MECHANISMS IN ENDOCRINOLOGY: Update on treatments for patients with genetic obesity.

Obesity, defined by an excess of body fat impacting on health, is a complex disease resulting from the interaction between many genetic/epigenetic factors and environmental triggers. For some clinical situations with severe obesity, it has been possible to classify these obesity forms according to the molecular alterations. These include: (i) syndromic obesity, which associates severe early-onset obesity with neurodevelopmental disorders and/or polymalformative syndrome and (ii) non-syndromic monogenic obesity, due to gene variants most often located in the leptin-melanocortin pathway. In addition to severe obesity, patients affected by these diseases display complex somatic conditions, eventually including obesity comorbidities, neuropsychological and psychiatric disorders. These conditions render the clinical management of these patients particularly challenging. Patients' early diagnosis is critical to allow specialized and multidisciplinary care, with a necessary interaction between the health and social sectors. Up to now, the management of genetic obesity was only based, above all, on controlling the patient's environment, which involves limiting access to food, ensuring a reassuring daily eating environment that limits impulsiveness, and the practice of adapted, supported, and supervised physical activity. Bariatric surgery has also been undertaken in genetic obesity cases with uncertain outcomes. The context is rapidly changing, as new innovative therapies are currently being tested both for syndromic and monogenic forms of obesity. This review focuses on care management and new therapeutic opportunities in genetic obesity, including the use of the melanocortin 4 agonist, setmelanotide. The results from ongoing trials will hopefully pave the way to a future precision medicine approach for genetic obesity.

Rare genetic forms of obesity: From gene to therapy.

Monogenic non-syndromic obesity is characterized by severe early-onset obesity with abnormal eating behaviour and endocrine disorders. Genes contributing to these rare forms of obesity are mainly located in the leptin/melanocortin pathway, with typically an autosomal additive inheritance of obesity. The normal function of this hypothalamic pathway is essential for the control of energy balance. Genetic variants are involved in 5-30 % of severe early-onset obesity depending on explored populations. Compared to other genes in the pathway especially leptin (LEP), leptin receptor (LEPR), pro-opiomelanocortin (POMC) and prohormone convertase subtilisin/kexin type 1 (PCSK1), Melanocortin 4 receptor (MC4R)-linked obesity is characterized by obesity of variable severity with no notable endocrine phenotypes. Managing patients with monogenic non-syndromic obesity is clinically challenging since they display complex phenotypes and the obesity is often morbid and refractory to classical treatments. Until recent years, there has been a lack of effective and targeted pharmaceutical molecules except for leptin therapy that was available for leptin deficiency. The picture has changed and new promising molecules acting on the leptin-melanocortin pathway such as setmelanotide -a new MC4R agonist- are now emerging as novel targeted therapeutic opportunities.

Effectiveness of exercise training after bariatric surgery-a systematic literature review and meta-analysis.

We aimed to conduct a systematic review and meta-analysis of controlled trials assessing exercise training programs in patients with obesity undergoing bariatric surgery. We systematically searched exercise training studies performed after bariatric surgery published up to June 2017. Studies reporting changes in body composition, physical fitness, functional capacity, objectively measured physical activity, quality of life or relevant health outcomes were included. The review protocol is available from PROSPERO (CRD42017069380). Meta-analyses were conducted using random-effects models when data were available from at least five articles. Twenty articles were included, describing 16 exercise training programs, of which 15 were included in the meta-analysis. Overall, exercise training was associated with higher weight loss (mean difference: -2.4 kg, 95% CI: -4.2; -0.6, I2  = 49%, n = 12), higher fat mass loss (-2.7 kg, 95% CI: -4.5; -1.0, I2  = 50%, n = 8) and improved VO2 max and functional walking (standardized mean difference: 0.86, 95% CI: 0.29; 1.44, I2  = 57%, n = 6; 1.45, 95% CI: 0.32; 2.58, I2  = 89%, n = 6, respectively). Exercise training was not associated with lean body mass changes. In conclusion, exercise training programs performed after bariatric surgery were found effective to optimize weight loss and fat mass loss and to improve physical fitness, although no additional effect on lean body mass loss was found.

Impact of transitional care on endocrine and anthropometric parameters in Prader-Willi syndrome.

CONTEXT: The transition of patients with Prader-Willi syndrome (PWS) to adult life for medical care is challenging because of multiple comorbidities, including hormone deficiencies, obesity and cognitive and behavioral disabilities. OBJECTIVE: To assess endocrine management, and metabolic and anthropometric parameters of PWS adults who received (n = 31) or not (n = 64) transitional care, defined as specialized pediatric care followed by a structured care pathway to a multidisciplinary adult team. PATIENTS AND STUDY DESIGN: Hormonal and metabolic parameters were retrospectively recorded in 95 adults with PWS (mean ± s.d. age 24.7 ± 8.2 years, BMI: 39.8 ± 12.1 kg/m²) referred to our Reference Center and compared according to transition. RESULTS: Among the entire cohort, 35.8% received growth hormone (GH) during childhood and 16.8% had a GH stimulation test after completion of growth. In adulthood, 14.7% were treated with GH, 56.8% received sex-hormone therapy, whereas 91.1% were hypogonadic and 37.9% had undergone valid screening of the corticotropic axis. The main reason for suboptimal endocrine management was marked behavioral disorders. Patients receiving transitional care were more likely to have had a GH stimulation test and hormonal substitutions in childhood. They also had a lower BMI, percentage of fat mass, improved metabolic parameters and fewer antidepressant treatments. Transitional care remained significantly associated with these parameters in multivariate analysis when adjusted on GH treatment. CONCLUSION: A coordinated care pathway with specialized pediatric care and transition to a multidisciplinary adult team accustomed to managing complex disability including psychiatric troubles are associated with a better health status in adults with PWS.

Decision-making in obesity without eating disorders: a systematic review and meta-analysis of Iowa gambling task performances.

BACKGROUND: There is evidence that obesity is associated with impairments in executive functions, such as deficits in decision-making, planning or problem solving, which might interfere with weight loss in obese individuals. We performed a systematic review and meta-analysis of decision-making abilities, as measured with the Iowa gambling task (IGT), in obesity without eating disorders. METHODS: A systematic search was conducted to identify studies comparing IGT performances between groups of obese patients without eating disorders and groups of healthy control groups. The standardized mean differences were calculated for the total IGT scores and for the course of IGT scores. Meta-regression analyses were performed to explore the influence of clinical variables on standardized mean differences. RESULTS: Total IGT scores were significantly lower in obese patients compared with normal-weight healthy controls. IGT performances did not differ between groups for the first trials of the task. Significant effect sizes for the last trials of the task were subjected to a high degree of heterogeneity. CONCLUSION: Risky decision-making is impaired in obesity. The clinical importance of non-food-related decision-making impairments remains to be assessed especially in terms of consequences in daily life or the achievement of weight loss. This meta-analysis has been registered in the Prospero database (CRD42016037533).

Economic burden and health-related quality of life associated with Prader-Willi syndrome in France.

BACKGROUND: To date, there has been no published comprehensive estimation of costs related to Prader-Willi syndrome (PWS). Our objective was therefore to provide data on the economic burden and health-related quality of life associated with PWS in France in order to raise awareness of the repercussions on individuals suffering from this syndrome and on caregivers as well as on the health and social care systems. METHOD: A retrospective cross-sectional study was carried out on 51 individuals recruited through the French PWS patient association. Data on their demographic characteristics and resource use were obtained from an online questionnaire, and costs were estimated by a bottom-up approach. The EQ-5D-5L health questionnaire was used to measure the health-related quality of life of individuals suffering from PWS and their caregivers. RESULTS: The average annual cost of PWS was estimated at €58 890 per individual, with direct healthcare accounting for €42 299, direct non-healthcare formal costs €13 865 and direct non-healthcare informal costs €8459. The main contributors to PWS costs were hospitalisations and social services. Indirect costs resulting from loss of productivity in the labour market was €32 542 for adults suffering from PWS. Mean EQ-5D utility scores were 0.4 for individuals with PWS and 0.7 for caregivers. CONCLUSIONS: Prader-Willi syndrome represents a major economic burden from a societal perspective and has a significant impact on health-related quality of life both for individuals suffering from PWS and for their caregivers in France. These results underscore the need to develop tailored policies targeted at improving care. Likewise, a larger study collecting a broader range of medical characteristics should be undertaken to achieve more precise estimations.

[Bariatric surgery in obese adolescents: When and how should the transition from pediatric to adult medical management be made?]. / Prise en charge médico-chirurgicale de l'obésité de l'adolescent : quand et comment réaliser la transition vers la prise en charge adulte ?

INTRODUCTION: In young obese patients, the transition from adolescence to adulthood, i.e., the transition from the pediatric to the adult medical team, is a new issue. In particular, it is important to define when and how this transition should be made in the setting of bariatric surgery. MATERIALS AND METHODS: Fourteen young obese patients (under the age of 20), who underwent bariatric surgery, were included in the study (nine cases of Roux-en-Y gastric by-pass, three sleeve gastrectomy, one gastric banding). After surgery, the patients were followed in both the pediatric and adult departments (protocol 1) or only in the pediatric department during the 1st year and then in the adult department afterwards (protocol 2). Anthropometric and metabolic data, before and after surgery, and compliance monitoring were analyzed using a retrospective design. Twelve patients completed a questionnaire assessing how they experienced the transition. RESULTS: Before surgery, mean age±SD was 16.3±1.8 years old and mean body mass index (BMI) 55.0±8.6kg/m(2). At 1 year after surgery, mean weight loss was -32.1±8.2% of initial body weight. Adherence to vitamin supplementation was judged to be adequate (vitamins were not taken less than once a week) for only 57.5% patients. Mean follow-up was 34.8±25.1 months [95% CI, 9.5-78.4]. None of the patients was lost to follow-up. Compliance was significantly better for patients following protocol 2. Adolescents reported being satisfied with meetings and newsletters about surgery, specific to this age group (91.7%). They also reported that information on the adult department was sufficient and 91.7% of them expressed satisfaction on the first outpatient visit in the adult department. However, all patients spontaneously reported having difficulties identifying members of the different teams: nutritionist pediatrician, nutritionist, and adult surgeon. DISCUSSION: These preliminary data suggest that, in obese adolescents, it is important to differentiate the transition period and the time and preparation for bariatric surgery. A prospective follow-up with a larger number of subjects and recommendations are needed to better define and improve the specific clinical management of obese adolescents transitioning to adulthood.

Medical, psychological and social features in a large cohort of adults with Prader-Willi syndrome: experience from a dedicated centre in France.

BACKGROUND: Prader-Willi syndrome (PWS) is a developmental genetic disorder characterised by a variable expression of medical, cognitive and behavioural symptoms. In adulthood, the prevalence and severity of these symptoms determine the quality of life of the affected persons. Because of their rare disease condition, data on health and social problems in adults with PWS are scarce. In this research, we present medical, psychological and social features of a large cohort of adults admitted to a specialised PWS centre in France and analyse the differences according to genotype, gender and age. METHODS: Data from 154 patients (68 men/86 women), with a median age of 27 years (range 16-54), were collected during their stay in our centre. Clinical histories were completed using information from parents or main caregivers, and the same medical team performed the diagnosis of different clinical conditions. Statistical analyses were performed to determine the influence of factors such as genotype, age or gender. RESULTS: Paternal deletion genotype was the most frequent (65%) at all ages. Most patients had mild or moderate intellectual disability (87%). Only 30% had studied beyond primary school and 70% were in some special educational or working programme. Most of them lived in the family home (57%). The most prevalent somatic comorbidities were scoliosis (78%), respiratory problems (75%), dermatological lesions (50%), hyperlipidaemia (35%), hypothyroidism (26%), Type 2 diabetes mellitus (25%) and lymph oedema (22%). Some form of psychotropic treatment was prescribed in 58% of subjects, and sex hormones in 43%. Patients with deletion had a higher body mass index (44 vs. 38.9 kg/m(2)) and displayed higher frequency of sleep apnoeas. Non-deletion patients received insulin treatment (19% vs. 4%) and antipsychotic treatment (54.8% vs. 32.7%) more frequently. No difference was observed in the prevalence of Type 2 diabetes between the two genotype groups. Patients >27 years of age had a higher rate of comorbidities (Type 2 diabetes, hypertension, respiratory problems and lymph oedema). Gender differences were minor. CONCLUSIONS: Adult patients with PWS showed high prevalence of comorbid health problems that need to be monitored for early treatment. Some of them are influenced by genotype and age. Another salient problem concerns the lack of adapted structures for better social integration. Further data about the real life and health conditions of adults with PWS are necessary to further our knowledge of the natural history of the disease and to design appropriate care strategies.

Association between melanocortin-4 receptor mutations and eating behaviors in obese patients: a case--control study.

Melanocortin-4 receptor (MC4R) gene mutations are involved in the leptin-melanocortin pathways that control food intake. The effect of these mutations on eating behavior phenotypes is still debated. To determine the association between functional MC4R mutations and eating behaviors, dietary intake and physical activity, we sequenced the MC4R gene in 4653 obese adults. Among them, 19 adults carriers of functional MC4R mutation were matched on age, sex and body mass index with two randomly-paired controls without MC4R mutation (n=57). We found that eating behaviors and physical activity did not differ between groups. In particular, cases were not at increased risk of binge eating disorders. Subjects carriers of MC4R mutation reported a higher proportion of dietary carbohydrates intakes (43.2±7.1 and 39.2±8.1% of total energy intake, respectively, P=0.048) and a lower proportion of dietary lipids (34.3±6.7 and 38.5±6.7% of total energy intake, respectively, P=0.018). In conclusion, mutation carriers differ from controls by a higher consumption of carbohydrates counterbalanced by a lower consumption of lipids expressed as percentage of total energy intake. However, functional MC4R mutations do not have a higher risk of compulsive eating contrary to what was previously suggested.

Macrophage gene expression in adipose tissue is associated with insulin sensitivity and serum lipid levels independent of obesity.

OBJECTIVE: Obesity is linked to both increased metabolic disturbances and increased adipose tissue macrophage infiltration. However, whether macrophage infiltration directly influences human metabolism is unclear. The aim of this study was to investigate if there are obesity-independent links between adipose tissue macrophages and metabolic disturbances. DESIGN AND METHODS: Expression of macrophage markers in adipose tissue was analyzed by DNA microarrays in the SOS Sib Pair study and in patients with type 2 diabetes and a BMI-matched healthy control group. RESULTS: The expression of macrophage markers in adipose tissue was increased in obesity and associated with several metabolic and anthropometric measurements. After adjustment for BMI, the expression remained associated with insulin sensitivity, serum levels of insulin, C-peptide, high density lipoprotein cholesterol (HDL-cholesterol) and triglycerides. In addition, the expression of most macrophage markers was significantly increased in patients with type 2 diabetes compared to the control group. CONCLUSION: Our study shows that infiltration of macrophages in human adipose tissue, estimated by the expression of macrophage markers, is increased in subjects with obesity and diabetes and associated with insulin sensitivity and serum lipid levels independent of BMI. This indicates that adipose tissue macrophages may contribute to the development of insulin resistance and dyslipidemia.

Quality of life after Roux-en-Y gastric bypass and changes in body mass index and obesity-related comorbidities.

AIM: Dynamics of improvement in health-related quality of life (QoL) after bariatric surgery have never been fully assessed, and neither has the potential influence of body mass index (BMI) and comorbidity modification. The objective of this study was to investigate early and medium-term changes in QoL following Roux-en-Y gastric bypass (RYGB), and their relationship to BMI and comorbidity variations. METHODS: A total of 71 obese subjects (80% women, mean age 42.1±11.2 years, mean baseline BMI 47.6±6.2kg/m(2)) undergoing RYGB filled in QoL questionnaires (SF-36) before and 3, 6 and 12 months after surgery. QoL was assessed using repeated-measures Anova, with associations between its changes and changes in BMI and comorbidities (diabetes, hypertension, dyslipidaemia, sleep apnoea, knee pain) assessed by mixed-effects models. RESULTS: Physical QoL scales (physical component summary, PCS) significantly increased over time (from 38.9±9.3 to 52.6±7.9; P<0.001) as did other physical SF-36 scales (all P<0.001), whereas mental QoL summary scale did not vary significantly (from 45.7±9.5 to 48.6±11.5; P=0.072). Major changes in QoL occurred at 3 months after surgical intervention to reach values comparable to those in the general population. PCS was mostly associated with changes in either BMI or comorbidity status except for diabetes, dyslipidaemia and sleep apnoea. CONCLUSION: Results show that improvements in physical QoL after RYGB are observed as early as 3 months after intervention, and are independently associated with weight loss and improvements in comorbidities.

Comparison of body composition, basal metabolic rate and metabolic outcomes of adults with Prader Willi syndrome or lesional hypothalamic disease, with primary obesity.

CONTEXT: The care of patients with hypothalamic obesity is challenging. OBJECTIVE: To compare body composition, basal metabolic rate (BMR) and metabolic outcomes of adults, with lesional or genetic hypothalamic obesity, with obese patients suffering from primary obesity, once matched for body mass index (BMI). DESIGN AND PATIENTS: Adults with hypothalamic obesity of genetic origin (Prader Willi syndrome (PWS)) or acquired hypothalamic damage (HD), such as craniopharygioma, were compared with obese control candidates awaiting bariatric surgery (C), with a BMI between 35 and 65 kg m(-)(2), and aged between 18 and 50 years. MAIN OUTCOME MEASURES: Body composition measured by whole-body dual-energy X-ray absorptiometry scanning, BMR using indirect calorimetry, hormonal and metabolic assessments. RESULTS: A total of 27 adults with a genetic diagnosis of PWS, 15 obese subjects with HD and 206 obese controls with similar BMI were studied. Compared with the control group, PWS patients had an increased percentage of fat mass (FM), and a decreased percentage of android FM. The BMR of PWS patients was significantly lower than controls and highly correlated with lean body mass in PWS and C patients. Body composition of HD was similar with those of obese patients. A trend toward an increased prevalence of diabetes in HD patients and of cytolysis in PWS was observed in comparison with primary obese patients. CONCLUSION: Genetic and lesional hypothalamic obesities have different consequences for phenotypic features such as body composition or BMR compared with primary obese patients. The mechanisms of adipose tissue development and metabolic complications may be different between genetic and lesional obesities.

Eating behaviour in obese patients with melanocortin-4 receptor mutations: a literature review.

Melanocortin-4 receptor (MC4R) mutations are the most common known cause of monogenic obesity and an important contributor to polygenic obesity. MC4R mutations with partial or total loss of function, as well as the variant rs17782313 mapped near MC4R, are positively associated with obesity. MC4R is involved in the leptin-melanocortin signalling system, located in hypothalamic nuclei, that controls food intake via both anorexigenic or orexigenic signals. Impairment in this receptor might affect eating behaviours. Thus, in the case of MC4R mutation carriers, obesity could be related, at least partly, to inadequate control over eating behaviours. Many published studies address eating behaviours in MC4R mutation carriers. Most studies focus on binge eating disorder, whereas others examine various aspects of intake and motivation. Up to now, no evaluation of this literature has been performed. In this review, we examine the available literature on eating behaviours in carriers of MC4R mutations and variant rs17782313 near MC4R gene. We address binge eating disorder, bulimia nervosa, mealtime hyperphagia, snacking, psychological factors, satiety responsiveness and intake of energy and macro/micronutrient. In a small number of studies, MC4R mutations seem to impair eating behaviours or motivation, but no clear causal effects can be found in the balance of the evidence presented. Improvements in methodologies will be necessary to clarify the behavioural effects of MC4R mutations.

Relationship between adiposity, emotional status and eating behaviour in obese women: role of inflammation.

BACKGROUND: Obesity is characterized by chronic low-grade inflammation that may lead to emotional distress and behavioural symptoms. This study assessed the relationship between adiposity, low-grade inflammation, eating behaviour and emotional status in obese women awaiting gastric surgery and investigated the effects of surgery-induced weight loss on this relationship. METHOD: A total of 101 women with severe or morbid obesity awaiting gastric surgery were recruited. Assessments were performed before and at 1 year post-surgery and included the measurement of neuroticism and extraversion using the revised Neuroticism-Extraversion-Openness personality inventory (NEO-PI-R) and eating behaviour using the Three-Factor Eating Questionnaire (TFEQ). Blood samples were collected for the measurement of serum inflammatory markers [interleukin-6 (IL-6), high-sensitive C-reactive protein (hsCRP)] and adipokines (leptin, adiponectin). RESULTS: At baseline, body mass index (BMI) was positively correlated with inflammatory markers and adipokines. Regression analyses adjusting for age and diabetes revealed that baseline concentrations of IL-6 and hsCRP were associated with the depression and anxiety facets of neuroticism, with higher inflammation predicting higher anxiety and depression. This association remained significant after adjusting for BMI. Gastric surgery induced significant weight loss, which correlated with reduced inflammation. After controlling for BMI variations, decreases in inflammatory markers, notably hsCRP, were associated with reduced anxiety and TFEQ-cognitive restraint scores. CONCLUSIONS: These findings indicate strong associations between adiposity, inflammation and affectivity in obese subjects and show that surgery-induced weight loss is associated concomitantly with reduced inflammation and adipokines and with significant improvement in emotional status and eating behaviour. Inflammatory status appears to represent an important mediator of emotional distress and psychological characteristics of obese individuals.

11beta-hydroxysteroid dehydrogenase type 1 of the subcutaneous adipose tissue is dysregulated but not associated with metabolic disorders in adults born small for gestational age.

INTRODUCTION: The mechanisms relating being born small for gestational age (SGA) and the later risk of metabolic disorders are not yet fully understood. Adipose 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) activity and expression have been positively associated with metabolic syndrome. In humans, no in vivo studies have explored 11beta-HSD1 activity and gene expression in sc adipose tissue of SGA subjects. SUBJECTS AND METHODS: Thirty-nine subjects SGA (birth weight<10th percentile) were matched on gender and age with 36 subjects born appropriate for gestational age (AGA) (25th percentile

Transcriptomics applied to obesity and caloric restriction.

Caloric restriction still remains the most efficient way to promote weight loss. Deciphering the molecular basis of adaptation to energy restriction is critical for the tailoring of new therapeutic strategies. This review focuses on the recent input of gene profiling on adipose tissue in obesity pathogenesis and on the new insights on adaptations occurring during very low caloric diet (VLCD) in humans. Hypocaloric diets improve a wide range of metabolic parameters including lipolytic efficiency, insulin sensitivity, and inflammatory profile. In the subcutaneous white adipose tissue (scWAT) the VLCD induced a decrease in the mRNA levels for the antilipolytic alpha2-adrenergic receptor associated with changes in catecholamine-induced adipocyte lipolytic capacity. The improvement in insulin sensitivity was not associated with a change in subcutaneous adipose tissue adiponectin gene expression or in its plasma level, suggesting that adiponectin is not involved in the regulation of VLCD-induced improvement of insulin sensitivity and that there is a small contribution of subcutaneous adipose tissue to plasma adiponectin levels. Pangenomic microarray studies in human scWAT revealed that a panel of inflammatory markers and acute phase reactants were over expressed in obese compared to lean subjects. Caloric restriction improved the inflammatory profile of obese subjects through a decrease of pro-inflammatory factors and an increase of anti-inflammatory molecules. These genes were mostly expressed in the stroma vascular fraction of the adipose tissue. Specific cell-type isolation and immunohistochemistry demonstrated that monocyte/macrophage lineage cells were responsible for the expression of both mRNA and protein inflammatory markers. The acute phase proteins serum amyloid A was highly expressed in mature adipocytes from obese subjects. Caloric restriction decreased both serum amyloid mRNA and circulating levels. Obesity now clearly appears as chronic low-grade inflammation state. Modulation of the inflammatory pathways may represent new therapeutic targets for the treatment of obesity-related complications.

Serum amyloid A: production by human white adipocyte and regulation by obesity and nutrition.

AIMS/HYPOTHESIS: The acute-phase proteins, serum amyloid As (SAA), are precursors of amyloid A, involved in the pathogenesis of AA amyloidosis. This work started with the characterisation of systemic AA amyloidosis concurrent with SAA overexpression in the subcutaneous white adipose tissue (sWAT) of an obese patient with a leptin receptor deficiency. In the present study a series of histopathological, cellular and gene expression studies was performed to assess the importance of SAA in common obesity and its possible production by mature adipocytes. MATERIALS AND METHODS: Gene expression profiling was performed in the sWAT of two extremely obese patients with a leptin receptor deficiency. Levels of the mRNAs of the different SAA isoforms were quantified in sWAT cellular fractions from lean subjects and from obese subjects before and after a very-low-calorie diet. These values were subsequently compared with serum levels of SAA in these individuals. In addition, histopathological analyses of sWAT were performed in lean and obese subjects. RESULTS: In sWAT, the expression of SAA is more than 20-fold higher in mature adipocytes than in the cells of the stroma vascular fraction (p<0.01). Levels of SAA mRNA expression and circulating levels of the protein are sixfold (p<0.001) and 3.5-fold (p<0.01) higher in obese subjects than in lean subjects, respectively. In lean subjects, 5% of adipocytes are immunoreactive for SAA, whereas the corresponding value is greater than 20% in obese subjects. Caloric restriction results in decreases of 45-75% in levels of the transcripts for the SAA isoforms and in circulating levels of the protein. CONCLUSIONS/INTERPRETATION: The results of the present study indicate that SAA is expressed by sWAT, and its production at this site is regulated by nutritional status. If amyloidosis is seen in the context of obesity, it is possible that production of SAA by adipocytes could be a contributory factor.