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1.
Obesity (Silver Spring) ; 31(10): 2493-2504, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37670579

RESUMEN

OBJECTIVE: Insulin resistance is characterized by ectopic fat accumulation leading to cardiac diastolic dysfunction and nonalcoholic fatty liver disease. The objective of this study was to determine whether treatment with the peroxisome proliferator-activated receptor-α (PPARα) agonist ciprofibrate has direct effects on cardiac and hepatic metabolism and can improve insulin sensitivity and cardiac function in insulin-resistant volunteers. METHODS: Ten insulin-resistant male volunteers received 100 mg/d of ciprofibrate and placebo for 5 weeks in a randomized double-blind crossover study. Insulin-stimulated metabolic rate of glucose (MRgluc) was measured using dynamic 18 F-fluorodeoxyglucose-positron emission tomography (18 F-FDG-PET). Additionally, cardiac function, whole-body insulin sensitivity, intrahepatic lipid content, skeletal muscle gene expression, 24-hour blood pressure, and substrate metabolism were measured. RESULTS: Whole-body insulin sensitivity, energy metabolism, and body composition were unchanged after ciprofibrate treatment. Ciprofibrate treatment decreased insulin-stimulated hepatic MRgluc and increased hepatic lipid content. Myocardial net MRgluc tended to decrease after ciprofibrate treatment, but ciprofibrate treatment had no effect on cardiac function and cardiac energy status. In addition, no changes in PPAR-related gene expression in muscle were found. CONCLUSIONS: Ciprofibrate treatment increased hepatic lipid accumulation and lowered MRgluc, without affecting whole-body insulin sensitivity. Furthermore, parameters of cardiac function or cardiac energy status were not altered upon ciprofibrate treatment.


Asunto(s)
Resistencia a la Insulina , Insulina , Masculino , Humanos , PPAR alfa , Estudios Cruzados , Hipoglucemiantes , Músculo Esquelético , Fluorodesoxiglucosa F18 , Lípidos
2.
Cell Rep ; 42(9): 113131, 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37708023

RESUMEN

Cold-induced brown adipose tissue (BAT) activation is considered to improve metabolic health. In murine BAT, cold increases the fundamental molecule for mitochondrial function, nicotinamide adenine dinucleotide (NAD+), but limited knowledge of NAD+ metabolism during cold in human BAT metabolism exists. We show that cold increases the serum metabolites of the NAD+ salvage pathway (nicotinamide and 1-methylnicotinamide) in humans. Additionally, individuals with cold-stimulated BAT activation have decreased levels of metabolites from the de novo NAD+ biosynthesis pathway (tryptophan, kynurenine). Serum nicotinamide correlates positively with cold-stimulated BAT activation, whereas tryptophan and kynurenine correlate negatively. Furthermore, the expression of genes involved in NAD+ biosynthesis in BAT is related to markers of metabolic health. Our data indicate that cold increases serum tryptophan conversion to nicotinamide to be further utilized by BAT. We conclude that NAD+ metabolism is activated upon cold in humans and is probably regulated in a coordinated fashion by several tissues.

3.
Nucl Med Commun ; 43(5): 510-517, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35081092

RESUMEN

OBJECTIVE: The aim of this study was to compare reprojected bone SPECT/CT (RBS) against planar bone scintigraphy (BS) in the detection of bone metastases in breast and prostate cancer patients. METHODS: Twenty-six breast and 105 prostate cancer patients with high risk for bone metastases underwent 99mTc-HMDP BS and whole-body SPECT/CT, 1.5-T whole-body diffusion-weighted MRI and 18F-NaF or 18F-PSMA-1007 PET/CT within two prospective clinical trials (NCT01339780 and NCT03537391). Consensus reading of all imaging modalities and follow-up data were used to define the reference standard diagnosis. The SPECT/CT data were reprojected into anterior and posterior views to produce RBS images. Both BS and RBS images were independently double read by two pairs of experienced nuclear medicine physicians. The findings were validated against the reference standard diagnosis and compared between BS and RBS on the patient, region and lesion levels. RESULTS: All metastatic patients detected by BS were also detected by RBS. In addition, three metastatic patients were missed by BS but detected by RBS. The average patient-level sensitivity of two readers for metastases was 75% for BS and 87% for RBS, and the corresponding specificity was 79% for BS and 39% for RBS. The average region-level sensitivity of two readers was 64% for BS and 69% for RBS, and the corresponding specificity was 96% for BS and 87% for RBS. CONCLUSION: Whole-body bone SPECT/CT can be reprojected into more familiar anterior and posterior planar images with excellent sensitivity for bone metastases, making additional acquisition of planar BS unnecessary.


Asunto(s)
Neoplasias Óseas , Neoplasias de la Próstata , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/secundario , Ensayos Clínicos como Asunto , Humanos , Masculino , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios Prospectivos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Sensibilidad y Especificidad , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único
4.
Clin Nucl Med ; 46(12): 952-957, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34619699

RESUMEN

PURPOSE OF THE REPORT: The aim of this study was to evaluate the distribution of hypoxia using 18F-EF5 as a hypoxia tracer in cervical cancer patients with PET/MRI. We investigated the association between this 18F-EF5-PET tracer and the immunohistochemical expression of endogenous hypoxia markers: HIF1α, CAIX, and GLUT1. PATIENTS AND METHODS: Nine patients with biopsy-proven primary squamous cell cervix carcinoma (FIGO 2018 radiological stages IB1-IIIC2r) were imaged with dual tracers 18F-EF5 and 18F-FDG using PET/MRI (Int J Gynaecol Obstet. 2019;145:129-135). 18F-EF5 images were analyzed by calculating the tumor-to-muscle ratio to determine the hypoxic tissue (T/M ratio >1.5) and further hypoxic subvolume (HSV) and percentage hypoxic area. These 18F-EF5 hypoxic parameters were correlated with the size and localization of tumors in 18F-FDG PET/MRI and the results of hypoxia immunohistochemistry. RESULTS: All primary tumors were clearly 18F-FDG and 18F-EF5 PET positive and heterogeneously hypoxic with multiple 18F-EF5-avid areas in locally advanced cancer and single areas in clinically stage I tumors. The location of hypoxia was detected mainly in the periphery of tumor. Hypoxia parameters 18F-EF5 max T/M ratio and HSV in primary tumors correlated independently with the advanced stage (P = 0.036 and P = 0.040, respectively), and HSV correlated with the tumor size (P = 0.027). The location of hypoxia in 18F-EF5 imaging was confirmed with a higher hypoxic marker expression HIF1α and CAIX in tumor fresh biopsies. CONCLUSIONS: The 18F-EF5 imaging has promising potential in detecting areas of tumor hypoxia in cervical cancer.


Asunto(s)
Hipoxia Tumoral , Neoplasias del Cuello Uterino , Hipoxia de la Célula , Etanidazol , Femenino , Radioisótopos de Flúor , Humanos , Hidrocarburos Fluorados , Hipoxia/diagnóstico por imagen , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Radiofármacos , Neoplasias del Cuello Uterino/diagnóstico por imagen
5.
Obesity (Silver Spring) ; 29(3): 543-549, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33528921

RESUMEN

OBJECTIVE: Gray matter (GM) volume in different brain loci has been shown to vary in obesity and diabetes, and elevated fasting plasma nonesterified fatty acid (NEFA) levels have been suggested as one potential mechanism. The hypothesis presented in this study is that brown adipose tissue (BAT) activity may correlate with GM volume in areas negatively associated with obesity and diabetes. METHODS: A total of 36 healthy patients (M/F: 12/24, age 39.7 ± 9.4 years, BMI 27.5 ± 5.6 kg/m2 ) were imaged with positron emission tomography using fatty acid analog [18 F]FTHA to measure NEFA uptake and with [15 O]H2 O to measure perfusion during cold exposure, at room temperature during fasting, or during a postprandial state. A 2-hour hyperinsulinemic euglycemic clamp was performed to measure whole-body insulin sensitivity (M value, mean 7.6 ± 3.9 mg/kg/min). T1-weighted magnetic resonance imaging at 1.5 T was performed on all patients. RESULTS: BAT NEFA uptake was associated directly with GM volume in anterior cerebellum and occipital lobe (P ≤ 0.04) when adjusted for age, gender, and intra-abdominal fat volume and with anterior cerebellum, limbic lobe, and temporal lobe GM volumes when adjusted for M value. CONCLUSIONS: BAT NEFA metabolism may participate in protection from cognitive degeneration associated with cardiometabolic risk factors, such as central obesity and insulin resistance. Potential causal relationships between BAT activity and GM volumes remain to be examined.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Sustancia Gris/diagnóstico por imagen , Tejido Adiposo Pardo/anatomía & histología , Tejido Adiposo Pardo/diagnóstico por imagen , Adulto , Ayuno/metabolismo , Ácidos Grasos/administración & dosificación , Ácidos Grasos/farmacocinética , Ácidos Grasos no Esterificados/administración & dosificación , Ácidos Grasos no Esterificados/farmacocinética , Femenino , Técnica de Clampeo de la Glucosa , Sustancia Gris/anatomía & histología , Voluntarios Sanos , Humanos , Resistencia a la Insulina/fisiología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Tomografía de Emisión de Positrones/métodos , Periodo Posprandial
6.
Physiol Rep ; 9(3): e14718, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33580902

RESUMEN

BACKGROUND: Sympathetic activity causes changes in electrocardiogram (ECG) during cold exposure and the changes have been studied mostly during hypothermia and less during mild acute nonshivering cold exposure. Cold-induced sympathetic activity also activates brown adipose tissue (BAT) and increases arterial blood pressure (BP) and plasma catecholamine levels. We examined changes in ECG parameters during acute nonshivering cold exposure and their associations with markers of sympathetic activity during cold exposure: brachial blood pressure (BP), plasma catecholamine levels, and BAT activity measured by positron emission tomography (PET). METHODS AND RESULTS: Healthy subjects (M/F = 13/24, aged 20-55 years) were imaged with [15 O]H2 O (perfusion, N = 37) and [18 F]FTHA to measure plasma nonesterified fatty acid uptake (NEFA uptake, N = 37) during 2-h nonshivering cold exposure. 12-lead ECG (N = 37), plasma catecholamine levels (N = 17), and brachial BP (N = 31) were measured at rest in room temperature (RT) and re-measured after a 2-h nonshivering cold exposure. There were significant differences between RT and cold exposure in P axis (35.6 ± 26.4 vs. 50.8 ± 22.7 degrees, p = 0.005), PR interval (177.7 ± 24.6 ms vs.163.0 ± 28.7 ms, p = 0.001), QRS axis (42.1 ± 31.3 vs. 56.9 ± 24.1, p = 0.003), and QT (411.7 ± 25.5 ms vs. 434.5 ± 39.3 ms, p = 0.001). There was no significant change in HR, QRS duration, QTc, JTc, and T axis during cold exposure. Systolic BP (127.2 ± 15.7 vs. 131.8 ± 17.9 mmHg, p = 0.008), diastolic BP (81.7 ± 12.0 vs. 85.4 ± 13.0 mmHg, p = 0.02), and plasma noradrenaline level increased during cold exposure (1.97 ± 0.61 vs. 5.07 ± 1.32 µmol/L, p = 0.001). Cold-induced changes in ECG parameters did not correlate with changes in BAT activity, brachial BP, plasma catecholamines, or skin temperature. CONCLUSIONS: During short-term nonshivering cold exposure, there were increases in P axis, PR interval, QRS axis, and QT compared to RT in healthy adults. Cold-induced changes in ECG parameters did not correlate with BAT activity, brachial BP, or plasma catecholamine levels which were used as markers of cold-induced sympathetic activity.


Asunto(s)
Tejido Adiposo Pardo/inervación , Presión Arterial , Arteria Braquial/inervación , Catecolaminas/sangre , Frío , Electrocardiografía , Voluntarios Sanos , Frecuencia Cardíaca , Sistema Nervioso Simpático/fisiología , Adaptación Fisiológica , Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Pardo/metabolismo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones , Sistema Nervioso Simpático/metabolismo , Factores de Tiempo , Adulto Joven
7.
Temperature (Austin) ; 7(4): 363-388, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33251282

RESUMEN

Noninvasive imaging methods of internal body temperature are in high demand in both clinical medicine and physiological research. Thermography and thermometry can be used to assess tissue temperature during thermal therapies: ablative and hyperthermia treatments to ensure adequate temperature rise in target tissues but also to avoid collateral damage by heating healthy tissues. In research use, measurement of internal body temperature enables us the production of thermal maps on muscles, internal organs, and other tissues of interest. The most used methods for noninvasive imaging of internal body temperature are based on different parameters acquired with magnetic resonance imaging, ultrasound, computed tomography, microwave radiometry, photoacoustic imaging, and near-infrared spectroscopy. In the current review, we examine the aforementioned imaging methods, their use in estimating internal body temperature in vivo with their advantages and disadvantages, and the physical phenomena the thermography or thermometry modalities are based on.

8.
Arterioscler Thromb Vasc Biol ; 40(5): 1289-1295, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31941384

RESUMEN

OBJECTIVE: Brown adipose tissue (BAT) activity correlates negatively with obesity and insulin resistance, and BAT has been suggested to act as a protective factor against atherogenesis. We aimed to examine subclinical atherosclerosis and risk factor levels in a group of individuals who had 5 years earlier participated in positron-emission tomography studies with measurements of BAT activity. Approach and Results: Study cohort (males/females=5/26, baseline age 41.4±7.9 years; body mass index, 26.8±6.3 kg/m2) underwent positron-emission tomography imaging at baseline with [18F] FDG (glucose uptake) and [15O] H2O (perfusion) to measure BAT activity during cold exposure. At 5-year follow-up, ultrasound was performed to measure carotid intima-media thickness, carotid distensibility (a marker of arterial elasticity), and brachial flow-mediated dilation (an estimate of endothelial function). Fasting plasma lipids and hemoglobin A1c were measured from venous samples at baseline and at follow-up. Median values were used as cut points for high cold-induced BAT activity (BAT glucose uptake >2.40 µmoL/100 g per minute and perfusion >8.4 mL/100 g per minute). Baseline cold-induced BAT glucose uptake and perfusion correlated directly with carotid distensibility and inversely with mean bulbus intima-media thickness and maximum intima-media thickness (P always ≤0.02). Baseline body mass index, plasma triglycerides, and HbA1c correlated negatively with BAT glucose uptake and perfusion in cold (P always ≤0.048). Correlations between cold-induced BAT activity, cardiovascular risk factors, and atherosclerosis were attenuated with corrections for multiple comparisons. CONCLUSIONS: Cold-induced BAT activity at baseline seems to correlate with lower levels of conventional cardiovascular risk factors at baseline and with lower carotid intima-media thickness and higher carotid elasticity at 5-year follow-up.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Enfermedades de las Arterias Carótidas/etiología , Metabolismo Energético , Tejido Adiposo Pardo/diagnóstico por imagen , Adulto , Enfermedades Asintomáticas , Glucemia/metabolismo , Índice de Masa Corporal , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/metabolismo , Grosor Intima-Media Carotídeo , Femenino , Fluorodesoxiglucosa F18/administración & dosificación , Hemoglobina Glucada/metabolismo , Humanos , Lípidos/sangre , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Valor Predictivo de las Pruebas , Pronóstico , Radiofármacos/administración & dosificación , Factores de Riesgo , Factores de Tiempo
9.
Cell Metab ; 28(2): 207-216.e3, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-29909972

RESUMEN

Human studies suggest that a meal elevates glucose uptake in brown adipose tissue (BAT). However, in postprandial state the thermogenic activity and the metabolism of non-esterified fatty acids (NEFAs) in BAT remain unclear. Using indirect calorimetry combined with positron emission tomography and computed tomography (PET/CT), we showed that whole-body and BAT thermogenesis (oxygen consumption) increases after the ingestion of a mixed carbohydrate-rich meal, to the same extent as in cold stress. Postprandial NEFA uptake into BAT is minimal, possibly due to elevated plasma insulin inhibiting lipolysis. However, the variation in postprandial NEFA uptake is linked to BAT thermogenesis. We identified several genes participating in lipid metabolism to be expressed at higher levels in BAT compared with white fat in postprandial state, and to be positively correlated with BAT UCP1 expression. These findings suggest that substrates preferred by BAT in postprandial state are glucose or LPL-released NEFAs due to insulin stimulation.


Asunto(s)
Tejido Adiposo Pardo/fisiología , Respuesta al Choque por Frío , Dieta de Carga de Carbohidratos , Ácidos Grasos no Esterificados/metabolismo , Consumo de Oxígeno , Termogénesis , Tejido Adiposo Blanco/metabolismo , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Insulina/metabolismo , Lipólisis , Masculino , Persona de Mediana Edad , Obesidad/metabolismo , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Periodo Posprandial , Proteína Desacopladora 1/metabolismo
10.
Metabolism ; 70: 23-30, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28403942

RESUMEN

OBJECTIVE: Brown adipose tissue (BAT) is compositionally distinct from white adipose tissue (WAT) in terms of triglyceride and water content. In adult humans, the most significant BAT depot is localized in the supraclavicular area. Our aim is to differentiate brown adipose tissue from white adipose tissue using fat T2* relaxation time mapping and signal-fat-fraction (SFF) analysis based on a commercially available modified 2-point-Dixon (mDixon) water-fat separation method. We hypothesize that magnetic resonance (MR) imaging can reliably measure BAT regardless of the cold-induced metabolic activation, with BAT having a significantly higher water and iron content compared to WAT. MATERIAL AND METHODS: The supraclavicular area of 13 volunteers was studied on 3T PET-MRI scanner using T2* relaxation time and SFF mapping both during cold exposure and at ambient temperature; and 18F-FDG PET during cold exposure. Volumes of interest (VOIs) were defined semiautomatically in the supraclavicular fat depot, subcutaneous WAT and muscle. RESULTS: The supraclavicular fat depot (assumed to contain BAT) had a significantly lower SFF and fat T2* relaxation time compared to subcutaneous WAT. Cold exposure did not significantly affect MR-based measurements. SFF and T2* values measured during cold exposure and at ambient temperature correlated inversely with the glucose uptake measured by 18F-FDG PET. CONCLUSIONS: Human BAT can be reliably and safely assessed using MRI without cold activation and PET-related radiation exposure.


Asunto(s)
Tejido Adiposo Pardo/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Tejido Adiposo Blanco/diagnóstico por imagen , Adulto , Frío , Fluorodesoxiglucosa F18 , Humanos , Hierro/metabolismo , Tomografía de Emisión de Positrones/métodos , Agua
11.
J Clin Endocrinol Metab ; 102(7): 2258-2267, 2017 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-28368474

RESUMEN

Context: Metabolic imaging studying brown adipose tissue (BAT) physiology has increased, in which computed tomography (CT) is commonly used as an anatomical reference for metabolic positron emission tomography (PET) imaging. However, the capacity of CT to provide metabolic information has been underexploited. Objective: To evaluate whether CT radiodensity of BAT could noninvasively estimate underlying tissue morphology, regarding amount of stored triglycerides. Furthermore, could the alteration in tissue characteristics due to cold stimulus, as a marker for active BAT, be detected with radiodensity? Can BAT be differentiated from white adipose tissue (WAT) solely using CT-based measurements? Design, Setting, and Participants: A cross-sectional study evaluating 66 healthy human subjects with CT, PET, and 1H-magnetic resonance spectroscopy (1H-MRS). Main Outcome Measures: BAT radiodensity was measured with CT. BAT-stored triglyceride content was measured with 1H-MRS. Arterial blood volume in BAT, as a marker of tissue vascularity, was measured with [15O]H2O, along with glucose or fatty acid uptake using [18F]2-fluoro-2-deoxy-D-glucose or 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid PET imaging, respectively. Results: BAT radiodensity was found to be correlating with tissue-retained blood and triglyceride content. Cold stimulus induced an increase in BAT radiodensity. Active BAT depots had higher radiodensity than both nonactive BAT and WAT. BAT radiodensity associated with systemic metabolic health parameters. Conclusion: BAT radiodensity can be used as a marker of underlying tissue morphology. Active BAT can be identified using CT, exploiting tissue composition information. Moreover, BAT radiodensity provides an insight into whole-body systemic metabolic health.


Asunto(s)
Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Pardo/metabolismo , Adulto , Antropometría/métodos , Frío , Estudios Transversales , Femenino , Humanos , Espectroscopía de Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos , Triglicéridos/metabolismo
12.
J Clin Endocrinol Metab ; 102(4): 1200-1207, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28323929

RESUMEN

Background and Aim: The metabolic activity of human brown adipose tissue (BAT) has been previously examined using positron emission tomography (PET). The aim of this study was to use proton magnetic resonance spectroscopy (1H MRS) to investigate whether the temperature and the fat fraction (FF) of BAT and white adipose tissue (WAT) are associated with BAT metabolic activity determined by deoxy-2-18F-fluoro-d-glucose (18F-FDG)-PET. Materials and Methods: Ten healthy subjects (four women, six men; 25 to 45 years of age) were studied using PET-magnetic resonance imaging during acute cold exposure and at ambient room temperature. BAT and subcutaneous WAT 1H MRS were measured. The tissue temperature and the FF were derived from the spectra. Tissue metabolic activity was studied through glucose uptake using dynamic FDG PET scanning during cold exposure. A 2-hour hyperinsulinemic euglycemic clamp was performed on eight subjects. Results: The metabolic activity of BAT associated directly with the heat production capacity and inversely with the FF of the tissue. In addition, the lipid-burning capacity of BAT associated with whole-body insulin sensitivity. During cold exposure, the FF of BAT was lower than at room temperature, and cold-induced FF of BAT associated inversely with high-density lipoprotein and directly with low-density lipoprotein cholesterol. Conclusion: Both 1H MRS-derived temperature and FF are promising methods to study BAT activity noninvasively. The association between the lipid-burning capacity of BAT and whole-body insulin sensitivity emphasizes the role of BAT in glucose handling. Furthermore, the relation of FF to high-density lipoprotein and low-density lipoprotein cholesterol suggests that BAT has a role in lipid clearance, thus protecting tissues from excess lipid load.


Asunto(s)
Tejido Adiposo Pardo/metabolismo , Adiposidad/fisiología , Regulación de la Temperatura Corporal/fisiología , Espectroscopía de Resonancia Magnética/métodos , Termometría/métodos , Tejido Adiposo Pardo/diagnóstico por imagen , Adulto , Frío , Estudios de Factibilidad , Femenino , Fluorodesoxiglucosa F18 , Técnica de Clampeo de la Glucosa , Voluntarios Sanos , Humanos , Resistencia a la Insulina , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo , Masculino , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Radiofármacos , Grasa Subcutánea/metabolismo
13.
PLoS One ; 11(9): e0163723, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27669153

RESUMEN

Bone marrow insulin sensitivity may be an important factor for bone health in addition to bone mineral density especially in insulin resistant conditions. First we aimed to study if prenatal maternal obesity plays a role in determining bone marrow insulin sensitivity in elderly female offspring. Secondly we studied if a four-month individualized resistance training intervention increases bone marrow insulin sensitivity in elderly female offspring and whether this possible positive outcome is regulated by the offspring's mother's obesity status. 37 frail elderly females (mean age 71.9 ± 3.1 years) of which 20 were offspring of lean/normal-weight mothers (OLM, maternal BMI ≤ 26.3 kg/m2) and 17 were offspring of obese/overweight mothers (OOM, maternal BMI ≥ 28.1 kg/m2) were studied before and after a four-month individualized resistance training intervention. Nine age- and sex-matched non-frail controls (maternal BMI ≤ 26.3 kg/m2) were studied at baseline. Femoral bone marrow (FBM) and vertebral bone marrow (VBM) insulin sensitivity were measured using [18F]fluoro-2-deoxy-D-glucose positron emission tomography with computer tomography under hyperinsulinemic euglycemic clamp. We found that bone marrow insulin sensitivity was not related to maternal obesity status but FBM insulin sensitivity correlated with whole body insulin sensitivity (R = 0.487, p = 0.001). A four-month resistance training intervention increased FBM insulin sensitivity by 47% (p = 0.006) only in OOM, while VBM insulin sensitivity remained unchanged regardless of the maternal obesity status. In conclusion, FBM and VBM glucose metabolism reacts differently to a four-month resistance training intervention in elderly women according to their maternal obesity status. TRIAL REGISTRATION: ClinicalTrials.gov NCT01931540.


Asunto(s)
Médula Ósea/metabolismo , Fémur , Resistencia a la Insulina , Obesidad/fisiopatología , Sobrepeso/fisiopatología , Entrenamiento de Fuerza , Anciano , Estudios de Casos y Controles , Femenino , Fémur/diagnóstico por imagen , Anciano Frágil , Glucosa/metabolismo , Humanos , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X
14.
Eur J Endocrinol ; 175(6): 571-582, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27634943

RESUMEN

OBJECTIVE: Non-pharmacological interventions are important in reducing risk for osteoporotic fractures. We investigated the effects of a 16-week individualized resistance training intervention on bone mineral density (BMD), bone turnover markers and 10-year relative risk (RR) for osteoporotic fracture. DESIGN: Interventional study with a follow-up. METHODS: In total, 37 elderly women (mean age 71.9 ± 3.1 years) with decreased muscle strength participated in the resistance training intervention three times per week with 60 min per session for 16 weeks under the supervision of a licensed physiotherapist. Total hip BMD with quantitative CT, bone markers (sclerostin, osteocalcin, CTX, PINP, IGF-1, 25(OH)-D) and 10-year RR for osteoporotic fracture were measured at baseline, post-intervention and at 1-year follow-up after the end of the intervention. Eleven age- and sex-matched controls did not participate in the intervention but were studied at baseline and at 1-year follow-up. RESULTS: Resistance training seemed to increase total hip BMD by 6% (P = 0.005). Sclerostin (P < 0.001) and total osteocalcin (P = 0.04) increased while other bone markers remained unchanged. A 10-year RR for major osteoporotic and hip fracture remained unchanged. At follow-up total hip BMD (P < 0.001) decreased back to the baseline level with a simultaneous decrease in serum sclerostin (P = 0.045), CTX (P < 0.001) and an increase in 25(OH)-D (P < 0.001), 10-year RR for major osteoporotic (P = 0.002) and hip fracture (P = 0.01). CONCLUSIONS: Our findings suggest an important role of continuous supervised resistance training for the prevention of osteoporotic fractures in elderly women with decreased muscle strength.


Asunto(s)
Densidad Ósea/fisiología , Intervención Médica Temprana/métodos , Fuerza Muscular/fisiología , Fracturas Osteoporóticas/prevención & control , Entrenamiento de Fuerza/métodos , Anciano , Femenino , Estudios de Seguimiento , Humanos , Fracturas Osteoporóticas/diagnóstico , Fracturas Osteoporóticas/metabolismo , Factores de Tiempo
15.
Eur J Nucl Med Mol Imaging ; 43(10): 1878-86, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26993316

RESUMEN

PURPOSE: Brown adipose tissue (BAT) is considered a potential target for combatting obesity, as it produces heat instead of ATP in cellular respiration due to uncoupling protein-1 (UCP-1) in mitochondria. However, BAT-specific thermogenic capacity, in comparison to whole-body thermogenesis during cold stimulus, is still controversial. In our present study, we aimed to determine human BAT oxygen consumption with [(15)O]O2 positron emission tomography (PET) imaging. Further, we explored whether BAT-specific energy expenditure (EE) is associated with BAT blood flow, non-esterified fatty acid (NEFA) uptake, and whole-body EE. METHODS: Seven healthy study subjects were studied at two different scanning sessions, 1) at room temperature (RT) and 2) with acute cold exposure. Radiotracers [(15)O]O2, [(15)O]H2O, and [(18)F]FTHA were given for the measurements of BAT oxygen consumption, blood flow, and NEFA uptake, respectively, with PET-CT. Indirect calorimetry was performed to assess differences in whole-body EE between RT and cold. RESULTS: BAT-specific EE and oxygen consumption was higher during cold stimulus (approx. 50 %); similarly, whole-body EE was higher during cold stimulus (range 2-47 %). However, there was no association in BAT-specific EE and whole-body EE. BAT-specific EE was found to be a minor contributor in cold induced whole-body thermogenesis (almost 1 % of total whole-body elevation in EE). Certain deep muscles in the cervico-thoracic region made a major contribution to this cold-induced thermogenesis (CIT) without any visual signs or individual perception of shivering. Moreover, BAT-specific EE associated with BAT blood flow and NEFA uptake both at RT and during cold stimulus. CONCLUSION: Our study suggests that BAT is a minor and deep muscles are a major contributor to CIT. In BAT, both in RT and during cold, cellular respiration is linked with circulatory NEFA uptake.


Asunto(s)
Tejido Adiposo Pardo/diagnóstico por imagen , Tejido Adiposo Pardo/fisiología , Respuesta al Choque por Frío/fisiología , Consumo de Oxígeno/fisiología , Tomografía de Emisión de Positrones/métodos , Termogénesis/fisiología , Adulto , Frío , Femenino , Humanos , Masculino , Radioisótopos de Oxígeno , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
16.
Diabetologia ; 59(1): 77-86, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26486356

RESUMEN

AIMS/HYPOTHESIS: Maternal obesity predisposes offspring to adulthood morbidities, including type 2 diabetes. Type 2 diabetes and insulin resistance have been associated with shortened telomere length. First, we aimed to investigate whether or not maternal obesity influences insulin sensitivity and its relationship with leucocyte telomere length (LTL) in elderly women. Second, we tested whether or not resistance exercise training improves insulin sensitivity in elderly frail women. METHODS: Forty-six elderly women, of whom 20 were frail offspring of lean/normal weight mothers (OLM, BMI ≤26.3 kg/m2) and 17 were frail offspring of overweight/obese mothers (OOM,BMI ≥28.1 kg/m2), were studied before and after a 4 month resistance training (RT) intervention. Muscle insulin sensitivity of glucose uptake was measured using 18F-fluoro-2-deoxyglucose and positron emission tomography with computed tomography during a hyperinsulinaemic­euglycaemic clamp. Muscle mass and lipid content were measured using magnetic resonance and LTL was measured using real-time PCR. RESULTS: The OOM group had lower thigh muscle insulin sensitivity compared with the OLM group (p=0.048) but similar whole body insulin sensitivity. RT improved whole body and skeletal muscle insulin sensitivity in the OOM group only (p=0.004 and p=0.013, respectively), and increased muscle mass in both groups (p <0 .01). In addition, in the OOM group, LTL correlated with different thigh muscle groups insulin sensitivity (ρ ≥ 0.53; p ≤ 0.05). Individuals with shorter LTL showed a higher increase in skeletal muscle insulin sensitivity after training (ρ ≥ −0.61; p ≤ 0.05). CONCLUSIONS/INTERPRETATION: Maternal obesity and having telomere shortening were associated with insulin resistance in adult offspring. A resistance exercise training programme may reverse this disadvantage among offspring of obese mothers. Trial registration: ClinicalTrials.gov NCT01931540.


Asunto(s)
Insulina/metabolismo , Músculo Esquelético/metabolismo , Obesidad/complicaciones , Sobrepeso/complicaciones , Efectos Tardíos de la Exposición Prenatal , Entrenamiento de Fuerza , Anciano , Femenino , Fluorodesoxiglucosa F18 , Anciano Frágil , Glucosa/química , Humanos , Hiperinsulinismo/metabolismo , Procesamiento de Imagen Asistido por Computador , Resistencia a la Insulina , Leucocitos/citología , Leucocitos Mononucleares/citología , Lípidos/química , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Músculo Esquelético/patología , Tomografía de Emisión de Positrones , Embarazo , Reacción en Cadena en Tiempo Real de la Polimerasa , Telómero/ultraestructura , Tomografía Computarizada por Rayos X
17.
Atherosclerosis ; 224(1): 208-12, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22840426

RESUMEN

AIMS: Hypofibrinolysis displayed by elevated serum plasminogen activator inhibitor 1 (PAI-1) level has been associated with cardiovascular disease (CVD) and its risk factors such as obesity and insulin resistance. However, no studies have examined associations between PAI-1 and CVD risk factors in healthy subjects. We examined associations between serum PAI-1, ultrasound markers of atherosclerosis and CVD risk factors and whether PAI-1 improves prediction of atherosclerosis over known risk factors in a cohort of asymptomatic adults. METHODS: We analyzed PAI-1 and CVD risk factors and assessed carotid intima-media thickness (cIMT), distensibility (CDist) and the presence of a carotid atherosclerotic plaque and flow-mediated dilation (FMD) ultrasonographically for 2202 adults (993 men and 1,209 women, aged 30-45 years) participating in the ongoing longitudinal cohort study, The Cardiovascular Risk in Young Finns Study. High cIMT was defined as >90th percentile and/or carotid plaque and low CDist and low FMD as <20th percentile. RESULTS: In bivariate analyses, PAI-1 correlated directly with cIMT and the risk factors: blood pressure, BMI, waist and hip circumference, alcohol use, total and LDL-cholesterol, triglycerides, glomerular filtration rate, high-sensitivity CRP and glucose (all P<0.005). PAI-1 was higher in men and increased with age. Inverse correlation was observed with CDist, HDL-cholesterol and adiponectin in both sexes, with testosterone and sex hormone binding globulin in men and with creatinine and oral contraceptive use in women (P<0.005). Independent direct associations were observed between PAI-1 and waist circumference, serum triglycerides, insulin, alcohol use and age and inverse with serum creatinine, HDL-cholesterol and adiponectin. PAI-1 did not improve estimation of high cIMT, low CDist and low FMD over conventional risk factors (P for difference in area under curve ≥ 0.37). CONCLUSION: PAI-1 was independently associated with several known CVD risk factors, especially obesity markers, in both men and women. However, addition of PAI-1 to known risk factors did not improve cross-sectional prediction of high cIMT, low CDist and low FMD suggesting that PAI-1 is not a clinically important biomarker in early atherosclerosis.


Asunto(s)
Enfermedades Cardiovasculares/fisiopatología , Inhibidor 1 de Activador Plasminogénico/sangre , Adulto , Biomarcadores/sangre , Enfermedades Cardiovasculares/etiología , Grosor Intima-Media Carotídeo , HDL-Colesterol/sangre , Femenino , Humanos , Masculino , Factores de Riesgo
18.
Eur Heart J ; 33(18): 2307-16, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22450427

RESUMEN

AIMS: High-throughput metabolite quantification holds promise for cardiovascular risk assessment. Here, we evaluated whether metabolite quantification by nuclear magnetic resonance (NMR) improves prediction of subclinical atherosclerosis in comparison to conventional lipid testing. METHODS AND RESULTS: Circulating lipids, lipoprotein subclasses, and small molecules were assayed by NMR for 1595 individuals aged 24-39 years from the population-based Cardiovascular Risk in Young Finns Study. Carotid intima-media thickness (IMT), a marker of subclinical atherosclerosis, was measured in 2001 and 2007. Baseline conventional risk factors and systemic metabolites were used to predict 6-year incidence of high IMT (≥ 90 th percentile) or plaque. The best prediction of high intima-media thickness was achieved when total and HDL cholesterol were replaced by NMR-determined LDL cholesterol and medium HDL, docosahexaenoic acid, and tyrosine in prediction models with risk factors from the Framingham risk score. The extended prediction model improved risk stratification beyond established risk factors alone; area under the receiver operating characteristic curve 0.764 vs. 0.737, P =0.02, and net reclassification index 17.6%, P =0.0008. Higher docosahexaenoic acid levels were associated with decreased risk for incident high IMT (odds ratio: 0.74; 95% confidence interval: 0.67-0.98; P = 0.007). Tyrosine (1.33; 1.10-1.60; P = 0.003) and glutamine (1.38; 1.13-1.68; P = 0.001) levels were associated with 6-year incident high IMT independent of lipid measures. Furthermore, these amino acids were cross-sectionally associated with carotid IMT and the presence of angiographically ascertained coronary artery disease in independent populations. CONCLUSION: High-throughput metabolite quantification, with new systemic biomarkers, improved risk stratification for subclinical atherosclerosis in comparison to conventional lipids and could potentially be useful for early cardiovascular risk assessment.


Asunto(s)
Aterosclerosis/diagnóstico , Biomarcadores/metabolismo , Metabolismo de los Lípidos/fisiología , Adulto , Grosor Intima-Media Carotídeo , Femenino , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Placa Aterosclerótica/diagnóstico , Valor Predictivo de las Pruebas , Curva ROC , Medición de Riesgo , Adulto Joven
19.
Ultrasound Med Biol ; 36(8): 1237-44, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20598433

RESUMEN

We examined tracking of ultrasound measurements of vascular structure and function in adulthood using data collected in the 2001 and 2007 follow-ups of Cardiovascular Risk in Young Finns Study. B-mode ultrasound measures of carotid artery intima-media thickness (IMT), carotid artery distensibility (CDist) and brachial artery flow-mediated dilatation (FMD) was obtained on 1809 apparently healthy Finnish adults aged 24 to 39 years in 2001 (1014 females; 795 males). Significant 6-year tracking was observed for IMT (males, r = 0.56; females, r = 0.46), CDist (males, r = 0.35; females, r = 0.36) and FMD (males, r = 0.23; females, r = 0.20). Subjects with 10-year risk of CVD (according to the SCORE risk score) above sex-specific median had improved IMT (r = 0.44; r = 0.57, p = 0.0001) and CDist (r = 0.31; r = 0.40, p = 0.03) tracking compared with those below median. Body mass index (BMI) >or= 30 kg/m(2) decreased tracking of CDist (r = 0.36; r = 0.19, p = 0.01). In conclusion, ultrasound measurements tracked low to moderate over 6-years and was influenced by cardiovascular disease (CVD) risk factor status.


Asunto(s)
Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/epidemiología , Ultrasonografía/estadística & datos numéricos , Adulto , Femenino , Finlandia/epidemiología , Humanos , Incidencia , Estudios Longitudinales , Masculino , Reproducibilidad de los Resultados , Medición de Riesgo/métodos , Factores de Riesgo , Sensibilidad y Especificidad
20.
Eur J Cardiovasc Prev Rehabil ; 17(5): 549-55, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20354441

RESUMEN

AIM: To study the utility of risk scores in the prediction of subclinical atherosclerosis in young adults. METHODS AND RESULTS: Participants were 2204 healthy Finnish adults aged 24-39 years in 2001 from a population-based follow-up study Cardiovascular Risk in Young Finns. We examined the performance of the Framingham, Reynolds, Systematic Coronary Risk Evaluation (SCORE), PROCAM, and Finrisk cardiovascular risk scores to predict subclinical atherosclerosis, that is carotid artery intima-media thickness (IMT) and plaque, carotid artery distensibility (CDist), and brachial artery flow-mediated dilatation (FMD) 6 years later. In a 6-year prediction of high IMT (highest decile or plaque), areas under the receiver operating characteristic curves (AUC) for baseline Finrisk (0.733), SCORE (0.726), PROCAM (0.712), and Reynolds (0.729) risk scores were similar as for Framingham risk score (0.728, P always ≥0.15). All risk scores had a similar discrimination in predicting low CDist (lowest decile) (0.652, 0.642, 0.639, 0.658, 0.652 respectively, P always ≥0.41). In the prediction of low FMD (lowest decile), Finrisk, PROCAM, Reynolds, and Framingham scores had similar AUCs (0.578, 0.594, 0.582, 0.568, P always ≥0.08) and SCORE discriminated slightly better (AUC=0.596, P<0.05). The prediction of subclinical outcomes was consistent when estimated from other statistical measures of discrimination, reclassification, and calibration. CONCLUSION: Cardiovascular disease risk scores had equal value in predicting subclinical atherosclerosis measured by IMT and CDist in young adults. SCORE was more accurate in predicting low FMD than Framingham risk score.


Asunto(s)
Aterosclerosis/etiología , Enfermedades Cardiovasculares/etiología , Adulto , Factores de Edad , Enfermedades Asintomáticas , Aterosclerosis/diagnóstico , Aterosclerosis/diagnóstico por imagen , Aterosclerosis/fisiopatología , Arteria Braquial/diagnóstico por imagen , Arteria Braquial/fisiopatología , Arterias Carótidas/diagnóstico por imagen , Arteria Carótida Común/diagnóstico por imagen , Arteria Carótida Común/fisiopatología , Elasticidad , Finlandia , Estudios de Seguimiento , Humanos , Modelos Logísticos , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Túnica Íntima/diagnóstico por imagen , Túnica Media/diagnóstico por imagen , Ultrasonografía , Vasodilatación , Adulto Joven
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