Regional differences and effect of weight reduction on human fat cell metabolism

Association between Periodontal Condition and Fat Distribution in Japanese Adults: A Cross-Sectional Study Using Check-Up Data

Some studies have reported a significant association between periodontal condition and obesity status. We hypothesized that visceral fat area (VFA) and subcutaneous fat area (SFA) volumes might be correlated with periodontal condition. The purpose of the present cross-sectional study was to investigate the association between periodontal condition and fat distribution in Japanese adults. A total of 158 participants, aged 35-74 years, underwent a health check-up including fat distribution and oral examinations. All of the participants underwent magnetic resonance imaging to quantify VFA and SFA. Periodontal condition was evaluated using the periodontal pocket depth (PPD) and clinical attachment level. The VFA volumes differed among the PPD score and clinical attachment level (CAL) code groups. On the other hand, no significant differences in SFA volume were observed among different periodontal conditions. Multiple regression analysis showed that VFA was positively correlated with a greater CAL (standardized coefficient β = 0.123, p = 0.009), but not with a greater PPD score. A larger VFA was positively associated with a greater CAL in Japanese adults, whereas no association was found between SFA and periodontal condition.

Skin and soft tissue infection of Nontuberculous mycobacterium after injection lipolysis

BACKGROUND

Injection lipolysis is used for body and face contouring due to its minimal invasiveness and cost-effectiveness, but related complications such as nontuberculous mycobacterium infection significantly affect its clinical application.

AIMS

This study aimed to review the literature on NTM infection after injection lipolysis.

METHODS

We conducted a literature review of scientific journals published in Medline and PubMed up to September 2022 on patients with NTM skin and soft tissue infections. We used the keywords: nontuberculous mycobacterium, infection, injection lipolysis, and lipolytic solution in various combinations with the Boolean operators AND, OR, and NOT. Only articles available in English and full version publications were considered for this review. Here, we reviewed the relevant mechanisms and drugs for injectable lipolysis and analyzed the possible correlation between NTM infection and injection lipolysis. We also summarize methods for the diagnosis and treatment of NTM infections and present some perspectives on this therapy.

RESULTS

Many patients with NTM infections had a history of fat-related surgery or therapy. NTM infection after injection lipolysis may be related to inadequate disinfection and sterilization of injection equipment and clinical procedures, the unqualified medication itself and free fatty acids released during injection lipolysis. Currently, diagnosis and treatment of NTM infection after lipolysis injections remains challenging.

CONCLUSIONS

Injection lipolysis represents a helpful option for local fat reduction. Doctors should strictly abide by the aseptic operation standards and use qualified products for there is a correlation between skin and soft tissue infection of nontuberculous mycobacterium and injection lipolysis. Providers should understand the mechanism, indications, and associated risks of injection lipolysis when injecting fat-dissolving drugs to reduce localized fat.

Potential Role of Oxidative Stress in the Production of Volatile Organic Compounds in Obesity

Obesity is associated with numerous health issues such as sleep disorders, asthma, hepatic dysfunction, cancer, renal dysfunction, diabetes, cardiovascular complications, and infertility. Previous research has shown that the distribution of excess body fat, rather than excess body weight, determines obesity-related risk factors. It is widely accepted that abdominal fat is a serious risk factor for illnesses associated with obesity and the accumulation of visceral fat promotes the release of pro-oxidants, pro-inflammatory, and reactive oxygen species (ROS). The metabolic process in the human body produces several volatile organic compounds (VOCs) via urine, saliva, breath, blood, skin secretions, milk, and feces. Several studies have shown that VOCs are released by the interaction of ROS with underlying cellular components leading to increased protein oxidation, lipid peroxidation, or DNA damage. These VOCs released via oxidative stress in obese individuals may serves as a biomarker for obesity-related metabolic alterations and disease. In this review, we focus on the relationship between oxidative stress and VOCs in obesity.

A new approach to cardiac fat volume assessment and the correlation with coronary artery calcification

BACKGROUND

Coronary artery disease (CAD) is the foremost cause of death in the most developed societies. Plaque formation in epicardial coronary arteries and ensuing inflammation are a known pathophysiologic factor of CAD.

OBJECTIVES

We aimed to separately and simultaneously evaluate the correlation between pericardial fat pad volume and overall peri-coronary epicardial adipose tissue (EAT) thickness with coronary calcium score (CCS) to improve risk stratification of CAD.

METHODS

We retrospectively reviewed patients who underwent a non-invasive contrast-enhanced coronary multidetector CT (MDCT) angiography. Peri-coronary EAT thickness, pericardial fat pad volume and CCS were obtained by an expert radiologist from the patients coronary multidetector CT (MDCT) angiography.

RESULTS

We included 141 symptomatic patients (86 men, 55 women) with an average age of 53.53 ± 12.92. An increment of overall peri-coronary EAT thickness (1/3 × (left anterior descending artery (LAD) + left circumflex artery (LCx) + right coronary artery (RCA)) was associated with a 49% increase in the odds for the presence of coronary artery calcification (CAC) (P = 0.004). Significant predictability of peri-coronary EAT-average was seen in diagnosing calcified plaque. Pericardial fat pad volume was positively correlated with overall peri-coronary EAT thickness in age and body mass index (BMI)-adjusted linear regression models, (P < 0.001).

CONCLUSION

Our results amplify previous idea that peri-coronary EAT and pericardial fat pad volume might act as useful markers and better indicators of CCS based on Agatston score in comparison with BMI or body weight in order to reveal subsequent CADs.

Profile of regional fat and fat-free soft tissue accumulation in male athletes

Background

It is unclear whether or not the breakpoint (BP), at which the proportion of each of fat mass (FM) and fat-free soft tissue mass (FFSTM) to body mass (BM) alter, exists in male athletes. We examined the hypothesis that in male athletes, the regional FM and FFSTM-BM relationships have a BP, but the body mass at BP (BM_BP) differs among the arms, trunk, and legs.

Methods

By using a dual X-ray absorptiometry, whole-body and regional FMs and FFSTMs in the arms, trunk, and legs were estimated in 198 male athletes (20.8 ± 2.1 years; 1.73 ± 0.07 m; 72.7 ± 14.8 kg). To detect the BP in the relationship between each of FM and FFSTM and BM, a piecewise linear regression analysis was used. If a BP was detected in the corresponding relationship, the significant difference between the regression slopes above and below the BP was examined.

Results

The regression analysis indicated that the BM_BP existed in the FM- and FFSTM-BM relationships regardless of region and whole body. For the whole body, BM_BP was 81.8 kg for FM and 82.2 kg for FFSTM. In regional FM-BM relationships, BM_BP was 80.5 kg for arms, 82.6 kg for trunk, and 63.3 kg for legs, and the regression slopes above the BM_BP became higher than those below the BP, and vice versa in regional FFSTM-BM relationships (BM_BP 104.6 kg for arms, 80.9 kg for trunk, and 79.0 kg for legs). The relative differences in the slopes between below and above BM_BP in the regional FM-BM relationships were higher in the arms and trunk than in the legs, and those in the regional FFSTM-BM relationships in the legs than in the trunk.

Conclusion

Whole-body and regional FM- and FFSTM-BM relationships for male athletes have breakpoints at which the proportion of the tissue masses to BM alters. The BM_BP and differences in the distribution of regional FM and FFSTM around the breakpoint are region specific.

Effects of a topical lotion containing aminophylline, caffeine, yohimbe, l-carnitine, and gotu kola on thigh circumference, skinfold thickness, and fat mass in sedentary females

Background and objective

Topical aminophylline, caffeine, yohimbe, l‐carnitine, and gotu kola (Centella asiatica) may aid in reducing body fat. Lipoxyderm™ contains these ingredients and was used to test if fat loss of the thigh, in conjunction with a low intensity exercise program and restricted calorie intake, was enhanced via the topical application of this lotion.

Methods

This was a double‐blind, placebo‐controlled, within‐group study that investigated the effects of Lipoxyderm™ on thigh fat mass, circumference, and skinfold thickness. Seven participants underwent pre/post‐exercise testing for weight, bilateral thigh circumference/skinfold thickness, and body composition/thigh fat mass assessment via dual‐energy X‐ray absorptiometry. Participants followed a hypocaloric diet, walked 150 minutes/wk, and were randomly assigned to apply a placebo to one leg and Lipoxyderm™ to their other leg for 28 days. Separate two‐way mixed factorial repeated measures ANOVAs were used to compare the effects of Lipoxyderm™ to the placebo on thigh circumference, skinfold thickness, and fat mass.

Results

A significant time x group interaction was found for thigh circumference (F_1,6 = 18.2, P = 0.005), skinfold thickness (F_1,6 = 14.6, P = 0.009), and fat mass (F_1,6 = 37.1, P = 0.001).

Conclusions

A twice‐daily topical application of Lipoxyderm™ for 28 days compared to a placebo combined with a walking program and a restricted caloric intake is more effective at reducing thigh circumference (1.2 vs 0.8 cm), thigh skinfold thickness (3.7 vs 2.0 mm), and thigh fat mass (100.0 g vs 57.3 g).

Influence of Sex on the Association Between Epicardial Adipose Tissue and Left Atrial Transport Function in Patients With Atrial Fibrillation: A Multislice Computed Tomography Study

BACKGROUND

Epicardial adipose tissue (EAT) is known to play an important role in atrial fibrillation substrate remodeling; however, the influence of sex on the association between EAT and left atrial (LA) transport function has not been elucidated.

METHODS AND RESULTS

Of the 514 patients who underwent an index atrial fibrillation ablation procedure, 123 postmenopausal women with no history of hormone replacement therapy and 123 men who were matched for age, body mass index, type of atrial fibrillation, and CHADS₂ score were enrolled. Before the procedure, LA volume, LA emptying fraction, and EAT volume were assessed using multislice computed tomography. Blood samples were obtained from a coronary sinus for analysis of serum adiponectin level before the ablation procedure. There were no differences in baseline demographics and laboratory findings between sexes. Compared with men, women had significantly less total EAT (P<0.001) and higher serum adiponectin levels (P=0.022) but higher proportions of periatrial EAT to total EAT volume (P/T EAT ratio, P<0.001), lower LA emptying fraction (P=0.042), and lower LA voltage (P=0.034). The ratio of periatrial to total EAT volume correlated significantly with LA emptying fraction and LA voltage in both sexes, whereas total EAT volume and serum adiponectin level did not. On multivariate analysis, increased LA volume and higher periatrial:total EAT volume ratio were independent predictors of decreased LA emptying fraction in both sexes.

CONCLUSIONS

Compared with matched men, postmenopausal women with atrial fibrillation had higher periatrial adiposity, which was independently correlated with decreased LA voltage and LA transport function.

Modern trends in lipomodeling

Lipomodeling is the process of relocating autologous fat to change the shape, volume, consistency, and profile of tissues, with the aim of reconstructing, rejuvenating, and regenerating body features. There have been several important advancements in lipomodeling procedures during the last thirty years. Four clinical steps are important for the success of engraftment: fat harvesting, fat processing, fat reinjection, and preconditioning of the recipient site. With the discovery of adipose derived stem cells and dedifferentiated cells, fat cells become a major tool of regenerative medicine. This article reviews recent trends in lipomodeling trying to understand most of the issues in this field.

Increased Dynamics of Tricarboxylic Acid Cycle and Glutamate Synthesis in Obese Adipose Tissue: IN VIVO METABOLIC TURNOVER ANALYSIS

Obesity is closely associated with various metabolic disorders. However, little is known about abnormalities in the metabolic change of obese adipose tissue. Here we use static metabolic analysis and in vivo metabolic turnover analysis to assess metabolic dynamics in obese mice. The static metabolic analyses showed that glutamate and constitutive metabolites of the TCA cycle were increased in the white adipose tissue (WAT) of ob/ob and diet-induced obesity mice but not in the liver or skeletal muscle of these obese mice. Moreover, in vivo metabolic turnover analyses demonstrated that these glucose-derived metabolites were dynamically and specifically produced in obese WAT compared with lean WAT. Glutamate rise in obese WAT was associated with down-regulation of glutamate aspartate transporter (GLAST), a major glutamate transporter for adipocytes, and low uptake of glutamate into adipose tissue. In adipocytes, glutamate treatment reduced adiponectin secretion and insulin-mediated glucose uptake and phosphorylation of Akt. These data suggest that a high intra-adipocyte glutamate level potentially relates to adipocyte dysfunction in obesity. This study provides novel insights into metabolic dysfunction in obesity through comprehensive application of in vivo metabolic turnover analysis in two obese animal models.

Impact of visceral fat on gene expression profile in peripheral blood cells in obese Japanese subjects

Background

Visceral fat plays a central role in the development of metabolic syndrome and atherosclerotic cardiovascular diseases. The association of visceral fat accumulation with cardio-metabolic diseases has been reported, but the impact of visceral fat on the gene expression profile in peripheral blood cells remains to be determined. The aim of this study was to determine the effects of visceral fat area (VFA) and subcutaneous fat area (SFA) on the gene expression profile in peripheral blood cells of obese subjects.

Methods

All 17 enrolled subjects were hospitalized to receive diet therapy for obesity (defined as body mass index, BMI, greater than 25 kg/m²). VFA and SFA were measured at the umbilical level by computed tomography (CT). Blood samples were subjected to gene expression profile analysis by using SurePrint G3 Human GE Microarray 8 × 60 k ver. 2.0. The correlation between various clinical parameters, including VFA and SFA, and peripheral blood gene expression levels was analyzed.

Results

Among the 17 subjects, 12 had normal glucose tolerance or borderline diabetes, and 5 were diagnosed with type 2 diabetes without medications [glycated hemoglobin (HbA1c); 6.3 ± 1.3%]. The mean BMI, VFA, and SFA were 30.0 ± 5.5 kg/m², 177 ± 67 and 245 ± 131 cm², respectively. Interestingly, VFA altered the expression of 1354 genes, including up-regulation of 307 and down-regulation of 1047, under the statistical environment that the parametric false discovery rate (FDR) was less than 0.1. However, no significant effects were noted for SFA or BMI. Gene ontology analysis showed higher prevalence of VFA-associated genes than that of SFA-associated genes, among the genes associated with inflammation, oxidative stress, immune response, lipid metabolism, and glucose metabolism.

Conclusions

Accumulation of visceral fat, but not subcutaneous fat, has a significant impact on the gene expression profile in peripheral blood cells in obese Japanese subjects.

An evaluation of the patient population for aesthetic treatments targeting abdominal subcutaneous adipose tissue

A large and growing population of patients currently seeks minimally invasive therapeutic options for the aesthetic treatment of localized, central abdominal subcutaneous adipose tissue (SAT). We sought to evaluate the ideal population for aesthetic treatment of central abdominal SAT, highlight the existing disparities between SAT in obese (body mass index [BMI] ≥ 30; BMI) and nonobese (BMI < 30) patients, and review the available FDA-cleared, minimally invasive treatment options for central abdominal adiposity. The cosmetic issue of localized, central (periumbilical) abdominal adiposity in nonobese individuals is quite distinct from abdominal bulging secondary to obesity. Given the recognized clinical and physiologic differences between obese and nonobese counterparts, the exclusion of obese patients from clinical study by currently available FDA-cleared devices targeting abdominal fat, and the status of obesity as a chronic, systemic disease requiring medical, surgical, and/or lifestyle-altering therapies, minimally invasive therapeutic options for aesthetic reductions in central abdominal SAT must be limited to the nonobese population.

Evidence for the role of AMPK in regulating PGC-1 alpha expression and mitochondrial proteins in mouse epididymal adipose tissue

OBJECTIVE

PGC-1α is a transcriptional co-activator and master regulator of mitochondrial biogenesis. While extensively studied in skeletal and cardiac muscle, recent findings suggest that white adipose tissue PGC-1α plays an important role in regulating glucose homeostasis. The purpose of the present investigation was to evaluate the role of AMPK in regulating PGC-1α and mitochondrial enzymes in mouse epididymal and inguinal subcutaneous adipose tissue.

METHODS

Mitochondrial protein content and norepinephrine and CL 316,243-induced PGC-1α mRNA expression were studied in mouse epididymal and inguinal adipose tissue from wild-type and AMPK β1(-/-) mice.

RESULTS

The protein content and phosphorylation of AMPKα was reduced in epididymal adipose tissue from AMPK β1(-/-) compared to WT mice, concomitant with decreases in PGC-1α and mitochondrial marker proteins. Norepinephrine and CL 316,243-mediated induction of PGC-1α were decreased in cultured epididymal adipose tissue from AMPK β1(-/-) relative to WT mice. In inguinal adipose tissue from AMPK β1(-/-) mice, mitochondrial marker protein content and norepinephrine and CL 316,243-mediated increases in PGC-1α were normal despite reductions in the content and phosphorylation of AMPKα.

CONCLUSIONS

Norepinephrine- and CL 316,243-mediated induction of PGC-1α and mitochondrial protein expression is regulated by AMPK in epididymal, but not inguinal adipose tissue.

Mesotherapy for local fat reduction

Mesotherapy, which is the injection of substances locally into mesodermally derived subcutaneous tissue, developed from empirical observations of a French physician in the 1950s. Although popular in Europe for many medical purposes, it is used for local cosmetic fat reduction in the United States. This paper reviews manuscripts indexed in PubMed/MEDLINE under 'mesotherapy', which pertains to local fat reduction. The history of lipolytic mesotherapy, the physiology of body fat distribution, the mechanism of action of different lipolytic stimulators and their increased efficacy in combination are reviewed. Mesotherapy falls into two categories. Lipolytic mesotherapy using lipolytic stimulators requires more frequent treatments as the fat cells are not destroyed and can refill over time. Ablative mesotherapy destroys fat cells with a detergent, causes inflammation and scarring from the fat necrosis, but requires fewer treatments. The historic and empiric mixing of sodium channel blocking local anaesthetics in mesotherapy solutions inhibits the intended lipolysis. Major mesotherapy safety concerns include injection site infections from poor sterile technique. Cosmetic mesotherapy directs the area from which fat is lost to improve self-image. Studies were of relatively small number, many with limited sample sizes. Future research should be directed towards achieving a Food and Drug Administration indication rather than continuing expansion of off-label use.

Vascular complications and changes in body mass index in Japanese type 2 diabetic patients with abdominal obesity

Background

Although many Asian type 2 diabetic patients have been considered to be not obese and have low capacity of insulin secretion, the proportion of obese patients with visceral fat accumulation has increased in recent years. We found previously considerable number of Japanese non-obese subjects (body mass index (BMI) < 25 kg/m²) with visceral fat accumulation and multiple cardiovascular risk factors. The aim of the study was to investigate the difference in clinical features of type 2 diabetic patients with and without visceral fat accumulation, focusing on vascular complications and changes in BMI.

Methods

We enrolled 88 Japanese hospitalized type 2 diabetic patients. Abdominal obesity represented waist circumference (WC) of ≥85 cm for males and ≥90 cm for females (corresponding to visceral fat area of 100 cm²). Subjects were divided into two groups; with or without abdominal obesity.

Results

Hypertension, dyslipidemia and cardiovascular diseases were significantly more in the patients with abdominal obesity. The prevalence of cardiovascular disease in the non-obese patients (BMI < 25 kg/m²) with abdominal obesity were similar in obese patients (BMI ≥25 kg/m²). The mean BMI of the patients with abdominal obesity was < 25 kg/m² at 20 years of age, but reached maximum to more than 30 kg/m² in the course. Furthermore, substantial portion of the type 2 diabetic patients (52% in males and 43% in females) were not obese at 20 year-old (BMI < 25 kg/m²), but developed abdominal obesity by the time of admission.

Conclusion

These results emphasize the need to control multiple risk factors and prevent atherosclerotic disease in patients with abdominal obesity. The significant weight gain after 20 years of age in patients with abdominal obesity stresses the importance of lifestyle modification in younger generation, to prevent potential development of type 2 diabetes and future atherosclerotic cardiovascular disease.

Exercise and Obesity

This paper reviews succinctly the evidence for a role of regular exercise in the prevention and the treatment of obesity and of its metabolic complications. Seventeen propositions relevant to an understanding of the topic are considered. The evidence suggests that regular exercise can be an important factor in the development of sustained negative energy balance conditions provided the volume of activity is high. This implies a program of low to moderate intensity exercise performed on an almost daily basis for at least one hour per session. To induce significant weight and fat losses and to treat overweight and obese patients, compliance to the program for several years becomes a necessity. Exercise increases lipid substrate oxidation and may favor carbohydrate intake for the same amount of energy intake. The acute effects of exercise on resting metabolic rate are well documented, but the long-term influences of exercise training seem to be small and are rapidly suppressed with the cessation of training. The obese benefits also from a regular exercise regimen in terms of improved insulin sensitivity, lipid and lipoprotein profile, and blood pressure, as well as reduced risk of death. Regular exercise, such as walking, is a healthy course of action for the overweight or the obese patients.

Adaptation of human adipose tissue to hypocaloric diet

Hypocaloric diet is a key component of the weight-reducing treatment of obesity and obesity-related disorders. Hypocaloric diets and the associated weight reduction promote improvement of metabolic profile of obese individuals. Among the mechanisms that underlie this beneficial metabolic outcome, the diet-induced modifications of morphological and functional characteristics of human adipose tissue (AT) are believed to have an important role. Prospective studies of hypocaloric weight-reducing dietary intervention demonstrate effects on adipocyte metabolism, namely lipolysis and lipogenesis, and associated changes of the adipocyte size. The endocrine function of AT, which involves cytokine and adipokine production by adipocytes, as well as by cells of stromavascular fraction, is also regulated by dietary intervention. Related inflammatory status of AT is modulated also as a consequence of the changes in recruitment of immune cells, mainly macrophages, in AT. Here, we give an overview of metabolic and endocrine modifications in human AT induced by a variety of hypocaloric diets.

Visceral adiposity as a target for the management of the metabolic syndrome

Atherosclerosis, the underlying cause of atherosclerotic cardiovascular disease (ACVD), develops due not only to a single cardiovascular risk factor but to a variety of complex factors. The concept of the multiple cardiometabolic risk factor clustering syndrome has been proposed as a highly atherogenic state, independent of hypercholesterolemia and smoking. Body fat distribution, especially visceral fat accumulation, is a major correlate of a cluster of diabetogenic, atherogenic, prothrombotic, and proinflammatory metabolic abnormalities referred to as the metabolic syndrome, with dysfunctional adipocytes and dysregulated production of adipocytokines (hypoadiponectinemia). Medical research has focused on visceral adiposity as an important component of the syndrome in Japanese subjects with a mild degree of adiposity compared with Western subjects. For the prevention of ACVD at least in Japan, it might be practical to stratify subjects with multiple risk factors for atherosclerotic cardiovascular disease based on visceral fat accumulation. Visceral fat reduction through health promotion programs using risk factor-oriented approaches may be effective in reducing ACVD events, as well as producing improvement in risks and hypoadiponectinemia. This review article discusses visceral adiposity as a key player in the syndrome. Visceral fat reduction with life-style modification is a potentially useful strategy in the prevention of ACVD in patients with the metabolic syndrome.

Predictors of very-low-energy diet outcome in obese women and men

OBJECTIVE

The aim of this study was to explore baseline outcome predictors of a 12-week very-low-energy diet (VLED) treatment.

METHODS

Obese patients (177 women and 90 men) started treatment. Multivariate linear and logistic regressions were used to predict weight loss (%), successful outcome (>or= 10% weight loss) and attrition. Potential predictors were anthropometry, socioeconomic variables, established questionnaires on health-related quality of life, and eating behavior, and additional questions related to dieting.

RESULTS

Mean weight loss was 13.5% (standard deviation (SD) 5.6) in women and 15.1% (6.1) in men (p = 0.054). Greater weight loss in women was predicted by having more children, lower education, and better perceived physical health (R-square (R(2)) = 12.7%), and in men by better ambulation capacity, living with a partner/children, and snacking on ice-cream more often (R(2) = 39.4%). Successful outcome in women was predicted by less obesity-related psychosocial dysfunction, and in men by better functioning in social interaction and ambulation capacity. Attrition was predicted by lower age and larger hip circumference in women, and in men by lower perceived general health. Two-week weight loss was independently associated with all outcomes except attrition in women.

CONCLUSION

Factors related to perceived physical health, social interaction, socio-economic factors, and obesity-related psychosocial problems predicted VLED outcome. The predictors differed by gender.

DEXA-assessed regional body composition changes in young female military soldiers following 12-weeks of periodised training

Dual-energy X-ray absorptiometry (DEXA) was used to assess whole body and regional soft tissue mass, fat mass and lean body mass compositional changes in 68 female recruits (age 20.8 +/- 1.14 years; body mass 59.5 +/- 8.79 kg; stature 159.57 +/- 5.53 cm) pre- and post 12-weeks of military basic training. A decrease in total body fat tissue mass (10.2%) and regional percent fat (10.9%) was measured with an increase in total lean body mass (8.7%). Of interest were the differences in the responses in the tissue composition of the arms (16.2% loss in fat mass with an 11.6% gain in lean mass), trunk (17.0% decrease in fat mass with a 10.4% increase in lean mass) and the legs (10.5% increase in lean mass but no change in fat mass). These findings show the importance of considering regional rather than whole body composition changes when assessing the effects of a training programme. STATEMENT OF RELEVANCE: Female soldiers experienced a change in total body fat tissue (-10.2%) and lean body mass (+8.7%) after basic training; however, no significant fat mass decrease was evident in the leg region. Regional rather than whole body composition changes need to be considered when assessing the effects of a training programme.

The associations between obesity, adipose tissue distribution and disease

Recent research has shown the marked differences in association with disease between obesity localized to the abdominal respectively to the gluteal-femoral regions. In this review systematic analyses were performed of the associations between obesity (body mass index, BMI) or abdominal obesity (increased waist-over-hip circumference ratio, WHR) on the one hand, and a number of disease end points, and their risk factors, as well as other factors on the other, WHR was associated with cardiovascular disease, premature death, stroke, non-insulin-dependent diabetes mellitus and female carcinomas. In contrast, BMI tended to be negatively correlated to cardiovascular disease, premature death, and stroke, but positively to diabetes. The established risk factors for these end points were found to correlate to WHR, while this was often not the case with BMI. BMI was positively correlated only to insulin, triglycerides and blood pressure. Together with diabetes mellitus, this seems to constitute a metabolic group of conditions which are thus associated with BMI. Androgens (in women), and perhaps cortisol, seem to be positively, and progesterone negatively correlated to WHR. The WHR was also positively associated with sick leave, several psychological maladjustments, psychosomatic and psychiatric disease. Attempts were made to interpret these findings. In a first alternative an elevation of FFA concentration, produced from abdominal adipose tissue, was considered to be the trigger factor for the pathologic aberrations associated with abdominal distribution of body fat. When obesity is added, the metabolic aberrations may be exaggerated. In a second alternative adrenal cortex hyperactivity was tested as the cause. When combined with the FFA hypothesis, this might explain many but not all of the findings. It seems possible to produce an almost identical syndrome in primates by defined experimental stress. Women with high WHR were found to have a number of symptoms of poor coping to stress. It was therefore suggested that part of the background to this syndrome might be a hypothalamic arousal syndrome developing with stress. It was concluded that obesity and abdominal distribution of adipose tissue constitute two separate entities with different pathogenesis, clinical consequences and probably treatment.

Role of antilipolytic mechanisms in adipose tissue distribution and function in man

Regional differences have been found in the hormone regulation of adipose tissue lipolysis. Lipolytic activity is greater in omental than in subcutaneous adipocytes owing, in part, to a less marked insulin action and lower alpha 2-adrenoceptor antilipolytic activity in the omental region. In the subcutaneous region catecholamines are less lipolytic in gluteal/femoral than in subcutaneous abdominal adipocytes, which is partly due to enhanced alpha 2-adrenoceptor responsiveness in the gluteal/femoral cells. Insulin action also differs in the two subcutaneous adipose regions in a complex way that is influenced by the degree of obesity and nutritional factors. The regional differences in the antilipolytic effects of hormones seem to be caused by site variations in the receptors as well as in the signals from the receptors. The site variations may be involved in the development of regional forms of obesity, such as android or gynoid obesity and may raise the free fatty acid levels in the portal system and therefore impair metabolism of glucose and insulin by the liver.

Physical training and changes in regional adipose tissue distribution

Obesity has been associated with numerous metabolic complications, such as changes in the concentration and/or composition of plasma lipoproteins, glucose intolerance and hyperinsulinemia leading to diabetes and hypertension. The relation of obesity to cardiovascular disease has not, however, been consistently reported. Recent prospective studies have clearly indicated that the distribution of adipose tissue was a significant cardiovascular risk factor and numerous studies have shown that metabolic disturbances were more closely associated with the level of abdominal fat than excess adiposity per se. As obese men generally store their energy excess in the abdominal region and women in the peripheral fat depots, the metabolic complications of obesity seem to be more closely related to adiposity in men than in women. It is suggested that the sex dimorphism observed in adipose tissue localization could partly explain the greater cardiovascular risk associated with obesity in men than in women. Indeed, obese women with a "male" (abdominal) distribution of body fat have greater metabolic complications than women with lower body fat. When aerobic exercise-training is used to induce weight loss, men generally lose more fat than women. In men, the loss of adipose tissue appears to be central, potentially reducing the risk of cardiovascular disease, whereas a relative resistance to fat loss is observed in women compared to men. Although resistance to fat loss is noted in women, those with a "male" distribution of adipose tissue (high waist-to-hip ratio and high intra-abdominal fat deposition) and with associated metabolic complications greatly benefit from aerobic exercise-training.(ABSTRACT TRUNCATED AT 250 WORDS)

Monounsaturatedn-9 fatty acids and adipocyte lipolysis in rats

To investigate the role of the monounsaturatedn-9 fatty acids (MUFA) in the lipolytic activity of adipocytes, a study was carried out in which an increase in MUFA was produced in the tissues by two different methods; by the dietary enrichment of oleic acid or by producing an essential fatty acid deficiency syndrome. For this, forty-five male Sprague–Dawley rats were fed with a normal-energy diet and were subdivided into three groups. The diets varied in the type of dietary fat; palmitic acid, olive oil, or soyabean oil+palmitic acid. At the end of the study measurements were taken of weight, plasma leptin, tissue concentration of fatty acids, fat-cell size in the epididymal and the omental adipose tissues, adipocyte lipolytic activity of both tissues after stimulation with adrenaline, and the capacity of insulin to inhibit lipolysis. The baseline and adrenaline-stimulated lipolytic activity were greater and the anti-lipolytic capacity of insulin lower in the animals undergoing an increase in MUFA in the tissues (palmitic-acid and olive-oil diets). The area under the curve of glycerol, used as an indicator of lipolytic activity, was positively correlated with the concentration of MUFA and negatively with polyunsaturated fatty acids in the adipose tissues. It is concluded that an increase in tissue MUFA, however obtained, induces an increase in lipolytic activity.

Prospective and controlled studies of the actions of insulin and catecholamine in fat cells of obese women following weight reduction

AIMS/HYPOTHESIS

Enlarged fat cells from obese subjects are characterised by insulin resistance and abnormal adrenergic regulation of lipolysis. The aim of the present study was to examine whether these aberrations return to normal following weight reduction.

MATERIALS AND METHODS

Obese women (n=25) were investigated before and 3+/-1 years (mean+/-SD) after steady-state weight reduction and compared with control women who were matched to the cases at re-examination in terms of age and BMI. Adipocyte volume, lipogenesis and lipolysis were determined in isolated subcutaneous fat cells following stimulation or inhibition at different steps of the lipolytic cascade.

RESULTS

Weight reduction decreased fat cell volume and basal and adrenergic-regulated lipolysis rates to values that were 20-40% lower than those in control women (p=0.0002-0.03), despite the fact that percentage body fat was almost identical in the two groups of women. Fat cell volume was directly proportional to lipolysis in obese subjects, both before and after weight reduction, and in control subjects. Insulin-induced antilipolysis and lipogenesis were completely normalised after weight reduction.

CONCLUSIONS/INTERPRETATION

Body-weight-reduced obese women had low basal and catecholamine-stimulated adipocyte lipolysis, presumably due to adipose tissue hyperplasia. This could make an important contribution to body weight gain following weight loss. Adipocyte insulin resistance is secondary to obesity.

Association of adiponectin and resistin with adipose tissue compartments, insulin resistance and dyslipidaemia

AIM

In this study, we investigated the association of plasma adiponectin and resistin concentrations with adipose tissue compartments in 41 free-living men with a wide range of body mass index (22-35 kg/m(2)).

METHODS

Using enzyme immunoassays, plasma adiponectin and resistin were measured. Intraperitoneal, retroperitoneal, subcutaneous abdominal and posterior subcutaneous abdominal adipose tissue masses (IPATM, RPATM, SAATM and PSAATM, respectively) were determined using magnetic resonance imaging. Total adipose tissue mass (TATM) was measured using bioelectrical impedance. Insulin resistance was estimated with the help of homeostasis model assessment (HOMA) score.

RESULTS

In univariate regression, plasma adiponectin levels were inversely related to IPATM (r = -0.389, p < 0.05), SAATM (r = -0.500, p < 0.001), PSAATM (r = -0.502, p < 0.001), anterior SAATM (r = -0.422, p < 0.01) and TATM (r = -0.421, p < 0.01). In multiple regression models, adiponectin was chiefly correlated with PSAATM. Plasma adiponectin concentrations were also inversely correlated with HOMA score (r = -0.540, p < 0.001) and triglyceride (r = -0.632, p < 0.001), and positively correlated with high-density lipoprotein cholesterol (r = 0.508, p < 0.001). There were no significant correlations between resistin levels and adipose tissue masses, insulin resistance or dyslipidaemia.

CONCLUSIONS

In men, total body fat is significantly correlated with plasma adiponectin, but not with plasma resistin levels. Low plasma adiponectin levels appear to be chiefly determined by the accumulation of posterior subcutaneous abdominal fat mass, as opposed to intra-abdominal fat, and are strongly predictive of insulin resistance and dyslipidaemia.

Regulation of lipolysis and lipoprotein lipase after weight loss in obese, postmenopausal women

OBJECTIVE

To test the hypothesis that the greater beta-adrenoceptor (beta-AR)-stimulated lipolysis and sensitivity (half-maximal lipolytic response) in abdominal (ABD) adipocytes, greater gluteal (GLT) adipose tissue-lipoprotein lipase (AT-LPL) activity, and dyslipidemia associated with obesity in older women are modifiable by weight loss (WL) and are not due to menopause or aging.

RESEARCH METHODS AND PROCEDURES

The metabolic effects of 6 months of hypocaloric diet and low-intensity walking WL program on the regional regulation of in vitro lipolysis and AT-LPL activity in subcutaneous ABD and GLT adipocytes were measured in 34 obese (48.7 +/- 0.7% body fat, mean +/- SE) postmenopausal (59 +/- 1 years) white women.

RESULTS

The lipolytic responsiveness to the beta-AR agonist isoproterenol and basal lipolysis in the presence of 1 U/mL adenosine deaminase-uninhibited (lipolysis) were greater (p < 0.01) in ABD than GLT adipocytes before and after WL, but there were no regional differences in postreceptor (dibutyryl 3',5'-cyclic adenosine monophosphate)-stimulated lipolysis. beta-AR sensitivity was greater in ABD than GLT adipocytes before (p < 0.01) but not after WL. Regional AT-LPL did not change after WL, but the change in the activity of ABD (but not GLT) AT-LPL correlated with the baseline adenosine deaminase-uninhibited lipolysis (r = 0.38, p = 0.03). There were no relationships between the declines in plasma triglyceride or increases in high-density lipoprotein cholesterol associated with WL and the changes in regional fat cell metabolism.

DISCUSSION

Thus, despite improving lipoprotein lipid profiles in obese, postmenopausal women, WL does not affect the regulation of regional fat metabolism, and a greater tonic inhibition of basal lipolysis by endogenous adenosine may increase the activity of AT-LPL after WL and predispose older women to develop ABD adiposity.

Fat compartments and apolipoprotein B-100 kinetics in overweight-obese men

OBJECTIVE

To examine the association between the kinetics of very-low-density-lipoprotein (VLDL)-apolipoprotein B-100 (apoB) and intraperitoneal, retroperitoneal, subcutaneous abdominal, and total adipose tissue masses (IPATM, RPATM, SAATM, and TATM, respectively) in overweight/obese men.

RESEARCH METHODS AND PROCEDURES

Hepatic secretion of VLDL was measured using an intravenous infusion of 1-[(13)C]-leucine in 51 men with a wide range of body mass index (25.1 to 42.2 kg/m(2)). Isotopic enrichment of VLDL-apoB was measured using gas chromatography-mass spectrometry and a multicompartmental model used to estimate VLDL-apoB metabolic parameters. IPATM, RPATM, and SAATM (kilograms) were quantified between T11 and S1 using magnetic resonance imaging; TATM (kilograms) was determined using bioelectrical impedance. Insulin resistance was estimated by homeostasis model assessment (HOMA) score.

RESULTS

In stepwise regression, IPATM was the best predictor of hepatic secretion of VLDL-apoB (r = 0.390, p < 0.005) and TATM was the best predictor of VLDL-apoB fractional catabolic rate (r = 0.282, p < 0.05). IPATM remained significantly associated with VLDL-apoB secretion after adjusting for TATM or HOMA score (r = 0.360, p < 0.01 and r = 0.310, p < 0.05, respectively). This association was also independent of age, dietary intake, and body mass index. None of the fat compartments were significantly associated with the fractional catabolic rate of VLDL-apoB after adjusting for HOMA score.

DISCUSSION

In overweight/obese men, the quantity of both IPATM and TATM determine the kinetics of VLDL-apoB. The effect of IPATM on VLDL-apoB secretion is independent of both total fat mass and the degree of insulin resistance.

Pericardial fat accumulation in men as a risk factor for coronary artery disease

An increment of abdominal visceral fat accumulation has been reported to be a coronary risk factor. We determined the predictive power of pericardial fat (Pfat) accumulation as intra-thoracic visceral fat, in the diagnosis of coronary artery disease (CAD). Among 251 (181 non-obese [body mass index<25], 70 obese [body mass index> or =25]) Japanese male patients who underwent computed tomography (CT), 128 (90 non-obese, 38 obese) patients were suffering from CAD. Pfat volume was determined by the sum of cross-sectional images 1cm thick from the atrial appendage to the apex over the diaphragm. Abdominal visceral fat (Vfat) and subcutaneous fat (Sfat) areas were measured by a single scan at the L4-L5 region. Pfat was most associated with Vfat in body fat distribution. In non-obese patients, Pfat was most associated with CAD among the various risk factors including body fat distribution. Moreover, Pfat was the strongest independent variable for the severity of CAD, determined by coronary angiogram. This result showed that pericardial fat accumulation was a stronger coronary risk factor than the other body fat distributions in non-obese men.

Short-term effects of weight loss with or without low-intensity exercise training on fat metabolism in obese men

BACKGROUND

Energy restriction is known to induce a decline in fat oxidation during the postdiet period. Reduced fat oxidation may contribute to weight regain.

OBJECTIVE

The present study investigated the effect of the addition of low-intensity exercise training to energy restriction on postdiet fat oxidation and on the contribution of the sympathetic nervous system to fat oxidation.

DESIGN

Forty obese men were divided randomly into 2 groups: diet (D) and diet plus exercise (DE). Both groups followed an energy restriction program for 10 wk. Subjects in the DE group also participated in a low-intensity exercise training program [40% maximal oxygen uptake (VO2max)] for 12 wk. Before the intervention and after 12 wk, with subjects at stable body weights, we measured body composition, VO2max, and substrate oxidation at rest, during exercise at 50% VO2max, and during recovery. Measurements were made with and without administration of the beta-adrenergic antagonist propranolol.

RESULTS

Both interventions led to significant decreases in body weight, fat mass, and fat-free mass (P < 0.001); these decreases did not differ significantly between the D and DE groups. Neither intervention significantly affected VO2max. The effect of the intervention on the respiratory exchange ratio differed significantly between the D and DE groups [two-way analysis of variance (ANOVA), P < 0.05]. The effect on the beta-adrenergic-mediated respiratory exchange ratio tended to be different between the 2 groups (two-way ANOVA, P = 0.09).

CONCLUSION

Addition of low-intensity exercise training to energy restriction counteracts the decline in fat oxidation during the postdiet period.

Impaired insulin action in subcutaneous adipocytes from women with visceral obesity

Visceral obesity is associated with resistance to the antilipolytic effect of insulin in vivo. We investigated whether subcutaneous abdominal and gluteal adipocytes from viscerally obese women exhibit insulin resistance in vitro. Subjects were obese black and white premenopausal nondiabetic women matched for visceral adipose tissue (VAT), total adiposity, and age. Independently of race and adipocyte size, increased VAT was associated with decreased sensitivity to insulin's antilipolytic effect in subcutaneous abdominal and gluteal adipocytes. Absolute lipolytic rates at physiologically relevant concentrations of insulin or the adenosine receptor agonist N(6)-(phenylisopropyl)adenosine were higher in subjects with the highest vs. lowest VAT area. Independently of cell size, abdominal adipocytes were less sensitive to the antilipolytic effect of insulin than gluteal adipocytes, which may partly explain increased nonesterified fatty acid fluxes in upper vs. lower body obese women. Moreover, increased VAT was associated with decreased responsiveness, but not decreased sensitivity, to insulin's stimulatory effect on glucose transport in abdominal adipocytes. These data suggest that insulin resistance of subcutaneous abdominal and, to a lesser extent, gluteal adipocytes may contribute to increased systemic lipolysis in both black and white viscerally obese women.

Cellulite: a review

Gynoid lipodystrophy (cellulite) is an extremely controversial topic. A lack of knowledge regarding specific aetiopathogenic factors, as well as the opportunism of some professionals and the media, has fuelled debate regarding the scientific basis of this condition. This article reviews the clinical, epidemiological, histopathological and therapeutic aspects of cellulite.

Regional body composition changes in women after 6 months of periodized physical training

Data are lacking regarding regional morphological changes among women after prolonged physical training. This study employed dual-energy X-ray absorptiometry to assess changes in whole body and regional (i.e., trunk, legs, arms) fat mass, lean mass, and bone mineral content body composition adaptations in 31 healthy women pre-, mid-, and post-6 mo of periodized physical training. These results were compared with those of 1) a control group of women who had not undergone the training program and were assessed pre- and post-6 mo and 2) a group of 18 men that was tested only once. Additionally, magnetic resonance imaging was used to assess changes in muscle morphology of the thigh in a subset of 11 members of the training group. Physical training consisted of a combination of aerobic and resistance exercise in which the subjects engaged for 5 days/wk for 24 wk. Overall, the training group experienced a 2.2% decrease, a 10% decrease, and a 2.2% increase for body mass, fat mass, and soft tissue lean mass, respectively. No changes in bone mineral content were detected. The women had less of their soft tissue lean mass distributed in their arms than did the men, both before and after the women were trained. Novel to this study were the striking differences in the responses in the tissue composition of the arms (31% loss in fat mass but no change in lean mass) compared with the legs (5.5% gain in lean mass but no change in fat mass). There was a 12% fat loss in the trunk with no change in soft tissue lean mass. Dual-energy X-ray absorptiometry and magnetic resonance imaging fat mass measurements showed good agreement (r = 0. 72-0.92); their lean mass measurements were similar as well, showing approximately 5.5% increases in leg lean tissue. These findings show the importance of considering regional body composition changes, rather than whole body changes alone when assessing the effects of a periodized physical training program.

Visceral obesity and metabolic syndrome

There is increasing evidence for the existence of a condition consisting of a cluster of metabolic disorders which include insulin resistance, alterations in glucose and lipid metabolism, increased blood pressure and visceral obesity. The metabolic syndrome is now the favoured definition of the cluster. Each single component of the cluster increases the cardiovascular risk, but the combination of factors is much more important. Insulin resistance is the most frequently associated factor to the singular components of the syndrome: most authors believe that it may be the common aetiological factor. However, visceral obesity seems to be the main driving factor by means of the increased production of free fatty acids whose activity, in turn, might interfere with the action of insulin. Some questions exist about the syndrome because of the frequent lack in the cluster of one of the factors. This does not mean that the missing factor does not belong to the syndrome, but only that it is not yet clinically evident. Weight gain has been shown to be a strong predictor of the metabolic syndrome. This aspect gives strength to treatment and prevention because it means that losing weight or stopping weight increase might reduce the risk of a future appearance of a factor that is still not evident. Interventions to treat visceral obesity by means of losing weight seem to be the most efficacious way to treat the metabolic syndrome thus improving the most widespread cardiovascular risk factor in western countries.

Ultrasonic assessment of variations in thickness of subcutaneous fat during the normal menstrual cycle

OBJECTIVE

To verify the occurrence of natural variations in thigh and abdominal subcutaneous fat thickness related to the phases of the menstrual cycle, to assess the value of ultrasonography as a reliable method for monitoring subcutaneous fat thickness changes and to evaluate their amplitudes.

METHODS

This study included 10 women (19-39 years) who menstruated regularly. None had used oral contraceptives or slimming products during the 3 months prior to the study. At cycle day 2 (CD2), CD6, CD14, CD22, CD27 and CD30 days (CD0: beginning of menstruation), the subjects were submitted to: (1) measurement of weight and thigh perimeters, (2) measurements of thigh and abdomen subcutaneous fatty tissue thickness on B-mode images acquired at 10 MHz. A protocol was designed to guarantee a reproducible repositioning during the whole time course of the study and ultrasound examinations (US) were always performed by the same trained person to avoid inter-examiner variability.

RESULTS

Subcutaneous fat thicknesses decreased during the first half of the cycle and reached their lowest values at day 22 (-2.0% for the thighs; -3.3% for the abdominal region). Both thigh and abdomen subcutaneous fat reached their maximum thicknesses during menstruation with respective increases of +2.2 and +4.0%. The observed cyclic amplitude variations in the subcutaneous adipose tissue thickness accounted for 7.3% for the abdominal region and 4.1% for the thighs.

CONCLUSION

Variations in adipose tissue thickness during the menstrual cycle could be quantified and monitored by US. The thickness of the thigh and abdominal hypodermis was more important during menstruation and decreased in mid-cycle with a minimum occurring 1 week after ovulation.

Sympathetic modulation of lipolysis in subcutaneous adipose tissue: effects of gender and energy restriction

To investigate the differences in the regulation of lipolysis between male and female obese subjects in vivo, we used an in situ microdialysis technique before and after 3 weeks of energy restriction. Using this method, we examined glycerol, glucose, and lactate responses after 5 minutes of epinephrine stimulation in the adipose tissues. Glycerol releases after the perfusion of phentolamine, orciprenaline, and propranolol were also studied. Sixteen subjects were studied (8 men, 8 women, 35 to 45 years of age, body mass index 38 to 50 kg/m2). In women, epinephrine provoked a greater glycerol release than in men in both abdominal and femoral regions (P < .05). In men and women there was a significant decrease in the concentration of glucose and a significant increase in lactate concentration after epinephrine stimulation (P < .001). After 3 weeks of energy restriction, glycerol release after epinephrine stimulation was greater in both sexes than that observed before energy restriction (P < .05). Both phentolamine and orciprenaline stimulated the release of glycerol (P < .01); phentolamine had a higher effect in women, while propranolol had no effect on glycerol release in both sexes. In summary, we have demonstrated that epinephrine provoked a greater lipolytic response in obese women in both abdominal and femoral adipose tissues. The lipolytic response was further enhanced after 3 weeks of energy restriction in each gender. The decrease in glucose concentration suggests that glucose may be reutilized for synthesis into new triacylglycerol. Knowledge about the sensitivity to lipolytic agents in subcutaneous adipose tissue may provide potential new approaches for modulating the lipolytic responses of subcutaneous adipose tissue differently in men and women.

Body fat distribution's impact on physiologic outcomes during cardiac rehabilitation

BACKGROUND

High waist-to-hip ratios (WHRs) predispose individuals to metabolic syndromes that may affect outcome responses to cardiac rehabilitation programs.

METHODS

A total of 101 male patients who had undergone coronary artery revascularization surgery and completed 12 weeks of cardiac rehabilitation were divided into lower (LOWHR, n = 51) and higher (HIWHR, n = 50) waist-to-hip groups. Outcomes were measured at week 1 and week 12 of cardiac rehabilitation.

RESULTS

Waist-to-hip ratio and body weight were greatest for HIWHR (P < 0.001) with no between-group differences in the amount of change from week 1 to 12. Triceps and subscapular skin-folds were greater for HIWHR (P < 0.001) with no difference in the amount of change between groups. Caloric expenditure during exercise class was higher for LOWHR (P = 0.022). Daily caloric expenditure was greater for LOWHR (P = 0.034) as was daily caloric intake (P < 0.001). There were no group differences for VO2peak and ventilatory anaerobic threshold (VAT) with nonsignificant trends for greater increases in LOWHR.

CONCLUSIONS

Cardiac rehabilitation patients with greater WHRs expend less calories during exercise classes. To enhance overall caloric expenditure and obtain positive outcomes, cardiac rehabilitation professionals must emphasize greater activity with less sedentary time throughout the patients normal daily routine. The validity of using self-reported caloric intake and expenditure values in the cardiac rehabilitation population is questionable.

Regional differences in adrenoceptor binding and fat cell lipolysis in obese, postmenopausal women

In women there is an increase in visceral obesity, subcutaneous abdominal adipocyte lipolysis, and risk of cardiovascular disease (CVD) associated with weight gain after menopause. The mechanisms underlying this increase in adrenoreceptor (AR)-agonist catecholamine-stimulated lipolysis and abdominal obesity in postmenopausal women were studied in intact adipocytes isolated from the abdominal and gluteal subcutaneous fat depots in 19 obese (48% +/- 1% body fat, mean +/- SE) women with a mean +/- SE age of 58 +/- 1 years. The fat cell size and adipose tissue lipoprotein lipase (ATLPL) activity were similar in both sites. The maximal lipolytic responsiveness and sensitivity to isoproterenol were higher (P < .05) in abdominal compared with gluteal adipocytes, but maximal lipolytic response to a post-AR agent was similar. Abdominal adipocytes had a higher beta-AR ([3H]-CGP-12177) and alpha2-AR ([3H]-yohimbine) affinity than gluteal cells (P < .05), lower alpha2-AR density (P < .05), but similar beta-AR density as gluteal cells. Both abdominal and gluteal cell size correlated with alpha2-AR density (P < .01), but not with beta-AR density. Thus, a higher beta-AR affinity and lower alpha2-AR relative to beta-AR density may explain the higher in vitro catecholamine-mediated lipolysis in abdominal compared with gluteal adipocytes in obese, postmenopausal women.

Exercise blunts declines in lipolysis and fat oxidation after dietary-induced weight loss in obese older women

Weight loss (WL) by hypocaloric diet decreases adipocyte lipolysis and fat oxidation, adaptations that might predispose individuals to regain weight. Our hypothesis was that the addition of endurance exercise (EX) to dietary-induced WL (6 mo; 250-350 kcal/day deficit) would prevent declines in abdominal (ABD) and gluteal (GLT) adipocyte lipolysis and fat oxidation in obese older women. At baseline, the WL (n = 9) and WL+EX (n = 11) groups had similar body composition, fat distribution, aerobic fitness (VO2max), and resting fat metabolism. Reductions in body weight (WL = 11%, WL+EX = 8%), percent body fat, and intra-abdominal fat area with the interventions were similar in both groups, but VO2max increased (9%, P < 0.01) only in the WL+EX group. Basal and adrenergic receptor- and postreceptor-stimulated lipolysis in ABD and GLT adipocytes decreased (20-70%, P < 0.05) in the WL group but did not change in the WL+EX group. Fat oxidation decreased (38%, P < 0.05) in the WL group but not in the WL+EX group. The changes in fat oxidation and GLT lipolysis differed significantly between groups. Fat oxidation correlated positively with ABD and GLT adipocyte basal lipolysis at baseline (r = 0.45 and r = 0.53, P < 0.05), and the changes in fat oxidation with the interventions correlated positively with changes in ABD and GLT adipocyte basal lipolysis (r = 0.50 and r = 0.42. P < 0.05) in the entire group of women. These results indicate that exercise counteracts the decline in fat oxidation with WL, in part by maintaining adipocyte lipolytic responsiveness in some weight-reduced postmenopausal women.