Associations between visceral fat and liver fat with insulin sensitivity and metabolic risk in obese adolescents

2015 ◽  
Vol 93 (5) ◽  
pp. 466-471 ◽  
Author(s):  
Ruth E. Brown ◽  
Jennifer L. Kuk ◽  
Ingrid Libman ◽  
Michelle Rivera-Vega ◽  
SoJung Lee

We examined the joint and independent associations between VAT and LF with insulin sensitivity (IS) and lipids in seventy-one obese adolescents (BMI ≥ 95th, 14.9 ± 1.8 years). VAT was assessed by magnetic resonance imaging, and LF was quantified by proton magnetic resonance spectroscopy. IS was evaluated by a 3 -h hyperinsulinemic (80 mU·m−2·min−1) euglycemic clamp. Independent associations between VAT and LF on metabolic variables were assessed in mutually adjusted multivariate models. The joint association between VAT and LF on metabolic variables was assessed by categorizing participants into a low VAT + low LF group (n = 35), high VAT + low LF group (n = 26), or high VAT + high LF group (n = 10), based on a VAT median split (1.17 kg) and high (≥5%) and low (<5%) LF. Both VAT and LF were independently associated with fasting insulin, 2 h insulin, insulin AUC, IS, and triglycerides (P < 0.05). Adolescents with high VAT + high LF had higher 2 h glucose, glucose AUC, 2 h insulin, triglycerides, and lower insulin sensitivity compared to adolescents with high VAT only (P < 0.025 for all). In obese adolescents, VAT and LF were independently associated with insulin sensitivity and dyslipidemia, and the concomitant presence of VAT and LF is strongly associated with metabolic risk factors.

2014 ◽  
Vol 7 ◽  
pp. MRI.S19362
Author(s):  
Arunima Pola ◽  
Suresh Anand Sadananthan ◽  
Venkatesh Gopalan ◽  
Min-Li Sandra Tan ◽  
Terry Yew Keong ◽  
...  

The focus of current treatments for obesity is to reduce the body weight or visceral fat, which requires longer duration to show effect. In this study, we investigated the short-term changes in fat metabolism in liver, abdomen, and skeletal muscle during antiobesity interventions including Sibutramine treatment and diet restriction in obese rats using magnetic resonance imaging, magnetic resonance spectroscopy, and blood chemistry. Sibutramine is an antiobesity drug that results in weight loss by increasing satiety and energy expenditure. The Sibutramine-treated rats showed reduction of liver fat and intramyocellular lipids on day 3. The triglycerides (TG) decreased on day 1 and 3 compared to baseline (day 0). The early response/nonresponse in different fat depots will permit optimization of treatment for better clinical outcome rather than staying with a drug for longer periods.


2007 ◽  
Vol 293 (6) ◽  
pp. E1663-E1669 ◽  
Author(s):  
Jong-Hee Hwang ◽  
Daniel T. Stein ◽  
Nir Barzilai ◽  
Min-Hui Cui ◽  
Julia Tonelli ◽  
...  

Recent studies have indicated that the mass/content of intramyocellular lipid (IMCL), intrahepatic triglyceride (IHTG), visceral fat (VF), and even deep abdominal subcutaneous fat (SF) may all be correlated with insulin resistance. Since simultaneous measurements of these parameters have not been reported, the relative strength of their associations with insulin action is not known. Therefore, the goals of this study were 1) to simultaneously measure IMCL, IHTG, VF, and abdominal SF in the same nondiabetic individuals using noninvasive 1H-magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) and 2) to examine how these fat stores are correlated with systemic insulin sensitivity as measured by whole body glucose disposal (Rd) during euglycemic-hyperinsulinemic clamp studies. Positive correlations were observed among IMCL, IHTG, and VF. There were significant inverse correlations between whole body Rd and both IMCL and VF. Notably, there was a particularly tight inverse correlation between IHTG and whole body Rd ( r = −0.86, P < 0.001), consistent with an association between liver fat and peripheral insulin sensitivity. This novel finding suggests that hepatic triglyceride accumulation has important systemic consequences that may adversely affect insulin sensitivity in other tissues.


Author(s):  
Direnç Özlem Aksoy ◽  
Alpay Alkan

Background: Neurometabolic diseases are a group of diseases secondary to disorders in different metabolic pathways, which lead to white and/or gray matter of the brain involvement. </P><P> Discussion: Neurometabolic disorders are divided in two groups as dysmyelinating and demyelinating diseases. Because of wide spectrum of these disorders, there are many different classifications of neurometabolic diseases. We used the classification according to brain involvement areas. In radiological evaluation, MRI provides useful information for these disseases. Conclusion: Magnetic Resonance Spectroscopy (MRS) provides additional metabolic information for diagnosis and follow ups in childhood with neurometabolic diseases.


2017 ◽  
Author(s):  
Joshua P Klein

Modern neuroimaging has revolutionized the practice of neurology by allowing visualization and monitoring of evolving pathophysiologic processes. High-resolution magnetic resonance imaging (MRI) can now resolve structural abnormalities on a near-cellular level. Advances in functional imaging can assess the in vivo metabolic, vascular, and functional states of neuronal and glial populations in real time. Given the high density of data obtained from neuroimaging studies, it is essential for the clinician to take an active role in understanding the nature and significance of imaging abnormalities. This chapter reviews computed tomography and MRI techniques (including angiography and advanced sequences), specialized protocols for investigating specific diagnoses, risks associated with imaging, disease-specific imaging findings with general strategies for interpretation, and incidental findings and artifacts. Figures include computed tomography, T1- and T2-weighted signal intensity, diffusion-weighted magnetic resonance imaging, magnetic resonance spectroscopy, imaging in epilepsy and dementia, extra-axial versus intra-axial lesions, typical lesions of multiple sclerosis, spinal imaging, spinal pathology, vascular pathology, intracranial hemorrhage, and common imaging artifacts. Tables list Hounsfield units, patterns of enhancement from imaging, advanced techniques in imaging, magnetic resonance imaging sequences, and the evolution of cerebral infarction and intraparenchymal hemorrhage on magnetic resonance imaging. This review contains 12 figures, 6 tables, and 213 references.


2021 ◽  
Vol 15 (9) ◽  
pp. 4009-4011
Author(s):  
Saulat Sarfraz ◽  
Mahwish Farzana

Background: In spite of recent advances in the use of diagnostic imaging modalities none of them has a hundred percent accuracy. So, misdiagnosis still occurs. Many trials are being done to evaluate the accuracy of these tools individually or in combination. The most useful investigation is MRI which broadly gives information of lesion as well its relationship with surrounding structures. While magnetic resonance spectroscopy further characterizes the lesion into benign or malignant. So this study is bit superior giving more details. By enlarge histopathology is gold standard for ultimate diagnosis. However these radiological investigations are extremely important for preoperative planning as well management of the lesion. In this study we compare the diagnostic accuracy of Magnetic Resonance Spectroscopy (MRS) with conventional MRI (Magnetic Resonance Imaging) sequences for diagnosis of brain tumors keeping histopathology as gold standard. Methods: The study was performed in 150 clinically suspected cases which were referred to Radiology Department from OPD, Indoor, Emergency and private sources from outside the hospital. Results: Majority 85(56.7%) were adult males and 65(43.3%) were adult females. The study was divided into two major age groups. There were 33cases (22%) with average age 20-35 years. The other age group 36-50 years had 40(26.7%) Majority of the cases 77(51.3%) were of average >50 years of age. The higher age groups showed a female dominance. Histopathology of 100(66.7%) cases confirmed positive and 50(33.3%) negative for MR Spectroscopy. On comparison of conventional MRI with contrast, and Histopathology it was observed that the sensitivity of MRI was 74.0% and the specificity 82.0%.The positive and negative predictive values gave a lower accuracy rate of 76.6%. Conclusion: The conclusion of our study is that MRS is a rigorous, non-invasive, safe and convenient imaging modality for the evaluation of brain tumors as compared to MRI. Keywords: Brain tumors, MRI, MRS, Histopathology


2018 ◽  
Vol 108 (6) ◽  
pp. 1264-1274 ◽  
Author(s):  
Sophie Schutte ◽  
Diederik Esser ◽  
Femke P M Hoevenaars ◽  
Guido J E J Hooiveld ◽  
Marion G Priebe ◽  
...  

ABSTRACT Background Whole-grain wheat (WGW) is described as nutritionally superior to refined wheat (RW) and thus advocated as the healthy choice, although evidence from intervention studies is often inconsistent. The liver, as the central organ in energy metabolism, might be an important target organ for WGW interventions. Objective The aim of this study was to investigate the potential benefits of WGW consumption compared with RW consumption on liver health and associated parameters. Design We performed a double-blind, parallel trial in which 50 overweight 45- to 70-y-old men and postmenopausal women were randomly allocated to a 12-wk intervention with either WGW (98 g/d) or RW (98 g/d) products. Before and after the intervention we assessed intrahepatic triglycerides (IHTGs) and fat distribution by proton magnetic resonance spectroscopy/magnetic resonance imaging, fecal microbiota composition, adipose tissue gene expression, and several fasting plasma parameters, as well as postprandial plasma lipids after a mixed meal. Results Fasting plasma cholesterol, triglycerides, nonesterified fatty acids, and insulin were not affected by RW or WGW intervention. We observed a substantial increase of 49.1% in IHTGs in the RW when compared with the WGW group (P = 0.033). Baseline microbiota composition could not predict the increase in IHTGs after RW, but gut microbiota diversity decreased in the RW group when compared with the WGW group (P = 0.010). In the WGW group, we observed increased postprandial triglyceride levels compared with the RW group (P = 0.020). In addition, the WGW intervention resulted in a trend towards lower fasting levels of the liver acute-phase proteins serum amyloid A (P = 0.057) and C-reactive protein (P = 0.064) when compared to the RW intervention. Conclusions A 12-wk RW intervention increases liver fat and might contribute to the development of nonalcoholic fatty liver disease, whereas a 12-wk 98-g/d WGW intervention prevents a substantial increase in liver fat. Our results show that incorporating feasible doses of WGW in the diet at the expense of RW maintains liver health. The study was registered at clinicaltrials.gov as NCT02385149.


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