Progesterone inhibits glucose uptake by affecting diverse steps of insulin signaling in 3T3-L1 adipocytes

High-dose oral contraceptives induce hyperinsulinemia without altering immune activation in diet-induced obesity which persists even following a dietary low-fat diet intervention

Combined oral contraceptives (COCs) are known to cause weight gain and alter metabolic and immunological pathways. However, modifications in arterial or venous thrombotic risk profiles of women of reproductive ages on COC remain unclear. The study aimed at assessing the impact of COC on immune activation in diet-induced obesity. We further established whether the dietary intervention of switching from a high-fat diet (HFD) to a low-fat diet (LFD) attenuates immunological responses. Twenty (n=20) five-week-old female Sprague Dawley rats were randomly divided into two diet groups of HFD (n=15) and LFD (n=5) and were monitored for eight weeks. After eight weeks, animals in the HFD group switched diets to LFD and were randomly assigned to receive high-dose COC (HCOC) or low-dose COC (LCOC) for six weeks. Animals on HFD significantly gained weight and had a higher lee index when compared to the LFD group (p < 0.05). Moreover, the triglyceride-glucose index, insulin, and other metabolic parameters also increased in the HFD group compared to the LFD group (p < 0.001). Consistently, the levels of interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α), were elevated in the HFD group when compared to the LFD group (p < 0.05). Upon switching from a high-fat to a low-fat diet, insulin levels persistently increased in animals receiving HCOC treatment compared to the LFD and HFD/LFD groups (p < 0.05). Thus, in a rat model of HFD-feeding, short-term HCOC treatment induces long-term metabolic dysregulation, which persists despite dietary intervention. However, further studies are recommended to confirm these findings.

Impact of Physiological Fluctuations of Sex Hormones During the Menstrual Cycle on Glucose Metabolism and the Gut Microbiota

Diabetes mellitus is one of the most prevalent chronic diseases. Previous studies have shown differences in glucose metabolism between males and females. Moreover, difficulties in medication adherence have been reported in females with type 2 diabetes. These observations are believed to be caused by fluctuations in sex hormone concentrations during the menstrual cycle. Furthermore, gut microbiota is linked to female host metabolism and sex hormone production. Understanding the interactions between fluctuating hormone concentrations during the menstrual cycle, gut microbiota, and glucose metabolism in humans is significant because of the increasing prevalence of diabetes and the consequent need to expand preventive efforts. A literature search was performed to determine and summarize the existing evidence, deduce future research needs to maintain female health, and investigate the relationship between the physiological menstrual cycle and glucose metabolism. Studies from 1967 to 2020 have already examined the relationship between variations during the menstrual cycle and glucose metabolism in healthy female subjects using an oral-glucose tolerance test or intravenous glucose tolerance test. However, the overall number of studies is rather small and the results are contradictory, as some studies detected differences in glucose concentrations depending on the different cycle phases, whereas others did not. Some studies reported lower glucose levels in the follicular phase than in the luteal phase, whereas another study detected the opposite. Data on gut microbiota in relation to the menstrual cycle are limited. Conflicting results exist when examining the effect of hormonal contraceptives on the gut microbiota and changes in the course of the menstrual cycle. The results indicate that the menstrual cycle, especially fluctuating sex hormones, might impact the gut microbiota composition.The menstrual cycle may affect the gut microbiota composition and glucose metabolism. These results indicate that glucose tolerance may be the greatest in the follicular phase; however, further well-conducted studies are needed to support this assumption.

Genetic and Epigenetic Factors in Gestational Diabetes Mellitus Pathology

Gestational diabetes (GDM) is the carbohydrate intolerance occurring during pregnancy. The risk factors of GDM include obesity, advanced maternal age, polycystic ovary syndrome, multigravidity, a sedentary lifestyle, and pre-existing hypertension. Additionally, complex genetic and epigenetic processes are also believed to play a crucial role in the development of GDM. In this narrative review, we discuss the role of genetic and epigenetic factors in gestational diabetes mellitus pathogenesis.

Patients with gestational diabetes mellitus may be treated in both early and late pregnancy, especially in patients with pre-pregnancy overweight: A cross-sectional study in Japan

The significance of diagnosing gestational diabetes mellitus (GDM) in early pregnancy is controversial. We used the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria to investigate whether clinical background and neonatal outcomes differ depending on when GDM is diagnosed in early or late pregnancy. This was a single-center, observational study conducted between November 2012 and March 2020 at St. Marianna University Hospital (Kawasaki, Japan). We compared the background and perinatal outcomes of patients with GDM depending on the time of diagnosis (at < 24 gestational weeks or ≥ 24 weeks). Insulin sensitivity index, homeostasis model assessment of insulin resistance, and β-cell function were calculated from a 75-g oral glucose tolerance test. Stratified analysis was performed by pre-pregnancy BMI in patients with early GDM. As a result, in the 507 patients, 89.9% gave birth at our hospital. The pre-pregnancy BMI was significantly higher in patients with early GDM than in those with late GDM (the median [interquartile range], 22.7 [20.3, 26.3] and 21.5 [19.3, 23.8] kg/m2, respectively; p = 0.001). Perinatal outcomes were not different between the two groups. However, in the subgroup analysis of patients with early GDM, the prevalence of large-for-gestational-age infants was significantly higher in the group with overweight (15.4% vs 2.1%, respectively; p = 0.008). In conclusion, patients with GDM using the IADPSG criteria in early pregnancy may be treated, especially in patients with pre-pregnancy overweight.

Understanding the female athlete: molecular mechanisms underpinning menstrual phase differences in exercise metabolism

Research should equitably reflect responses in men and women. Including women in research, however, necessitates an understanding of the ovarian hormones and menstrual phase variations in both cellular and systems physiology. This review outlines recent advances in the multiplicity of ovarian hormone molecular signaling that elucidates the mechanisms for menstrual phase variability in exercise metabolism. The prominent endogenous estrogen, 17-β-estradiol (E2), molecular structure is bioactive in stabilizing plasma membranes and quenching free radicals and both E2 and progesterone (P4) promote the expression of antioxidant enzymes attenuating exercise-induced muscle damage in the late follicular (LF) and mid-luteal (ML) phases. E2 and P4 bind nuclear hormone receptors and membrane-bound receptors to regulate gene expression directly or indirectly, which importantly includes cross-regulated expression of their own receptors. Activation of membrane-bound receptors also regulates kinases causing rapid cellular responses. Careful analysis of these signaling pathways explains menstrual phase-specific differences. Namely, E2-promoted plasma glucose uptake during exercise, via GLUT4 expression and kinases, is nullified by E2-dominant suppression of gluconeogenic gene expression in LF and ML phases, ameliorated by carbohydrate ingestion. E2 signaling maximizes fat oxidation capacity in LF and ML phases, pending low-moderate exercise intensities, restricted nutrient availability, and high E2:P4 ratios. P4 increases protein catabolism during the luteal phase by indeterminate mechanisms. Satellite cell function supported by E2-targeted gene expression is countered by P4, explaining greater muscle strengthening from follicular phase-based training. In totality, this integrative review provides causative effects, supported by meta-analyses for quantitative actuality, highlighting research opportunities and evidence-based relevance for female athletes.

Circulating fructose regulates a germline stem cell increase via gustatory receptor-mediated gut hormone secretion in mated Drosophila

Oogenesis is influenced by multiple environmental factors. In the fruit fly, Drosophila melanogaster, nutrition and mating have large impacts on an increase in female germline stem cells (GSCs). However, it is unclear whether these two factors affect this GSC increase interdependently. Here, we report that dietary sugars are crucial for the GSC increase after mating. Dietary glucose is required for mating-induced release of neuropeptide F (NPF) from enteroendocrine cells (EECs), followed by NPF-mediated enhancement of GSC niche signaling. Unexpectedly, dietary glucose does not directly act on NPF-positive EECs. Rather, it contributes to elevation of hemolymph fructose generated through the polyol pathway. Elevated fructose stimulates the fructose-specific gustatory receptor, Gr43a, in NPF-positive EECs, leading to NPF secretion. This study demonstrates that circulating fructose, derived from dietary sugars, is a prerequisite for the GSC increase that leads to enhancement of egg production after mating.

Type 1 Diabetes and the Menstrual Cycle: Where/How Does Exercise Fit in?

Regular exercise is associated with substantial health benefits for individuals with type 1 diabetes (T1D). However, the fear of hypoglycemia (low blood glucose) due to activity-induced declines in blood glucose levels acts as a major barrier to partaking in exercise in this population. For females with T1D, hormonal fluctuations during the menstrual cycle and their effects on blood glucose levels can act as an additional barrier. The impact that these cyclic changes may have on blood glucose and insulin needs and the consequent risk of hypoglycemia during or after exercise are still unknown in this population. Therefore, in this narrative review, we gathered existing knowledge about the menstrual cycle in T1D and the effects of different cyclic phases on substrate metabolism and glucose response to exercise in females with T1D to increase knowledge and understanding around exercise in this underrepresented population. This increased knowledge in such an understudied area can help to better inform exercise guidelines for females with T1D. It can also play an important role in eliminating a significant barrier to exercise in this population, which has the potential to increase activity, improve mental health and quality of life, and decrease the risk of diabetes-related complications.

Biochemical and molecular biomarkers: unraveling their role in gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is the most prevalent metabolic disorder during pregnancy, causing short- and long-term complications for both mother and baby. GDM is a multifactorial disease, and it may be affected by interactions between genetic, epigenetic, and environmental factors. However, the exact etiology is poorly understood. Despite the high prevalence of GDM, there is still debate regarding the optimal time for screening, the diagnostic threshold to apply, and the best strategies for treatment. Identifying effective strategies for therapeutic purposes as well as accurate biomarkers for prognostic and diagnostic purposes will reduce the GDM incidence and improve its management. In recent years, new biochemical and molecular biomarkers such as microRNAs, single-nucleotide polymorphisms, and DNA methylation have received great interest in the diagnosis of GDM. In this review, we discuss current and future diagnostic approaches for the detection of GDM and evaluate lifestyle and pharmacological strategies for GDM prevention.

Predictors for pharmacological therapy and perinatal outcomes with metformin treatment in women with gestational diabetes

BACKGROUND

The prevalence of gestational diabetes mellitus (GDM) has been increasing in Australia and worldwide. The study aims were to examine, in comparison with dietary intervention, perinatal outcomes for women with gestational diabetes who were attending a single hospital clinic and to identify predictors for their pharmacological GDM treatment.

METHODS

A prospective, observational study of women with GDM, treated with "Diet, N= 50", "Metformin, N = 35", "Metformin and Insulin, N = 46" or "Insulin, N = 20".

FINDINGS

The mean BMI for the whole cohort was 25.8 ± 4.7 kg/m². The Metformin group, compared to the Diet group, had OR=3.1 (95% CI:1.13 to 8.25) for caesarean section birth (LSCS) compared to normal vaginal birth mode with no longer such a significant association after controlling for the number of their elective LSCS. The insulin treated group had the highest number of small for gestational age neonates (20%, p<0.05) with neonatal hypoglycaemia (25%, p< 0.05). Fasting glucose value on oral GTT (glucose tolerance test) was the strongest predictor for a pharmacological intervention requirement with OR = 2.77 (95CI%: 1.16 to 6.61), followed by timing of OGTT with OR=0.90 (95% CI: 0.83 to 0.97) and previous pregnancy loss with OR=0.28 (95% CI:0.10 to 0.74).

INTERPRETATION

These data suggest that metformin may be a safe alternative treatment to insulin treatment in GDM. Raised fasting glucose on oral GTT was the strongest indicator that GDM women with BMI < 35 kg/m² may require pharmacological therapy. Further studies are needed to identify the most effective and safe management of gestational diabetes within the public hospital setting.

AUSTRALIAN NEW ZEALAND CLINICAL TRIAL REGISTRY ANZCTR TRIAL ID

ACTRN12620000397910.

Metabolomics during canine pregnancy and lactation

During pregnancy and parturition, female dogs have to cope with various challenges such as providing nutrients for the growth of the fetuses, hormonal changes, whelping, nursing, milk production, and uterine involution. Metabolomic research has been used to characterize the influence of several factors on metabolism such as inter- and intra-individual factors, feeding, aging, inter-breed differences, drug action, behavior, exercise, genetic factors, neuter status, and pathologic processes. Aim of this study was to identify metabolites showing specific changes in blood serum at the different phases of pregnancy and lactation. In total, 27 privately owned female dogs of 21 different breeds were sampled at six time points: during heat, in early, mid and late pregnancy, at the suspected peak of lactation and after weaning. A validated and highly automated canine-specific NMR metabolomics technology was utilized to quantitate 123 measurands. It was evaluated which metabolite concentrations showed significant changes between the different time points. Metabolites were then grouped into five clusters based on concentration patterns and biochemical relationships between the metabolites: high in mid-pregnancy, low in mid-pregnancy, high in late pregnancy, high in lactation, and low in lactation. Several metabolites such as albumin, glycoprotein acetyls, fatty acids, lipoproteins, glucose, and some amino acids show similar patterns during pregnancy and lactation as shown in humans. The patterns of some other parameters such as branched-chain amino acids, alanine and histidine seem to differ between these species. For most metabolites, it is yet unstudied whether the observed changes arise from modified resorption from the intestines, modified production, or metabolism in the maternal or fetal tissues. Hence, further species-specific metabolomic research may support a broader understanding of the physiological changes caused by pregnancy that are likely to be key for the normal fetal growth and development. Our findings provide a baseline of normal metabolic changes during healthy canine pregnancy and parturition. Combined with future metabolomics findings, they may help monitor vital functions of pre-, intra-, and post-partum bitches and may allow early detection of illness.

Effect of dietary resveratrol on placental function and reproductive performance of late pregnancy sows

Placental function is vital to the fetal growth of sows, and resveratrol (RES) can protect cells against oxidative stress, which is one of the major factors impairing placental function. This study aimed to investigate the effect of dietary resveratrol (RES) on placental function and reproductive performance during late pregnancy in a sow model from the aspects of oxidative stress, insulin resistance, and gut microbiota. A total of 26 hybrid pregnant sows (Landrace × Yorkshire) with similar parity were randomly allocated into two groups (n = 13) and fed with a basal diet or a diet containing 200 mg/kg of resveratrol from day 85 of gestation until parturition. The dietary supplementation of RES increased the litter weight at parturition by 12.53% (p = 0.145), with ameliorated insulin resistance (HOMA-IR), increased triglyceride (TG) levels, and decreased interleukin (IL)-1β and IL-6 levels in serum (p &lt; 0.05). Moreover, resveratrol increased the placental vascular density (p &lt; 0.05) with the enhanced expression of nutrient transporter genes (SLC2A1 and SLC2A3) and antioxidant genes, such as superoxide dismutase 2 (SOD2) and heme oxygenase-1 (HO-1) but declined the expression of inflammatory genes, such as IL-1β and IL-6 (p &lt; 0.05). The characterization of the fecal microbiota revealed that resveratrol decreased the relative abundance of the Christensensllaceae R-7 group and Ruminococcaceae UCG-008 (p &lt; 0.05), which had a positive linear correlation with the expression of IL-1β and IL-6 (p &lt; 0.05), but had a negative linear correlation with the expression of SOD2, HO-1, SLC2A1, and SCL2A3 genes (p &lt; 0.05). These data demonstrated that dietary supplementation with resveratrol can improve placental function with ameliorated insulin resistance, oxidative stress, and inflammation potentially by regulating Ruminococcaceae UCG-008 and the Christensensllaceae R-7 group in sows.

Maternal Chromium Levels in Gestational Diabetes: Systematic Review and Meta-Analysis

The topic of maternal Chromium (Cr) levels in Gestational Diabetes Mellitus (GDM) has remained controversial; some studies have found lower levels of Cr in GDM population, whereas others found no significant changes in Cr status in GDM. Therefore, this systematic review and meta-analysis was aimed at qualitatively and quantitatively synthesizing past studies to find the relationship of maternal Cr levels with GDM. The study protocol was registered at International prospective register for systematic reviews (PROSPERO) (ID CRD42021272979). Strict adherence to the Preferred Reporting Items for Systematic review and Meta-analysis checklist, 2009 was followed during the entire study. Random-effect model for calculation of distribution of true effect sizes was used for the meta-analysis with a confidence interval (CI) of 95%. The pooled Standard Mean Difference of control and GDM groups were compared using Z statistics with a P value of <.05 as significant. Six studies were included for the systematic review and four studies entered meta-analysis. The test of overall effect revealed that the pooled Cr values did not differ significantly between controls and GDM group (Z = 1.52, P =0.13). Heterogeneity between the studies was high (I2 = 97%). A subgroup analysis revealed that results varied as per place of study, trimester of pregnancy, and Cr estimation technique. Results from meta regression analysis revealed that sample size of individual studies (Q = 0.003, P =0.67) and year of publication of studies (Q = 0.22, P =.48) had no significant effect on the overall Standard Mean Difference. Factors such as ethnicity, lack of history of infection, and diet history can influence the results of this study.

The adaptation of maternal energy metabolism to lactation and its underlying mechanisms

Maternal energy metabolism undergoes a singular adaptation during lactation that allows for the caloric enrichment of milk. Changes in the mammary gland, changes in the white adipose tissue, brown adipose tissue, liver, skeletal muscles and endocrine pancreas are pivotal for this adaptation. The present review details the landmark studies describing the enzymatic modulation and the endocrine signals behind these metabolic changes. We will also update this perspective with data from recent studies showing transcriptional and post-transcriptional mechanisms that mediate the adaptation of the maternal metabolism to lactation. The present text will also bring experimental and observational data that describe the long-term consequences that short periods of lactation impose to maternal metabolism.

The intestine and the microbiota in maternal glucose homeostasis during pregnancy

It is now well established that, beyond its role in nutrient processing and absorption, the intestine and its accompanying gut microbiome constitute a major site of immunological and endocrine regulation that mediates whole-body metabolism. Despite the growing field of host-microbe research, few studies explore what mechanisms govern this relationship in the context of pregnancy. During pregnancy, significant maternal metabolic adaptations are made to accommodate the additional energy demands of the developing fetus and to prevent adverse pregnancy outcomes. Recent data suggest that the maternal gut microbiota may play a role in these adaptations, but changes to maternal gut physiology and the underlying intestinal mechanisms remain unclear. In this review, we discuss selective aspects of intestinal physiology including the role of the incretin hormone, glucagon-like peptide 1 (GLP-1), and the role of the maternal gut microbiome in the maternal metabolic adaptations to pregnancy. Specifically, we discuss how bacterial components and metabolites could mediate the effects of the microbiota on host physiology, including nutrient absorption and GLP-1 secretion and action, and whether these mechanisms may change maternal insulin sensitivity and secretion during pregnancy. Finally, we discuss how these pathways could be altered in disease states during pregnancy including maternal obesity and diabetes.

New insights on hyperglycemia in 17-hydroxylase/17,20-lyase deficiency

OBJECTIVE

The adrenal glands of patients with 17-hydroxylase/17,20-lyase deficiency (17OHD) synthesize excessive 11-deoxycorticosterone(DOC) and progesterone, and produce less amount of sex steroid production. Mineralocorticoids and sex hormones play an important role in regulating glucose homeostasis. This study aimed to describe the glucose metabolism in 17OHD patients diagnosed at Peking Union Medical College Hospital (PUMCH).

DESIGN/METHODS

A total of 69 patients diagnosed with 17OHD after adolescence in PUMCH from 1995 to June in 2021. Among them 23 patients underwent a 3-hours oral glucose tolerance test (3hOGTT) after being diagnosed with 17OHD. Insulin response in patients with normal glucose tolerance (NGT) were further compared between the study two groups with different kalemia status. Another 19 patients were followed up to 30 years and older. All clinical data were obtained from the hospital information system of PUMCH.

RESULTS

Baseline: (1) The average body mass index(BMI) of all patients at baseline was 20.3 ± 3.7kg/m². Twenty-three patients underwent 3hOGTT, of whom three were diagnosed with diabetes mellitus, and one with impaired glucose tolerance (IGT). Positive correlation between the ratio of progesterone to upper limit of normal range (P times) and hyperglycaemia was exist(r=0.707, P=0.005). (2) In 19 NGT patients, the insulin concentrations at 0 minute, results of the homeostasis model assessment for β-cell function and insulin resistance were lower in the hypokalaemia group than in the normal kalemia group(7.0(5.8-13.2) vs 12.4(8.9-14.9) μIU/ml, P=0.017; 115.5(88.2-240.9) vs 253.1(177.2-305.8), P=0.048; 1.54(1.17-2.61) vs 2.47(1.91-2.98), P=0.022, respectively). Follow-up: Four patients had IGT, while seven patients had diabetes mellitus. Of the 19 patients,11 had hyperglycaemia. P times was significantly higher(7.6(5.0-11.0) vs 3.75(2.2-5.3), P=0.008) in hyperglycemia group than in the normal glucose group.

CONCLUSIONS

Abnormal glucose metabolism was common in 17OHD patients, which was possibly associated with hypokalaemia and high progesterone levels. Routine monitoring on glucose metabolism in 17OHD patient should be conducted.

Loss of imprinting of the Igf2-H19 ICR1 enhances placental endocrine capacity via sex-specific alterations in signalling pathways in the mouse

Imprinting control region (ICR1) controls the expression of the Igf2 and H19 genes in a parent-of-origin specific manner. Appropriate expression of the Igf2-H19 locus is fundamental for normal fetal development, yet the importance of ICR1 in the placental production of hormones that promote maternal nutrient allocation to the fetus is unknown. To address this, we used a novel mouse model to selectively delete ICR1 in the endocrine junctional zone (Jz) of the mouse placenta (Jz-ΔICR1). The Jz-ΔICR1 mice exhibit increased Igf2 and decreased H19 expression specifically in the Jz. This was accompanied by an expansion of Jz endocrine cell types due to enhanced rates of proliferation and increased expression of pregnancy-specific glycoprotein 23 in the placenta of both fetal sexes. However, changes in the endocrine phenotype of the placenta were related to sexually-dimorphic alterations to the abundance of Igf2 receptors and downstream signalling pathways (Pi3k-Akt and Mapk). There was no effect of Jz-ΔICR1 on the expression of targets of the H19-embedded miR-675 or on fetal weight. Our results demonstrate that ICR1 controls placental endocrine capacity via sex-dependent changes in signalling.

Relationship Between Insulin Sensitivity and Menstrual Cycle Is Modified by BMI, Fitness, and Physical Activity in NHANES

CONTEXT

There is evidence demonstrating variation in insulin sensitivity across the menstrual cycle. However, to date, research has yielded inconsistent results.

OBJECTIVE

This study investigated variation in insulin sensitivity across the menstrual cycle and associations with body mass index (BMI), physical activity, and cardiorespiratory fitness (CRF).

METHODS

Data from 1906 premenopausal women in NHANES cycles 1999 to 2006 were analyzed. Menstrual cycle day was assessed using questionnaire responses recording days since last period. Rhythmic variation of plasma glucose, triglycerides, and insulin, homeostatic model of insulin resistance (HOMA-IR), and adipose tissue insulin resistance index (ADIPO-IR) across the menstrual cycle were analyzed using cosinor rhythmometry. Participants were assigned low or high categories of BMI, physical activity, and CRF, and category membership included in cosinor models as covariates.

RESULTS

Rhythmicity was demonstrated by a significant cosine fit for glucose (P = .014) but not triglycerides (P = .369), insulin (P = .470), HOMA-IR (P = .461), and ADIPO-IR (P = .335). When covariates were included, rhythmicity was observed when adjusting for: 1) BMI: glucose (P < .001), triglycerides (P < .001), insulin (P < .001), HOMA-IR (P < .001), and ADIPO-IR (P < .001); 2) physical activity: glucose (P < .001), triglycerides (P = .006), and ADIPO-IR (P = .038); and 3) CRF: triglycerides (P = .041), insulin (P = .002), HOMA-IR (P = .004), and ADIPO-IR (P = .004). Triglyceride amplitude, but not acrophase, was greater in the high physical activity category compared to low (P = .018).

CONCLUSION

Rhythmicity in insulin sensitivity and associated metabolites across the menstrual cycle are modified by BMI, physical activity, and CRF.

Combined effects of progesterone and SOCS3 DNA methylation on T2DM: a case-control study

BACKGROUND

This study aims to investigate the independent and combined effects of progesterone and suppressor of cytokine signaling (SOCS)-3 DNA methylation on type 2 diabetes mellitus (T2DM) among men and postmenopausal women in rural China.

METHODS

A case-control study with 914 participants (329 T2DM, 585 controls) was conducted. Serum progesterone was detected with liquid chromatography-tandem mass spectrometry. DNA methylation of SOCS3 was determined by MethylTarget™. Linear regression was applied to evaluate the associations of progesterone and SOCS3 methylation with marks of glucose metabolism. Logistic regression was employed to investigate the independent and combined effects of progesterone and SOCS3 methylation with T2DM in men and postmenopausal women.

RESULTS

After multiple adjustment, progesterone was positively associated with T2DM in both men (odds ratio (OR) (95% confidence interval (CI)): 2.77 (1.79, 4.29)) and postmenopausal women (OR (95% CI): 1.85 (1.26, 2.72)). Methylation level of Chr17:76,356,190 or Chr17:76,356,199 (SOCS3) was negatively associated with T2DM in both men (OR (95% CI): 0.58 (0.39, 0.86) or 0.27 (0.14, 0.51)) and postmenopausal women (OR (95% CI): 0.43 (0.29, 0.65) or 0.53 (0.28, 0.99)). Subjects with high progesterone and low Chr17:76,356,190 or Chr17:76,356,199 methylation were more susceptible to have a higher prevalence of T2DM (men: OR (95% CI): 5.20 (2.49, 10.85) or 5.62 (2.74, 11.54); postmenopausal women: OR (95% CI): 3.66 (1.85, 7.26) or 3.27 (1.66, 6.45)).

CONCLUSIONS

The independent and combined effects of progesterone and SOCS3 methylation on T2DM were found among men and postmenopausal women, suggesting that ensuring low levels of progesterone and high methylation of SOCS3 could reduce the prevalence of T2DM. Trial registration The Chinese Clinical Trial registration: The Henan Rural Cohort Study, ChiCTR-OOC-15006699. Registered 06 July 2015, http://www.chictr.org.cn/showproj.aspx?proj=11375.

Pyometra-associated insulin resistance assessment by insulin binding assay and tyrosine kinase activity evaluation in canine muscle tissue

Diestrus is associated with insulin resistance in bitches and pyometra can further impair insulin sensitivity. This study aimed to compare insulin sensitivity, insulin binding, and tyrosine kinase activity in bitches in anestrus, diestrus, or with pyometra. Patients submitted to elective ovariohysterectomy were divided into anestrus (n = 11) or diestrus (n = 13) according to reproductive history, vaginal cytology, and uterine histology. The group pyometra (n = 8) included bitches diagnosed with the disease based on clinical presentation and abdominal ultrasound findings and further confirmed by uterine histopathology. All patients were submitted to an intravenous glucose tolerance test (IVGTT) before ovariohysterectomy, and rectus abdominis muscle samples were collected during surgery for plasmatic membrane suspension preparation. Muscle-membranes were submitted to cold saturation insulin binding assay for dissociation constant (Kd) and maximum binding capacity (Bmax) determination, as well as exogenous substrate Poly (Glu: Tyr 4:1) phosphorylation assay for basal tyrosine kinase evaluation. Bitches with pyometra showed higher basal insulin (P < 0.001) and higher area under the curve (AUC) for insulin (P = 0.01) and glucose (P < 0.001) response during the IVGTT in comparison with bitches in anestrus or diestrus. Diestrus (P < 0.0001) and pyometra (P = 0.001) were associated with reduced tyrosine kinase activity in comparison with anestrus. No differences were documented in Kd and Bmax results for the low-affinity/high-capacity insulin receptors; however, high-affinity/low-capacity insulin receptors showed higher Kd and Bmax results in bitches in diestrus or with pyometra (P < 0.05) in comparison with anestrus. Despite the pyometra group showed the highest Kd values (P < 0.01), its Bmax results did not differ from the diestrus group (P > 0.05). Diestrus' higher Kd values and reduced tyrosine kinase activity in muscle tissue were compensated by increased total insulin binding capacity. Absent differences in IVGTT results between diestrus and anestrus bitches corroborate this finding. However, in bitches with pyometra, the highest Kd values were not compensated by increased total insulin binding capacity. This finding was associated with insulin resistance and glucose intolerance in IVGTT results. Moreover, pyometra resolution restored insulin sensitivity and glucose tolerance. These features can play a key role in pyometra-associated CDM, as well as in diabetic remission after pyometra resolution.

The Impact of a Plant-Based Diet on Gestational Diabetes: A Review

Gestational diabetes mellitus (GDM) represents a challenging pregnancy complication in which women present a state of glucose intolerance. GDM has been associated with various obstetric complications, such as polyhydramnios, preterm delivery, and increased cesarean delivery rate. Moreover, the fetus could suffer from congenital malformation, macrosomia, neonatal respiratory distress syndrome, and intrauterine death. It has been speculated that inflammatory markers such as tumor necrosis factor-alpha (TNF-α), interleukin (IL) 6, and C-reactive protein (CRP) impact on endothelium dysfunction and insulin resistance and contribute to the pathogenesis of GDM. Nutritional patterns enriched with plant-derived foods, such as a low glycemic or Mediterranean diet, might favorably impact on the incidence of GDM. A high intake of vegetables, fibers, and fruits seems to decrease inflammation by enhancing antioxidant compounds. This aspect contributes to improving insulin efficacy and metabolic control and could provide maternal and neonatal health benefits. Our review aims to deepen the understanding of the impact of a plant-based diet on oxidative stress in GDM.

Gender-Specific Independent and Combined Effects of the Progesterone and 17-Hydroxyprogesterone on Metabolic Syndrome: From the Henan Rural Cohort Study

BACKGROUND

Although the concentrations of progesterone (P4) and 17-hydroxyprogesterone (17-OHP) have been correlated with some characteristics of metabolic syndrome (MetS), the relationships with MetS are inconclusive. Therefore, we investigated the relationship between P4 and 17-OHP with MetS.

METHODS

In all, the present study includes 4807 participants. Serum P4 and 17-OHP were measured through liquid chromatography-tandem mass spectrometry. Logistic regression and restricted cubic splines were used to assess the independent and combined effects of P4 and 17-OHP on MetS.

RESULTS

After adjusting for multiple variables, the positive association of P4 with MetS was observed in postmenopausal women (Third tertiles vs First tertiles: OR = 1.49, 95% CI: 1.20-1.86) and the negative association of 17-OHP with MetS was observed in men (Third tertiles vs First tertiles: OR = 0.43, 95% CI: 0.32-0.58). Compared with the combination of low P4 and low 17-OHP, the combination of high P4 and high 17-OHP were significantly related to MetS in postmenopausal women (OR = 1.71, 95% CI: 1.18-2.48). Moreover, the combination of low P4 and high 17-OHP was negatively associated with MetS in men (OR = 0.41, 95% CI: 0.24-0.69).

CONCLUSION

The association between P4 and MetS in postmenopausal women was positive, whereas 17-OHP was negatively associated with MetS in men. Additionally, their combination has a synergistic effect on MetS in postmenopausal women and an antagonistic effect on MetS in men.

Plasma Prolactin and Progesterone Levels and the Risk of Gestational Diabetes: A Prospective and Longitudinal Study in a Multiracial Cohort

Objective: Prolactin and progesterone are implicated in glucose homeostasis in and outside of pregnancy. However, their associations with gestational diabetes (GDM) risk were not well-understood. This study investigates this question in a prospective and longitudinal cohort. Methods: This is a nested case-control study of 107 incident GDM cases and 214 matched non-GDM controls within the NICHD Fetal Growth Studies-Singleton Cohort. Blood samples were collected at gestational weeks 10-14, 15-26, 23-31, and 33-39. The odds ratios (OR) of GDM were estimated using conditional logistic regression. The longitudinal changes in prolactin and progesterone were estimated using linear mixed-effects models. Results: Compared to controls, cases have significantly higher prolactin levels at weeks 10-14 (median: 50.4 vs. 42.1 ng/mL), and significantly lower progesterone levels at weeks 10-14 (median: 109.4 vs. 126.5 nmol/L). Prolactin levels at weeks 10-14 were significantly and positively associated with GDM risk; the adjusted ORs across increasing quartiles were 1.00, 1.13, 1.80, 2.33 (p-trend = 0.02). A similar but slightly attenuated association was observed at weeks 15-26 (p-trend = 0.05). Progesterone was not associated with GDM risk at either time points. Longitudinal changes in prolactin and progesterone between the first two visits were not associated with GDM risk. In addition, prolactin was significantly and positively associated with insulin and C-peptide levels at weeks 10-14, and significantly and inversely associated with C-peptide levels at weeks 15-26; progesterone was significantly and inversely associated with glucose and insulin levels. Conclusions: This study provided the first prospective evidence of a positive association between prolactin levels in early pregnancy and GDM risk.

Progestogens for the prevention of preterm birth and risk of developing gestational diabetes mellitus: a meta-analysis

BACKGROUND

Several articles have implied that progestogen supplementation during pregnancy to reduce the risk of preterm birth may increase the risk for developing gestational diabetes mellitus.

OBJECTIVE

The purpose of the present meta-analysis was to accumulate existing evidence concerning this correlation.

DATA SOURCES

We searched Medline (1966-2019), Scopus (2004-2019), Clinicaltrials.gov (2008-2019), EMBASE (1980-2019), Cochrane Central Register of Controlled Trials CENTRAL (1999-2019), and Google Scholar (2004-2019) databases.

STUDY ELIGIBILITY CRITERIA

Randomized trials and observational studies were considered eligible for inclusion in the present meta-analysis. To minimize the possibility of article losses, we avoided language, country, and date restrictions.

STUDY APPRAISAL AND SYNTHESIS METHODS

The methodological quality of included studies was evaluated with the Cochrane risk of bias and the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I) tool. Meta-analysis was performed with the RevMan 5.3 and secondary analysis with the Open Meta-Analyst software. Trial sequential analysis was conducted with the trial sequential analysis program.

RESULTS

Overall, 11 studies were included in the present meta-analysis that recruited 8085 women. The meta-analysis revealed that women who received 17-alpha hydroxyprogesterone caproate had increased the risk of developing gestational diabetes mellitus (risk ratio, 1.73, 95% confidence interval, 1.32-2.28), whereas women who received vaginal progesterone had a decreased risk, although the effect did not reach statistical significance because of the unstable estimate of confidence intervals (risk ratio, 0.82, 95% confidence interval, 0.50-1.12). Meta-regression analysis indicated that neither the methodological rationale for investigating the prevalence of gestational diabetes mellitus (incidence investigated as primary or secondary outcome) (coefficient of covariance, -0.36, 95% confidence interval, -0.85 to 0.13, P = .154) nor the type of investigated study (randomized controlled trial/observational) (coefficient of covariance -0.361, 95% confidence interval, -1.049 to 0.327, P = .304) significantly altered the results of the primary analysis. Trial sequential analysis suggested that the meta-analysis concerning the correlation of 17-alpha hydroxyprogesterone caproate was of adequate power to reach firm conclusions, whereas this was not confirmed in the case of vaginal progesterone.

CONCLUSION

The results of the present meta-analysis clearly indicate that women who receive supplemental 17-alpha hydroxyprogesterone caproate for the prevention of preterm birth have an increased risk of developing gestational diabetes mellitus. On the other hand, evidence concerning women treated with vaginal progesterone remains inconclusive.

Assisted conception as a potential prognostic factor predicting insulin therapy in pregnancies complicated by gestational diabetes mellitus

BACKGROUND

Advanced maternal age, family history of diabetes, pre-gestational obesity, increased level of HbA1c, history of gestational diabetes mellitus (GDM), and poor pregnancy consequences are considered risk factors for antenatal insulin requirement in women with GDM. However, the role of assisted reproductive technology (ART) in increasing the risk of insulin therapy in pregnancies complicated with GDM remained elusive. The current study aimed to determine the role of ART in predicting insulin therapy in GDM women and investigate the clinical and biochemical factors predicting the need for insulin therapy in pregnancies complicated with GDM.

METHODS

In this prospective cohort study, 236 Iranian women with GDM were diagnosed by one-step oral glucose tolerance test (OGTT) between October 2014 and June 2017. They were mainly assigned to two groups; the first group (n = 100) was designated as ART which was further subdivided into two subgroups as follows: 60 participants who received medical nutrition therapy (MNT) and 40 participants who received MNT plus insulin therapy (MNT-IT). The second group (n = 136) was labeled as the spontaneous conception (SC), consisting of 102 participants receiving MNT and 34 participants receiving MNT in combination with IT (MNT-IT). The demographic, clinical, and biochemical data were compared between groups. Multivariate logistic regression was performed to estimate prognostic factors for insulin therapy.

RESULTS

A higher rate of insulin therapy was observed in the ART group as compared with the SC group (40% vs. 25%; P < 0.001). Multivariate logistic regression demonstrated that maternal age ≥ 35 years [OR: 2.91, 95% CI: (1.28-6.62)], high serum FBS [1.10: (1.04-1.16)], HbA1c [1.91 (1.09-3.34)], and ART treatment [2.94: (1.24-6.96)] were independent risk factors for insulin therapy in GDM women.

CONCLUSIONS

Apart from risk factors mentioned earlier, ART may be a possible prognostic factor for insulin therapy in pregnancies complicated with GDM.

Sex hormones, aging and cardiometabolic syndrome

It is well documented that the metabolic syndrome predisposes patients to increased cardiovascular risk. Emerging data indicates that cardiovascular risk conferred by metabolic syndrome is highly dependent on sex and sex hormone status throughout the lifetime. Both male and female sex hormones, as well as sex chromosomes themselves, contribute to the development of obesity and intervene in the control of insulin homeostasis and blood pressure. Furthermore, men and women develop age-associated cardiometabolic risk in a sex-specific fashion in association with changes in these sex hormonal levels. Therefore, the current notion of the metabolic syndrome as a sex-independent diagnosis is antiquated, and novel studies and clinical trials utilizing these known sex differences in the development of metabolic dysregulation and cardiometabolic risk are warranted.

[Correlation analysis of serum progesterone with clinical indicators and common traditional Chinese medicine syndrome types in male type 2 diabetic patients]

OBJECTIVE

To analyze the correlation of serum progesterone (PROG) level with blood biochemical parameters and common traditional Chinese medicine (TCM) syndromes in male patients with type 2 diabetes mellitus (T2DM).

METHODS

We collected the clinical data of 192 male patients with T2DM, who were admitted in the Department of Endocrinology, Nanjing Hospital of Chinese Medical Affiliated to Nanjing University of Chinese Medicine between January, 2018 and March, 2019. The general clinical data, C-peptide level, blood glucose level, glycated hemoglobin (HbA1c), HOMA, blood lipid level, and sex hormones were compared between the patients with normal PROG and elevated PROG levels and also between the patients with two common TCM syndromes, namely qi and Yin deficiency syndrome and damp- heat accumulation in the spleen syndrome. We further compared the sex hormones, C-peptide level, HOMA, HbA1c, and blood glucose level among the patients with the two TCM syndromes having normal or elevated PROG levels.

RESULTS

Compared with those in patients with normal PROG level, BMI, C-peptide, HOMA-β, and HOMA2-IR were significantly lowered and HOMA-IS, E2, and T were significantly increased in patients with elevated PROG level; no statistical differences were found in age, disease duration, waist-to-hip ratio (WHR), smoking history, blood pressure, blood glucose, blood lipids, HbA1c, LH, FSH or PRL between the two groups. Compared with the patients with damp-heat accumulation syndrome group, the patients with qi and Yin deficiency syndrome were older and had a longer disease duration, a greater BMI, and higher levels of PROG, C-Peptide, HOMA-β, HOMA2-IR and HOMA-IS, but the smoking history, WHR, HbA1c, blood glucose, and sex hormone levels were comparable between the two groups. Among the 4 groups of patients with different PROG levels and TCM syndromes, significant differences were found in the levels of C-peptide, HOMA-β, HOMA-IS, HOMA2-IR, PROG, E2, T, LH and FSH, and the patients with qi and Yin deficiency syndrome as well as an elevated PROG level had the lowest C-peptide level, HOMA-β and HOMA2-IR and the highest HOMA-IS, PROG, E2, T, LH and FSH.

CONCLUSIONS

An elevated PROG level is closely related to islet cell dysfunction and TCM syndrome types in male patients with T2DM.

High progesterone levels are associated with family history of premature coronary artery disease in young healthy adult men

BACKGROUND & AIMS

The offspring of patients with premature coronary artery disease (P-CAD) are at higher risk for cardiovascular disease, compared with subjects without a family history (FH) of P-CAD. The increased risk for cardiovascular disease in subjects with FH of early-onset CAD results from unfavorable genetic variants as well as social, behavioral and environmental factors, which are more prevalent in this group. Previous studies have shown that specific sex hormone levels may be associated with the risk of cardiovascular disease. The aim of this study was to compare wide range of biochemical marker levels including i.e. the levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone, estradiol, testosterone and sex-hormone binding globulin (SHBG) between young healthy male adults with and without FH of P-CAD.

METHODS

The study group consisted of young healthy Polish male adults enrolled in a MAGNETIC case-control study, who were recruited between July 2015 and October 2017. The inclusion criteria were as follows: male sex, age ≥18 and ≤35 years old, FH of P-CAD (cases) or no P-CAD in first-degree relatives (controls). The comparison of continuous and categorical variables was performed using the Student's t-test or the U-Mann-Whitney test, and Fisher's exact test, respectively. The correlations between FSH, LH, testosterone, progesterone, SHBG and other laboratory parameters were assessed using the Spearman rank correlation test. Both univariable and multivariable logistic regression analyses were performed to assess the association between analyzed variables and FH of P-CAD.

RESULTS

A total of 411 subjects (223 cases and 188 controls) were included in the study. There was a higher prevalence of major cardiovascular risk factors in subjects with FH of P-CAD (smoking, higher total and LDL cholesterol levels, higher body mass index and lower HDL cholesterol level). Moreover, the offspring of patients with P-CAD had lower SHBG level, and higher LH and progesterone levels in the crude comparison, compared with individuals without FH of P-CAD. After adjustment for confounding variables, progesterone and LH were determined to be independently associated with FH of P-CAD.

CONCLUSION

Progesterone and LH levels are significantly associated with FH of P-CAD, independent of traditional risk factors for CAD.

Skeletal muscle as a protagonist in the pregnancy metabolic syndrome

The pregnant woman normally shows clinical manifestations similar to a metabolic syndrome (MS), due to her metabolic and hemodynamic adaptations in order to share nutrients with the child. If those adjustments are surpassed, a kind of pregnancy MS (PregMS) could appear, characterized by excessive insulin resistance and vascular maladaptation. Skeletal muscle (SKM) must be a protagonist in the PregMS: SKM strength and mass have been associated inversely with MS incidence in non-pregnant patients, and in pregnant women muscular activity modulates metabolic and vascular adaptations that favor better outcomes. Of note, a sedentary lifestyle affects exactly in the other way. Those effects may be explained not only by the old paradigm of SKM being a great energy consumer and store, but because it is an endocrine organ whose chronic activity or deconditioning correspondingly releases myokines modulating insulin sensitivity and cardiovascular adaptation, by direct or indirect mechanisms not well understood. In this document, we present evidence to support the concept of a PregMS and hypothesize on the role of the SKM mass, fiber types composition and myokines in its pathophysiology. Also, we discuss some exercise interventions in pregnancy as a way to test our hypotheses.

Impact of central and peripheral estrogen treatment on anxiety and depression phenotypes in a mouse model of postmenopausal obesity

Obesity and diabetes increase the risk of depression, and the incidence of these conditions increases rapidly after menopause, but few animal models of postmenopausal obesity have been available. We developed a mouse model of postmenopausal obesity that exhibited anxiety and depressive phenotypes in behavioral tests. To examine the effect of estradiol (E2) in the model, we prepared 4 experimental groups: 1) control, sham-operated female C57BL/6 mice fed a regular diet; 2) OVX-HF, ovariectomized (OVX) mice fed a high-fat diet (HF); 3) E2-SC, OVX-HF mice administered subcutaneous (SC) E2 (50 μg/kg/day); and 4) E2-ICV, OVX-HF mice administered intracerebroventricular (ICV) E2 (1 μg/kg/day). OVX-HF mice exhibited anxiety phenotypes in the open field test, but not in the light-dark box test, and E2 treatment via both routes effectively ameliorated it. OVX-HF mice demonstrated depressive phenotypes in the tail suspension test and forced swim test. Both E2 treatments achieved significant improvement in the tail suspension test, but not in the forced swim test. Serum corticosterone levels did not differ among the groups. Hippocampal expression of glucocorticoid receptor mRNA and serotonin 1A receptor mRNA was significantly increased in OVX-HF mice and was decreased in E2-treated mice. The hypothalamic level of pro-brain-derived neurotrophic factor (proBDNF) protein was tended to decrease in OVX-HF mice, but neither E2 treatment increased it. Since this mouse model exhibited anxiety and depressive phenotypes in relatively short experimental periods without genetic manipulations, it would be useful for further exploring psychiatric phenotypes or screening of therapeutic candidates in postmenopausal obesity.

Relationship between threatened miscarriage and gestational diabetes mellitus

Background

Both threatened miscarriage and gestational diabetes mellitus (GDM) are common complications of pregnancy. However, only one pilot study has reported that these complications are not related. We aimed to investigate whether threatened miscarriage is one of the risk factors of GDM.

Methods

An unmatched case-control study of 1567 pregnant Korean women who underwent a two-step approach to diagnose GDM was retrospectively conducted. The eligible women were classified into normal (n = 840), borderline GDM (n = 480), and GDM (n = 247) groups. We analyzed the associations with threatened miscarriage in all groups with adjustment for confounding factors.

Results

The proportion of women who experienced threatened miscarriage was significantly lower in the GDM group than in the normal group (adjusted odds ratio (OR), 0.38; 95% confidence interval (CI), 0.18–0.78). It was significantly lower in the maternal hyperglycemia group (borderline GDM and GDM groups) than in the normal group (adjusted OR, 0.66; 95% CI, 0.47–0.91). The proportion of women who experienced threatened miscarriage was also significantly lower in the GDM group than in the normal (adjusted OR, 0.35; 95% CI, 0.17–0.70) and borderline GDM groups (adjusted OR, 0.46; 95% CI, 0.22–0.94). Moreover, the proportion of women who experienced threatened miscarriage significantly decreased according to the severity of glucose intolerance (adjusted OR, 0.94; 95% CI, 0.76–1.16).

Conclusion

This study demonstrates that threatened miscarriage is associated with decreased risk of GDM and the severity of glucose intolerance in Korean women. Additional studies are warranted to understand the pathophysiologic mechanisms that might exist between these frequent complications of pregnancy.

Effect of maternal metabolism on fetal supply: Glucose, non-esterified fatty acids and beta-hydroxybutyrate concentrations in canine maternal serum and fetal fluids at term pregnancy

The progressive adaptations in carbohydrate and lipid metabolism during canine pregnancy are reflected in the concentrations of glucose, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB). The levels of these metabolites in the bitch likely affect fetal concentrations and the composition of amniotic and allantoic fluids (AMF and ALF, respectively). We studied 31 canine parturitions (Cesarean sections) and found that glucose, NEFA and BHB concentrations were significantly higher in maternal serum than in AMF or ALF. Glucose levels in maternal serum, AMF and ALF were closely related (R² ≥ 0.821, P < 0.0001) as well as serum and AMF BHB levels (R² = 0.661, P < 0.0001). In maternal serum, increases in NEFA were associated with increased BHB, and both were negatively related to glucose (P ≤ 0.010). To estimate the effect of the metabolic burden of pregnancy, we evaluated these variables in relation to the dam's body weight and to the ratio of litter weight to the dam's body weight (LW/BW). Maternal serum glucose was not influenced by LW/BW, but it was lower in small than in large/giant bitches. Small breed dogs and those with >10% LW/BW had significantly higher serum NEFA and BHB concentrations. Glucose in AMF and ALF was independent of LW/BW (P ≥ 0.399). AMF NEFA was lower and BHB higher, if LW/BW was >10% (P ≤ 0.048). In conclusion, the extent of the metabolic load of pregnancy in bitches depends on breed size and on the ratio of litter weight to dam's body weight. Maternal concentrations of glucose, BHB and NEFA determine the concentrations of these metabolites in fetal fluids.

Low glucose availability stimulates progesterone production by mouse ovaries in vitro

Steroid production by the ovary is primarily stimulated by gonadotropins but can also be affected by biological cues that provide information about energy status and environmental stress. To further understand which metabolic cues the ovary can respond to, we exposed gonadotropin-stimulated mouse ovaries in vitro to glucose metabolism inhibitors and measured steroid accumulation in media. Gonadotropin-stimulated ovaries exposed to 2-deoxy-d-glucose increased progesterone production and steroidogenic acute regulatory protein mRNA levels. However, oocytes and granulosa cells in antral follicles do not independently mediate this response because targeted treatment of these cell types with a different inhibitor of glucose metabolism (bromopyruvic acid) did not affect progesterone production. Elevated progesterone production is consistent with the homeostatic role of progesterone in glucose regulation in mammals. It also may regulate follicle growth and/or atresia within the ovary. These results suggest that ovaries can regulate glucose homeostasis in addition to their primary role in reproductive activity.

Lack of cyclical fluctuations of endometrial GLUT4 expression in women with polycystic ovary syndrome: Evidence for direct regulation of GLUT4 by steroid hormones

Background Determination of the role of steroid hormones in expression and regulation of endometrial glucose transport 4 (GLUT4) in humans is important for understanding endometrial disorders such as polycystic ovary syndrome (PCOS), a common hormone-imbalance disease. Methods Endometrial biopsy samples were collected from non-PCOS patients with regular menstrual cycles or with hyperplasia and from PCOS patients with or without hyperplasia. In addition, endometrial tissues from postmenopausal women were incubated with human chorionic gonadotropin (hCG, 10 IU/ml), 17β-estradiol (E2, 10 nM), progesterone (P4, 100 nM), or a combination of E2 and P4 for 24 h. The expression of GLUT4 was measured at the mRNA level using quantitative real-time polymerase chain reaction (qRT-PCR) and at the protein level using Western blot analysis and immunohistochemistry. Results A cyclical change in GLUT4 expression pattern was observed in non-PCOS patients, and a high level of GLUT4 expression was seen in the proliferative phase compared to the secretory phase. Low levels of GLUT4 expression were found in PCOS patients compared to menstrual cycle phase-matched non-PCOS patients, and there was no significant change in GLUT4 expression in PCOS patients during the menstrual cycle. GLUT4 was localized in both epithelial and stromal cells, with notable changes in epithelial cells. We postulate that decreased GLUT4 expression might be regulated by steroid hormones. In support of this, we showed that in cultured endometrial tissues hCG and E2 alone had no effect on GLUT4 expression. However, P4 alone and P4 in combination with E2 decreased GLUT4 expression. Compared with non-PCOS controls, PCOS patients with endometrial hyperplasia exhibited decreased GLUT4 expression in particular in the epithelial cells. Conclusion We conclude that P4 can induce changes in endometrial GLUT4 expression during the menstrual cycle and that abnormal hormonal conditions such as PCOS disrupt normal patterns of GLUT4 expression in endometrial cells.

Indicators of glycemic control in patients with gestational diabetes mellitus and pregnant women with diabetes mellitus

Recently, it has become clear that mild abnormal glucose tolerance increases the incidence of perinatal maternal-infant complications, and so the definition and diagnostic criteria of gestational diabetes mellitus (GDM) have been changed. Therefore, in patients with GDM and pregnant women with diabetes mellitus, even stricter glycemic control than before is required to reduce the incidence of perinatal maternal-infant complications. Strict glycemic control cannot be attained without an indicator of glycemic control; this review proposes a reliable indicator. The gold standard indicator of glycemic control in patients with diabetes mellitus is hemoglobin A1c (HbA1c); however, we have demonstrated that HbA1c does not reflect glycemic control accurately during pregnancy because of iron deficiency. It has also become clear that glycated albumin, another indicator of glycemic control, is not influenced by iron deficiency and therefore might be a better indicator of glycemic control in patients with GDM and pregnant women with diabetes mellitus. However, large-population epidemiological studies are necessary in order to confirm our proposal. Here, we outline the most recent findings about the indicators of glycemic control during pregnancy including fructosamine and 1,5-anhydroglucitol.

Relationship among insulin resistance, growth hormone, and insulin-like growth factor I concentrations in diestrous Swedish Elkhounds

Background

In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates local canine mammary growth hormone (GH) production, which may act systemically and contribute to insulin resistance. Swedish Elkhounds are predisposed to progesterone‐related diabetes mellitus, and the relationship among insulin resistance, GH, and insulin‐like growth factor I (IGF‐I) is of particular interest.

Objective

To study insulin resistance in relation to GH and IGF‐I in nondiabetic Swedish Elkhounds during diestrus. We also assessed whether alterations in these hormones could predict diestrus‐linked diseases and all‐cause mortality.

Animals

Eighty‐four privately owned female intact Swedish Elkhounds >4 years of age.

Methods

Blood sampling and clinical examination during luteal phase, with a follow‐up questionnaire after 20 months. Insulin resistance was calculated by homeostasis model assessment (HOMA‐IR).

Results

In multivariable regression analysis, GH was positively associated with HOMA‐IR (P = .009). An increase in GH of 1 ng/mL was associated with a 12.7% increase in HOMA‐IR. Moreover, C‐peptide was positively associated with IGF‐I (P = .04), and an increase in C‐peptide of 0.1 ng/mL was associated with a 6.9% increase in IGF‐I. Structural equation modeling supported these results. Twenty‐three animals were found to have previously unrecognized mammary masses and had higher GH (P < .0001) and IGF‐I (P = .007) than dogs without mammary masses (n = 61). There was no association between high GH and IGF‐I concentrations at sampling and future mammary masses.

Conclusion

We showed that GH was strongly associated with insulin resistance in older Swedish Elkhounds during diestrus.

Normal pregnancy- a state of insulin resistance

BACKGROUND

Purpose of insulin resistance (IR) adapted by mother is to deliver enough quantity of nutrients to the growing fetus. Many maternal hormones and factors play role in causation of IR during pregnancy.

AIM

The study aims at evaluating IR at different trimesters of pregnancy.

MATERIALS AND METHODS

Pregnant women at 1(st), 2(nd) and 3(rd) trimester were grouped into groups I, II and III respectively (n=20 in each group). Healthy non-pregnant women were taken as controls (n=30). Fasting plasma glucose (FPG) and fasting serum insulin (FSI) were measured and IR indices such as fasting glucose to insulin ratio (FGIR), quantitative insulin sensitivity check index (QUICKI), log FSI and log HOMA1-IR were calculated. The student's t-test and one way Analysis of variance (ANOVA) were used for data analysis.

RESULTS

The mean FSI, log FSI and log HOMA 1-IR were significantly higher in 2(nd) and 3(rd) trimesters while QUICKI was significantly lower in 2(nd) and 3(rd) trimesters of pregnancy when compared with controls. Also, mean FGIR was found to be significantly lower in 3rd trimester when compared with controls.

CONCLUSION

As pregnancy advances, IR increases. Increased IR is associated with poor maternal and fetal outcome. Screening of all pregnancy for IR and early intervention may help to reduce the associated complications.

Normal pregnancy- a state of insulin resistance

BACKGROUND

Purpose of insulin resistance (IR) adapted by mother is to deliver enough quantity of nutrients to the growing fetus. Many maternal hormones and factors play role in causation of IR during pregnancy.

AIM

The study aims at evaluating IR at different trimesters of pregnancy.

MATERIALS AND METHODS

Pregnant women at 1(st), 2(nd) and 3(rd) trimester were grouped into groups I, II and III respectively (n=20 in each group). Healthy non-pregnant women were taken as controls (n=30). Fasting plasma glucose (FPG) and fasting serum insulin (FSI) were measured and IR indices such as fasting glucose to insulin ratio (FGIR), quantitative insulin sensitivity check index (QUICKI), log FSI and log HOMA1-IR were calculated. The student's t-test and one way Analysis of variance (ANOVA) were used for data analysis.

RESULTS

The mean FSI, log FSI and log HOMA 1-IR were significantly higher in 2(nd) and 3(rd) trimesters while QUICKI was significantly lower in 2(nd) and 3(rd) trimesters of pregnancy when compared with controls. Also, mean FGIR was found to be significantly lower in 3rd trimester when compared with controls.

CONCLUSION

As pregnancy advances, IR increases. Increased IR is associated with poor maternal and fetal outcome. Screening of all pregnancy for IR and early intervention may help to reduce the associated complications.

Short-term effect of ovariectomy on measures of insulin sensitivity and response to dexamethasone administration in horses

OBJECTIVE

To evaluate the effect of ovariectomy on insulin sensitivity in horses and determine whether the effects of suppression of the hypothalamo-pituitary-adrenal axis differ before and after ovariectomy.

ANIMALS

6 healthy mares.

PROCEDURES

The horses underwent an IV glucose tolerance test (IVGTT), an insulin sensitivity test, and a dexamethasone suppression test before and 5 weeks after ovariectomy. Body weight, serum cortisol and plasma ACTH concentrations, serum insulin-to-blood glucose concentration ratios, and changes in blood glucose concentration with time after injection of glucose or insulin were compared before and after ovariectomy.

RESULTS

The dexamethasone injection resulted in a decrease in serum cortisol concentration before and after ovariectomy. In all horses, baseline plasma ACTH concentrations were within the reference range before and after ovariectomy. For each mare, results of an IVGTT before and after ovariectomy were considered normal. No significant differences in basal blood glucose concentration or time to reach baseline glucose concentration after an IVGTT were observed. Basal serum insulin concentration and serum insulin-to-blood glucose concentration ratios were not significantly different before or after ovariectomy, nor was the mean time to attain a 50% decrease in blood glucose concentration after insulin injection.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that ovariectomy does not appear to modify dexamethasone response in horses and that it does not modify short-term measures of insulin sensitivity. Findings suggested that horses undergoing ovariectomy are not at higher risk of developing equine metabolic syndrome or hypothalamo-pituitary-adrenal axis dysfunction and associated morbidity.

Risks for gestational diabetes mellitus and pregnancy-induced hypertension are increased in polycystic ovary syndrome

Objectives. To evaluate pregnancy outcomes and its determinants in women with polycystic ovary syndrome (PCOS). Methods. Two-hundred and twenty pregnant PCOS and 594 healthy women were followed from early pregnancy. Incidences of gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH), preterm birth, twinning, and fetal growth restriction (FGR) were determined. Results. The incidence of GDM was notably higher among all PCOS combined (54.9%; OR: 2.9, 95% CI: 2.0–4.1) and PCOS subgroups, whether they conceived spontaneously (51.5%; OR: 3.3, 95% CI: 2.0–5.4), or via IVF-ET or ovarian stimulation, compared with controls (14.3%; P < 0.001). The incidence of PIH was also higher among all PCOS (10.4%; OR: 2.2, 95% CI: 1.1–4.4) and the subgroup conceiving spontaneously (11.8%; OR: 2.6, 95% CI: 1.1–6.2; P < 0.001) but not for those conceiving with IVF-ET (9.1%) or ovarian stimulation (9.4%). Lean women with PCOS (BMI <24 kg/m²) had higher incidences of GDM (51.1% versus 14.5%; OR: 5.6, 95% CI: 3.4–9.0) and PIH (8.9% versus 3.2%; OR: 3.0, 95% CI: 1.3–7.1) than lean controls. PCOS woemn with normal glucose tolerance had higher risk for PIH than their comparable control group (OR: 4.0, 95% CI: 1.3–11.7). Conclusion. This study suggested that PCOS is an independent risk factor for the development of GDM and PIH. This trial is registered with ChiCTR-RCC-11001824.

Different roles for contracture and calpain in calcium paradox-induced heart injury

The Ca(2+) paradox represents a good model to study Ca(2+) overload injury in ischemic heart diseases. We and others have demonstrated that contracture and calpain are involved in the Ca(2+) paradox-induced injury. This study aimed to elucidate their roles in this model. The Ca(2+) paradox was elicited by perfusing isolated rat hearts with Ca(2+)-free KH media for 3 min or 5 min followed by 30 min of Ca(2+) repletion. The LVDP was measured to reflect contractile function, and the LVEDP was measured to indicate contracture. TTC staining and the quantification of LDH release were used to define cell death. Calpain activity and troponin I release were measured after Ca(2+) repletion. Ca(2+) repletion of the once 3-min Ca(2+) depleted hearts resulted in almost no viable tissues and the disappearance of contractile function. Compared to the effects of the calpain inhibitor MDL28170, KB-R7943, an inhibitor of the Na(+)/Ca(2+) exchanger, reduced the LVEDP level to a greater extent, which was well correlated with improved contractile function recovery and tissue survival. The depletion of Ca(2+) for 5 min had the same effects on injury as the 3-min Ca(2+) depletion, except that the LVEDP in the 5-min Ca(2+) depletion group was lower than the level in the 3-min Ca(2+) depletion group. KB-R7943 failed to reduce the level of LVEDP, with no improvement in the LVDP recovery in the hearts subjected to the 5-min Ca(2+) depletion treatment; however, KB-R7943 preserved its protective effects in surviving tissue. Both KB-R7943 and MDL28170 attenuated the Ca(2+) repletion-induced increase in calpain activity in 3 min or 5 min Ca(2+) depleted hearts. However, only KB-R7943 reduced the release of troponin I from the Ca(2+) paradoxic heart. These results provide evidence suggesting that contracture is the main cause for contractile dysfunction, while activation of calpain mediates cell death in the Ca(2+) paradox.

A new recombinant pituitary adenylate cyclase-activating peptide-derived peptide efficiently promotes glucose uptake and glucose-dependent insulin secretion

The recombinant peptide, DBAYL, a promising therapeutic peptide for type 2 diabetes, is a new, potent, and highly selective agonist for VPAC2 generated through site-directed mutagenesis based on sequence alignments of pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal peptide (VIP), and related analogs. The recombinant DBAYL was used to evaluate its effect and mechanism in blood glucose metabolism and utilization. As much as 28.9 mg recombinant DBAYL peptide with purity over 98% can be obtained from 1 l of Luria-Bertani medium culture by the method established in this study and the prepared DBAYL with four mutations (N10Q, V18L, N29Q, and M added to the N-terminal) were much more stable than BAY55-9837. The half-life of recombinant DBAYL was about 25 folds compared with that of BAY55-9837 in vitro. The bioactivity assay of DBAYL showed that it displaced [(125)I]PACAP38 and [(125)I]VIP from VPAC2 with a half-maximal inhibitory concentration of 48.4 ± 6.9 and 47.1 ± 4.9 nM, respectively, which were significantly lower than that of BAY55-9837, one established VPAC2 agonists. DBAYL enhances the cAMP accumulation in CHO cells expressing human VPAC2 with a half-maximal stimulatory concentration (EC(50)) of 0.68 nM, whereas the receptor potency of DBAYL at human VPAC1 (EC(50) of 737 nM) was only 1/1083 of that at human VPAC2, and DBAYL had no activity toward human PAC1 receptor. Western blot analysis of the key proteins of insulin receptor signaling pathway: insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT4) indicated that the DBAYL could significantly induce the insulin-stimulated IRS-1 and GLUT4 expression more efficiently than BAY55-9837 and VIP in adipocytes. Compared with BAY55-9837 and PACAP38, the recombinant peptide DBAYL can more efficiently promote insulin release and decrease plasma glucose level in Institute of Cancer Research (ICR) mice. These results suggested that DBAYL could efficiently improve glucose uptake and glucose-dependent insulin secretion by VPAC2-mediated effect.

NOD1 activation induces proinflammatory gene expression and insulin resistance in 3T3-L1 adipocytes

Chronic inflammation is associated with obesity and insulin resistance; however, the underlying mechanisms are not fully understood. Pattern recognition receptors Toll-like receptors and nucleotide-oligomerization domain-containing proteins play critical roles in innate immune response. Here, we report that activation of nucleotide binding oligomerization domain-containing protein-1 (NOD1) in adipocytes induces proinflammatory response and impairs insulin signaling and insulin-induced glucose uptake. NOD1 and NOD2 mRNA are markedly increased in differentiated murine 3T3-L1 adipocytes and human primary adipocyte culture upon adipocyte conversion. Moreover, NOD1 mRNA is markedly increased only in the fat tissues in diet-induced obese mice, but not in genetically obese ob/ob mice. Stimulation of NOD1 with a synthetic ligand Tri-DAP induces proinflammatory chemokine MCP-1, RANTES, and cytokine TNF-α and MIP-2 (human IL-8 homolog) and IL-6 mRNA expression in 3T3-L1 adipocytes in a time- and dose-dependent manner. Similar proinflammatory profiles are observed in human primary adipocyte culture stimulated with Tri-DAP. Furthermore, NOD1 activation suppresses insulin signaling, as revealed by attenuated tyrosine phosphorylation and increased inhibitory serine phosphorylation, of IRS-1 and attenuated phosphorylation of Akt and downstream target GSK3α/3β, resulting in decreased insulin-induced glucose uptake in 3T3-L1 adipocytes. Together, our results suggest that NOD1 may play an important role in adipose inflammation and insulin resistance in diet-induced obesity.

Longitudinal study of insulin resistance and sex hormones over the menstrual cycle: the BioCycle Study

CONTEXT

Conflicting findings have been reported regarding the effect of menstrual cycle phase and sex hormones on insulin sensitivity.

OBJECTIVE

The aim was to determine the pattern of insulin resistance over the menstrual cycle and whether variations in sex hormones explain these patterns.

DESIGN

The BioCycle study is a longitudinal study that measured hormones at different phases of the menstrual cycle. Participants had up to eight visits per cycle; each visit was timed using fertility monitors to capture sensitive windows of hormonal changes.

SETTING

The study was conducted in the general community of the University at Buffalo (Buffalo, NY).

PARTICIPANTS

A total of 257 healthy, premenopausal women (age, 27±8 yr; body mass index, 24±4 kg/m2) participated in the study.

MAIN OUTCOME MEASURES

We measured fasting insulin, glucose, and insulin resistance by the homeostasis model of insulin resistance (HOMA-IR).

RESULTS

Significant changes in HOMA-IR were observed over the menstrual cycle; from a midfollicular phase level of 1.35, levels rose to 1.59 during the early luteal phase and decreased to 1.55 in the late-luteal phase. HOMA-IR levels primarily reflected changes in insulin and not glucose. After adjustment for age, race, cycle, and other sex hormones, HOMA-IR was positively associated with estradiol (β=0.082; P<0.001) and progesterone (β=0.025; P<0.001), and inversely associated with FSH (adjusted β=-0.040; P<0.001) and SHBG (β=-0.085; P<0.001). LH was not associated with HOMA-IR. Further adjustment for BMI weakened the association with SHBG (β=-0.057; P=0.06) but did not affect other associations.

CONCLUSION

Insulin exhibited minor menstrual cycle variability. Estradiol and progesterone were positively associated with insulin resistance and should be considered in studies of insulin resistance among premenopausal women.

Conventional progesterone receptors (PR) B and PRA are expressed in human spermatozoa and may be involved in the pathophysiology of varicocoele: a role for progesterone in metabolism

The physiological roles of intracellular progesterone (PRG) receptors (PRs) have been studied intensively in female mammals, while their functions in male are scarce. Conventional PRs were evidenced in our study by Western blotting, concomitantly in healthy spermatozoa and in oligoasthenoteratozoospermic samples without and with varicocoele. Transmission electron microscopy revealed the presence of the PRs on the membrane as well as in the nucleus, mitochondria and flagellum. A reduced expression of the PRs was observed only in varicocoele spermatozoa. Responses to PRG treatment on cholesterol efflux, tyrosine phosphorylation, src and Akt activities, acrosin activity and acrosome reaction in varicocoele spermatozoa were reduced or absent. To further investigate PRG significance in human male gamete, we focused its action on lipid and glucose metabolism. The evaluation of the triglycerides content, lipase and acyl-CoA dehydrogenase activities suggests that PRG through the PRs exerts a lipolytic effect on human spermatozoa. An increase in glucose-6-phosphate dehydrogenase activity was also obtained, evidencing a role for PRG on glucose metabolism. In 'varicocoele' spermatozoa, the PRG did not induce energy consumption. The action of PRs on sperm metabolism is a novel finding that renews the importance of PRG in male fertility. Our results showed that varicocoele may lead to male factor infertility by a mechanism involving a decreased PR expression in human spermatozoa that evidences a detrimental effect on spermatozoa at the molecular level, going beyond the abnormal sperm morphology described to date.