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Polycystic ovarian syndrome: signs and feedback effects of hyperandrogenism and insulin resistance.
Hernández-Jiménez, JL, Barrera, D, Espinoza-Simón, E, González, J, Ortíz-Hernández, R, Escobar, L, Echeverría, O, Torres-Ramírez, N
Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology. 2022;(1):2-9
Abstract
Polycystic ovary syndrome (PCOS) is a disease whose diagnosis is based on the detection of hyperandrogenism (HA) and ovulatory dysfunction. Women with PCOS frequently develop insulin resistance (IR), which generates a metabolic condition that involves a decrease in the action of insulin at the cellular level and is linked to compensatory hyperinsulinemia (HI). In PCOS, the ovary remains sensitive to the action of insulin. Additionally, it has been observed that the main effect of insulin in the ovary is the stimulation of androgen synthesis, resulting in HA, one of the fundamental characteristics of the PCOS. In this sense, the excess of androgens favors the development of IR, thus perpetuating the cycle of IR-HI-HA, and therefore PCOS. Moreover, mitochondrial dysfunction is present in PCOS patients and is a common feature in both IR and HA. This review places electron transfer as a key element in HA and IR development, with emphasis on the relationship between androgen biosynthesis and mitochondrial function. Indeed, metformin has been involved in repair mitochondrial dysfunction, decrease of oxidative stress, reduction of androgens levels and the enhancing of insulin sensitivity. Therefore, we propose that treatment with metformin could decrease HI and consequently HA, restoring, at least in part, the metabolic and hormonal disorders of PCOS.
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Mechanistic Targets and Nutritionally Relevant Intervention Strategies to Break Obesity-Breast Cancer Links.
Bustamante-Marin, XM, Merlino, JL, Devericks, E, Carson, MS, Hursting, SD, Stewart, DA
Frontiers in endocrinology. 2021;:632284
Abstract
The worldwide prevalence of overweight and obesity has tripled since 1975. In the United States, the percentage of adults who are obese exceeds 42.5%. Individuals with obesity often display multiple metabolic perturbations, such as insulin resistance and persistent inflammation, which can suppress the immune system. These alterations in homeostatic mechanisms underlie the clinical parameters of metabolic syndrome, an established risk factor for many cancers, including breast cancer. Within the growth-promoting, proinflammatory milieu of the obese state, crosstalk between adipocytes, immune cells and breast epithelial cells occurs via obesity-associated hormones, angiogenic factors, cytokines, and other mediators that can enhance breast cancer risk and/or progression. This review synthesizes evidence on the biological mechanisms underlying obesity-breast cancer links, with emphasis on emerging mechanism-based interventions in the context of nutrition, using modifiable elements of diet alone or paired with physical activity, to reduce the burden of obesity on breast cancer.
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Triglyceride/High-Density Lipoprotein Cholesterol Ratio: A Clue to Metabolic Syndrome, Insulin Resistance, and Severe Atherosclerosis.
Azarpazhooh, MR, Najafi, F, Darbandi, M, Kiarasi, S, Oduyemi, T, Spence, JD
Lipids. 2021;(4):405-412
Abstract
High serum levels of triglycerides (Tg) and low levels of high-density lipoprotein cholesterol (HDL-C) are characteristic of the Metabolic Syndrome (MetS). We assessed the ratio of Tg to HDL-C as a way to identify MetS and insulin resistance. We also evaluated its association with severity of carotid atherosclerosis. Data were analyzed from three cohorts totaling 13,908 participants. MetS was defined according to the International Diabetes Federation criteria. Optimal cut-off for Tg/HDL-C ratio was obtained using Youden's index in receiver-operating characteristic (ROC) curve analyses. The risk of MetS and IR in those with a Tg/HDL-C ratio above the optimum cutoff was evaluated by logistic regression analysis. A Tg/HDL-C ratio above the optimal cutoff level significantly increased the odds ratio for MetS in the three cohorts (OR 6.00, 4.04, and 3.50, least in the healthy population), identified insulin resistance defined by the homeostatic model of insulin resistance (HOMA-IR) (p < 0.0001), and was strongly associated with atherosclerosis severity (p = 0.0001). Tg/HDL-C ratio identifies persons with MetS, insulin resistance, and severe atherosclerosis. It should be used more widely to identify patients at high risk. This is clinically important because insulin resistance is treatable.
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4.
Effects of Tea Consumption on Anthropometric Parameters, Metabolic Indexes and Hormone Levels of Women with Polycystic Ovarian Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Shen, W, Pan, Y, Jin, B, Zhang, Z, You, T, Qu, Y, Han, M, Yuan, X, Zhang, Y
Frontiers in endocrinology. 2021;:736867
Abstract
OBJECTIVE Our aim was to conduct a systematic review and meta-analysis to assess the effectiveness and safety of tea supplements for patients with polycystic ovary syndrome (PCOS). METHODS We conducted searches of the published literature in PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure (CNKI), VIP database, and Wanfang Database in 1985 to September 2021. Data from randomized controlled trials (RCTs) were obtained to assess the effects of tea versus placebo in women with PCOS. Weighted mean differences (WMDs) were pooled using a random-effects model or risks ratios (RRs) using a random-effects model. RESULTS Six RCTs (235 participants) were included in our systematic review. Tea supplements as adjuvant therapy led to greater improvement in body weight (WMD -2.71, 95% CI -4.95 to -0.46, P = 0.02, I2 = 0%), fasting blood glucose (FBG: WMD -0.40, 95% CI -0.59 to -0.20, P < 0.0001, I2 = 0%) and fasting insulin (FINS: WMD -3.40, 95% CI -4.76 to -2.03, P < 0.00001, I2 = 0%) when compared with placebo. There were no significant differences of body mass index, waist circumference, hip circumference, waist-to-hip ratio (WHR), body fat rate, total testosterone, free testosterone (FT), dehydroepiandrosterone, luteinizing hormone or follicular-stimulating hormone (FSH) between the two groups. In addition, subgroup analysis suggested that green tea was effective on body weight, FINS, FBG, FT, and FSH, and herbal tea can also reduce FT levels, tea supplements had a significant impact on FBG and FSH in trials with intervention duration ≥ 3 months, and intervention lasting less than 3 months can improve FINS. Tea had significant effect on reducing WHR, FBG and FSH in Asian PCOS patients, but not in Caucasians. And there was no statistically significant effect of tea on weight and FINS in Asians, but it was effective for Caucasian participants. Compared with placebo, tea supplements did not cause significant adverse reactions (RR 1.45, 95% CI 0.30 to 6.90, P = 0.65, I2 = 0%). CONCLUSION This meta-analysis suggests that consumption of tea supplementation in women with PCOS could significantly decrease the levels of FBG and FINS as well as reduce body weight. Especially green tea, not only has the above effects, but also has a significant effect on improving a variety of reproductive hormone indexes. Furthermore, tea supplementation is a relatively safe therapy for PCOS patients. SYSTEMATIC REVIEW REGISTRATION PROSPERO https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=212755, identifier CRD42021249196.
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Defining the underlying defect in insulin action in type 2 diabetes.
Batista, TM, Haider, N, Kahn, CR
Diabetologia. 2021;(5):994-1006
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Abstract
Insulin resistance is one of the earliest defects in the pathogenesis of type 2 diabetes. Over the past 50 years, elucidation of the insulin signalling network has provided important mechanistic insights into the abnormalities of glucose, lipid and protein metabolism that underlie insulin resistance. In classical target tissues (liver, muscle and adipose tissue), insulin binding to its receptor initiates a broad signalling cascade mediated by changes in phosphorylation, gene expression and vesicular trafficking that result in increased nutrient utilisation and storage, and suppression of catabolic processes. Insulin receptors are also expressed in non-classical targets, such as the brain and endothelial cells, where it helps regulate appetite, energy expenditure, reproductive hormones, mood/behaviour and vascular function. Recent progress in cell biology and unbiased molecular profiling by mass spectrometry and DNA/RNA-sequencing has provided a unique opportunity to dissect the determinants of insulin resistance in type 2 diabetes and the metabolic syndrome; best studied are extrinsic factors, such as circulating lipids, amino acids and other metabolites and exosomal microRNAs. More challenging has been defining the cell-intrinsic factors programmed by genetics and epigenetics that underlie insulin resistance. In this regard, studies using human induced pluripotent stem cells and tissues point to cell-autonomous alterations in signalling super-networks, involving changes in phosphorylation and gene expression both inside and outside the canonical insulin signalling pathway. Understanding how these multi-layered molecular networks modulate insulin action and metabolism in different tissues will open new avenues for therapy and prevention of type 2 diabetes and its associated pathologies.
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The Effect of Exercise Intensity and Volume on Metabolic Phenotype in Patients with Metabolic Syndrome: A Randomized Controlled Trial.
von Korn, P, Keating, S, Mueller, S, Haller, B, Kraenkel, N, Dinges, S, Duvinage, A, Scherr, J, Wisløff, U, Tjønna, AE, et al
Metabolic syndrome and related disorders. 2021;(2):107-114
Abstract
Background: Moderate intensity continuous training (MICT) ameliorates dysmetabolism in patients with metabolic syndrome (MetS). The impact of low- (1HIIT) versus high-volume high-intensity interval training (4HIIT) versus MICT on central adiposity, insulin resistance, and atherogenic dyslipidemia in patients with MetS has not yet been reported. Methods: Twenty-nine patients with MetS according to International Diabetes Federation criteria (nine females, age 61 ± 5 years, body mass index 31.1 ± 3.7 kg/m2, waist circumference (WC) ♀ 102.2 ± 10.6 cm, ♂ 108.5 ± 8.6 cm) were randomized (1:1:1) to 16 weeks of (1) MICT (5 × 30 min/week, 35%-50% heart rate reserve (HRR), (2) 1HIIT (3 × 17 min/week incl. 4 min @80%-90% HRR), and (3) 4HIIT (3 × 38 min/week incl. 4 × 4 min @80%-90% HRR). Peak oxygen uptake (V̇O2peak), WC and anthropometric/metabolic indices indicative of MetS, fasting glucose/insulin, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), dyslipidemia, and respiratory exchange ratio (RER) at warm-up were quantified at baseline and study completion. Analysis of variance and paired t tests were used for statistical analysis. Analyses were performed after checking for parametric distribution. Results: There were no significant differences between groups in waist-to-height ratio (♀: Δ -0.10 ± -0.05, ♂: Δ -0.08 ± -0.06, P = 0.916), WC (♀: Δ -1.4 ± -0.1 cm, ♂: Δ 0.1 ± 0.9 cm, P = 0.590), fasting glucose (Δ -1.18 ± 16.7 μU/mL, P = 0.773), fasting insulin (Δ 0.76 ± 13.4 μU/mL, P = 0.509), HOMA-IR (Δ 0.55 ± 4.1, P = 0.158), atherogenic dyslipidemia [triglycerides (TAG) Δ -10.1 ± 46.9 mg/dL, P = 0.468, high-density lipoprotein cholesterol (HDL-C) Δ 1.5 ± 5.4, P = 0.665, TAG/HDL-C -0.19 ± 1.3, P = 0.502], V̇O2peak (P = 0.999), or RER (P = 0.842). In the entire group, waist-to-height-ratio and V̇O2peak significantly improved by a clinically meaningful amount (Δ 2.7 ± 0.9 mL/min/kg; P < 0.001) and RER at warm-up significantly decreased (Δ -0.03 ± 0.06, P = 0.039). Conclusion: In patients with MetS, there was no significant difference between HIIT, irrespective of volume, to MICT for improving exercise capacity or metabolic health.
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Mechanisms of Insulin Resistance at the Crossroad of Obesity with Associated Metabolic Abnormalities and Cognitive Dysfunction.
Barber, TM, Kyrou, I, Randeva, HS, Weickert, MO
International journal of molecular sciences. 2021;(2)
Abstract
Obesity mediates most of its direct medical sequelae through the development of insulin resistance (IR). The cellular effects of insulin occur through two main postreceptor pathways that are the phosphatidylinositol 3-kinase (PI3-K) and the mitogen-activated protein kinase (MAP-K) pathways. Obesity-related IR implicates the PI3-K pathway that confers the metabolic effects of insulin. Numerous and complex pathogenic pathways link obesity with the development of IR, including chronic inflammation, mitochondrial dysfunction (with the associated production of reactive oxygen species and endoplasmic reticulum stress), gut microbiota dysbiosis and adipose extracellular matrix remodelling. IR itself plays a key role in the development of metabolic dysfunction, including hypertension, dyslipidaemia and dysglycaemia. Furthermore, IR promotes weight gain related to secondary hyperinsulinaemia, with a resulting vicious cycle of worsening IR and its metabolic sequelae. Ultimately, IR underlies obesity-related conditions such as type 2 diabetes mellitus (T2D) and polycystic ovary syndrome (PCOS). IR also underlies many obesity-related malignancies, through the effects of compensatory hyperinsulinaemia on the relatively intact MAP-K insulin pathway, which controls cellular growth processes and mitoses. Furthermore, the emergent data over recent decades support an important role of obesity- and T2D-related central IR in the development of cognitive dysfunction, including effects on hippocampal synaptic plasticity. Importantly, IR is largely reversible through the optimisation of lifestyle factors that include regular engagement in physical activity with the avoidance of sedentariness, improved diet including increased fibre intake and sleep sufficiency. IR lies at the key crossroad between obesity and both metabolic and cognitive dysfunction. Given the importance of IR in the pathogenesis of many 21st century chronic diseases and its eminent reversibility, it is important that we all embrace and facilitate optimised lifestyles to improve the future health and wellbeing of the populace.
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Mechanisms of action of duodenal mucosal resurfacing in insulin resistant women with polycystic ovary syndrome.
Kaur, V, Dimitriadis, GK, Pérez-Pevida, B, Bansi, DS, Jayasena, C, Bate, D, Houghton, R, Fielding, BA, Balfoussia, D, Webber, L, et al
Metabolism: clinical and experimental. 2021;:154908
Abstract
BACKGROUND Duodenal mucosal resurfacing (DMR) is a novel day-case endoscopic intervention which results in weight loss-independent reductions in HbA1c in patient with type 2 diabetes mellitus (T2DM). We hypothesized that DMR works by increasing insulin sensitivity and we aimed to investigate the mechanism of action of DMR through longitudinal metabolic phenotyping in humans. METHODS Thirty-two insulin-resistant women with polycystic ovary syndrome (PCOS) and obesity were randomised in a double-blinded manner to DMR or sham endoscopy. They underwent measurements of insulin sensitivity using euglycaemic hyperinsulinaemic clamps, insulin secretion using oral glucose tolerance tests and reproductive function using weekly reproductive hormone profiles and ovarian ultrasonography for 6 months post-intervention. RESULTS A small increase in total body insulin sensitivity measured by the clamp was observed in both groups at week 12. An increase in insulin sensitivity, as measured by HOMA-IR, was observed in both groups at week 24. There was an increase in the number of menses (median 2 DMR, 0.5 sham). There were no significant differences between the two groups in these outcomes or insulin secretion. CONCLUSIONS These findings suggest that DMR does not work by increasing insulin sensitivity in euglycaemic, insulin resistant women with PCOS. The procedure may exert its effects only in the context of hyperglycaemia or pathologically hyperplastic, insulin-desensitised duodenal mucosa.
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Randomized double blind clinical trial evaluating the Ellagic acid effects on insulin resistance, oxidative stress and sex hormones levels in women with polycystic ovarian syndrome.
Kazemi, M, Lalooha, F, Nooshabadi, MR, Dashti, F, Kavianpour, M, Haghighian, HK
Journal of ovarian research. 2021;(1):100
Abstract
OBJECTIVE The design of this study was due to the report of the antioxidant properties of Ellagic acid (EA) for its evaluation on the Insulin resistance (IR), oxidative stress and sex hormones levels in women with polycystic ovarian syndrome (PCOS). METHODS In this randomized, double-blind, placebo-controlled clinical trial, 60 patients were recruited. Patients were randomly allocated consumed a capsule containing 200 mg of EA per day (n = 30) or placebo (n = 30) for 8 weeks. The fasting blood sugar (FBS), insulin, IR, total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), total antioxidant capacity (TAC), Malondialdehyde (MDA), C-reactive protein (CRP), Tumor necrosis factor-alpha (TNF-α), sex hormones and anti-mullerian hormone (AMH) were measured at the beginning and end of the study. RESULT At the end of the study, the mean of FBS, insulin, IR, TC, TG, LDL, MDA, CRP, TNF-α, total testosterone, prolactin and AMH were significantly decreased in the intervention group compared to the placebo group (P < 0.05). Also, there was a significant increase in the mean of TAC after supplementation with EA (P < 0.05). At the end of the study, no significant changes were observed in the mean of anthropometric factors, physical activity and food intake (P > 0.05). CONCLUSION EA supplementation can be helpful as a diet supplement in women with PCOS through improvement in insulin resistance. This supplement may be used to reduce metabolic disorders in women. TRIAL REGISTRATION This study was retrospectively (07-07-2019) registered in the Iranian website ( www.irct.ir ) for registration of clinical trials ( IRCT20141025019669N12 ).
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Insulin Resistance Is Central to Long-Term Reversal of Histologic Nonalcoholic Steatohepatitis After Metabolic Surgery.
Russo, MF, Lembo, E, Mari, A, Angelini, G, Verrastro, O, Nanni, G, Pompili, M, Raffaelli, M, Vecchio, FM, Bornstein, SR, et al
The Journal of clinical endocrinology and metabolism. 2021;(3):750-761
Abstract
CONTEXT Nonalcoholic steatohepatitis (NASH) is considered the hepatic counterpart of metabolic syndrome. OBJECTIVE This work aimed to investigate the determinants of NASH reversal in patients undergoing biliopancreatic diversion (BPD) in a 5-year follow-up study. METHODS This prospective study was conducted at Policlinico Universitario Agostino Gemelli. A total of 37 patients underwent fine-needle liver biopsy during BPD. Ultrasonography-guided percutaneous liver biopsy was obtained 5 years after the operation. The primary outcome of our study was histologic NASH reversal at 5-year follow-up. To better characterize the clinical variables involved in the resolution of NASH, we also compared patients without histologic NASH resolution at 5 years with those in whom NASH had disappeared. RESULTS At follow-up, NASH had reversed in 56.5% of the patients. The NAFLD activity score (NAS) improved from 3.7 ± 0.93 to 2 ± 1.11 (P < .001). Fibrosis reversed in 16% patients (P = .022), and 32% improved (95% CI, 0.05-0.54). No significant differences in body mass index or clinical parameters changes explained the effect of surgery on NASH, apart from the measure of insulin sensitivity post surgery. The Homeostasis Model Assessment of Insulin Resistance decreased from 3.31 ± 1.72 at baseline to 1.73 ± 1.08 (P < .001) after BPD, and the Matsuda index improved from 2.66 ± 1.79 to 4.73 ± 3.05 (P < .001). The lipid profile normalized (total cholesterol from 4.75 ± 1.18 to 3.32 ± 0.77 mmol/L, P < .001; low-density lipoprotein cholesterol from 2.92 ± 0.91 to 1.60 ± 0.51 mmol/L, P = .0001; high-density lipoprotein cholesterol from 0.97 ± 0.33 to 1.10 ± 0.35 mmol/L, P = .023; triglycerides from 2.52 ± 1.6 to 1.47 ± 0.67 mmol/L, P = .003). Neural network analysis showed that the end-study Matsuda index discriminated between responders and nonresponders with high accuracy (receiver operating characteristic area under the curve = 0.98%). CONCLUSION Remission of NASH is driven by reversal of whole-body insulin resistance post intervention.