Sex hormones, intestinal inflammation, and the gut microbiome: Major influencers of the sexual dimorphisms in obesity

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications-2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

The Gut Microbiota and Diabetes: Research, Translation, and Clinical Applications-2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarizes the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organized by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: 1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g., genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomization in humans; 2) the highly individualized nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; 3) because single-time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and 4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

Sex-dependent effects of a high fat diet on metabolic disorders, intestinal barrier function and gut microbiota in mouse

Obesity is often associated with sex-dependent metabolic complications, in which altered intestinal barrier function and gut microbiota contribute. We aimed to characterize in mice the sex-dependent effects of a high fat diet on these parameters. Male and female C57BL/6 mice received a standard (SD) or high fat diet (HFD; 60% kcal from fat) during 14 weeks (W14). Body composition, glucose tolerance, insulin sensitivity, intestinal permeability, colonic expression of 44 genes encoding factors involved in inflammatory response and gut barrier function, cecal microbiota, plasma adipokines and white adipose tissue response have been assessed. Both male and female HFD mice exhibited an increase of body weight and fat mass gain and glucose intolerance compared to SD mice. However, only male HFD mice tended to develop insulin resistance associated to increased Tnfα and Ccl2 mRNA expression in perigonadal adipose tissue. By contrast, only female HFD mice showed significant intestinal hyperpermeability that was associated with more markedly altered colonic inflammatory response. Cecal microbiota richness was markedly reduced in both sexes (Observed species) with sex-dependent modifications at the phyla or family level, e.g. decreased relative abundance of Bacillota and Lachnospiraceae in females, increased of Bacteroidaceae in males. Interestingly, some of these microbiota alterations were correlated with peripheral metabolic and inflammatory markers. In conclusions, male and female mice exhibit different responses to a high fat diet with specific changes of gut microbiota, intestinal barrier function, colonic and white adipose tissue inflammation, metabolic markers and body weight gain. The underlying mechanisms should be deciphered in further investigations.

Impact of Microbiota and Metabolites on Intestinal Integrity and Inflammation in Severe Obesity

Obesity is a multifactorial disease associated with low-grade inflammation. The gut is thought to be involved in obesity-related inflammation, as it is continuously exposed to antigens from food, microbiota and metabolites. However, the exact underlying mechanisms are still unknown. Therefore, we examined the relation between gut pathology, microbiota, its metabolites and cytokines in adults with severe obesity. Individuals eligible for bariatric surgery were included. Fecal and plasma samples were collected at surgery timepoint, to assess microbiota and metabolite composition. Jejunal biopsies were collected during surgery and stained for cytotoxic T cells, macrophages, mast cells and tight junction component zonula occludens-1. Based on these stainings, the cohort was divided into four groups: high versus low intestinal inflammation and high versus low intestinal integrity. We found no significant differences in microbiota diversity between groups, nor for individual bacterial species. No significant differences in metabolites were observed between the intestinal inflammatory groups. However, some metabolites and cytokines differed between the intestinal integrity groups. Higher plasma levels of interleukin-8 and tauro-chenodeoxycholic acid were found, whereas isovaleric acid and acetic acid were lower in the high intestinal integrity group. As the results were very subtle, we suggest that our cohort shows very early and minor intestinal pathology.

Sex- and Gender-Related Differences in Obesity: From Pathophysiological Mechanisms to Clinical Implications

Obesity, primarily characterized by excessive fat accumulation, is a multifactorial chronic disease with an increasing global prevalence. Despite the well-documented epidemiology and significant advances in understanding its pathophysiology and clinical implications, the impact of sex is typically overlooked in obesity research. Worldwide, women have a higher likelihood to become obese compared to men. Although women are offered weight loss interventions more often and at earlier stages than men, they are more vulnerable to psychopathology. Men, on the other hand, are less likely to pursue weight loss intervention and are more susceptible to the metabolic implications of obesity. In this narrative review, we comprehensively explored sex- and gender-specific differences in the development of obesity, focusing on a variety of biological variables, such as body composition, fat distribution and energy partitioning, the impact of sex steroid hormones and gut microbiota diversity, chromosomal and genetic variables, and behavioural and sociocultural variables influencing obesity development in men and women. Sex differences in obesity-related comorbidities and varying effectiveness of different weight loss interventions are also extensively discussed.

The gut microbiota and diabetes: research, translation, and clinical applications - 2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarises the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organised by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: (1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g. genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomisation in humans; (2) the highly individualised nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; (3) because single time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and (4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

The Loss of Estradiol by Androgen Deprivation in Prostate Cancer Patients Shows the Importance of Estrogens in Males

The role of estradiol (E2; an estrogen) in men needs to be more appreciated. In this review, we address the clinical situations that allow the study of the clinical consequences of E2 deficiency in men and discuss the effects of restoration of levels of this reproductive steroid hormone. In men with advanced prostate cancer (PCa) undergoing androgen deprivation therapy (ADT), E2 is suppressed along with testosterone, leading to side effects affecting the quality of life. These include hot flashes, arthralgia, fatigue, mood changes, cognition problems, weight gain, bone loss, and increased risk of cardiovascular disease. Transdermal E2 alone for ADT has shown equivalent testosterone suppression compared to gonadotropin-releasing hormone (GnRH) agonists while also preventing estrogen-deficiency side effects, including hot flashes and bone loss. Co-treatment of ADT with fetal estrogen estetrol (E4) has shown significant improvements of estrogen-deficiency symptoms. These observations emphasize the need to raise awareness of the importance of estrogens in men among clinicians and the lay public.

Gender Differences in the Interplay between Vitamin D and Microbiota in Allergic and Autoimmune Diseases

The synergic role of vitamin D and the intestinal microbiota in the regulation of the immune system has been thoroughly described in the literature. Vitamin D deficiency and intestinal dysbiosis have shown a pathogenetic role in the development of numerous immune-mediated and allergic diseases. The physiological processes underlying aging and sex have proven to be capable of having a negative influence both on vitamin D values and the biodiversity of the microbiome. This leads to a global increase in levels of systemic inflammatory markers, with potential implications for all immune-mediated diseases and allergic conditions. Our review aims to collect and analyze the relationship between vitamin D and the intestinal microbiome with the immune system and the diseases associated with it, emphasizing the effect mediated by sexual hormones and aging.

Causal relationship between gut microbiome and sex hormone-binding globulin: A bidirectional two-sample Mendelian randomization study

PROBLEM

Currently, there is a variety of evidence linking the gut microbiota to changes in sex hormones. In contrast, the causal relationship between SHBG, a carrier of sex hormones, and the gut microbiota is unclear.

METHOD OF STUDY

Bidirectional two-sample Mendelian randomization (MR) analysis was used to detect the causal effect between SHBG and the gut microbiome. Summary statistics of genome-wide association studies (GWASs) for the gut microbiome and SHBG were obtained from public datasets. Inverse-variance weighting (IVW), weighted median, weighted mode, MR-Egger and simple mode methods were used to operate the MR analysis. F-statistics and sensitivity analyses performed to evaluate bias and reliability.

RESULTS

When we set gut microbiome as exposure and SHBG as outcome, we identified nine causal relationships. In males, Coprobacter (PIVW = 2.01 × 10-6 ), Ruminococcus2 (PIVW = 3.40 × 10-5 ), Barnesiella (PIVW = 2.79 × 10-2 ), Actinobacteria (PIVW = 3.25 × 10-2 ) and Eubacterium fissicatena groups (PIVW = 3.64 × 10-2 ) were associated with lower SHBG levels; Alphaproteobacteria (PIVW = 1.61 × 10-2 ) is associated with higher SHBG levels. In females, Lachnoclostridium (PIVW = 9.75 × 10-3 ) and Defluviitaleaceae UCG011 (PIVW = 3.67 × 10-2 ) were associated with higher SHBG levels; Victivallaceae (PIVW = 2.23 × 10-2 ) was associated with lower SHBG levels. According to the results of reverse MR analysis, three significant causal effect of SHBG was found on gut microbiota. In males, Dorea (PIVW = 4.17 × 10-2 ) and Clostridiales (PIVW = 4.36 × 10-2 ) were associated with higher SHBG levels. In females, Lachnoclostridium (PIVW = 7.44 × 10-4 ) was associated with higherr SHBG levels. No signifcant heterogeneity of instrumental variables or horizontal pleiotropy was found in bidirectional two-sample MR analysis.

CONCLUSIONS

This study may provide new insights into the causal relationship between the gut microbiome and sex hormone-binding protein levels, as well as new treatment and prevention strategies for diseases such as abnormal changes in sex hormones.

Insights into estrogen impact in oral health & microbiome in COVID-19

BACKGROUND

COVID-19 emerged in late 2019 and has occasioned more than 765 millions cumulative cases and 6.9 millions of deaths globally. Notably, around 70% of patients with severe COVID-19 are men. Therefore, it is to be presumed that women have a hormonal protector factor in inflammation and ACE2 expression. On the other hand, oral health status, and local microbiome can be key factors to respiratory viral infections control. Nevertheless, it has been poorly investigated. In our study 20 premenopausal, 18 postmenopausal and 22 men with COVID-19 were included. Oral health status, viral load, lingual ACE2 expression, as well as microbiome, estrogens and cytokines in saliva were analyzed.

RESULTS

Our results showed a lower expression of ACE2 in tongue cells of postmenopausal compared with premenopausal (p = 0.05), and a strong negative correlation between saliva estrogen and viral load (r = -0.76; p = 0.001). Respect to IFN-γ (p = 0.05), IL-1β, TNF-α, IL-18, and IL-23 levels were increased in postmenopausal. Oral microbiome signature of premenopausal was characterized by Prevotella melaninogenica (Log2 = 26.68; p = 1.34e-10), Haemophilus (Log2 = 23.99; p = 2.96e-9), and Alloprevotella (Log2 = 7.92; p = 0.0001). On the other hand, Leptotrichia (Log2 = -18.74; p = 0.001), Tanerella (Log2 = -17.08; p = 0.004), and Clostridiales (Log2 = -2.88; p = 0.04) represented the poor oral health group compared with the adequate group which was enriched with the commensal microorganism Neisseria perflava (Log2 = 26.70; p = 1.74e-7). Furthermore, the high viral load group was characterized by Prevotella nanceiensis (Log2 = 19.60; p = 6.06e-8), Prevotella melaninogenica (Log2 = 21.45; p = 9.59e-6), Alloprevotella (Log2 = 23.50; p = 2.70e-7) and bacteria from the red complex Porphyromonas endodentalis (Log2 = 21.97; p = 1.38e-7).

CONCLUSIONS

Postmenopausal and men have a poor oral health status which could be related to a detrimental progression of COVID-19 also linked to a lower expression of ACE2, lower saliva estrogen levels and oral dysbiosis. Nevertheless, functional studies are required for a deeper knowledge.

Association between weight-adjusted-waist index and gallstones: an analysis of the National Health and Nutrition Examination Survey

BACKGROUND

The weight-adjusted-waist index (WWI) is a novel obesity index, and gallstones are associated with obesity. This study aimed to investigate the possible relationship between WWI and gallstones.

METHODS

The datasets from the National Health and Nutrition Examination Survey (NHANES) 2017-2020 were used in a cross-sectional investigation. Multivariate linear regression models were used to examine the linear connection between WWI and gallstones incidence. Fitted smoothing curves and threshold effect analysis were used to describe the nonlinear relationship.

RESULTS

The study comprised 8004 participants over the age of 20, including 833 reported with gallstones. Participants in the higher WWI tertile tended to have a higher gallstones prevalence. In the final adjusted model, a positive association between WWI and gallstones prevalence was observed (OR = 1.34, 95% CI: 1.20‒1.49). Participants in the highest WWI tertile had a significantly 71% higher risk of gallstones than those in the lowest WWI tertile (OR = 1.71, 95% CI: 1.35‒2.17). A nonlinear correlation was found between the WWI and gallstones prevalence, with an inflection point of 12.7.

CONCLUSIONS

Our study found that higher WWI levels connected with increased prevalence of gallstones. However, more prospective studies are needed to validate our findings.

Effects of Weight Change and Weight Cycling on Lung Function in Overweight and Obese Adults

Rationale: Epidemiological studies have reported on the detrimental effects on lung function after natural, and thus limited, weight gain in unselected populations. Studies on bariatric surgery, on the contrary, have indicated large improvements in lung function after substantial weight loss. Objectives: To study the associations between profound weight loss or gain and pulmonary function within the same population. A second objective was to investigate the effect of weight cycling on pulmonary function. Methods: From our lung function database, we selected the records of subjects in follow-up for continuous positive airway pressure therapy for sleep apnea with a weight change of ⩾20 kg within 5 years. Lung function (N = 255) at baseline was normal except for a tendency toward mild restriction in morbid obesity. Within this sample, 73 subjects were identified with significant "weight cycling", defined as a ⩾10-kg opposite change in body weight before or after the ⩾20-kg weight change. Results: Weight change affected pulmonary function more in men than in women (P < 0.001). In men, forced vital capacity (FVC) increased an average of 1.4% predicted per unit of body mass index after weight loss and the reverse after weight gain, whereas women exhibited a smaller change of 0.9% predicted per unit of body mass index. Weight loss slightly increased the ratio of forced expiratory volume in 1 second to FVC and decreased the specific airway resistance, whereas the opposite occurred with weight gain. Greater effects of weight change on lung function were observed in leaner subjects (P = 0.02) and in older subjects (P < 0.002). Changes in total lung capacity followed the changes in FVC, with no change in residual volume, and the greatest change was observed in functional residual capacity. In subjects with weight cycling, the improvement in lung function due to weight loss was reversed by subsequent weight gain and vice versa. Conclusions: This study provides evidence that the detrimental effect of obesity on lung function is a passive and reversible process.

Unravelling the Crosstalk between Estrogen Deficiency and Gut-biotaDysbiosis in the Development of Diabetes Mellitus

Estrogens are classically considered essential hormonal signals, but they exert profound effects in a number of physiological and pathological states, including glucose homeostasis and insulin resistance. Estrogen deficiency after menopause in most women leads to increased androgenicity and changes in body composition, and it is recommended to manipulate the β-cell function of the pancreas, insulin-induced glucose transport, and hepatic glucose output, hence, the increasing incidence of type 2 diabetes mellitus. Recently, studies have reported that gut biota alteration due to estrogen deficiency contributes to altered energy metabolism and, hence, accentuates the pathology of diabetes mellitus. Emerging research suggests estrogen deficiency via genetic disposition or failure of ovaries to function in old age modulates the insulin resistance and glucose secretion workload on pancreatic beta cells by decreasing the levels of good bacteria such as Akkermansia muciniphila, Bifidobacterium spp., Lactobacillus spp., Faecalibacterium prausnitzii, Roseburia spp., and Prevotella spp., and increasing the levels of bad bacteria's such as Bacteroides spp., Clostridium difficile, Escherichia coli, and Enterococcus spp. Alteration in these bacteria's concentrations in the gut further leads to the development of impaired glucose uptake by the muscles, increased gluconeogenesis in the liver, and increased lipolysis and inflammation in the adipose tissues. Thus, the present review paper aims to clarify the intricate interactions between estrogen deficiency, gut microbiota regulation, and the development of diabetes mellitus.

Excessive weight gain onset-age and risk of developing diabetes mellitus: a large, prospective Chinese cohort study

Background

Excessive weight gain and obesity are widely accepted as risk factors for diabetes mellitus, and the age at which obesity onsets may be related to the development of cardiovascular diseases and certain cancers. Here, we aimed to investigate associations between the onset-age of overweight/obesity and risk of developing diabetes mellitus in China.

Methods

42,144 people with the normal weight range and without diabetes at baseline, were enrolled from the Kailuan cohort which began on the 1st June 2006. All participants were followed-up, biennially, until 31st December 2017. During follow-up, 11,220 participants had become overweight/obese. For each case, one normal-weight control was matched according to age ( ± 1 year) and sex. Our final analysis included 10,858 case-control pairs. An age-scaled Cox model was implemented to estimate hazard ratios (HR) with corresponding 95% confidence intervals (CI) for diabetes mellitus incidence across age-groups.

Results

At a median follow-up of 5.46 years, 1,403 cases of diabetes mellitus were identified. After multivariate adjustments, age-scaled Cox modelling suggested that risk gradually attenuated with every 10 year increase in age of onset of overweight/obesity. Diabetes mellitus adjusted HRs (aHRs) for new-onset overweight/obesity at <45years, 45-54 years, and 55-64 years were 1.47 (95%CI, 1.12-1.93), 1.38 (95%CI, 1.13-1.68), 1.32 (95%CI, 1.09-1.59), respectively. However, new-onset of overweight/obesity at ≥65 years did not relate to diabetes mellitus (aHR, 1.20; 95%CI, 0.92-1.57). This trend was not observed in women or the new-onset obesity subgroup but was evident in men and the new overweight onset subgroup.

Conclusion

Participants with early onset of excessive weight gain issues are at considerably higher risk of developing diabetes mellitus compared to those who maintain a normal weight.

Postbiotics in rheumatoid arthritis: emerging mechanisms and intervention perspectives

Rheumatoid arthritis (RA) is a prevalent chronic autoimmune disease that affects individuals of all age groups. Recently, the association between RA and the gut microbiome has led to the investigation of postbiotics as potential therapeutic strategies. Postbiotics refer to inactivated microbial cells, cellular components, or their metabolites that are specifically intended for the microbiota. Postbiotics not only profoundly influence the occurrence and development of RA, but they also mediate various inflammatory pathways, immune processes, and bone metabolism. Although they offer a variety of mechanisms and may even be superior to more conventional "biotics" such as probiotics and prebiotics, research on their efficacy and clinical significance in RA with disruptions to the intestinal microbiota remains limited. In this review, we provide an overview of the concept of postbiotics and summarize the current knowledge regarding postbiotics and their potential use in RA therapy. Postbiotics show potential as a viable adjunctive therapy option for RA.

Gender-based research underscores sex differences in biological processes, clinical disorders and pharmacological interventions

Earlier research has presumed that the male and female biology is similar in most organs except the reproductive system, leading to major misconceptions in research interpretations and clinical implications, with serious disorders being overlooked or misdiagnosed. Careful research has now identified sex differences in the cardiovascular, renal, endocrine, gastrointestinal, immune, nervous, and musculoskeletal systems. Also, several cardiovascular, immunological, and neurological disorders have shown differences in prevalence and severity between males and females. Genetic variations in the sex chromosomes have been implicated in several disorders at young age and before puberty. The levels of the gonadal hormones estrogen, progesterone and testosterone and their receptors play a role in the sex differences between adult males and premenopausal women. Hormonal deficiencies and cell senescence have been implicated in differences between postmenopausal and premenopausal women. Specifically, cardiovascular disorders are more common in adult men vs premenopausal women, but the trend is reversed with age with the incidence being greater in postmenopausal women than age-matched men. Gender-specific disorders in females such as polycystic ovary syndrome, hypertension-in-pregnancy and gestational diabetes have attained further research recognition. Other gender-related research areas include menopausal hormone therapy, the "Estrogen Paradox" in pulmonary arterial hypertension being more predominant but less severe in young females, and how testosterone may cause deleterious effects in the kidney while having vasodilator effects in the coronary circulation. This has prompted the National Institutes of Health (NIH) initiative to consider sex as a biological variable in research. The NIH and other funding agencies have provided resources to establish state-of-the-art centers for women health and sex differences in biology and disease in several academic institutions. Scientific societies and journals have taken similar steps to organize specialized conferences and publish special issues on gender-based research. These combined efforts should promote research to enhance our understanding of the sex differences in biological systems beyond just the reproductive system, and provide better guidance and pharmacological tools for the management of various clinical disorders in a gender-specific manner.

Germ-Free C57BL/6 Mice Have Increased Bone Mass and Altered Matrix Properties but Not Decreased Bone Fracture Resistance

The gut microbiome impacts bone mass, which implies a disruption to bone homeostasis. However, it is not yet clear how the gut microbiome affects the regulation of bone mass and bone quality. We hypothesized that germ-free (GF) mice have increased bone mass and decreased bone toughness compared with conventionally housed mice. We tested this hypothesis using adult (20- to 21-week-old) C57BL/6J GF and conventionally raised female and male mice (n = 6-10/group). Trabecular microarchitecture and cortical geometry were measured from micro-CT of the femur distal metaphysis and cortical midshaft. Whole-femur strength and estimated material properties were measured using three-point bending and notched fracture toughness. Bone matrix properties were measured for the cortical femur by quantitative back-scattered electron imaging and nanoindentation, and, for the humerus, by Raman spectroscopy and fluorescent advanced glycation end product (fAGE) assay. Shifts in cortical tissue metabolism were measured from the contralateral humerus. GF mice had reduced bone resorption, increased trabecular bone microarchitecture, increased tissue strength and decreased whole-bone strength that was not explained by differences in bone size, increased tissue mineralization and fAGEs, and altered collagen structure that did not decrease fracture toughness. We observed several sex differences in GF mice, most notably for bone tissue metabolism. Male GF mice had a greater signature of amino acid metabolism, and female GF mice had a greater signature of lipid metabolism, exceeding the metabolic sex differences of the conventional mice. Together, these data demonstrate that the GF state in C57BL/6J mice alters bone mass and matrix properties but does not decrease bone fracture resistance. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Inherited stress resiliency prevents the development of metabolic alterations in diet-induced obese mice

OBJECTIVE

Chronic stress promotes obesity and metabolic comorbidities. The ability of individuals to cope with stress may serve as an important parameter in the development of obesity-related metabolic outcomes. The aim of this study was to clarify whether differences in stress response affect metabolic health under obesity.

METHODS

The study was performed in a selectively bred mouse model of social dominance (Dom) and submissiveness (Sub), which exhibit stress resilience or vulnerability, respectively. Mice were given a high-fat diet (HFD) or standard diet, followed by physiological, histological, and molecular analyses.

RESULTS

The HFD caused hyperleptinemia, glucose intolerance, insulin resistance, steatosis of the liver and pancreas, and brown adipose tissue whitening in Sub mice, whereas Dom mice were protected from these consequences of the HFD. The HFD increased circulating levels of interleukin (IL)-1β and induced the expression of proinflammatory genes in the liver and in epididymal white adipose tissue of Sub mice, with no changes in Dom mice. The Cox2 inhibitor celecoxib (15 mg/kg/d) reduced serum IL-1β, improved glucose tolerance and insulin sensitivity, and prevented hepatic and brown adipose tissue whitening in HFD-fed Sub mice.

CONCLUSIONS

The extent of stress resiliency is associated with inflammation and contributes to population heterogeneity in the development of healthy or unhealthy obesity.

Hormonal and inflammatory signatures of different mood episodes in bipolar disorder: a large-scale clinical study

BACKGROUND

Bipolar disorder (BD) is characterized by intensive mood fluctuations. While hormones imbalance plays important role in the mood swings, it is unknown whether peripheral hormones profiles could differentiate the manic and depressive mood episodes in BD. In this study, we investigated the changes of various hormones and inflammatory markers across distinct mood episodes of BD in a large clinical study to provide mood episode-specific peripheral biomarkers for BD.

METHODS

A total of 8332 BD patients (n = 2679 depressive episode; n = 5653 manic episode) were included. All patients were in acute state of mood episodes and need hospitalization. A panel of blood tests were performed for levels of sex hormones (serum levels of testosterone, estradiol, and progesterone), stress hormones (adrenocorticotropic hormone and cortisol), and an inflammation marker (C-reactive protein, CRP). A receiver operating characteristic (ROC) curve was used to analyze the discriminatory potential of the biomarkers for mood episodes.

RESULTS

In overall comparison between mood episodes, the BD patients expressed higher levels of testosterone, estradiol, progesterone, and CRP (P < 0.001) and lower adrenocorticotropic hormone (ACTH) level (P < 0.001) during manic episode. The episode-specific changes of testosterone, ACTH, and CRP levels remained between the two groups (P < 0.001) after correction for the confounding factors including age, sex, BMI, occupation, marital status, tobacco use, alcohol consumption, psychotic symptoms, and age at onset. Furthermore, we found a sex- and age-specific impact of combined biomarkers in mood episodes in male BD patients aged ≥ 45 years (AUC = 0.70, 95% CI, 0.634-0.747), not in females.

CONCLUSIONS

While both hormone and inflammatory change is independently associated with mood episodes, we found that the combination of sex hormones, stress hormones and CRP could be more effective to differentiate the manic and depressive episode. The biological signatures of mood episodes in BD patients may be sex- and age-specific. Our findings not only provide mood episode-related biological markers, but also better support for targeted intervention in BD treatments.

Genetic variants in genes involved in creatine biosynthesis in patients with severe obesity or anorexia nervosa

Increased thermogenesis in brown adipose tissue might have an obesity-reducing effect in humans. In transgenic mice, depletion of genes involved in creatine metabolism results in disrupted thermogenic capacity and altered effects of high-fat feeding on body weight. Data analyses of a sex-stratified genome-wide association study (GWAS) for body mass index (BMI) within the genomic regions of genes of this pathway (CKB, CKMT1B, and GATM) revealed one sex-dimorphic BMI-associated SNP in CKB (rs1136165). The effect size was larger in females than in males. A mutation screen of the coding regions of these three candidate genes in a screening group (192 children and adolescents with severe obesity, 192 female patients with anorexia nervosa, and 192 healthy-lean controls) identified five variants in each, CKB and GATM, and nine variants in the coding sequence of CKMT1B. Non-synonymous variants identified in CKB and CKMT1B were genotyped in an independent confirmation study group (781 families with severe obesity (trios), 320 children and adolescents with severe obesity, and 253 healthy-lean controls). In silico tools predicted mainly benign yet protein-destabilizing potentials. A transmission disequilibrium test in trios with severe obesity indicated an obesity-protective effect of the infrequent allele at rs149544188 located in CKMT1B. Subsequent correlation analyses in 1,479 individuals of the Leipzig Obesity BioBank revealed distinct correlations of CKB with the other two genes in omental visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (SAT). Furthermore, between-subject comparisons of gene expression levels showed generally higher expressions of all three genes of interest in VAT than in SAT. Future in vitro analyses are needed to assess the functional implications of these findings.

Adipocyte Metabolism and Health after the Menopause: The Role of Exercise

Postmenopausal women represent an important target population in need of preventative cardiometabolic approaches. The loss of estrogen following the menopause eliminates protections against metabolic dysfunction, largely due to its role in the health and function of adipose tissue. In addition, some studies associate the menopause with reduced physical activity, which could potentially exacerbate the deleterious cardiometabolic risk profile accompanying the menopause. Meanwhile, exercise has adipocyte-specific effects that may alleviate the adverse impact of estrogen loss through the menopausal transition period and beyond. Exercise thus remains the best therapeutic agent available to mitigate menopause-associated metabolic dysfunction and represents a vital behavioral strategy to prevent and alleviate health decline in this population.