, and microvascular disease. METHODS: In August 2022, PubMed/EMBASE were searched for articles reporting (i) coronary artery disease, cerebrovascular disease, peripheral vascular disease, amputation; (ii) heart failure; and (iii) retinopathy, neuropathy, nephropathy (albuminuria, chronic kidney disease [CKD], end-stage renal disease) by age at diagnosis of type 2 diabetes. Random effects, non-linear dose-response meta-analysis was undertaken for each outcome to assess the association with age at diagnosis (40 years = reference), using both crude and maximally adjusted odds ratios separately, with and without adjustment for current age (age at sampling). RESULTS: We identified 42 articles (230,003 to 3,465,590 participants; 1035 to 391,140 events). Age at diagnosis was positively associated with the risk of macrovascular diseases, heart failure, and CKD, independent of current age, and negatively associated with retinopathy. For other microvascular outcomes, when adjusting for current age, a "reverse U" relationship was observed (peak risk = 55-60 years). DISCUSSION: Retinopathy was negatively associated with age at diagnosis, highlighting the importance of retinopathy screening in early-onset type 2 diabetes. The implications of other associations were unclear due to the heterogeneity in methodologies and findings.
ABSTRACT
The combination of glucagon-like peptide-1 (GLP-1) with other gut hormones including the glucose-dependent insulinotropic polypeptide (GIP) has been explored to complement and enhance further the GLP-1 effects on glycemia and weight loss. Tirzepatide is the first dual GLP-1/GIP receptor co-agonist which has been approved for treatment of type 2 diabetes mellitus (T2DM) based on the findings from the SURPASS program. The SURPASS trials assessed the safety and efficacy of tirzepatide in people with T2DM, from monotherapy through to insulin add-on in global populations, with another two trials dedicated to Japanese population. Over periods of treatment up to 104 weeks, once weekly tirzepatide 5 to 15 mg reduced glycosylated hemoglobin (1.87% to 3.02%), body weight (5.4 to 12.9 kg) and improved multiple cardiometabolic risk factors (including reduction in liver fat, new-onset macroalbuminuria, blood pressure, and lipids) across the T2DM spectrum. Tirzepatide provided better efficacy than placebo and other commonly used glucose-lowering medications such as semaglutide 1 mg, dulaglutide, insulin degludec, and glargine. All tirzepatide doses were well tolerated with similar side-effect profile to the GLP-1 receptor analogues. In people without diabetes, tirzepatide 5 to 15 mg once weekly for the treatment for obesity (SURMOUNT-1) resulted in substantial reductions in body weight (16.5% to 22.4%) over 72 weeks. Overall, the SURPASS program and SURMOUNT-1 study suggest that tirzepatide is marking a new era in T2DM and/or obesity management through dual agonism of gut hormones.
ABSTRACT
Weight-lowering pharmacotherapies provide an option for weight management; however, their effects on physical activity, function, and cardiorespiratory fitness are not fully understood. We conducted a systematic review and meta-analysis of randomized controlled trials to investigate the effect of licensed weight loss pharmacotherapies on physical activity, physical function, and cardiorespiratory fitness in individuals with obesity. Fourteen trials met our prespecified inclusion criteria: Five investigated liraglutide, four semaglutide, three naltrexone/bupropion, and two phentermine/topiramate. All 14 trials included a self-reported measure of physical function, with the pooled findings suggesting an improvement favoring the pharmacotherapy intervention groups (SMD: 0.27; 95% CI: 0.22 to 0.32) and effects generally consistent across different therapies. Results were also consistent when stratified by the two most commonly used measures: The Short-Form 36-Item Questionnaire (SF-36) (0.24; 0.17 to 0.32) and the Impact of Weight on Quality Of Life-Lite (IWQOL-Lite) (0.29; 0.23 to 0.35). Meta-regression confirmed a significant association between pharmacotherapy induced weight loss and improved physical function for IWQOL-Lite (p = 0.003). None of the studies reported a physical activity outcome, and only one study reported objectively measured cardiorespiratory fitness. Improvements in self-reported physical function were observed with weight loss therapy, but the effect on physical activity or objectively measured physical function and fitness could not be determined.