scholarly journals Characterization of Intra-myocellular Lipids Using 2d Localized Correlated Spectroscopy and Abdominal Fat Using Mri in Type 2 Diabetes

2012 ◽  
Vol 5 ◽  
pp. MRI.S10489 ◽  
Author(s):  
Preethi Srikanthan ◽  
Aparna Singhal ◽  
Cathy C. Lee ◽  
Rajakumar Nagarajan ◽  
Neil Wilson ◽  
...  

A major goal of this pilot study was to quantify intramyocellular lipids (IMCL), extra-myocellular lipids (EMCL), unsaturation index (UI) and metabolites such as creatine (Cr), choline (Ch) and carnosine (Car), in the soleus muscle using two-dimensional (2D) localized correlated spectroscopy (L-COSY). Ten subjects with type 2 diabetes (T2D), controlled by lifestyle management alone, and 9 healthy control subjects, were studied. In T2D patients only, the following measurements were obtained: body mass index (BMI); waist circumference (WC); abdominal visceral and subcutaneous fat quantified using breath-held magnetic resonance imaging (MRI); a fasting blood draw for assessment of glucose, insulin, and estimation of homeostasis model assessment of insulin resistance (HOMA-IR), HbA1c, and high-sensitivity c-reactive protein (hs-CRP). Analysis of the soleus muscle 2D L-COSY spectral data showed significantly elevated IMCL ratios with respect to Cr and decreased IMCL UI in T2D when compared to healthy subjects ( P < 0.05). In T2D subjects, Pearson correlation analysis showed a positive correlation of IMCL/Cr with EMCL/Cr (0.679, P < 0.05) and HOMA-IR (0.633, P < 0.05), and a non-significant correlation of visceral and subcutaneous fat with magnetic resonance spectroscopy (MRS) and other metrics. Characterization of muscle IMCL and EMCL ratios, UI, and abdominal fat, may be useful for the noninvasive assessment of the role of altered lipid metabolism in the pathophysiology of T2D, and for assessment of the effects of future therapeutic interventions designed to alter metabolic dysfunction in T2D.

Author(s):  
Zhu Li ◽  
Yan-Ling Yang ◽  
Yan-Juan Zhu ◽  
Chen-Guang Li ◽  
Yun-Zhao Tang ◽  
...  

Abstract Objective Myonectin is one of the myokines and has gained interest as a potential new strategy to combat obesity and its associated disorders, such as type 2 diabetes mellitus (T2DM).The objective of this study was to investigate circulating serum myonectin levels in nondiabetes and T2DM and elucidate possible relationships between serum myonectin levels and metabolic parameters in patients with T2DM. Design A total of 362 Chinese patients with T2DM and 100 age- and sex-matched healthy controls were recruited in this study. Clinical characteristics, blood biochemistry, and circulating myonectin levels were measured by enzyme-linked immunosorbent assay. Results Circulating myonectin levels were significantly decreased in T2DM compared with controls. Obese nondiabetic controls had significantly lower serum myonectin levels compared with lean nondiabetic controls. In diabetic patients, serum myonectin concentrations were significantly negatively correlated with body mass index (BMI), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), hemoglobin A1c (HbA1c), fasting insulin (Fins), the homeostatic model assessment of insulin resistance (HOMA-IR), visceral fat area, and subcutaneous fat area. After adjusting for covariates, multivariate stepwise regression analysis demonstrated that BMI, LDL-C, TG, HOMA-IR, and visceral fat were the main independent predictors of low serum myonectin concentrations. Conclusions Circulating myonectin levels were decreased in T2DM patients and in obese subjects. Moreover, serum myonectin levels were correlated with metabolic markers of T2DM. These data suggest that myonectin may be a useful marker in predicting the development of obesity and T2DM.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xinlei Wang ◽  
Xiaoqin Zhao ◽  
Yunjuan Gu ◽  
Xiaohui Zhu ◽  
Tong Yin ◽  
...  

In China, most normal BMI (body mass index of ≥18.5 to <25 kg/m2) adults with type 2 diabetes (T2DM) exhibit visceral adiposity. This study compared the effects of exenatide and humalog Mix25 on normal BMI patients with T2DM and visceral adiposity. A total of 95 patients were randomized to receive either exenatide or humalog Mix25 treatment for 24 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were quantified by magnetic resonance imaging (MRI) and liver fat content (LFC) by liver proton magnetic resonance spectroscopy (1H MRS). Each patient’s weight, waist circumference, BMI, blood glucose, insulin sensitivity, pancreatic β-cell function, and fibroblast growth factor 21 (FGF-21) levels were measured. Data from 81 patients who completed the study (40 and 41 in the exenatide and humalog Mix25 groups, respectively) were analysed. The change in 2 h plasma blood glucose was greater in the exenatide group (P=0.039). HOMA-IR and MBCI improved significantly after exenatide therapy (P<0.01, P=0.045). VAT and LFC decreased in both groups (P<0.01 for all) but to a greater extent in the exenatide group, while SAT only decreased with exenatide therapy (P<0.01). FGF-21 levels declined more in the exenatide group (P<0.01), but were positively correlated with VAT in the entire cohort before (r=0.244, P=0.043) and after (r=0.290, P=0.016) the intervention. The effects of exenatide on glycaemic metabolism, insulin resistance, pancreatic β-cell function, and fat deposition support its administration to normal BMI patients with T2DM and visceral adiposity.


2006 ◽  
Vol 100 (2) ◽  
pp. 609-614 ◽  
Author(s):  
Martin Torriani ◽  
Bijoy J. Thomas ◽  
Robert B. Barlow ◽  
Jamie Librizzi ◽  
Sara Dolan ◽  
...  

The human immunodeficiency virus (HIV)-lipodystrophy syndrome is associated with fat redistribution and metabolic abnormalities, including insulin resistance. Increased intramyocellular lipid (IMCL) concentrations are thought to contribute to insulin resistance, being linked to metabolic and body composition variables. We examined 46 women: HIV infected with fat redistribution ( n = 25), and age- and body mass index-matched HIV-negative controls ( n = 21). IMCL was measured by 1H-magnetic resonance spectroscopy, and body composition was assessed with computed tomography, dual-energy X-ray absorptiometry (DEXA), and magnetic resonance imaging. Plasma lipid profile and markers of glucose homeostasis were obtained. IMCL was significantly increased in tibialis anterior [135.0 ± 11.5 vs. 85.1 ± 13.2 institutional units (IU); P = 0.007] and soleus [643.7 ± 61.0 vs. 443.6 ± 47.2 IU, P = 0.017] of HIV-infected subjects compared with controls. Among HIV-infected subjects, calf subcutaneous fat area (17.8 ± 2.3 vs. 35.0 ± 2.5 cm2, P < 0.0001) and extremity fat by DEXA (11.8 ± 1.1 vs. 15.6 ± 1.2 kg, P = 0.024) were reduced, whereas visceral abdominal fat (125.2 ± 11.3 vs. 74.4 ± 12.3 cm2, P = 0.004), triglycerides (131.1 ± 11.0 vs. 66.3 ± 12.3 mg/dl, P = 0.0003), and fasting insulin (10.8 ± 0.9 vs. 7.0 ± 0.9 μIU/ml, P = 0.004) were increased compared with control subjects. Triglycerides ( r = 0.39, P = 0.05) and extremity fat as percentage of whole body fat by DEXA ( r = −0.51, P = 0.01) correlated significantly with IMCL in the HIV but not the control group. Extremity fat (β = −633.53, P = 0.03) remained significantly associated with IMCL among HIV-infected patients, controlling for visceral abdominal fat, abdominal subcutaneous fat, and antiretroviral medications in a regression model. These data demonstrate increased IMCL in HIV-infected women with a mixed lipodystrophy pattern, being most significantly associated with reduced extremity fat. Further studies are necessary to determine the relationship between extremity fat loss and increased IMCL in HIV-infected women.


2015 ◽  
Vol 128 (10) ◽  
pp. 707-713 ◽  
Author(s):  
Mavin Macauley ◽  
Fiona E Smith ◽  
Peter E Thelwall ◽  
Kieren G Hollingsworth ◽  
Roy Taylor

In health, food carbohydrate is stored as glycogen in muscle and liver, preventing a deleterious rise in osmotically active plasma glucose after eating. Glycogen concentrations increase sequentially after each meal to peak in the evening, and fall to fasting levels thereafter. Skeletal muscle accounts for the larger part of this diurnal buffering capacity with liver also contributing. The effectiveness of this diurnal mechanism has not been previously studied in Type 2 diabetes. We have quantified the changes in muscle and liver glycogen concentration with 13C magnetic resonance spectroscopy at 3.0 T before and after three meals consumed at 4 h intervals. We studied 40 (25 males; 15 females) well-controlled Type 2 diabetes subjects on metformin only (HbA1c (glycated haemoglobin) 6.4±0.07% or 47±0.8 mmol/mol) and 14 (8 males; 6 females) glucose-tolerant controls matched for age, weight and body mass index (BMI). Muscle glycogen concentration increased by 17% after day-long eating in the control group (68.1±4.8 to 79.7±4.2 mmol/l; P=0.006), and this change inversely correlated with homoeostatic model assessment of insulin resistance [HOMA-IR] (r=−0.56; P=0.02). There was no change in muscle glycogen in the Type 2 diabetes group after day-long eating (68.3±2.6 to 67.1±2.0 mmol/mol; P=0.62). Liver glycogen rose similarly in normal control (325.9±25.0 to 388.1±30.3 mmol/l; P=0.005) and Type 2 diabetes groups (296.1±16.0 to 350.5±6.7 mmol/l; P<0.0001). In early Type 2 diabetes, the major physiological mechanism for skeletal muscle postprandial glycogen storage is completely inactive. This is directly related to insulin resistance, although liver glycogen storage is normal.


2014 ◽  
Vol 4 (2) ◽  
pp. 9-12
Author(s):  
OK Shrestha ◽  
GL Shrestha

To compare abdominal visceral fat with subcutaneous fat in relation to their association with type 2 diabetes. Abdominal fat distribution was measured using Computed Tomography in 60 subjects (30 diabetics and 30 non-diabetics). Computed tomography images obtained at two intervertebral locations L2-L3 and L4-L5 were used to measure areas of total fat, visceral fat and subcutaneous fat using slice thickness of 5mm and attenuation range of -190 to -30 Hounsfield units. Data were analyzed using logistic regression. At L2-L3 level, taking visceral fat and subcutaneous fat as predictor variables, diabetes was correctly classified at 78.0% and 66.10% respectively. At L4-L5 level, taking visceral fat and subcutaneous fat as predictor variables, diabetes was correctly classified at 72.88% and 67.80% respectively. Regardless of the measurement site, visceral fat has significantly stronger association with diabetes, compared to subcutaneous fat. Visceral fat at L2-L3 level alone may be a better predictor of diabetes. Abdominal fat distribution, visceral fat, subcutaneous fat, type 2 diabetes. DOI: http://dx.doi.org/10.3126/jcmc.v4i2.10853 Journal of Chitwan Medical College 2014; 4(2): 9-12


2021 ◽  
Author(s):  
Sharmaine Thirunavukarasu ◽  
Nicholas Jex ◽  
Amrit Chowdhary ◽  
Imtiaz Ul Hassan ◽  
Sam Straw ◽  
...  

Sodium–glucose-cotransporter-2 (SGLT2) inhibitors reduce the risk of major adverse CV events and hospitalization for heart failure in type 2 diabetes (T2D) patients. Utilising cardiovascular magnetic resonance imaging (CMR) and 31phosphorus magnetic resonance spectroscopy(<sup>31</sup>P-MRS) in a longitudinal cohort study, we aimed to investigate the effects of the selective SGLT2i empagliflozin on myocardial energetics, cellular volume, function and perfusion. Eighteen T2D patients underwent CMR and <sup>31</sup>P-MRS scans before and after twelve-week empagliflozin treatment. Plasma N-terminal pro hormone B-type natriuretic peptide (NT-proBNP) levels were measured. Ten volunteers with normal glycaemic control underwent an identical scan protocol on a single visit.<i> </i>Empagliflozin treatment was associated with significant improvements in PCr/ATP ratio (1.52 to 1.76, p=0.009). This was accompanied by a 7% absolute increase in the mean LVEF (p=0.001), 3% absolute increase in the mean global longitudinal strain (p=0.01), 8 ml/m2 absolute reduction in the mean myocardial cell volume (p=0.04) and 61% relative reduction in the mean NT-proBNP (p=0.05) from baseline measurements. No significant change in myocardial blood flow or diastolic strain was detected.<b> </b>Empagliflozin thus ameliorates the ‘cardiac energy-deficient’ state, regresses adverse myocardial cellular remodelling, and improves cardiac function, offering therapeutic opportunities to prevent or modulate heart failure in T2D.


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