Estimated pulse wave velocity (ePWV) as a potential gatekeeper for MRI-assessed PWV: a linear and deep neural network based approach in 2254 participants of the Netherlands Epidemiology of Obesity study.

Pulse wave velocity (PWV) assessed by magnetic resonance imaging (MRI) is a prognostic marker for cardiovascular events. Prediction modelling could enable indirect PWV assessment based on clinical and anthropometric data. The aim was to calculate estimated-PWV (ePWV) based on clinical and anthropometric measures using linear ridge regression as well as a Deep Neural Network (DNN) and to determine the cut-off which provides optimal discriminative performance between lower and higher PWV values. In total 2254 participants from the Netherlands Epidemiology of Obesity study were included (age 45-65 years, 51% male). Both a basic and expanded prediction model were developed. PWV was estimated using linear ridge regression and DNN. External validation was performed in 114 participants (age 30-70 years, 54% female). Performance was compared between models and estimation accuracy was evaluated by ROC-curves. A cut-off for optimal discriminative performance was determined using Youden's index. The basic ridge regression model provided an adjusted R2 of 0.33 and bias of < 0.001, the expanded model did not add predictive performance. Basic and expanded DNN models showed similar model performance. Optimal discriminative performance was found for PWV < 6.7 m/s. In external validation expanded ridge regression provided the best performance of the four models (adjusted R2: 0.29). All models showed good discriminative performance for PWV < 6.7 m/s (AUC range 0.81-0.89). ePWV showed good discriminative performance with regard to differentiating individuals with lower PWV values (< 6.7 m/s) from those with higher values, and could function as gatekeeper in selecting patients who benefit from further MRI-based PWV assessment.

Endobronchial ultrasound for T4 staging in patients with resectable NSCLC.

BACKGROUND: In lung cancer patients, accurate assessment of mediastinal and vascular tumor invasion (stage T4) is crucial for optimal treatment allocation and to prevent unnecessary thoracotomies. We assessed the diagnostic accuracy of linear endobronchial ultrasound (EBUS) for T4-status in patients with centrally located lung cancer. METHODS: This is a retrospective study among consecutive patients who underwent EBUS for diagnosis and staging of lung cancer in four hospitals in The Netherlands (Amsterdam, Leiden), Italy (Bologna) and Poland (Zakopane) between 04-2012 and 04-2019. Patients were included if the primary tumor was detected by EBUS and subsequent surgical-pathological staging was performed, which served as the reference standard. T4-status was extracted from EBUS and pathology reports. Chest CT's were re-reviewed for T4-status. RESULTS: 104 patients with lung cancer in whom EBUS detected the primary tumour, and who underwent subsequent surgical-pathological staging were included. 36 patients (35 %) had T4-status, based on vascular (n = 17), mediastinal (n = 15), both vascular and mediastinal (n = 3), or oesophageal invasion (n = 1). For EBUS, sensitivity, specificity, PPV and NPV for T4-status were (n = 104): 63.9 % (95 %CI 46.2-79.2 %), 92.6 % (83.7-97.6 %), 82.1 % (65.6-91.7 %), and 82.9 % (75.7-88.2 %), respectively. For chest CT (n = 72): 61.5 % (95 %CI 40.6-79.8 %), 37.0 % (23.2-52.5 %), 35.6 % (27.5-44.6 %), and 63.0 % (47.9-75.9 %), respectively. When combining CT and EBUS with concordant T4 status (n = 33): 90.9 % (95 %CI 58.7-99.8 %), 77.3 % (54.6-92.20 %), 66.7 % (47.5-81.6 %), and 94.4 % (721-99.1%), respectively. CONCLUSION: Both EBUS and CT alone are inaccurate for assessing T4-status as standalone test. However, combining a negative EBUS with a negative CT may rule out T4-status with high certainty.

Validation and Feasibility of Echocardiographic Assessment of Systemic Right Ventricular Function: Serial Correlation With MRI.

Background: Inherent to its geometry, echocardiographic imaging of the systemic right ventricle (RV) is challenging. Therefore, echocardiographic assessment of systemic RV function may not always be feasible and/or reproducible in daily practice. Here, we aim to validate the usefulness of a comprehensive range of 32 echocardiographic measurements of systemic RV function in a longitudinal cohort by serial assessment of their correlations with cardiac magnetic resonance (CMR)-derived systemic RV ejection fraction (RVEF). Methods: A single-center, retrospective cohort study was performed. Adult patients with a systemic RV who underwent a combination of both CMR and echocardiography at two different points in time were included. Off-line analysis of echocardiographic images was blinded to off-line CMR analysis and vice versa. In half of the echocardiograms, measurements were repeated by a second observer blinded to the results of the first. Correlations between echocardiographic and CMR measures were assessed with Pearson's correlation coefficient and interobserver agreement was quantified with intraclass correlation coefficients (ICC). Results: Fourteen patients were included, of which 4 had congenitally corrected transposition of the great arteries (ccTGA) and 10 patients had TGA late after an atrial switch operation. Eight patients (57%) were female. There was a mean of 8 years between the first and second imaging assessment. Only global systemic RV function, fractional area change (FAC), and global longitudinal strain (GLS) were consistently, i.e., at both time points, correlated with CMR-RVEF (global RV function: r = -0.77/r = -0.63; FAC: r = 0.79/r = 0.67; GLS: r = -0.73/r = -0.70, all p-values < 0.05). The ICC of GLS (0.82 at t = 1, p = 0.006, 0.77 at t = 2, p = 0.024) was higher than the ICC of FAC (0.35 at t = 1, p = 0.196, 0.70 at t = 2, p = 0.051) at both time points. Conclusion: GLS appears to be the most robust echocardiographic measurement of systemic RV function with good correlation with CMR-RVEF and reproducibility.

Normal and reference values for cardiovascular magnetic resonance-based pulse wave velocity in the middle-aged general population.

BACKGROUND: Aortic stiffness, assessed through pulse wave velocity (PWV), is an independent predictor for cardiovascular disease risk. However, the scarce availability of normal and reference values for cardiovascular magnetic resonance imaging (CMR) based PWV is limiting clinical implementation. The aim of this study was to determine normal and reference values for CMR assessed PWV in the general population. METHODS: From the 2,484 participants of the Netherlands Epidemiology of Obesity (NEO) study that have available CMR-PWV data, 1,394 participants free from cardiovasculard disease, smokers or treatment for diabetes, hypertension or dyslipidaemia were selected (45-65 years, 51% female). Participants were divided into sex, age and blood pressure (BP) subgroups. Normal values were specified for participants with a BP < 130/80 mmHg and reference values for elevated BP subgroups (≥ 130/80 and < 140/90 mmHg; and ≥ 140/90 mmHg). Differences between groups were tested with independent samples t-test or ANOVA. Due to an oversampling of obese individuals in this study, PWV values are based on a weighted analysis making them representative of the general population. RESULTS: Normal mean PWV was 6.0 m/s [95% CI 5.8-6.1]. PWV increased with advancing age and BP categories (both p < 0.001). There was no difference between sex in normal PWV, however in the BP > 140/90 mmHg women had a higher PWV (p = 0.005). The interpercentile ranges were smaller for participants < 55 years old compared to participants ≥ 55 years, indicating an increasing variability of PWV with age. PWV upper limits were particularly elevated in participants ≥ 55 years old in the high blood pressure subgroups. CONCLUSION: This study provides normal and reference values for CMR-assessed PWV per sex, age and blood pressure category in the general population.

The role of insulin resistance in the relation of visceral, abdominal subcutaneous and total body fat to cardiovascular function.

BACKGROUND AND AIMS: The separate cardiovascular effects of type 2 diabetes and adiposity remain to be examined. This study aimed to investigate the role of insulin resistance in the relations of visceral (VAT), abdominal subcutaneous (aSAT) adipose tissue and total body fat (TBF) to cardiovascular remodeling. METHODS AND RESULTS: In this cross-sectional analysis of the population-based Netherlands Epidemiology of Obesity study, 914 middle-aged individuals (46% men) were included. Participants underwent magnetic resonance imaging. Standardized linear regression coefficients (95%CI) were calculated, adjusted for potential confounding factors. All fat depots and insulin resistance (HOMA-IR), separate from VAT and TBF, were associated with lower mitral early and late peak filling rate ratios (E/A): -0.04 (-0.09;0.01) per SD (54 cm2) VAT; -0.05 (-0.10;0.00) per SD (94 cm2) aSAT; -0.09 (-0.16;-0.02) per SD (8%) TBF; -0.11 (-0.17;-0.05) per 10-fold increase in HOMA-IR, whereas VAT and TBF were differently associated with left ventricular (LV) end-diastolic volume: -8.9 (-11.7;-6.1) mL per SD VAT; +5.4 (1.1;9.7) mL per SD TBF. After adding HOMA-IR to the model to evaluate the mediating role of insulin resistance, change in E/A was -0.02 (-0.07;0.04) per SD VAT; -0.03 (-0.08;0.02) per SD aSAT; -0.06 (-0.13;0.01) per SD TBF, and change in LV end-diastolic volume was -7.0 (-9.7;-4.3) mL per SD VAT. In women, adiposity but not HOMA-IR was related to higher aortic arch pulse wave velocity. CONCLUSION: Insulin resistance was associated with reduced diastolic function, separately from VAT and TBF, and partly mediated the associations between adiposity depots and lower diastolic function.

Is Hepatic Triglyceride Content Associated with Aortic Pulse Wave Velocity and Carotid Intima-Media Thickness? The Netherlands Epidemiology of Obesity Study.

Purpose To test the hypothesis that hepatic triglyceride content is associated with subclinical vascular impairment and is not confounded by various cardiometabolic risk factors. Materials and Methods This study was approved by the institutional review board, and all participants gave written informed consent. In this cross-sectional analysis of baseline measurements of the Netherlands Epidemiology of Obesity study, a population-based cohort study, 1899 participants (52% men; mean age, 55 years ± 6 [standard deviation]) underwent magnetic resonance (MR) spectroscopy and MR imaging to assess hepatic triglyceride content, aortic pulse wave velocity (PWV), and visceral fat. Carotid intima-media thickness (IMT) was acquired and measured by trained research nurses according to standard procedures. Multivariate regression analyses were used to study associations of hepatic triglyceride content with total and regional aortic PWV and carotid IMT while adjusting for several possible confounding factors, including the metabolic syndrome. Results Total aortic PWV (mean difference, 0.5 m/sec; 95% confidence interval [CI]: 0.3, 0.7) and carotid IMT (mean difference, 37 µm; 95% CI: 25, 49) were higher in participants with hepatic steatosis. After adjusting for various covariates, a 10-fold increase in hepatic triglyceride content was associated with an increased mean aortic PWV of 0.19 m/sec (95% CI: 0.03, 0.36) in total and an increased mean aortic PWV of 0.42 m/sec (95% CI: 0.03, 0.81) in the abdominal segment. A 10-fold increase in hepatic triglyceride content was also associated with an increased mean carotid IMT of 15 µm (95% CI: 0, 29) but not after additional adjustments for visceral and total body fat. Conclusion In this relatively large population-based cohort study, hepatic triglyceride content was associated with aortic pulse wave velocity and carotid IMT. These associations were only partly explained by the metabolic syndrome and visceral adiposity, suggesting a possible specific contribution of hepatic steatosis to subclinical vascular impairment. © RSNA, 2017 Online supplemental material is available for this article.

Malignant Epithelial Transformation in Phyllodes Tumor: A Population-Based Case Series.

Background Phyllodes tumor (PT) of the breast is an uncommon fibroepithelial neoplasm. Malignant epithelial transformation in PT is rare. This study reports clinicopathologic characteristics and outcomes of patients with malignant epithelial transformation in PT. Methods From an institutional database of 183 patients with newly diagnosed PT referred to a Canadian provincial cancer institution between 1999 and 2014, 11 cases of PT with concomitant in situ or invasive carcinoma were identified. Descriptive analysis was performed to document the characteristics, treatment and outcomes of this cohort. Results Prevalence of malignant epithelial transformation in PT was 6.0%. Median (range) age was 54 (35-75) years. Types of carcinoma were ductal carcinoma in situ (DCIS) (n = 6), lobular carcinoma in situ (n = 4), and invasive ductal carcinoma (IDC) (n = 1). Median PT size was 5 (1-15) cm. Three PTs were classified as benign (27%), five as borderline (45%), and three as malignant (27%). Mastectomy was performed in six (55%) and breast conserving surgery in five (45%) patients. Hormonal therapy was used in two cases: one with a 1 cm, grade 2 DCIS, and one with an 11 cm, grade 1 IDC, the latter also receiving radiotherapy. Mean follow-up duration was 54 (6-175) months. None of the cases showed any evidence of disease after treatment at the time of their last follow-up. Conclusion This case series showed a higher prevalence of malignant epithelial transformation in PT than reported in previous literature. Outcomes were favourable despite the presence of either in situ or invasive carcinoma within PT.

Association between Hepatic Triglyceride Content and Left Ventricular Diastolic Function in a Population-based Cohort: The Netherlands Epidemiology of Obesity Study.

PURPOSE: To investigate the association between hepatic triglyceride content and left ventricular (LV) diastolic function while taking potential confounding factors into account, including the components of the metabolic syndrome. MATERIALS AND METHODS: The study was approved by the institutional review board, and all participants gave informed consent. In this cross-sectional analysis of baseline data from the Netherlands Epidemiology of Obesity study, a population-based, prospective cohort study, participants (45% men; mean age ± standard deviation, 55.3 years ± 6.2) underwent magnetic resonance (MR) spectroscopy and MR imaging to assess hepatic triglyceride content and LV diastolic heart function (ratio of peak filling rates of the early filling phase and atrial contraction [E/A ratio]). Multivariate linear regression analysis was performed while adjusting for confounding factors, and results were additionally stratified according to body mass index. RESULTS: Adjustment for age, sex, heart rate, alcohol consumption, pack-years of smoking, all components of the metabolic syndrome, and visceral adiposity attenuated crude observed associations. A 10-fold increase in hepatic triglyceride content was associated with a change in mean E/A ratio of -0.004 (95% confidence interval [CI]: -0.134, 0.125) in the total study population, -0.194 (95% CI: -0.430, 0.042) in the normal-weight subgroup, 0.079 (95% CI: -0.090, 0.248) in the overweight subgroup, and -0.109 (95% CI: -0.186, -0.032) in the obese subgroup. CONCLUSION: Fatty liver itself could, at least in obesity, pose a risk of myocardial dysfunction above and beyond known cardiovascular risk factors that are clustered within the metabolic syndrome. The association in the obese subgroup was small, and future studies with larger samples sizes are required to investigate to what extent the association exists and differs in normal-weight, overweight, and obese persons to unravel its clinical relevance.

Individual contributions of visceral fat and total body fat to subclinical atherosclerosis: The NEO study.

BACKGROUND: Both overall and abdominal adiposity are established risk factors for cardiovascular disease. Visceral adipose tissue (VAT) and total body fat (TBF) are strongly correlated and previous studies did not make this distinction. OBJECTIVE: We aimed to distinguish individual contributions of TBF, VAT, and the ratio of VAT to abdominal subcutaneous adipose tissue (VAT/SAT) to subclinical atherosclerosis in men and women. METHODS: In this cross-sectional analysis of the Netherlands Epidemiology of Obesity (NEO) study, we assessed VAT and SAT with magnetic resonance imaging, TBF with bio-electrical impendence analysis, and carotid Intima-Media Thickness (cIMT) with ultrasound. We performed linear regression analyses of standardized values of TBF, VAT, VAT/SAT with cIMT. We adjusted the models for confounding factors (age, sex, ethnicity, education, smoking, alcohol, physical activity), and either for VAT or TBF. RESULTS: This analysis included 2451 participants, 53% men with mean (SD) cIMT of 615 (91)µm. After adjustment for confounding factors, the difference in cIMT (95% CI) per SD in VAT was 14 (8,21)µm in men and 18 (13,24)µm in women. After adjustment for TBF, this attenuated to 5 (-3,13)µm in men and 13 (5,20)µm in women. In the full model, differences in cIMT (95% CI) per SD of TBF were 14 (6,22)µm in men and 8 (0,16)µm in women, and per SD of VAT/SAT were 7 (-1,15)µm and 9 (3,16)µm respectively. CONCLUSIONS: In this population-based study, VAT contributed beyond overall adiposity to subclinical atherosclerosis, particularly in women. This implies a specific role of VAT in the early development of atherosclerosis.

Visceral adipose tissue is associated with microstructural brain tissue damage.

OBJECTIVE: Obesity has been associated with microstructural brain tissue damage. Different fat compartments demonstrate different metabolic and endocrine behaviors. The aim was to investigate the individual associations between abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) and microstructural integrity in the brain. METHODS: This study comprised 243 subjects aged 65.4 ± 6.7 years. The associations between abdominal VAT and SAT, assessed by CT, and magnetization transfer imaging markers of brain microstructure for gray and white matter were analyzed and adjusted for confounding factors. RESULTS: VAT was associated with normalized MTR peak height in gray (ß -0.216) and white matter (ß -0.240) (both P < 0.01) after adjustment for confounding factors. After adjustment for sex, age, and descent, SAT was associated with normalized MTR peak height in gray and white matter, but not after additional correction for BMI, hypertension, current smoking, statin use, and type 2 diabetes (respectively, ß -0.055 and ß 0.035, both P > 0.05). Stepwise linear regression analysis showed that only VAT was associated with normalized MTR peak height in gray and white matter (both P < 0.001). CONCLUSIONS: Our data indicate that increased abdominal VAT rather than SAT is associated with microstructural brain tissue damage in elderly individuals.

Adiposity and hand osteoarthritis: the Netherlands Epidemiology of Obesity study.

INTRODUCTION: Obesity, usually characterized by the body mass index (BMI), is a risk factor for hand osteoarthritis (OA). We investigated whether adipose tissue and abdominal fat distribution are associated with hand OA. METHODS: The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45 to 65 years, including 5315 participants (53% women, median BMI 29.9 kg/m²). Fat percentage and fat mass (FM) (kg) were estimated using bioelectrical impedance analysis. The waist-to-hip ratio (WHR) was calculated. In 1721 participants, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) (cm²) were assessed using abdominal MR imaging. Hand OA was defined according to the ACR criteria. RESULTS: Hand OA was present in 8% of men and 20% of women. Fat percentage was associated with hand OA in men (OR 1.34 (95% CI 1.11 to 1.61)) and women (OR 1.26 (1.05 to 1.51)), as was FM. WHR was associated with hand OA in men (OR 1.45 (1.13 to 1.85)), and to a lesser extent in women (OR 1.17 (1.00 to 1.36)). Subgroup analysis revealed that VAT was associated with hand OA in men (OR1.33 (1.01 to 1.75)). This association increased after additional adjustment for FM (OR 1.51 (1.13 to 2.03)). CONCLUSIONS: Fat percentage, FM and WHR were associated with hand OA. VAT was associated with hand OA in men, suggesting involvement of visceral fat in hand OA.

Effects of short-term nutritional interventions on right ventricular function in healthy men.

BACKGROUND: A physiological model of increased plasma nonesterified fatty acid (NEFA) levels result in myocardial triglyceride (TG) accumulation, which is related to cardiac dysfunction. A pathophysiological model of increased plasma NEFA levels result in hepatic steatosis, which has been linked to abnormal myocardial energy metabolism. Hepatic steatosis is accompanied by hepatic inflammation, reflected by plasma cholesteryl ester transfer protein (CETP) levels. The current study aimed to investigate effects of these models via different nutritional interventions on right ventricular (RV) function. METHODS: Fifteen men (age 25.0±6.6 years) were included and underwent magnetic resonance imaging and spectroscopy in this prospective crossover intervention study. RV function, myocardial and hepatic TG content, and CETP levels were assessed on three occasions: after normal diet, very low-calorie diet (VLCD, physiological model) and high-fat high-energy (HFHE, pathophysiological model) diet (all 3-days diets, randomly ordered, washout phase at least 14 days). RESULTS: VLCD induced a decrease in mean E deceleration by 27%. Myocardial TG content increased by 55%, whereas hepatic TG content decreased by 32%. Plasma CETP levels decreased by 14% (all P<0.05). HFHE diet induced a decrease in E/A by 19% (P<0.05). Myocardial TG content did not change, whereas hepatic TG content increased by 112% (P<0.01). Plasma CETP levels increased by 14% (P<0.05). CONCLUSIONS: These findings show that RV diastolic function is impaired after short-term VLCD and HFHE diet in healthy men, respectively a physiological and a pathophysiological model of increased plasma NEFA levels. After short-term VLCD, myocardial lipotoxicity may be of importance in decreased RV diastolic function. RV diastolic dysfunction is accompanied by increased hepatic TG content and plasma CETP levels after short-term HFHE diet, suggesting that systemic inflammation reflecting local macrophage infiltration in the heart may be involved in RV dysfunction.

Exercise and type 2 diabetes mellitus: changes in tissue-specific fat distribution and cardiac function.

PURPOSE: To prospectively assess the effects of an exercise intervention on organ-specific fat accumulation and cardiac function in type 2 diabetes mellitus. MATERIALS AND METHODS: Written informed consent was obtained from all participants, and the study protocol was approved by the medical ethics committee. The study followed 12 patients with type 2 diabetes mellitus (seven men; mean age, 46 years ± 2 [standard error]) before and after 6 months of moderate-intensity exercise, followed by a high-altitude trekking expedition with exercise of long duration. Abdominal, epicardial, and paracardial fat volume were measured by using magnetic resonance (MR) imaging. Cardiac function was quantified with cardiac MR, and images were analyzed by a researcher who was supervised by a senior researcher (4 and 21 years of respective experience in cardiac MR). Hepatic, myocardial, and intramyocellular triglyceride (TG) content relative to water were measured with proton MR spectroscopy at 1.5 and 7 T. Two-tailed paired t tests were used for statistical analysis. RESULTS: Exercise reduced visceral abdominal fat volume from 348 mL ± 57 to 219 mL ± 33 (P < .01), and subcutaneous abdominal fat volume remained unchanged (P = .9). Exercise decreased hepatic TG content from 6.8% ± 2.3 to 4.6% ± 1.6 (P < .01) and paracardial fat volume from 4.6 mL ± 0.9 to 3.7 mL ± 0.8 (P = .02). Exercise did not change epicardial fat volume (P = .9), myocardial TG content (P = .9), intramyocellular lipid content (P = .3), or cardiac function (P = .5). CONCLUSION: A 6-month exercise intervention in type 2 diabetes mellitus decreased hepatic TG content and visceral abdominal and paracardial fat volume, which are associated with increased cardiovascular risk, but cardiac function was unaffected. Tissue-specific exercise-induced changes in body fat distribution in type 2 diabetes mellitus were demonstrated in this study.

Right ventricular involvement in diabetic cardiomyopathy.

OBJECTIVE: To compare magnetic resonance imaging-derived right ventricular (RV) dimensions and function between men with type 2 diabetes and healthy subjects, and to relate these parameters to left ventricular (LV) dimensions and function. RESEARCH DESIGN AND METHODS: RV and LV volumes and functions were assessed in 78 men with uncomplicated type 2 diabetes and 28 healthy men within the same range of age using magnetic resonance imaging. Steady-state free precession sequences were used to assess ventricular dimensions. Flow velocity mapping across the pulmonary valve and tricuspid valve was used to assess RV outflow and diastolic filling patterns, respectively. Univariate general linear models were used for statistical analyses. RESULTS: RV end-diastolic volume was significantly decreased in patients compared with healthy subjects after adjustment for BMI and pulse pressure (177 ± 28 mL vs. 197 ± 47 mL, P < 0.01). RV systolic function was impaired: peak ejection rate across the pulmonary valve was decreased (433 ± 54 mL/s vs. 463 ± 71 mL/s, P < 0.01) and pulmonary flow acceleration time was longer (124 ± 17 ms vs. 115 ± 25 ms, P < 0.05). Indexes of RV diastolic function were impaired: peak filling rate and peak deceleration gradient of the early filling phase were 315 ± 63 mL/s vs. 356 ± 90 mL/s (P < 0.01) and 2.3 ± 0.8 mL/s(2) × 10(-3) vs. 2.8 ± 0.8 mL/s(2) × 10(-3) (P < 0.01), respectively. All RV parameters were strongly associated with its corresponding LV parameter (P < 0.001). CONCLUSIONS: Diabetic cardiomyopathy affects the right ventricle, as demonstrated by RV remodeling and impaired systolic and diastolic functions in men with type 2 diabetes, in a similar manner as changes in LV dimensions and functions. These observations suggest that RV impairment might be a component of the diabetic cardiomyopathy phenotype.

Short-term caloric restriction normalizes hypothalamic neuronal responsiveness to glucose ingestion in patients with type 2 diabetes.

The hypothalamus is critically involved in the regulation of feeding. Previous studies have shown that glucose ingestion inhibits hypothalamic neuronal activity. However, this was not observed in patients with type 2 diabetes. Restoring energy balance by reducing caloric intake and losing weight are important therapeutic strategies in patients with type 2 diabetes. We hypothesized that caloric restriction would have beneficial effects on the hypothalamic neuronal response to glucose ingestion. Functional magnetic resonance imaging was performed in 10 male type 2 diabetic patients before and after a 4-day very-low-calorie diet (VLCD) at a 3.0 Tesla scanner using a blood oxygen level-dependent technique for measuring neuronal activity in the hypothalamus in response to an oral glucose load. Hypothalamic signals were normalized to baseline value, and differences between the pre- and postdiet condition were tested using paired t tests. Pre-VLCD scans showed no response of the hypothalamus to glucose intake (i.e., no signal decrease after glucose intake was observed). Post-VLCD scans showed a prolonged signal decrease after glucose ingestion. The results of the current study demonstrate that short-term caloric restriction readily normalizes hypothalamic responsiveness to glucose ingestion in patients with type 2 diabetes.

Increased amygdalar and hippocampal volumes in elderly obese individuals with or at risk of cardiovascular disease.

BACKGROUND: The basal ganglia, hippocampus, and thalamus are involved in the regulation of human feeding behavior. Recent studies have shown that obesity [body mass index (BMI; in kg/m(2)) > 30] is associated with loss of gray and white matter. OBJECTIVE: It is unknown whether the subcortical brain structures that are actually involved in feeding behavior also show volume changes in obesity. Therefore, the purpose of this study was to evaluate the volumes of the basal ganglia, hippocampus, and thalamus in obesity. DESIGN: Three-dimensional T1-weighted magnetic resonance imaging scans of the brain were analyzed by using automatic segmentation to measure volumes of the nucleus accumbens, globus pallidus, amygdala, putamen, caudate nucleus, thalamus, and hippocampus in 471 subjects (mean age: 74.4 y; 56% men). RESULTS: Obese subjects had larger left (P = 0.013) and right (P = 0.003) amygdalar volumes and a larger left hippocampal volume (P = 0.040) than did normal-weight subjects (BMI < 25). None of the other subcortical structures differed in size between these groups. After correction for age, sex, smoking, hypertension, and pravastatin use, BMI was associated with left (ß = 0.175, P = 0.001) and right (ß = 0.157, P = 0.001) amygdalar volumes and with left hippocampal volume (ß = 0.121, P = 0.016). CONCLUSIONS: This study showed that the amygdala and hippocampus are enlarged in obesity. In consideration of the function of these structures, this finding may indicate that hedonic memories could be of major importance in the regulation of feeding. Because of the cross-sectional design, cause and effect could not be discriminated in this study.