Prediction of type 2 diabetes mellitus using noninvasive MRI quantitation of visceral abdominal adiposity tissue volume

Association between type 2 diabetes mellitus and body composition based on MRI fat fraction mapping

Purpose

To explore the association between type 2 diabetes mellitus (T2DM) and body composition based on magnetic resonance fat fraction (FF) mapping.

Methods

A total of 341 subjects, who underwent abdominal MRI examination with FF mapping were enrolled in this study, including 68 T2DM patients and 273 non-T2DM patients. The FFs and areas of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and abdominal muscle (AM) were measured at the level of the L1-L2 vertebral. The FF of bone marrow adipose tissue (BMAT) was determined by the averaged FF values measured at the level of T12 and L1 vertebral, respectively. The whole hepatic fat fraction (HFF) and pancreatic fat fraction (PFF) were measured based on 3D semi-automatic segmentation on the FF mapping. All data were analyzed by GraphPad Prism and MedCalc.

Results

VAT area, VAT FF, HFF, PFF of T2DM group were higher than those of non-T2DM group after adjusting for age and sex (P < 0.05). However, there was no differences in SAT area, SAT FF, BMAT FF, AM area and AM FF between the two groups (P > 0.05). VAT area and PFF were independent risk factors of T2DM (all P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) for VAT area and PFF in differentiating between T2DM and non-T2DM were 0.685 and 0.787, respectively, and the AUC of PFF was higher than VAT area (P < 0.05). Additionally, in seemingly healthy individuals, the SAT area, VAT area, and AM area were found to be significantly associated with being overweight and/or obese (BMI ≥ 25) (all P < 0.05).

Conclusions

In this study, it was found that there were significant associations between T2DM and VAT area, VAT FF, HFF and PFF. In addition, VAT area and PFF were the independent risk factors of T2DM. Especially, PFF showed a high diagnostic performance in discrimination between T2DM and non-T2DM. These findings may highlight the crucial role of PFF in the pathophysiology of T2DM, and it might be served as a potential imaging biomarker of the prevention and treatment of T2DM. Additionally, in individuals without diabetes, focusing on SAT area, VAT area and AM area may help identify potential health risks and provide a basis for targeted weight management and prevention measures.

Effect of the glucagon-like peptide-1 receptor agonist liraglutide, compared to caloric restriction, on appetite, dietary intake, body fat distribution and cardiometabolic biomarkers: A randomized trial in adults with obesity and prediabetes

AIMS

To investigate the hypothesis that weight loss with the glucagon-like peptide-1 receptor agonist (GLP-1RA) liraglutide alone would lead to a greater reduction in the proportion of fat to lean tissue mass when compared to caloric restriction (CR) alone, as well as when compared to treatment with sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, that also enhances GLP-1 activity - to determine the independent effects of each treatment.

METHODS

A total of 88 adults with obesity and prediabetes were randomized to 14 weeks of intervention with CR (-390 kcal/d), liraglutide (1.8 mg/d), or the dipeptidyl peptidase-4 inhibitor sitagliptin (100 mg/d) as a weight-neutral comparator. Changes between groups in appetite and hunger ratings measured via visual analogue scales, dietary intakes, body weight, body composition via dual energy x-ray absorptiometry, and resting energy expenditure via indirect calorimetry were assessed using the Kruskal-Wallis test or Pearson's chi-squared test.

RESULTS

Weight loss ≥5% of baseline body weight occurred in 44% of participants in the CR group, 22% of the liraglutide group and 5% of the sitagliptin group (p = 0.02). The ratio of fat to lean mass decreased by 6.5% in the CR group, 2.2% in the liraglutide group, and 0% in the sitagliptin group (p = 0.02). Visceral fat reduced by 9.5% in the CR group, 4.8% in the liraglutide group, and 0% in the sitagliptin group (p = 0.04). A spontaneous reduction in dietary simple carbohydrates in the CR group was associated with improved homeostatic model assessment of insulin resistance score (HOMA-IR).

CONCLUSIONS

Although both liraglutide and CR are valuable strategies for cardiometabolic risk reduction, CR was associated with greater weight loss and more favourable improvements in body composition than treatment with liraglutide alone. Differences in the response to each of these interventions enables patients to be stratified to the most optimal intervention for their personal risk factors.

Aerobic training reduces pancreatic fat content and improves β-cell function: A randomized controlled trial using IDEAL-IQ magnetic resonance imaging

AIMS

To explore the effects of six months of moderate-intensity aerobic exercise on pancreatic fat content and its impact on β-cell function.

MATERIALS AND METHODS

A total of 106 patients with type 2 diabetes mellitus were randomized to either a moderate-intensity aerobic training group (three times a week, including 5 min warm-up, 50 min aerobic dancing, and 5 min relaxation, n = 53) or control group (n = 53) with 6-month intervention. The primary endpoint was change in pancreatic fat content. An intention-to-treat analysis was conducted.

RESULTS

Eighty-six patients completed the study with 43 patients in the aerobic training group. The average age, HbA1c, and pancreatic fat content for all participants (106 patients) were 66.39 ± 5.59 years, 7.05 ± 1.24%, and 10.35 ± 9.20%, respectively. Nearly half (49.06%) of patients were males. Subjects in the aerobic training group saw a significant reduction in pancreatic fat content when compared to controls (p = 0.001). In logistic regression models containing age, diabetes duration, change in BMI, smoking/drinking status, changes in lipid indices, and other abdominal fat content, only reduction in pancreatic fat content (p < 0.05) was an independent protective factor for β-cell function and HbA1c.

CONCLUSIONS

Six months of moderate-intensity aerobic training significantly reduced the pancreatic fat content. The reduction of pancreatic fat content was an independent protective factor for β-cell function and HbA1c.

Quantification of brown adipose tissue in vivo using synthetic magnetic resonance imaging: an experimental study with mice model

BACKGROUND

The white adipose tissue (WAT) and brown adipose tissue (BAT) are associated with the development of several obesity-associated disorders. The use of imaging techniques to differentiate BAT from WAT and quantify BAT volume remains challenging, due to limitations such as spatial resolution and magnetic field inhomogeneity. This study aimed to investigate the feasibility for differentiating BAT from WAT, and quantify the BAT volume in vivo using synthetic magnetic resonance imaging (MRI).

METHODS

A total of 16 C57BL/6 mice were scanned using synthetic MRI. Quantitative longitudinal relaxation time (T1) and transverse relaxation time (T2) maps were obtained from the original synthetic MRI data using the synthetic MRI software offline. The T1 and T2 values of interscapular BAT (IBAT) and dorsal subcutaneous WAT were measured. The IBAT volume was calculated using synthetic MRI-derived T2-weighted images (T2WIs) based on its morphological characteristics and quantitative tissue values. The body weight of mice was measured, and the IBAT specimens were excised and weighted. The correlation between IBAT volume and the weight of IBAT gross specimen and between IBAT volume and mouse body weight was analyzed.

RESULTS

The T1 values of BAT (330.3±19.57 ms) were higher than those of WAT (304.42±4.14 ms) (P<0.001), whereas the T2 values of BAT (66.06±5.06 ms) were lower than those of WAT (88.23±7.68 ms) (P<0.001). The area under the curve (AUC) values of the T1 and T2 for differentiating BAT from WAT was 0.942 and 0.995, respectively. The AUC of the T2 values was higher than that of T1 (P=0.04) using the DeLong test. The optimal cut-off value for T2 was 76 ms for differentiating BAT from WAT (100% sensitivity, 93.7% specificity). A moderate correlation was observed between IBAT volume and the weight of the IBAT gross specimen (r=0.662, P=0.014), and between IBAT volume and mouse body weight (r=0.653, P=0.016).

CONCLUSIONS

The quantitative parameters derived using synthetic MRI may be used to detect and differentiate BAT from WAT in vivo. Synthetic MRI may help quantify BAT volume in vivo.

Magnetic Resonance Imaging Assessment of Abdominal Ectopic Fat Deposition in Correlation With Cardiometabolic Risk Factors

PURPOSE

Ectopic fat accumulation and abdominal fat distribution may have different cardiometabolic risk profiles. This study aimed to assess the associations between various magnetic resonance imaging (MRI)-acquired fat depots and cardiometabolic risk factors.

METHODS

A total of 320 subjects with median age of 59 years, 148 men and 172 women, were enrolled in the study. Visceral adipose tissue (VAT) area and fat fraction (FF), subcutaneous adipose tissue (SAT) area and FF at the L1-L2 levels, preperitoneal adipose tissue (pPAT) area and FF, hepatic FF, pancreatic FF, and intramuscular FF were assessed by MRI FF maps. The associations of various MRI-acquired fat depots with blood pressure, glucose, and lipid were examined using sex-stratified linear regression. Logistic regression stratified by sex was used to analyze the association of various MRI-acquired fat depots with the risk of hypertension, T2DM, and dyslipidemia.

RESULTS

The intraclass correlation coefficient (ICC) values were >0.9, which suggested good interobserver and intraobserver agreement. VAT area, V/S, hepatic fat, pancreatic fat, and pPAT rather than SAT area were significantly associated with multiple cardiometabolic risk factors (all p < 0.05). However, the patterns of these correlations varied by sex and specific risk factors. Also, VAT and SAT FF were only significantly associated with multiple cardiometabolic risk factors in women (all p < 0.05).

CONCLUSIONS

VAT, hepatic fat, pancreatic fat, and pPAT were associated with cardiovascular metabolic risk factors independent of BMI. The patterns of these correlations were related to gender. These findings further the understanding of the association between ectopic fat deposition and cardiometabolic risk factors and help to better understand the obesity heterogeneity.

MRI-Derived Radiomics Features of Hepatic Fat Predict Metabolic States in Individuals without Cardiovascular Disease

RATIONALE AND OBJECTIVES

To investigate radiomics features of hepatic fat as potential biomarkers of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) in individuals without overt cardiovascular disease, and benchmarking against hepatic proton density fat fraction (PDFF) and the body mass index (BMI).

MATERIALS AND METHODS

This study collected liver radiomics features of 310 individuals that were part of a case-controlled imaging substudy embedded in a prospective cohort. Individuals had known T2DM (n = 39; 12.6 %) and MetS (n = 107; 34.5 %) status, and were divided into stratified training (n = 232; 75 %) and validation (n = 78; 25 %) sets. Six hundred eighty-four MRI radiomics features were extracted for each liver volume of interest (VOI) on T₁-weighted dual-echo Dixon relative fat water content (rfwc) maps. Test-retest and inter-rater variance was simulated by additionally extracting radiomics features using noise augmented rfwc maps and deformed volume of interests. One hundred and seventy-one features with test-retest reliability (ICC(1,1)) and inter-rater agreement (ICC(3,k)) of ≥0.85 on the training set were considered stable. To construct predictive random forest (RF) models, stable features were filtered using univariate RF analysis followed by sequential forward aggregation. The predictive performance was evaluated on the independent validation set with area under the curve of the receiver operating characteristic (AUROC) and balanced accuracy (Accuracy_B).

RESULTS

On the validation set, the radiomics RF models predicted T2DM with AUROC of 0.835 and Accuracy_B of 0.822 and MetS with AUROC of 0.838 and Accuracy_B of 0.787, outperforming the RF models trained on the benchmark parameters PDFF and BMI.

CONCLUSION

Hepatic radiomics features may serve as potential imaging biomarkers for T2DM and MetS.

Association of Adiposity With Incident Diabetes Among Black Adults in the Jackson Heart Study

Background

The prognostic value of anthropometric, adipokine, and computed tomography measures of adiposity to predict diabetes in Black, specifically by normoglycemia versus prediabetes, remains incompletely understood.

Methods and Results

Among Black participants without diabetes in the JHS (Jackson Heart Study), waist circumference [WC], body mass index, adiponectin, leptin, and leptin:adiponectin ratio were standardized in sample 1 (2422 participants at baseline [2000–2004]) and WC, body mass index, visceral adipose tissue (VAT), subcutaneous adipose tissue, and liver attenuation in 1537 participants at examination 2 (2005–2008) (sample 2). Hazard ratios (HRs) for diabetes were estimated using interval‐censored Cox modeling adjusting for traditional risk factors and validated with the C index. Over 5 years, 300 and 122 incident diabetes cases occurred in sample 1 and sample 2, respectively. In sample 1 and sample 2, a 1‐SD higher log‐leptin:adiponectin ratio and VAT had the strongest associations (HR, 1.95 [95% CI, 1.67–2.27] and 1.76 [95% CI, 1.52–2.04]) and discriminatory power (C index 0.68 [95% CI, 0.64–0.71] and C index 0.67 [95% CI, 0.61–0.74]) with diabetes. The normoglycemic compared with the prediabetes group had a 1.3 to 1.9 times greater magnitude of associations with diabetes for WC, liver attenuation, and VAT (P interaction <0.10). In sample 2, C indices for WC (HR, 0.84; 95% CI, 0.73–0.95), VAT (HR, 0.91; 95% CI, 0.85–0.98), and liver attenuation (HR, 0.90; 95% CI, 0.77–1.00) were greater than HbA_1c (HR, 0.74; 95% CI, 0.57–0.90) in normoglycemia, whereas HbA_1c was best in prediabetes (HR, 0.72; 95% CI, 0.66–0.78).

Conclusions

Overall, among Black adults, multiple measures of adiposity were associated with incident diabetes with modest predictive ability. In Black patients with normoglycemia, WC, liver attenuation, and VAT may appropriately identify those at high risk for diabetes, whereas HbA_1c was the best predictor in individuals with prediabetes.

Left ventricular myocardial deformation: a study on diastolic function in the Chinese male population and its relationship with fat distribution

Background

Obesity has become an epidemic in China with its increased prevalence, especially in the male population. Disparities in fat distribution rather than increasing body mass index (BMI) confer the risk of different diseases, including cardiac abnormalities. Therefore, early detection of cardiac abnormalities is important for treatment to reverse the progression to heart failure. Nowadays, strain analysis based on cardiac magnetic resonance (CMR) imaging has been established to assess myocardial function in diverse cardiac diseases. We aimed to assess the relationship between fat distribution and subclinical diastolic dysfunction in obese Chinese men assessed by deformation registration algorithm (DRA)-based myocardial strain rate (SR) analysis.

Methods

A total of 115 male participants with different BMI underwent CMR scanning using a 1.5T MAGNETOM Aera (Siemens Healthcare, Erlangen, Germany) and computed tomography (CT) scan. All the participants were enrolled from September 2017 to April 2018. They were classified into 3 groups according to their BMIs with 23 and 27.5 kg/m² being the cutoff values. A Trufi-Strain prototype software (version 2.0, Siemens Healthcare, Erlangen, Germany) was used to quantify SR in both early and late diastole from CMR cine images. Ratios of early and late SRs were calculated. Areas of epicardial and pericardial adipose tissue (EAT and PAT) were measured on a single 4-chamber-view slice of cine images. Volumes of visceral and subcutaneous adipose tissue (VAT and SAT) were acquired semi-automatically from CT images using the dedicated software Cardiac Risk2.0 (Siemens Healthcare). Waist and hip circumferences were manually measured (WC and HC). Analysis of variance or nonparametric tests, along with correlation and stepwise multivariate regression analysis models, was applied for statistical analysis.

Results

Peak late diastolic SRs were higher in obese men compared with their lean counterparts [-36.25±10.46 vs. -29.46±8.17, 66.97±18.58 vs. 45.62 (42.44, 55.96), and 56.81±15.07 vs. 41.40±6.41 for radial, circumferential, and longitudinal SRs, respectively; P<0.05]. All SR ratios in the obese subgroups were lower than those of lean men (3.12±1.14 vs. 4.63±1.24, 2.12±0.58 vs. 2.96±0.62 and 1.63±0.50 vs. 2.20±0.63 for radial, circumferential, and longitudinal directions, respectively; P<0.05). EAT was a significant predictor of diastolic function assessed by radial and circumferential SR ratios (β=-0.439 and -0.337 respectively; all P<0.001), while VAT was a significant predictor of circumferential and longitudinal SR ratios (β=-0.216 and -0.355, respectively, P<0.05).

Conclusions

Decreased LV diastolic function assessed by DRA-based SR analysis in obesity is associated with fat distribution. Furthermore, EAT and VAT might be better predictors of a decrease of diastolic function in obese Chinese men than BMI.