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Impact of dietary interventions on pre-diabetic oral and gut microbiome, metabolites and cytokines.
Shoer, S, Shilo, S, Godneva, A, Ben-Yacov, O, Rein, M, Wolf, BC, Lotan-Pompan, M, Bar, N, Weiss, EI, Houri-Haddad, Y, et al
Nature communications. 2023;14(1):5384
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Pre-diabetes, a condition characterized by elevated blood glucose levels but below diabetes thresholds, is a significant risk factor for the development of type 2 diabetes, as well as other comorbidities including cardiovascular and kidney diseases. Diet plays a critical role in the development of hyperglycaemia and the onset of pre-diabetes. The aim of this study was to assess the impact of a personalized postprandial glucose-targeting diet (PPT), as well as the standard of care Mediterranean diet (MED), on the oral and gut microbiome, metabolites and cytokines in 200 pre-diabetic individuals. This study was a biphasic, randomised, controlled, single-blind dietary intervention. Phase one included a six-month intervention that compared two diets targeting glycaemic control, while phase two included a six-month follow-up period. Participants (n = 225) were randomly assigned in a 1:1 ratio to a PPT (n = 113) or a MED (n = 112). Results showed that participants assigned to the PPT diet had significant changes in 19 gut microbial species, 14 gut and one oral microbial pathway, 86 serum metabolites and four cytokines. Participants assigned to the MED diet showed significant changes in five gut and one oral microbial species, 18 gut microbial pathways, 27 serum metabolites and four cytokines. Authors conclude that dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host. Thus, diets such as the PPT used in this study, which takes into account microbiome features, could be designed to affect the microbiome and inflict desired metabolic outcomes.
Abstract
Diabetes and associated comorbidities are a global health threat on the rise. We conducted a six-month dietary intervention in pre-diabetic individuals (NCT03222791), to mitigate the hyperglycemia and enhance metabolic health. The current work explores early diabetes markers in the 200 individuals who completed the trial. We find 166 of 2,803 measured features, including oral and gut microbial species and pathways, serum metabolites and cytokines, show significant change in response to a personalized postprandial glucose-targeting diet or the standard of care Mediterranean diet. These changes include established markers of hyperglycemia as well as novel features that can now be investigated as potential therapeutic targets. Our results indicate the microbiome mediates the effect of diet on glycemic, metabolic and immune measurements, with gut microbiome compositional change explaining 12.25% of serum metabolites variance. Although the gut microbiome displays greater compositional changes compared to the oral microbiome, the oral microbiome demonstrates more changes at the genetic level, with trends dependent on environmental richness and species prevalence in the population. In conclusion, our study shows dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host, and that these factors are well associated with each other, and can be harnessed for new therapeutic modalities.
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Eight-hour time-restricted feeding improves endocrine and metabolic profiles in women with anovulatory polycystic ovary syndrome.
Li, C, Xing, C, Zhang, J, Zhao, H, Shi, W, He, B
Journal of translational medicine. 2021;19(1):148
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Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine and metabolic disorders that affects up to 10% women of childbearing age. The aim of this study was to explore the effects of time-restricted feeding (TRF) on menstruation, gonadal and metabolic parameters in women with anovulatory PCOS and propose a basis for its inclusion in the treatment of PCOS. This study is a 6-week trial with 2 consecutive periods: (1) 1-week baseline weight stabilization period; and (2) 5-week TRF period. Fifteen subjects were included in the study whose age varied between 18 and 31 years. Results show that five weeks of TRF improved menstruation, gonadal profiles, body weight, body mass index, body composition profiles, hyperinsulinemia and insulin resistance profiles, decreasing chronic inflammation markers and increasing insulin growth factor –1 [hormone]. Authors conclude that TRF may be suitable for PCOS women with appropriate counselling and patient management.
Abstract
BACKGROUND Time-restricted feeding (TRF) is a form of intermittent fasting, which is beneficial for weight loss and cardiometabolic health. Polycystic ovary syndrome (PCOS) is one of the most common reproductive endocrine and metabolic diseases affecting women of childbearing age. It is associated with an increased prevalence of metabolic syndrome, cardiovascular diseases and type 2 diabetes. The effects of TRF on PCOS patients remains undefined, here we investigated the impact of TRF on women with anovulatory PCOS. METHODS Eighteen PCOS women aged between 18 and 31 with anovulation participated in a 6-week trial which were divided into two consecutive periods: (1) 1-week baseline weight stabilization period and (2) 5-week TRF period. Fifteen participants completed the study. Changes in body weight, body mass index (BMI), Waist-to-Hip Ratio, skeletal muscle mass, body fat mass (BFM), body fat percentage (BF%), visceral fat area (VFA), luteinizing hormone (LH), follicle-stimulating hormone (FSH), LH/FSH, total testosterone (TT), sex hormone-binding globulin (SHBG), free androgen index (FAI), fasting glucose, fasting insulin (FINS), homeostasis model assessment-insulin resistance (HOMA-IR), area under the curve (AUC) for insulin (AUCIns), area under the curve (AUC) for glucose (AUCGlu), AUCIns/AUCGlu Ratio, lipids, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase, high-sensitivity C-reactive protein (hsCRP), insulin-like growth factor (IGF-1), menstrual cycle and eating behaviors were evaluated. RESULTS Significant changes in body weight, BMI, BFM, BF%, VFA, TT, SHBG, FAI, FINS, HOMA-IR, AUCIns, AUCIns/AUCGlu Ratio, ALT, hsCRP and IGF-1 were found after the TRF period. An improvement in menstrual cycle irregularity was detected in 73.3% (11/15) patients. CONCLUSION The diet of TRF may be beneficial to anovulatory PCOS on weight loss especially reducing body fat, improving menstruation, hyperandrogenemia, insulin resistance and chronic inflammation. Trial registration Clinicaltrial.gov, NCT04580433, registered October 8, 2020, https://clinicaltrials.gov/ct2/show/NCT04580433.
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Pilot trial of a group cognitive behavioural therapy program for comorbid depression and obesity.
Lores, T, Musker, M, Collins, K, Burke, A, Perry, SW, Wong, ML, Licinio, J
BMC psychology. 2020;8(1):34
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Depression and obesity are significant global health concerns. Depression can significantly impact physical health and reduced immune function. The aim of this study was to examine the potential benefits of a novel group psychological intervention program. The study is a preliminary quasi-experimental (single-arm) before-after pilot trial of a newly developed group-based psychological intervention program for people with depression and comorbid obesity. The program consisted of 10 two-hour group sessions held weekly. A total of 24 participants were recruited to the program across two pilot groups. Results indicate that there was a significant reduction in participants’ depression and anxiety scores by program-end. Some evidence also shows improvements in weight-related negative cognitions. Authors conclude that the group therapy program therefore has considerable potential to be effective in helping people enjoy better mental health and improve health outcomes.
Abstract
BACKGROUND Depression and obesity are significant global health concerns that commonly occur together. An integrated group cognitive behavioural therapy program was therefore developed to simultaneously address comorbid depression and obesity. METHODS Twenty-four participants (63% women, mean age 46 years) who screened positively for depression with a body mass index ≥25 were recruited from a self-referred general population sample. The group therapy program (10 two-hour weekly sessions) was examined in a single-arm, before-after pilot trial, conducted in a behavioural health clinic in Adelaide, Australia. Primary outcomes included survey and assessment-based analyses of depression, anxiety, body image, self-esteem, and weight (kg), assessed at four time-points: baseline, post-intervention, three-months and 12-months post program. Eighteen participants (75%) completed the program and all assessments. RESULTS Significant improvements in depression, anxiety, self-esteem and body shape concern scores, several quality of life domains, eating behaviours and total physical activity (among others) - but not weight - were observed over the course of the trial. CONCLUSIONS Results from this pilot trial suggest that combining interventions for depression and obesity may be useful. Further development of the program, particularly regarding the potential for physical health benefits, and a randomised controlled trial, are warranted. TRIAL REGISTRATION Trial registration: ANZCTR, ACTRN12617001079336, 13 July 2017. Retrospectively registered after date of the first consent (6 July 2017), but before the date of the first intervention session (20 July 2017).
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A structured weight loss program increases gut microbiota phylogenetic diversity and reduces levels of Collinsella in obese type 2 diabetics: A pilot study.
Frost, F, Storck, LJ, Kacprowski, T, Gärtner, S, Rühlemann, M, Bang, C, Franke, A, Völker, U, Aghdassi, AA, Steveling, A, et al
PloS one. 2019;14(7):e0219489
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The global obesity epidemic is a major cause of the increase in type 2 diabetes mellitus (T2DM) and ensuing cardiovascular disease. The causes of obesity are complex ,and it has been shown that changes in the microbiome are associated with obesity. The microbiome can be altered through dietary intervention and weight loss. The aim of this open label pilot study was to investigate the microbiome of obese patients with T2DM during a weight loss programme. During the first six weeks the diet consisted of formula drink providing 800kcal per day, followed by nine weeks during which a regular diet of 1,200-1,500kcal per day was reintroduced, depending on the individuals’ needs. All participants lost weight continuously over the 15 weeks, from an average BMI of 39.6 at the start to 33.1 at the end of the programme. This was accompanied with an improvement in glucose metabolism, total and LDL cholesterol and uric acid levels, but not HDL cholesterol or triglycerides. All participants experienced changes in their microbiome towards greater diversity after the first six weeks of the low-calorie formula diet but these changes were partially reversed at the end of the study period at 15 weeks. A particular type of bacteria, Collinsella, which has been associated with poor metabolic health, was the only type found to remain reduced at the end of the 15 weeks, an 8.4-fold decrease. The authors hypothesise that this reduction in Collinsella may be associated with the improvement of metabolic factor in these patients at the end of the study.
Abstract
The global obesity epidemic constitutes a major cause of morbidity and mortality challenging public health care systems worldwide. Thus, a better understanding of its pathophysiology and the development of novel therapeutic options are urgently needed. Recently, alterations of the intestinal microbiome in the obese have been discussed as a promoting factor in the pathophysiology of obesity and as a contributing factor to related diseases such as type 2 diabetes and metabolic syndrome. The present pilot study investigated the effect of a structured weight loss program on fecal microbiota in obese type 2 diabetics. Twelve study subjects received a low-calorie formula diet for six weeks, followed by a nine week food reintroduction and stabilization period. Fecal microbiota were determined by 16S rRNA gene sequencing of stool samples at baseline, after six weeks and at the end of the study after fifteen weeks. All study subjects lost weight continuously throughout the program. Changes in fecal microbiota were most pronounced after six weeks of low-calorie formula diet, but reverted partially until the end of the study. However, the gut microbiota phylogenetic diversity increased persistently. The abundance of Collinsella, which has previously been associated with atherosclerosis, decreased significantly during the weight loss program. This study underlines the impact of dietary changes on the intestinal microbiome and further demonstrates the beneficial effects of weight loss on gut microbiota. Trial registration: ClinicalTrials.gov NCT02970838.
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Dietary Intake after Weight Loss and the Risk of Weight Regain: Macronutrient Composition and Inflammatory Properties of the Diet.
Muhammad, HFL, Vink, RG, Roumans, NJT, Arkenbosch, LAJ, Mariman, EC, van Baak, MA
Nutrients. 2017;9(11)
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In 2015, 107.7 million children and 603.7 million adults worldwide were obese. Effective actions to prevent the increasing rate of obesity and to treat those who are already obese are required. The aim of the study is to investigate the influence of macronutrients composition and inflammatory properties of the diet on weight regain during a weight maintenance period after weight loss of overweight and obese individuals. The study enrolled 57 Caucasian adult participants (27 males and 30 females) who had a body mass index more than 28kg/m2. The dietary intervention program consisted of three periods i.e. weight loss period, weight stable period and follow-up period. The study shows that the macronutrient composition of the weight maintenance diet was not associated with weight regain. However, the dietary inflammatory index was positively correlated with weight regain. In fact, intake of micronutrients with anti-inflammatory properties was found to be negatively correlated with weight regain. Authors conclude that the inflammatory properties of the diet during the weight maintenance period play a role in weight regain after a diet-induced weight loss program in overweight and obese adults.
Abstract
Weight regain after successful weight loss is a big problem in obesity management. This study aimed to investigate whether weight regain after a weight loss period is correlated with the macronutrient composition and/or the inflammatory index of the diet during that period. Sixty one overweight and obese adults participated in this experimental study. Subjects lost approximately 10% of their initial weight by means of very low-calorie diet for five weeks, or a low calorie diet for 12 weeks. After that, subjects in both groups followed a strict weight maintenance diet based on individual needs for four weeks, which was followed by a nine-month weight maintenance period without dietary counseling. Anthropometrics and dietary intake data were recorded before weight loss (baseline) and during the weight maintenance period. On average, participants regained approximately half of their lost weight. We found no evidence that macronutrient composition during the weight maintenance period was associated with weight regain. The dietary inflammatory index (r = 0.304, p = 0.032) was positively correlated with weight regain and remained significant after correction for physical activity (r = 0.287, p = 0.045). Our data suggest that the inflammatory properties of diet play a role in weight regain after weight loss in overweight and obese adults.
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Acceptability of a very-low-energy diet in Type 2 diabetes: patient experiences and behaviour regulation.
Rehackova, L, Araújo-Soares, V, Adamson, AJ, Steven, S, Taylor, R, Sniehotta, FF
Diabetic medicine : a journal of the British Diabetic Association. 2017;34(11):1554-1567
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Patients with type 2 diabetes can return to normal blood glucose levels through substantial weight loss. While many studies have addressed this, very few have assessed the effects of adherence to a very-low-energy diet (VLED) on patients’ quality of life. The aim of this study was to evaluate the experiences of adhering to VLED for patients in remission for type 2 diabetes. Fifteen participants were interviewed before and after the 8-week VLED intervention and narratives were analysed. This study identified common barriers, facilitators and strategies used by the participants. Overall, participants found adherence easier than anticipated, and found barriers to be offset by suggested behaviour-regulation strategies. Based on this study, the authors conclude dietary treatment for reversal of type 2 diabetes is acceptable and feasible in motivated patients, and suggest further controlled research be done to confirm the validity and applicability of these findings.
Abstract
AIMS: To evaluate the acceptability of an 8-week very-low-energy diet for remission of Type 2 diabetes, and to identify barriers and facilitators of adherence and behaviour-regulation strategies used by participants in the Counterbalance study. METHODS Eighteen of 30 participants in the Counterbalance study (ISRCTN88634530) took part in semi-structured interviews. Of these, 15 participants were interviewed before and after the 8-week very-low-energy diet intervention. Thematic analysis was used to analyse the narratives. RESULTS The prospect of diabetes remission, considerable weight loss, and long-term health improvement provided participants with substantial initial motivation. This motivation was sustained through the experience of rapid weight loss, improvements in blood glucose levels, social support and increased physical and psychological well-being. Overall, adherence to the very-low-energy diet for 8 weeks was perceived as much easier than anticipated, but required personal effort. Participants addressed challenges by removing food from the environment, planning, avoidance of tempting situations or places, and self-distraction. Weight loss and improvements in blood glucose levels lead to a sense of achievement and improvements in physical and psychological wellbeing. CONCLUSIONS Dietary treatment for reversal of Type 2 diabetes is acceptable and feasible in motivated participants, and the process is perceived as highly gratifying. Research outside of controlled trial settings is needed to gauge the generalisability of these findings.
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Postprandial Glucose Surges after Extremely Low Carbohydrate Diet in Healthy Adults.
Kanamori, K, Ihana-Sugiyama, N, Yamamoto-Honda, R, Nakamura, T, Sobe, C, Kamiya, S, Kishimoto, M, Kajio, H, Kawano, K, Noda, M
The Tohoku journal of experimental medicine. 2017;243(1):35-39
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Carbohydrate-restricted diets are prevalent not only in obese people but also in the general population to maintain appropriate body weight. The aim of the study was to investigate, through continuous glucose monitoring, whether carbohydrate restriction for one day in actual life could affect the subsequent blood glucose levels in healthy subjects. The study enrolled ten healthy volunteers (2 males and 8 females), who had normal haemoglobin A1c, with an age range between 20 years and 65 years. The participants wore a continuous glucose monitoring device and were given isoenergetic test meals for 4 consecutive days. Results show that after extreme restriction of carbohydrate, an influence on the blood glucose variability persisted for at least 24 hours in healthy subjects. The day after the low-carbohydrate/high-fat diet, the glucose fluctuation increased significantly when compared with the fluctuations on days after the ingestion of normal carbohydrate diet. Authors conclude that low carbohydrate/high-fat diets can induce increasing blood glucose fluctuations that last for at least all the following day and have adverse effects in daily life.
Abstract
Carbohydrate-restricted diets are prevalent not only in obese people but also in the general population to maintain appropriate body weight. Here, we report that extreme carbohydrate restriction for one day affects the subsequent blood glucose levels in healthy adults. Ten subjects (median age 30.5 years, BMI 21.1 kg/m2, and HbA1c 5.5%), wearing with a continuous glucose monitoring device, were given isoenergetic test meals for 4 consecutive days. On day 1, day 2 (D2), and day 4 (D4), they consumed normal-carbohydrate (63-66% carbohydrate) diet, while on day 3, they took low-carbohydrate/high-fat (5% carbohydrate) diet. The daily energy intake was 2,200 kcal for males and 1,700 kcal for females. On D2 and D4, we calculated the mean 24-hr blood glucose level (MEAN/24h) and its standard deviation (SD/24h), the area under the curve (AUC) for glucose over 140 mg/dL within 4 hours after each meal (AUC/4h/140), the mean amplitude of the glycemic excursions (MAGE), the incremental AUC of 24-hr blood glucose level above the mean plus one standard deviation (iAUC/MEAN+SD). Indexes for glucose fluctuation on D4 were significantly greater than those on D2 (SD/24h; p = 0.009, MAGE; p = 0.013, AUC/4h/140 after breakfast and dinner; p = 0.006 and 0.005, and iAUC/MEAN+SD; p = 0.007). The value of MEAN/24h and AUC/4h/140 after lunch on D4 were greater than those on D2, but those differences were not statistically significant. In conclusion, consumption of low-carbohydrate/high-fat diet appears to cause higher postprandial blood glucose on subsequent normal-carbohydrate diet particularly after breakfast and dinner in healthy adults.
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Spexin peptide is expressed in human endocrine and epithelial tissues and reduced after glucose load in type 2 diabetes.
Gu, L, Ma, Y, Gu, M, Zhang, Y, Yan, S, Li, N, Wang, Y, Ding, X, Yin, J, Fan, N, et al
Peptides. 2015;71:232-9
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Little is known about the functions of the peptide spexin. Recent studies have shown a relationship between spexin and body weight regulation. It is thought that spexin might be related to glucose control and fat metabolism in type 2 diabetes mellitus (T2DM). The aim of this study was to examine the location of spexin in human tissue and measure spexin levels after a glucose load in T2DM patients. First, the researchers examined human tissue samples. Blood samples were then collected from 121 adults with T2DM and 105 healthy individuals. Additionally, an oral glucose tolerance test (OGTT) was performed on 12 healthy volunteers. In human tissue samples, the levels of spexin were highest in the adrenal gland, skin, stomach, small intestine, liver, thyroid, pancreatic islets, visceral fat, lung, colon, and kidney, and lowest in muscle and connective tissue. Blood levels of spexin were significantly lower in T2DM patients compared to healthy controls. Spexin levels were found to be inversely related to fasting blood glucose and lipids. During the OGTT, spexin levels were also inversely correlated with blood glucose levels. The authors concluded that spexin is highly expressed among endocrine and epithelial tissues. Changes in the blood levels of spexin could represent an adaptation to the rise of glucose and lipids associated with T2DM. However, the exact role of spexin in endocrine diseases is still to be discovered.
Abstract
Spexin mRNA and protein are widely expressed in rat tissues and associate with weight loss in rodents of diet-induced obesity. Its location in endocrine and epithelial cells has also been suggested. Spexin is a novel peptide that involves weight loss in rodents of diet-induced obesity. Therefore, we aimed to examine its expression in human tissues and test whether spexin could have a role in glucose and lipid metabolism in type 2 diabetes mellitus (T2DM). The expression of the spexin gene and immunoreactivity in the adrenal gland, skin, stomach, small intestine, liver, thyroid, pancreatic islets, visceral fat, lung, colon, and kidney was higher than that in the muscle and connective tissue. Immunoreactive serum spexin levels were reduced in T2DM patients and correlated with fasting blood glucose (FBG, r=-0.686, P<0.001), hemoglobin A1c (HbA1c, r=-0.632, P<0.001), triglyceride (TG, r=-0.236, P<0.001) and low density lipoprotein-cholesterol (LDL-C, r=-0.382, P<0.001). A negative correlation of blood glucose with spexin was observed during oral glucose tolerance test (OGTT). Spexin is intensely expressed in normal human endocrine and epithelial tissues, indicating that spexin may be involved in physiological functions of endocrine and in several other tissues. Circulating spexin levels are low in T2DM patients and negatively related to blood glucose and lipids suggesting that the peptide may play a role in glucose and lipid metabolism in T2DM.
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Enhanced cortisol production rates, free cortisol, and 11beta-HSD-1 expression correlate with visceral fat and insulin resistance in men: effect of weight loss.
Purnell, JQ, Kahn, SE, Samuels, MH, Brandon, D, Loriaux, DL, Brunzell, JD
American journal of physiology. Endocrinology and metabolism. 2009;296(2):E351-7
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Excess abdominal fat in men is a risk factor for both type 2 diabetes and cardiovascular disease. The aim of this study was to test the hypothesis that increased cortisol levels contribute to increased abdominal fat and insulin resistance in men. Twenty-four healthy men aged 18-70 took part in the study. Eight of the participants, who were obese, were put on a calorie-controlled weight loss diet. Cortisol production rate (CPR) and free cortisol (FC) were correlated with increased intra-abdominal fat (IAF) and decreased insulin sensitivity (Si). Cortisol levels were not correlated with subcutaneous fat (SQF). CPR and FC did not change with weight loss, suggesting that cortisol levels could influence the distribution of body fat upon weight regain. The authors concluded that their findings support a role for activation of the HPA axis and abnormal cortisol secretion in determining body fat distribution and predisposing these men to type 2 diabetes.
Abstract
Controversy exists as to whether endogenous cortisol production is associated with visceral obesity and insulin resistance in humans. We therefore quantified cortisol production and clearance rates, abdominal fat depots, insulin sensitivity, and adipocyte gene expression in a cohort of 24 men. To test whether the relationships found are a consequence rather than a cause of obesity, eight men from this larger group were studied before and after weight loss. Daily cortisol production rates (CPR), free cortisol levels (FC), and metabolic clearance rates (MCR) were measured by stable isotope methodology and 24-h sampling; intra-abdominal fat (IAF) and subcutaneous fat (SQF) by computed tomography; insulin sensitivity (S(I)) by frequently sampled intravenous glucose tolerance test; and adipocyte 11beta-hydroxysteroid dehydrogenase-1 (11beta-HSD-1) gene expression by quantitative RT-PCR from subcutaneous biopsies. Increased CPR and FC correlated with increased IAF, but not SQF, and with decreased S(I). Increased 11beta-HSD-1 gene expression correlated with both IAF and SQF and with decreased S(I). With weight loss, CPR, FC, and MCR did not change compared with baseline; however, with greater loss in body fat than lean mass during weight loss, both CPR and FC increased proportionally to final fat mass and IAF and 11beta-HSD-1 decreased compared with baseline. These data support a model in which increased hypothalamic-pituitary-adrenal activity in men promotes selective visceral fat accumulation and insulin resistance and may promote weight regain after diet-induced weight loss, whereas 11beta-HSD-1 gene expression in SQF is a consequence rather than cause of adiposity.