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1.
Mol Cell ; 77(4): 810-824.e8, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-31901447

RESUMO

Lipid droplets (LDs) provide a reservoir for triacylglycerol storage and are a central hub for fatty acid trafficking and signaling in cells. Lipolysis promotes mitochondrial biogenesis and oxidative metabolism via a SIRT1/PGC-1α/PPARα-dependent pathway through an unknown mechanism. Herein, we identify that monounsaturated fatty acids (MUFAs) allosterically activate SIRT1 toward select peptide-substrates such as PGC-1α. MUFAs enhance PGC-1α/PPARα signaling and promote oxidative metabolism in cells and animal models in a SIRT1-dependent manner. Moreover, we characterize the LD protein perilipin 5 (PLIN5), which is known to enhance mitochondrial biogenesis and function, to be a fatty-acid-binding protein that preferentially binds LD-derived monounsaturated fatty acids and traffics them to the nucleus following cAMP/PKA-mediated lipolytic stimulation. Thus, these studies identify the first-known endogenous allosteric modulators of SIRT1 and characterize a LD-nuclear signaling axis that underlies the known metabolic benefits of MUFAs and PLIN5.


Assuntos
Ácidos Graxos Monoinsaturados/metabolismo , Gotículas Lipídicas/química , Perilipina-5/metabolismo , Sirtuína 1/metabolismo , Regulação Alostérica , Animais , Transporte Biológico , Linhagem Celular , Células Cultivadas , Dieta , Ácidos Graxos/metabolismo , Lipase/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Azeite de Oliva , Perilipina-5/fisiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Transcrição Gênica
2.
Br J Nutr ; 130(2): 344-352, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-36250527

RESUMO

Nutritional interventions often rely on subjective assessments of energy intake (EI), but these are susceptible to measurement error. To introduce an accelerometer-based intake-balance method for assessing EI using data from a time-restricted eating (TRE) trial. Nineteen participants with overweight/obesity (25-63 years old; 16 females) completed a 12-week intervention (NCT03129581) in a control group (unrestricted feeding; n 8) or TRE group (n 11). At the start and end of the intervention, body composition was assessed by dual-energy X-ray absorptiometry (DXA) and daily energy expenditure (EE) was assessed for 2 weeks via wrist-worn accelerometer. EI was back-calculated as the sum of net energy storage (from DXA) and EE (from accelerometer). Accelerometer-derived EI estimates were compared against estimates from the body weight planner of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Mean EI for the control group declined by 138 and 435 kJ/day for the accelerometer and NIDDK methods, respectively (both P ≥ 0·38), v. 1255 and 1469 kJ/day, respectively, for the TRE group (both P < 0·01). At follow-up, the accelerometer and NIDDK methods showed excellent group-level agreement (mean bias of -297 kJ/day across arms; standard error of estimate 1054 kJ/day) but high variability at the individual level (limits of agreement from -2414 to +1824 kJ/day). The accelerometer-based intake-balance method showed plausible sensitivity to change, and EI estimates were biologically and behaviourally plausible. The method may be a viable alternative to self-report EI measures. Future studies should assess criterion validity using doubly labelled water.


Assuntos
Ingestão de Energia , Obesidade , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Acelerometria , Peso Corporal , Metabolismo Energético , Sobrepeso
3.
J Lipid Res ; 63(5): 100201, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35315332

RESUMO

FA esters of hydroxy FAs (FAHFAs) are lipokines with extensive structural and regional isomeric diversity that impact multiple physiological functions, including insulin sensitivity and glucose homeostasis. Because of their low molar abundance, FAHFAs are typically quantified using highly sensitive LC-MS/MS methods. Numerous relevant MS databases house in silico-spectra that allow identification and speciation of FAHFAs. These provisional chemical feature assignments provide a useful starting point but could lead to misidentification. To address this possibility, we analyzed human serum with a commonly applied high-resolution LC-MS untargeted metabolomics platform. We found that many chemical features are putatively assigned to the FAHFA lipid class based on exact mass and fragmentation patterns matching spectral databases. Careful validation using authentic standards revealed that many investigated signals provisionally assigned as FAHFAs are in fact FA dimers formed in the LC-MS pipeline. These isobaric FA dimers differ structurally only by the presence of an olefinic bond. Furthermore, stable isotope-labeled oleic acid spiked into human serum at subphysiological concentrations showed concentration-dependent formation of a diverse repertoire of FA dimers that analytically mimicked FAHFAs. Conversely, validated FAHFA species did not form spontaneously in the LC-MS pipeline. Together, these findings underscore that FAHFAs are endogenous lipid species.  However, nonbiological FA dimers forming in the setting of high concentrations of FFAs can be misidentified as FAHFAs. Based on these results, we assembled a FA dimer database to identify nonbiological FA dimers in untargeted metabolomics datasets.


Assuntos
Ácidos Graxos , Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Ésteres/química , Ácidos Graxos/química , Humanos , Metabolômica , Espectrometria de Massas em Tandem/métodos
4.
Dig Dis Sci ; 66(10): 3542-3547, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33063187

RESUMO

BACKGROUND: Microscopic colitis (MC) is a subtype of inflammatory bowel disease (IBD) with overlapping risk factors for low bone density (LBD). While LBD is a known complication of IBD, its association with MC is not well-established. AIMS: Assess the prevalence of LBD in MC compared to control populations, and evaluate if MC predicts LBD when controlling for confounders. METHODS: Retrospective, observational case control study of adult patients with pathologically confirmed MC from 2005 to 2015. Bone density measurements were abstracted from dual-energy X-ray absorptiometry (DEXA) reports, and bone density was classified using T-score: normal (T ≥ - 1.0), osteopenia (- 1.0 > T > -2.5) or osteoporosis (T ≤ - 2.5). Demographics, disease, medication history and LBD risk factors were obtained from chart review. Prevalence of LBD was compared to national and local controls. A matched control cohort to MC patients without prior diagnosis of LBD was analyzed with logistic regression to assess the relationship of MC to LBD. RESULTS: One hundred and eighteen patients with MC were identified. Osteopenia in women with MC was more prevalent compared to national controls (67% vs. 49%, p = 0.0004), and LBD was more prevalent in MC patients compared to local controls (82% vs. 55%, p < 0.0001). In MC patients without prior diagnosis of LBD matched to controls, there was a higher prevalence of osteopenia (53.2% vs. 36.7%, p = 0.04). However, after controlling for confounders, MC was not associated with LBD (OR 0.83, 95% CI 0.22, 3.16, p = 0.8). CONCLUSIONS: While LBD was more prevalent in MC patients compared to control populations, with adjustment for key confounders (including BMI, steroids, smoking, vitamin D and calcium use), MC was not an independent predictor of LBD.


Assuntos
Densidade Óssea , Colite Microscópica/complicações , Osteoporose/etiologia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos de Coortes , Colite Microscópica/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
5.
J Biomed Inform ; 103: 103379, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32001388

RESUMO

The presence of missing data at the time of prediction limits the application of risk models in clinical and research settings. Common ways of handling missing data at the time of prediction include measuring the missing value and employing statistical methods. Measuring missing value incurs additional cost, whereas previously reported statistical methods results in reduced performance compared to when all variables are measured. To tackle these challenges, we introduce a new strategy, the MMTOP algorithm (Multiple models for Missing values at Time Of Prediction), which does not require measuring additional data elements or data imputation. Specifically, at model construction time, the MMTOP constructs multiple predictively equivalent risk models utilizing different risk factor sets. The collection of models are stored and to be queried at prediction time. To predict an individual's risk in the presence of incomplete data, the MMTOP selects the risk model based on measurement availability for that individual from the collection of predictively equivalent models and makes the risk prediction with the selected model. We illustrate the MMTOP with severe hypoglycemia (SH) risk prediction based on data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study. We identified 77 predictively equivalent models for SH with cross-validated c-index of 0.77 ± 0.03. These models are based on 77 distinct risk factor sets containing 12-17 risk factors. In terms of handling missing data at the time of prediction, the MMTOP outperforms all four tested competitor methods and maintains consistent performance as the number of missing variables increase.


Assuntos
Diabetes Mellitus Tipo 2 , Hipoglicemia , Algoritmos , Diabetes Mellitus Tipo 2/diagnóstico , Humanos , Modelos Estatísticos , Projetos de Pesquisa , Fatores de Risco
6.
J Clin Densitom ; 22(2): 287-292, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30064815

RESUMO

Obesity is a well-established risk factor for insulin resistance and type 2 diabetes mellitus, and body fat distribution has important implications for this metabolic risk. In this cross-sectional study, we used dual X-ray absorptiometry body composition data from 123 young adult participants with overweight or obesity, and correlatedwith 2 indices of insulin resistance calculated from oral glucose tolerance tests. Participants were 70% women, with mean (standard error) age 30.1 (0.6) yr, body mass index (BMI) 34.0 (0.6) kg/m2, homeostatic model assessment of insulin resistance (HOMA-IR) of 2.1 (0.2), and Matsuda insulin sensitivity index (Matsuda ISI) of 5.8 (0.4). In women, the strongest correlations were observed with the android-to-gynoid ratio (r = 0.52, p < 0.001 for HOMA-IR; r = -0.46, p < 0.001 for Matsuda ISI), and these correlations remained significant after adjustment for BMI. For men, the strongest correlations were with android fat mass (r = 0.40, p = 0.01 for HOMA-IR; r = -0.37, p = 0.02 for Matsuda ISI). Visceral adipose tissue was correlated with HOMA-IR and Matsuda ISI in women, and only with Matsuda ISI in men. BMI correlated with HOMA-IR and with Matsuda ISI in both women and men. Regional adiposity determined by dual X-ray absorptiometry correlates with indices of insulin resistance in sedentary young adults with overweight and obesity.


Assuntos
Distribuição da Gordura Corporal , Resistência à Insulina , Gordura Intra-Abdominal/diagnóstico por imagem , Obesidade/diagnóstico por imagem , Gordura Subcutânea Abdominal/diagnóstico por imagem , Abdome , Gordura Abdominal/diagnóstico por imagem , Absorciometria de Fóton , Adiposidade , Adulto , Feminino , Humanos , Masculino , Obesidade/metabolismo , Sobrepeso/diagnóstico por imagem , Sobrepeso/metabolismo , Pelve , Comportamento Sedentário , Coxa da Perna
7.
Diabetologia ; 59(8): 1659-65, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27181604

RESUMO

AIMS/HYPOTHESIS: The prospective association between cardiorespiratory fitness (CRF) measured in young adulthood and middle age on development of prediabetes, defined as impaired fasting glucose and/or impaired glucose tolerance, or diabetes by middle age remains unknown. We hypothesised that higher fitness levels would be associated with reduced risk for developing incident prediabetes/diabetes by middle age. METHODS: Participants were from the Coronary Artery Risk Development in Young Adults (CARDIA) study who were free from prediabetes/diabetes at baseline (year 0 [Y0]: 1985-1986). CRF was quantified by treadmill duration (converted to metabolic equivalents [METs]) at Y0, Y7 and Y20 and prediabetes/diabetes status was assessed at Y0, Y7, Y10, Y15, Y20 and Y25. We use an extended Cox model with CRF as the primary time-varying exposure. BMI was included as a time-varying covariate. The outcome was development of either prediabetes or diabetes after Y0. Model 1 included age, race, sex, field centre, CRF and BMI. Model 2 additionally included baseline (Y0) smoking, energy intake, alcohol intake, education, systolic BP, BP medication use and lipid profile. RESULTS: Higher fitness was associated with lower risk for developing incident prediabetes/diabetes (difference of 1 MET: HR 0.99898 [95% CI 0.99861, 0.99940], p < 0.01), which persisted (difference of 1 MET: HR 0.99872 [95% CI 0.99840, 0.99904], p < 0.01] when adjusting for covariates. CONCLUSIONS/INTERPRETATION: Examining participants who had fitness measured from young adulthood to middle age, we found that fitness was associated with lower risk for developing prediabetes/diabetes, even when adjusting for BMI over this time period. These findings emphasise the importance of fitness in reducing the health burden of prediabetes and diabetes.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Aptidão Física/fisiologia , Estado Pré-Diabético/epidemiologia , Adolescente , Adulto , Pressão Sanguínea/fisiologia , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Estudos Multicêntricos como Assunto , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
8.
Pediatr Res ; 79(1-1): 49-54, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26389821

RESUMO

BACKGROUND: We examined whether sympathetic nervous system activity influences hypertension status and systolic blood pressure (SBP) independent of adiposity in youth ranging from normal-weight to severe obesity. METHODS: We examined the association of heart rate variability (HRV) with hypertension status and SBP among youth (6-18 y old; n = 188; 103 female). Seated SBP was measured using an automated cuff. Prehypertension (SBP percentile ≥ 90th to <95th) and hypertension (SBP percentile ≥ 95th) were defined by age-, sex-, and height-norms. Autonomic nervous system activity was measured using HRV via SphygmoCor MM3 system and analyzed for time- and frequency-domains. Total body fat was measured via dual-energy X-ray absorptiometry. RESULTS: Logistic regression models demonstrated lower values in each time-domain HRV measure and larger low-frequency (LF):high-frequency (HF) ratio to be significantly associated with higher odds of being prehypertensive/hypertensive (11-47% higher odds) independent of total body fat (P < 0.05). In linear regression analysis, lower time-domain, but not frequency-domain, HRV measures were significantly associated with higher SBP independent of total body fat (P < 0.05). CONCLUSION: These data suggest that impaired cardiac autonomic nervous system function, at rest, is associated with higher odds of being prehypertensive/hypertensive and higher SBP which may be independent of adiposity in youth.


Assuntos
Adiposidade , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Hipertensão/fisiopatologia , Adolescente , Antropometria , Pressão Sanguínea , Composição Corporal , Criança , Estudos Transversais , Feminino , Frequência Cardíaca , Humanos , Modelos Logísticos , Masculino , Obesidade/fisiopatologia , Pré-Hipertensão/fisiopatologia , Puberdade
9.
Diabetologia ; 58(6): 1160-6, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25652389

RESUMO

AIMS/HYPOTHESIS: In patients with diabetes, intensive glycaemic control reduces microvascular complications. However, severe hypoglycaemia frequently complicates intensive glycaemic control. Blood biomarkers that predict successful intensification of glycaemic control in patients with type 2 diabetes without the development of severe hypoglycaemia would advance patient care. In patients who received intensive treatment for type 2 diabetes from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, we hypothesised that insulin deficiency and islet autoantibodies would be associated with severe hypoglycaemia and failure to achieve near-normal glycaemia (HbA1c <6.0% [42 mmol/mol]). METHODS: A nested case-control design was used. Cases (n = 326) were defined as participants having severe hypoglycaemia and failure to achieve an HbA1c level of <6.0% (42 mmol/mol) prior to the ACCORD transition or death. Controls (n = 1,075) were those who achieved an HbA1c level of <6.0% (42 mmol/mol) prior to the ACCORD transition or death without severe hypoglycaemia. Each case was matched (for race, age and BMI) by up to four controls. Baseline insulin deficiency (fasting C-peptide ≤0.15 nmol/l) and islet autoantibodies (glutamic acid decarboxylase [GAD], tyrosine phosphatase-related islet antigen 2 [IA2], insulin [IAA] and zinc transporter 8 [ZnT8]) were measured. Conditional logistic regression with and without adjustment for age, BMI and diabetes duration was used on the full cohort and after removal of patients who died and their respective controls. RESULTS: Severe hypoglycaemia accompanied by an inability to achieve an HbA1c level of <6.0% (42 mmol/mol) was associated with insulin deficiency (adjusted OR 23.2 [95% CI 9.0, 59.5], p < 0.0001), the presence of IAA autoantibodies or baseline insulin use (adjusted OR 3.8 [95% CI 2.7, 5.3], p < 0.0001), GAD autoantibodies (OR 3.9 [95% CI 2.5, 6.0], p < 0.0001), IA2 autoantibodies (OR 16.7 [95% CI 3.9, 71.6], p = 0.0001) and ZnT8 autoantibodies (adjusted OR 3.9 [95% CI 1.2, 12.4], p = 0.02). CONCLUSIONS: C-peptide and islet autoantibodies may serve as biomarkers to predict the risk of severe hypoglycaemia during intensification of type 2 diabetes treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT00000620 (original ACCORD study).


Assuntos
Biomarcadores/sangue , Doenças Cardiovasculares/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Hipoglicemia/sangue , Idoso , Autoanticorpos/química , Autoanticorpos/imunologia , Índice de Massa Corporal , Peptídeo C/sangue , Doenças Cardiovasculares/complicações , Estudos de Casos e Controles , Proteínas de Transporte de Cátions/sangue , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/imunologia , Feminino , Glutamato Descarboxilase/sangue , Humanos , Hipoglicemia/imunologia , Insulina/sangue , Ilhotas Pancreáticas/imunologia , Masculino , Microcirculação , Pessoa de Meia-Idade , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/sangue , Transportador 8 de Zinco
11.
Biol Blood Marrow Transplant ; 21(7): 1278-83, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25865649

RESUMO

Along with other childhood cancer survivors (CCS), hematopoietic cell transplantation (HCT) survivors are at high risk of treatment-related late effects, including cardiovascular disease and diabetes. Cardiometabolic risk factor abnormalities may be exacerbated by inadequate physical activity (PA). Relationships between PA and cardiometabolic risk factors have not been well described in CCS with HCT. PA (self reported), mobility (timed up and go test), endurance (6-minute walk test), handgrip strength, and cardiometabolic risk factors were measured in 119 HCT survivors and 66 sibling controls ages ≥18 years. Adjusted comparisons between HCT survivors and controls and between categories of low and high PA, mobility, endurance, and strength were performed with linear regression. Among HCT survivors, the high PA group had lower waist circumference (WC) (81.9 ± 2.5 versus 88.6 ± 3.1 cm ± standard error (SE), P = .009) than the low PA group, whereas the high endurance group had lower WC (77.8 ± 2.6 versus 87.8 ± 2.5 cm ± SE, P = .0001) and percent fat mass (33.6 ± 1.8 versus 39.4 ± 1.7% ± SE, P = .0008) and greater insulin sensitivity (IS) (10.9 ± 1.0 versus 7.42 ± 1.14 mg/kg/min ± SE via euglycemic insulin clamp, P = .001) than the low endurance group. Differences were greater in HCT survivors than in controls for WC between low and high PA groups, triglycerides between low and high mobility groups, and WC, systolic blood pressure, and IS between low and high endurance groups (all Pinteraction <.05). Higher endurance was associated with a more favorable cardiometabolic profile in HCT survivors, suggesting that interventions directed to increase endurance in survivors may reduce the risk of future cardiovascular disease.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Atividade Motora , Sobreviventes , Adulto , Pressão Sanguínea , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Feminino , Força da Mão/fisiologia , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/patologia , Humanos , Resistência à Insulina , Masculino , Resistência Física , Estudos Prospectivos , Fatores de Risco , Irmãos , Transplante Homólogo , Triglicerídeos/sangue , Circunferência da Cintura
12.
Pediatr Blood Cancer ; 62(2): 305-310, 2015 02.
Artigo em Inglês | MEDLINE | ID: mdl-25327738

RESUMO

BACKGROUND: Childhood cancer survivors (CCS) are at high risk of developing treatment-related late effects, including cardiovascular disease and diabetes. Late effects can be exacerbated by low physical activity (PA) levels. Relationships between PA and cardiovascular risk factors during childhood have not been well described in CCS. PROCEDURE: PA and cardiovascular risk factors were measured cross-sectionally in 319 CCS and 208 sibling controls aged 9-18 years. Comparisons between CCS and controls and associations of outcomes with PA (dichotomized at 60 min/day or treated as continuous) were performed with linear regression. RESULTS: Among CCS, the high PA group had lower percent fat mass (24.4% vs. 29.8%, P < 0.0001), abdominal subcutaneous fat (67.9 vs. 97.3 cm3 , P = 0.0004), and abdominal visceral fat (20.0 vs. 24.9 cm3 , P = 0.007) and greater lean body mass (41.3 vs. 39.5 kg, P = 0.009) than the low PA group. Comparing CCS to controls, differences in waist circumference (Pinteraction = 0.04), percent fat mass (Pinteraction = 0.04), and abdominal subcutaneous (Pinteraction = 0.02) and visceral (Pinteraction = 0.004) fat between low and high PA groups were greater in CCS than controls, possibly due to greater overall adiposity in CCS. CONCLUSIONS: High PA in CCS resulted in an improved cardiovascular profile, consisting primarily of lower fat mass and greater lean mass, similar to that observed in controls. This suggests interventions directed to increase PA in CCS may reduce the risk of future cardiovascular disease. Pediatr Blood Cancer 2015;62:305-310. © 2014 Wiley Periodicals, Inc.


Assuntos
Adiposidade/fisiologia , Doenças Cardiovasculares/epidemiologia , Exercício Físico/fisiologia , Neoplasias/terapia , Obesidade/fisiopatologia , Adolescente , Composição Corporal/fisiologia , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Fatores de Risco , Circunferência da Cintura/fisiologia
13.
Am J Physiol Endocrinol Metab ; 307(1): E124-31, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24844260

RESUMO

How endurance training alters muscle lipid metabolism while preserving insulin sensitivity remains unclear. Because acute free fatty acid (FFA) elevation by lipid infusion reduces insulin sensitivity, we hypothesized that training status would alter accumulation of muscle triacylglycerol (TAG), diacylglycerol (DAG), ceramide, and acylcarnitine during acute FFA elevation. Trained (n = 15) and sedentary (n = 13) participants matched for age, sex, and BMI received either a 6-h infusion of lipid (20% Intralipid at 90 ml/h) or glycerol (2.25 g/100 ml at 90 ml/h) during a hyperinsulinemic euglycemic clamp. Muscle biopsies were taken at 0, 120, and 360 min after infusion initiation to measure intramyocellular concentrations of TAG, DAG, ceramides, and acylcarnitines by liquid chromatography-tandem mass spectrometry. Trained participants had a higher Vo2 max and insulin sensitivity than sedentary participants. The lipid infusion produced a comparable elevation of FFA (594 ± 90 µmol/l in trained, 721 ± 30 µmol/l in sedentary, P = 0.4) and a decline in insulin sensitivity (-44.7% trained vs. -47.2% sedentary, P = 0.89). In both groups, lipid infusion increased the linoleic and linolenic acid content of TAG without changing total TAG. In the sedentary group, lipid infusion increased total, oleic, and linoleic acid and linolenic acid content of DAG. Regardless of training status, lipid infusion did not alter total ceramide, saturated ceramide, palmitoyl-carnitine, or oleoyl-carnitine. We conclude that during acute FFA elevation, trained adults have a similar decline in insulin sensitivity with less accumulation of muscle DAG than sedentary adults, suggesting that lipid-induced insulin resistance can occur without elevation of total muscle DAG.


Assuntos
Diglicerídeos/metabolismo , Exercício Físico/fisiologia , Ácidos Graxos não Esterificados/sangue , Músculo Esquelético/fisiologia , Condicionamento Físico Humano/métodos , Resistência Física/fisiologia , Aptidão Física/fisiologia , Adulto , Humanos , Masculino , Adulto Jovem
14.
Trends Endocrinol Metab ; 35(5): 413-424, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38331668

RESUMO

Most adults with type 1 diabetes (T1DM) are either overweight or obese. As such, dietary management is recommended as an adjunct to insulin treatment to improve glycemic control and facilitate weight loss in these patients. Time-restricted eating (TRE) is a form of intermittent fasting that offers a simplified approach to treating obesity in T1DM. TRE typically involves restricting eating to 6 to 10 h per day, with water and medications allowed outside the eating window. This review examines the efficacy of TRE and other fasting protocols in improving weight and glycemic control in patients with obesity and T1DM. This review will also evaluate the safety of these regimens and provide advice to clinicians on implementing intermittent fasting in T1DM.


Assuntos
Diabetes Mellitus Tipo 1 , Jejum , Humanos , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/terapia , Jejum/fisiologia , Obesidade/metabolismo , Obesidade/dietoterapia
15.
J Diabetes Complications ; 38(5): 108725, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38520820

RESUMO

AIM: To assess the association of adipose-to-lean ratio (ALR) with incident type 2 diabetes mellitus (T2DM), hypertension, and dyslipidemia in middle adulthood. METHOD: Black and White Coronary Artery Risk Development in Young Adults participants without T2DM, hypertension, or dyslipidemia in 2005-06 (baseline) were included. Baseline adipose and lean mass were assessed via dual-energy X-ray absorptiometry. ALR was calculated as adipose divided by lean mass and then standardized within sex strata. Single time-point incident morbidity was assessed every five years from baseline through 2016. Cox proportional hazards regression was used to estimate hazard ratios (HR) for morbidity over 10 years per 1-SD increment in ALR adjusted for cardiovascular risk factors. RESULT: The cumulative incidence of T2DM was 7.9 % (129 events/N = 1643; 16,301 person-years), 26.7 % (485 events/N = 1819; 17,895 person-years) for hypertension, and 49.1 % (435 events/N = 855, 8089 person-years) for dyslipidemia. In the adjusted models, ALR was positively associated with a risk of T2DM (HR [95 % CI]; 1.69 [1.31, 2.19]) and hypertension (1.23 [1.08, 1.40]). There was no significant interaction between ALR and sex for any morbidity. CONCLUSION: ALR in middle adulthood is associated with incident T2DM and hypertension. The extent to which localized body composition measures might inform morbidity risk merits further investigation.


Assuntos
Diabetes Mellitus Tipo 2 , Dislipidemias , Hipertensão , Humanos , Masculino , Feminino , Adulto , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Incidência , Estudos Longitudinais , Hipertensão/epidemiologia , Hipertensão/complicações , Adulto Jovem , Dislipidemias/epidemiologia , Dislipidemias/complicações , Adiposidade/fisiologia , Adolescente , Pessoa de Meia-Idade , Composição Corporal , Tecido Adiposo , Doenças Cardiovasculares/epidemiologia , Estados Unidos/epidemiologia , Fatores de Risco Cardiometabólico , Absorciometria de Fóton
16.
PLoS One ; 19(5): e0300037, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38709787

RESUMO

Fatty acid esters of hydroxy fatty acid (FAHFA) are anti-diabetic and anti-inflammatory lipokines. Recently FAHFAs were also found to predict cardiorespiratory fitness in a cross-sectional study of recreationally trained runners. Here we report the influences of body composition and gender on static FAHFA abundances in circulation. We compared the association between circulating FAHFA concentrations and body composition, determined by dual x-ray absorptiometry, in female recreational runners who were lean (BMI < 25 kg/m2, n = 6), to those who were overweight (BMI ≥ 25 kg/m2, n = 7). To characterize the effect of gender we also compared circulating FAHFAs in lean male recreational runners (n = 8) to recreationally trained lean female (n = 6) runner group. Circulating FAHFAs were increased in females in a manner that was modulated by specific adipose depot sizes, blood glucose, and lean body mass. As expected, circulating FAHFAs were diminished in the overweight group, but strikingly, within the lean cohort, increases in circulating FAHFAs were promoted by increased fat mass, relative to lean mass, while the overweight group showed a significantly attenuated relationship. These studies suggest multimodal regulation of circulating FAHFAs and raise hypotheses to test endogenous FAHFA dynamic sources and sinks in health and disease, which will be essential for therapeutic target development. Baseline circulating FAHFA concentrations could signal sub-clinical metabolic dysfunction in metabolically healthy obesity.


Assuntos
Composição Corporal , Corrida , Humanos , Feminino , Corrida/fisiologia , Masculino , Adulto , Ácidos Graxos/sangue , Fatores Sexuais , Sobrepeso/sangue , Absorciometria de Fóton , Estudos Transversais , Índice de Massa Corporal , Caracteres Sexuais
17.
J Pediatr ; 163(5): 1432-6, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23968741

RESUMO

OBJECTIVES: Little is known about the relation of pubertal development on endothelial function and arterial elasticity in children and adolescents; therefore, we compared brachial artery flow-mediated dilation and carotid artery elasticity across Tanner (pubertal) stages in children and adolescents. STUDY DESIGN: Blood pressure, fasting lipids, glucose and insulin, body fat, insulin sensitivity adjusted for lean body mass, brachial flow-mediated dilation (percent dilation and area under the curve), endothelium-independent dilation (peak dilation and area under the curve), and carotid artery elasticity were evaluated across pubertal stages (Tanner I vs Tanner II-IV vs Tanner V) in 344 children and adolescents (184 males, 160 females; ages 6 to 21 years). RESULTS: One hundred twenty-four subjects (mean age 8.23 ± 0.15 years; 52 females) were Tanner stage I; 105 subjects (mean age 13.19 ± 0.17 years; 47 females) were Tanner stages II-IV; and 115 subjects (mean age 17.19 ± 0.16 years; 61 females) were Tanner stage V. There were no significant differences for any of the measures of vascular structure and function across pubertal stages. CONCLUSION: Results of the current study indicate that smooth-muscle and endothelial function, as well as carotid artery elasticity, do not differ throughout pubertal development and that accounting for pubertal stage when reporting vascular data in children and adolescents may be unnecessary.


Assuntos
Velocidade do Fluxo Sanguíneo , Artéria Braquial/fisiologia , Artéria Carótida Primitiva/fisiologia , Endotélio Vascular/fisiologia , Puberdade , Tecido Adiposo , Adolescente , Área Sob a Curva , Glicemia/metabolismo , Pressão Sanguínea , Composição Corporal/fisiologia , Criança , Estudos Transversais , Elasticidade , Feminino , Humanos , Insulina/sangue , Lipídeos/sangue , Masculino , Adulto Jovem
18.
Pediatr Blood Cancer ; 60(3): 467-73, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23002034

RESUMO

BACKGROUND: Childhood cancer survivors (CCS) are at risk for growth hormone (GH) deficiency. CCS are also at increased risk for early mortality from cardiovascular (CV) disease, but the association between GH levels and CV risk remains poorly understood. The goal of this study was to examine the cross-sectional association between stimulated GH levels and CV risk factors in CCS younger than 18 years. PROCEDURE: A total of 276 CCS (147 males, 14.4 ± 2.6 years) ≥5 years after cancer diagnosis, and 208 sibling controls (112 males, 13.6 ± 2.4 years) participated in this cross-sectional study, which included anthropometry, body composition, and metabolic studies. Blunted response (BR) was defined as peak GH level <7 µg/L after clonidine and arginine. Insulin sensitivity (M(lbm) ) was measured by euglycemic hyperinsulinemic clamp. Statistical analyses used linear and logistic regression accounting for sibling clustering, adjusted for age, sex, Tanner stage, and adiposity. RESULTS: Thirty-four (12%) CCS showed BR to GH stimulation. BR CCS were shorter and had a lower IGF-1 than controls; only 6 of 34 received cranial radiation therapy. CCS with normal stimulated GH response were similar to controls for CV risk factors. Conversely, BR CCS had greater adiposity, higher lipids, and lower M(lbm) than controls. Differences in lipids and M(lbm) between BR CCS and controls remained significant after adjustment for BMI or visceral fat. CONCLUSIONS: BR to GH stimulation is prevalent in CCS youth and is associated with an unfavorable CV risk factor profile. Further studies are needed to establish the mechanisms of these associations.


Assuntos
Doenças Cardiovasculares/complicações , Hormônio do Crescimento Humano/deficiência , Neoplasias/complicações , Sobreviventes , Adiposidade/fisiologia , Adolescente , Doenças Cardiovasculares/metabolismo , Criança , Estudos Transversais , Feminino , Técnica Clamp de Glucose , Humanos , Resistência à Insulina/fisiologia , Masculino , Fatores de Risco
19.
BMC Pediatr ; 13: 133, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-24004899

RESUMO

BACKGROUND: Few studies have examined the relations of adiposity and lifestyle factors in young offspring with their parents as children (parentschild) or at their current age (parentsadult). Therefore, we compared measures of adiposity and lifestyle in parentschild and parentsadult with their offspring. METHODS: Two generations (one parent and his/her offspring) participated in this study: 234 parents from a previously established cohort and 382 offspring. Parentsadult and offspring underwent measurements for height, weight, waist circumference, % body fat, visceral fat, and lifestyle habits. Participants were classified as normal weight, overweight, obese based on age-specific BMI criteria. Mixed model linear regression analysis evaluated the associations of adiposity and lifestyle factors of parentschild and parentsadult with that of their offspring, adjusting for age, sex, race, and family membership. RESULTS: The prevalence of obesity was greater among offspring mean age 12.3 years compared to their parentschild mean age 12.6 years (18.4% vs 10.1%, p<0.001) even though hours of television (TV) watching were similar between the two generations as children (p=0.80). Sixty percent of parents (as children and adults) and offspring reported more than 2 hours of TV/day. Offspring of parents who were overweight and obese as children had greater BMI (all p<0.001) than offspring of parents who were normal weight as children. For both parentadult and offspring, adiposity was greater with greater total screen time. CONCLUSIONS: Identifying high-risk families is important for early intervention of overweight, especially in children.


Assuntos
Adiposidade/fisiologia , Computadores/estatística & dados numéricos , Obesidade , Sobrepeso , Pais , Comportamento Sedentário , Televisão/estatística & dados numéricos , Absorciometria de Fóton , Adolescente , Adulto , Fatores Etários , Índice de Massa Corporal , Criança , Feminino , Humanos , Masculino , Prevalência , Fatores de Risco , Fatores de Tempo
20.
J Diabetes Sci Technol ; : 19322968231184497, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37381607

RESUMO

BACKGROUND: The recent availability of high-quality data from clinical trials, together with machine learning (ML) techniques, presents exciting opportunities for developing prediction models for clinical outcomes. METHODS: As a proof-of-concept, we translated a hypoglycemia risk model derived from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study into the HypoHazardScore, a risk assessment tool applicable to electronic health record (EHR) data. To assess its performance, we conducted a 16-week clinical study at the University of Minnesota where participants (N = 40) with type 2 diabetes mellitus (T2DM) had hypoglycemia assessed prospectively by continuous glucose monitoring (CGM). RESULTS: The HypoHazardScore combines 16 risk factors commonly found within the EHR. The HypoHazardScore successfully predicted (area under the curve [AUC] = 0.723) whether participants experienced least one CGM-assessed hypoglycemic event (glucose <54 mg/dL for ≥15 minutes from two CGMs) while significantly correlating with frequency of CGM-assessed hypoglycemic events (r = 0.38) and percent time experiencing CGM-assessed hypoglycemia (r = 0.39). Compared to participants with a low HypoHazardScore (N = 19, score <4, median score of 4), participants with a high HypoHazardScore (N = 21, score ≥4) had more frequent CGM-assessed hypoglycemic events (high: 1.6 ± 2.2 events/week; low: 0.3 ± 0.5 events/week) and experienced more CGM-assessed hypoglycemia (high: 1.4% ± 2.0%; low: 0.2% ± 0.4% time) during the 16-week follow-up. CONCLUSIONS: We demonstrated that a hypoglycemia risk model can be successfully adapted from the ACCORD data to the EHR, with validation by a prospective study using CGM-assessed hypoglycemia. The HypoHazardScore represents a significant advancement toward implementing an EHR-based decision support system that can help reduce hypoglycemia in patients with T2DM.

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