Fat Volume Changes Research Articles

Analysis of Anatomy and Age-related Changes in Infraorbital Cheek Using Computed Tomography.

There is no consensus regarding age-related facial anatomical changes. In this study, aging-related changes in soft and hard cheek tissues were quantitatively analyzed using computed tomography. We performed a retrospective study of 90 Asian females who underwent facial computed tomography. Three-dimensional model of soft tissue in apple zone was reconstructed, and age-related changes in fat volume and pyriform aperture area were quantified using Mimics software. The apple zone is an aesthetic unit of the infraorbital cheek, with soft tissue located between the lateral wall of the pyriform aperture and the zygomatic major muscle. The superficial fat volume significantly decreased with age (P < 0.05). In contrast, a significant decrease in total fat volume was only observed between the young and old groups (P < 0.05). In linear regression modeling, age was a significant predictor of pyriform aperture area (R2 = 0.194, P < 0.001). These results suggest that superficial fat atrophy and bone remodeling in the cheek with age, and both of which combine to contribute to an aging facial appearance. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Impact of Interventional Weight Loss on Bone Marrow Adipose Tissue in People Living with Obesity and Its Connection to Bone Metabolism.

This review focuses on providing physicians with insights into the complex relationship between bone marrow adipose tissue (BMAT) and bone health, in the context of weight loss through caloric restriction or metabolic and bariatric surgery (MBS), in people living with obesity (PwO). We summarize the complex relationship between BMAT and bone health, provide an overview of noninvasive imaging techniques to quantify human BMAT, and discuss clinical studies measuring BMAT in PwO before and after weight loss. The relationship between BMAT and bone is subject to variations based on factors such as age, sex, menopausal status, skeletal sites, nutritional status, and metabolic conditions. The Bone Marrow Adiposity Society (BMAS) recommends standardizing imaging protocols to increase comparability across studies and sites, they have identified both water-fat imaging (WFI) and spectroscopy (1H-MRS) as accepted standards for in vivo quantification of BMAT. Clinical studies measuring BMAT in PwO are limited and have shown contradictory results. However, BMAT tends to be higher in patients with the highest visceral adiposity, and inverse associations between BMAT and bone mineral density (BMD) have been consistently found in PwO. Furthermore, BMAT levels tend to decrease after caloric restriction-induced weight loss. Although weight loss was associated with overall fat loss, a reduction in BMAT did not always follow the changes in fat volume in other tissues. The effects of MBS on BMAT are not consistent among the studies, which is at least partly related to the differences in the study population, skeletal site, and duration of the follow-up. Overall, gastric bypass appears to decrease BMAT, particularly in patients with diabetes and postmenopausal women, whereas sleeve gastrectomy appears to increase BMAT. More research is necessary to evaluate changes in BMAT and its connection to bone metabolism, either in PwO or in cases of weight loss through caloric restriction or MBS, to better understand the role of BMAT in this context and determine the local or systemic factors involved.

Correlation of spinal epidural fat volume with body mass index: a longitudinal study

PurposeSpinal epidural lipomatosis is abnormal accumulation of normal fat in the epidural space with weight loss suggested as first-line therapy in select symptomatic patients. However, moderate to large longitudinal studies establishing concordant changes between body mass index and epidural fat are lacking. The purpose of this study was to longitudinally assess this relationship. MethodsWe performed an ancillary study of the Habitual Diet and Avocado Trial. Baseline and six-month abdominal MRIs were analyzed for 98 overweight or obese but otherwise healthy subjects. Dorsal epidural fat volumes in the lumbar spine were measured and correlated with changes in body mass index, changes in visceral fat volume, and demographic information. ResultsThere was a linear relationship between body mass index changes and epidural fat volume changes with a one-point change in body mass index corresponding to a 45 mm3 change in dorsal epidural fat volume (p < 0.001, 95% CI 31.87 to 76.77) as well as between visceral fat volume changes and epidural fat volume changes (regression coefficient 0.51, p < 0.001, 95% CI 0.22 to 0.47). Age was inversely related with subjects older than 45.7 years tending to lose epidural fat (regression coefficient −0.22, p = 0.025, 95% CI -10.43 to −0.72). ConclusionChanges in spinal dorsal epidural fat volume parallel changes in body mass index and visceral fat, supporting weight loss as initial treatment for uncomplicated obesity-associated spinal epidural lipomatosis.

Deciphering the molecular mechanisms involved in HIV-associated lipoatrophy by transcriptomics: a pilot study.

HIV-associated lipoatrophy (LA) has considerable implications for risk of metabolic diseases, quality of life, and adherence to treatments. Although it has decreased in high-income countries, it is still very common in resource-limited countries. Understanding the pathophysiological mechanisms of LA can open the possibility to explore new ways to treat or prevent this condition. To identify new markers for an accurate and quick diagnosis will be also of interest. Thus, we aimed to examine functional classes of genes implicated in LA and to identify potential new markers for an accurate/quick diagnosis of LA and future complications. Eighteen participants were recruited: seven healthy volunteers, five non-LA-HIV patients, and six LA-HIV subjects. Clinical lipoatrophy was considered when changes in fat volume in the cheeks next to the nose, lateral aspect of the face, legs, arms, and buttocks were observed by the physicians. mRNA was isolated from peripheral blood mononuclear cells (PBMCs) to perform a transcriptomic and Gene Ontology analysis. To confirm RNA sequencing results, qPCRs were developed. A total of 55 genes were differentially expressed between LA and non-LA patients. Thirty-seven genes were overexpressed, whereas 18 genes were repressed. Functional analysis showed that overexpressed genes were involved in lymphocyte/neutrophil activation, inflammation, and atherogenesis. Several lymphoma markers and members of the lipocalin and aquaporin families were also found more expressed in LA patients. In contrast, most of the genes found less expressed in LA subjects were involved in angiogenesis and protection against myocardial infarction. Our results demonstrated a distinct transcriptomic signature in PBMCs of LA patients in comparison with non-LA-HIV subjects and, therefore, provided novel insights to the pathogenesis of HIV-associated lipoatrophy. Our study also highlights the potential usage of some of these genes as early markers of future complications.

Changes of Fat Volume and Adipocytokines by the Randomized Intervention Program for Obesity Control Program (SCOP)

Adipocytokines arebioactive substances synthesizedand secretedbyfat cell. Previous studies have reported an association between weight loss and adipocytokines. However, these studies are inconsistent and they have not clarified the relationship between weight regain and changes in circulating levels of adipocytokines. In this study, we analyzed the relationship between weight and fat volume changes and adipocytokines. The subjects were 235obese people recruited in the Saku Control Obesity Program (SCOP). Participants were randomly assigned to either immediate (Group A) or delayed (Group B, control group). Group A participants were followed for another two years after completion of the one year intervention. As controls, Group B participants received the same intervention as Group A after a delay of one year. Then they were followed up for one year. The intervention consisted in a one-year lifestyle program to induce weight loss, based on a cognitive-behavioral approach. After the first year of the study, body weight, BMI, body fat and abdominal fat areas were significantly lower in group A participants, compared to controls. After the intervention, leptin levels were significantly lowered both in men and women. After one year follow-up, both men and women re-gained about 1.5 kg body weight on average. BMI, waist circumference, fat areas by CT and HBA1c significantly increased during the follow-up period. The change of adipocytokine levels by analysis of the quartile of body weight decrease and regain revealed that increased adiponectin and decreased leptin was noteworthy for weight reduction, while increase of leptin influenced the weight regain. In conclusion, our results suggest that leptin could have broad effects on the distribution off at tissues and on lipid metabolism. Leptin inversely associated with adiponectin, which in turn was necessary to decrease body weight. In particular, leptin decreased remarkably in the process of weight reduction, and its increase seemed to be related in weight regain. The observed increase of adiponectin seemed to be induced by reduction in fat volume.

Volumetric evaluation of fat in the renal sinus in normal subjects using stereological method on computed tomography images and its relationship with body composition.

The aim of the study was: to describe a simple, accurate and practical technique for estimating the volume of adipose tissue within the renal sinus (RS) using stereological method on computed tomography (CT) images; to establish a population database for volume of fat within the RS from 21 to 80 years of age; to investigate the effect of age, gender, body mass index (BMI) and abdominal diameters on RS fat volume in normal subjects. We retrospectively reviewed abdominal CT examinations of 240 patients without renal pathology between the ages of 21 and 80 years. There were 6 groups of patients, with 40 patients for each decade. RS fat volumes in the left and right kidney were 5.70 ± 2.87 cm³ and 4.15 ± 2.39 cm³, respectively, in males and 3.51 ± 2.67 cm³ and 2.49 ± 2.16 cm³, respectively, in females. RS fat volume and age were positively correlated for both kidneys (left: r = 0.46; right: r = 0.44; p < 0.001, both), though it appeared to decline after age 70. Quantitative data may allow clinicians to better estimate the age-related RS fat volume changes and help them in decision making.

Vagus nerve preservation results in visceral fat maintenance after distal gastrectomy.

Although preservation of the vaguas nerve is recommended in surgery for earlystage gastric cancer, the physiological effect of vagotomy on the postoperative course has not been well documented. We assessed the effect of vagotomy on the change in fat volume after gastrectomy. Subcutaneous fat area (SFA) and visceral fat area (VFA) were separately measured in computed tomographic images taken before and more than 6 months after surgery, using Fat Scan software. The ratios of postoperative/ preoperative values of these two fat areas as well as body weight were calculated in 45 patients who underwent DG with (n=24) or without (n=21) vagotomy. Vagotomy did not affect the change in body weight (91.3±1.7% vs. 92.1±1.7%). In patients with vagotomy, VFA was reduced to 59.0±5.1%, which was significantly greater than the reduction in SFA (74.3±8.7%, p=0.042). In contrast, the reduction ratios of VFA and SFA were equal in vagus nerve-preserved patients (78.4±6.7% vs. 78.2±6.9%, p=0.97). The vagus nerve may have a function to locally regulate the intra-abdominal fat volume and preservation of the vagus nerve results in the maintenance of visceral fat after DG.

Pioglitazone Increases the Proportion of Small Cells in Human Abdominal Subcutaneous Adipose Tissue

Rodent and in vitro studies suggest that thiazolidinediones promote adipogenesis but there are few studies in humans to corroborate these findings. The purpose of this study was to determine whether pioglitazone stimulates adipogenesis in vivo and whether this process relates to improved insulin sensitivity. To test this hypothesis, 12 overweight/obese nondiabetic, insulin-resistant individuals underwent biopsy of abdominal subcutaneous adipose tissue at baseline and after 12 weeks of pioglitazone treatment. Cell size distribution was determined via the Multisizer technique. Insulin sensitivity was quantified at baseline and postpioglitazone by the modified insulin suppression test. Regional fat depots were quantified by computed tomography (CT). Insulin resistance (steady-state plasma insulin and glucose (SSPG)) decreased following pioglitazone (P < 0.001). There was an increase in the ratio of small-to-large cells (1.16 +/- 0.44 vs. 1.52 +/- 0.66, P = 0.03), as well as a 25% increase in the absolute number of small cells (P = 0.03). The distribution of large cell diameters widened (P = 0.009), but diameter did not increase in the case of small cells. The increase in proportion of small cells was associated with the degree to which insulin resistance improved (r = -0.72, P = 0.012). Visceral abdominal fat decreased (P = 0.04), and subcutaneous abdominal (P = 0.03) and femoral fat (P = 0.004) increased significantly. Changes in fat volume were not associated with SSPG change. These findings demonstrate a clear effect of pioglitazone on human subcutaneous adipose cells, suggestive of adipogenesis in abdominal subcutaneous adipose tissue, as well as redistribution of fat from visceral to subcutaneous depots, highlighting a potential mechanism of action for thiazolidinediones. These findings support the hypothesis that defects in subcutaneous fat storage may underlie obesity-associated insulin resistance.

Recovery of fat following a switch to nucleoside reverse transcriptase inhibitor‐sparing therapy in patients with lipoatrophy: results from the 96‐week randomized ANRS 108 NoNuke Trial

To evaluate the impact on peripheral fat tissue of a nucleoside reverse transcriptase inhibitor (NRTI)-sparing regimen in lipoatrophic HIV-1 infected patients. This 96-week prospective, randomized study compared lipoatrophic patients switched to an NRTI-sparing regimen with patients remaining on an NRTI-containing regimen. The primary endpoint was the change in thigh subcutaneous fat tissue volume between baseline and week 48, as assessed by computerized tomography. One hundred patients were included, 50 in each arm. At baseline, patients had been on highly active antiretroviral therapy (HAART) for a median time of 6.6 years (4.9-9.7); 71% of the patients had received thymidine analogues [stavudine (37%), zidovudine (34%)]. The mean change in fat volume between baseline and week 48 significantly favoured the NRTI-sparing arm over the NRTI-maintaining arm in the intent-to-treat analysis, with a last-observation-carried-forward approach [+34 cm(3); 95% confidence interval (CI) 5-63 cm(3); P=0.002]. This was confirmed in the intent-to-treat analysis of available data, with a mean difference of +109 cm(3) (95% CI 34-185 cm(3)) at week 96 (n=53; P=0.001). This corresponded to increases of 12 and 30% in fat volume at weeks 48 and 96, respectively, in the NRTI-sparing arm. Switching from an effective NRTI-containing regimen to an NRTI-sparing regimen preserves immunovirological status and increases subcutaneous fat volume at weeks 48 and 96.

A physiologically based pharmacokinetic model for lactational transfer of PCB 153 with or without PCB 126 in mice

Chemical exposure via breast milk is one of the great concerns in public health. Previously, we demonstrated that most body burden of PCB 153 can be transferred from the mother to the pups in mice during lactational period. Here we present a physiologically based pharmacokinetic (PBPK) model to describe the lactational transfer of PCB 153 with or without PCB 126 in mice. The model incorporated physiological changes on the volume and the blood flow into mammary tissues, and considered mechanistic information on the movement of PCB 153 from adipose tissue to the mammary gland during lactational period. The mechanistic consideration includes fat volume changes, binding of PCB 153 to very low density lipoprotein (VLDL) and increased uptake of VLDL in mammary tissues. Model parameters depicting physiological changes were obtained from research articles dealing with chemical transfer during lactational period in rodents. Chemical-specific parameters were derived from previous PBPK models focusing on the PCB disposition in rodents. The developed model adequately described the lactational transfer of PCB 153 with or without PCB 126 in mice. Our model will provide a useful mechanistic tool to estimate the disposition of PCBs in diverse experimental designs regarding PCB effects during developmental period and to improve quantitative risk assessment of PCBs in the developing organisms.