Molecular effects of Vitamin-D and PUFAs metabolism in skeletal muscle combating Type-II diabetes mellitus

Multiple post-receptor intracellular alterations such as impaired glucose transfer, glucose phosphorylation, decreased glucose oxidation, and glycogen production contribute to insulin resistance (IR) in skeletal muscle, manifested by diminished insulin-stimulated glucose uptake. Type-2 diabetes mellites (T2DM) has caused by IR, which is also seen in obese patients and those with metabolic syndrome. The Vitamin-D receptor (VDR) and poly unsaturated fatty acids (PUFAs) roles in skeletal muscle growth, shapes, and function for combating type-2 diabetes have been clarified throughout this research. VDR and PUFAs appears to show a variety of effects on skeletal muscle, in addition it shows a promising role on bone and mineral homeostasis. Individuals having T2DM are reported to suffer from severe muscular weakness and alterations in shape of the muscle. Several studies have investigated the effect on VDR on muscular strength and mass, which leads to Vitamin-D deficiency (VDD) in individuals, in which most commonly seen in elderly. VDR has been shown to affect skeletal cellular proliferation, intracellular calcium handling, as well as genomic activity in a variety of different ways such as muscle metabolism, insulin sensitivity, which is the major characteristic pathogenesis for IR in combating T2DM. The identified VDR gene polymorphisms are ApaI, TaqI, FokI, and BsmI that are associated with T2DM. This review collates informations on the mechanisms by which VDR activation takes place in skeletal muscles. Despite the significant breakthroughs made in recent decades, various studies show that IR affects VDR and PUFAs metabolism in skeletal muscle. Therefore, this review collates the data to show the role of VDR and PUFAs in the skeletal muscles to combat T2DM.

Impaired Fibroblast Growth Factor 21 (FGF21) Associated with Visceral Adiposity Leads to Insulin Resistance: The Core Defect in Diabetes Mellitus

The Central nervous system (CNS) is the prime regulator of signaling pathways whose function includes regulation of food intake (consumption), energy expenditure, and other metabolic responses like glycolysis, gluconeogenesis, fatty acid oxidation, and thermogenesis that have been implicated in chronic inflammatory disorders. Type 2 diabetes mellitus (T2DM) and obesity are two metabolic disorders that are linked together and have become an epidemic worldwide, thus raising significant public health concerns. Fibroblast growth factor 21 (FGF21) is an endocrine hormone with pleiotropic metabolic effects that increase insulin sensitivity and energy expenditure by elevating thermogenesis in brown or beige adipocytes, thus reducing body weight and sugar intake. In contrast, during starvation conditions, FGF21 induces its expression in the liver to initiate glucose homeostasis. Insulin resistance is one of the main anomalies caused by impaired FGF21 signaling, which also causes abnormal regulation of other signaling pathways. Tumor necrosis factor alpha (TNF-α), the cytokine released by adipocytes and inflammatory cells in response to chronic inflammation, is regarded major factor that reduces the expression of FGF21 and modulates underlying insulin resistance that causes imbalanced glucose homeostasis. This review aims to shed light on the mechanisms underlying the development of insulin resistance in obese individuals as well as the fundamental flaw in type 2 diabetes, which is malfunctioning obese adipose tissue.

Is chromium(III) pharmacologically relevant? An update focused on studies with diabetic rodent models

A decade ago, the author assessed the status of chromium as the trivalent ion as an essential element and as a therapeutic agent based on rodent studies for this journal. The current review was undertaken to update considerations regarding the status of chromium, focusing on studies of Cr supplementation of diabetic rodent models over the last decade. Cr can no longer be considered an essential trace element for humans. Observed effects of Cr on rodent models of insulin resistance and diabetes are best interpreted in terms of a pharmacological role for Cr. The review of studies on the effects of Cr on rat models of diabetes is updated, and the results continue to suggest Cr increases insulin sensitivity in peripheral tissues of the rodent models. The lack of effects in human studies may stem from humans receiving a comparably smaller dose than the rodent models. However, given the different responses to Cr in the rodent models, humans could potentially have different responses to Cr. Recent studies primary utilizing rodents suggest two potential complementary but also contradictory modes of action for Cr(III) at a molecular level.

Associations Among Diabetes Medication Use, Serum Magnesium, and Insulin Resistance in a Cohort of Older Puerto Rican Adults

BACKGROUND

Hypomagnesemia is commonly observed in individuals with diabetes, but how diabetes medications alter magnesium (Mg) status remains unclear.

OBJECTIVE

We aimed to 1) examine the association between diabetes medication and hypomagnesemia and 2) evaluate whether serum Mg mediates the association between diabetes medication and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) in a prospective cohort.

METHODS

Adults from the Boston Puerto Rican Health Study were included (n=1106). Multivariable logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) for cross-sectional association between diabetes medication and hypomagnesemia (serum Mg < 0.75 mmol/L). Longitudinal mediation analysis was performed to evaluate the direct and indirect (via serum Mg) associations between diabetes medication and 4-year (y) HOMA-IR in 341 participants with baseline hemoglobin A1c (HbA1c) ≥ 6.5%.

RESULTS

Mean age at baseline was 59.0±7.6 y, with 28.0% male and 45.8% with hypomagnesemia. Use of metformin [OR (95% CI) = 3.72 (2.53, 5.48)], sulfonylureas [OR (95% CI) = 1.68 (1.00, 2.83)], and glitazones [OR (95% CI) = 2.09 (1.10, 3.95)], but not insulin, was associated with higher odds of hypomagnesemia. Use of multiple diabetes medications and longer duration of use were associated with higher odds of hypomagnesemia. Serum Mg partially mediated the association between metformin and HOMA-IR [indirect association: β (95% CI) = 1.11 (0.15, 2.07)], which weakened the direct association [β (95% CI) = -5.16 (-9.02, -1.30)] by 22% [total association: β (95% CI) = -4.05 (-7.59, -0.51)]. Similarly, serum Mg mediated 17% of the association between sulfonylureas and elevated HOMA-IR. However, the mediation by serum Mg was weak for insulin and glitazones.

CONCLUSIONS

Diabetes medication, especially metformin, was associated with elevated odds of hypomagnesemia, which may weaken the association between metformin and lowering of HOMA-IR. The causal inference needs to be confirmed in further studies.

Liver ChREBP deficiency inhibits fructose-induced insulin resistance in pregnant mice and female offspring

High fructose intake during pregnancy increases insulin resistance (IR) and gestational diabetes mellitus (GDM) risk. IR during pregnancy primarily results from elevated hormone levels. We aim to determine the role of liver carbohydrate response element binding protein (ChREBP) in insulin sensitivity and lipid metabolism in pregnant mice and their offspring. Pregnant C57BL/6J wild-type mice and hepatocyte-specific ChREBP-deficient mice were fed with a high-fructose diet (HFrD) or normal chow diet (NC) pre-delivery. We found that the combination of HFrD with pregnancy excessively activates hepatic ChREBP, stimulating progesterone synthesis by increasing MTTP expression, which exacerbates IR. Increased progesterone levels upregulated hepatic ChREBP via the progesterone-PPARγ axis. Placental progesterone activated the progesterone-ChREBP loop in female offspring, contributing to IR and lipid accumulation. In normal dietary conditions, hepatic ChREBP modestly affected progesterone production and influenced IR during pregnancy. Our findings reveal the role of hepatic ChREBP in regulating insulin sensitivity and lipid homeostasis in both pregnant mice consuming an HFrD and female offspring, and suggest it as a potential target for managing gestational metabolic disorders, including GDM.

Non-Insulin-Based Indices of Insulin Resistance for Predicting Incident Albuminuria: A Nationwide Population-Based Study

Background

Studies have shown that incident albuminuria is associated with insulin resistance (IR); however, an IR marker that best predicts the prevalence of albuminuria has not yet been established. This study explored the association between IR and incident albuminuria using various IR indices, including the homeostasis model assessment of IR (HOMA-IR), metabolic score for IR (METS-IR), and triglyceride-glucose (TyG) index, and compared their predictive abilities for the prevalence of albuminuria.

Methods

A total of 4,982 Korean adults from the 2019 Korea National Health and Nutritional Examination Survey were analyzed. The odds of albuminuria were determined using the quartiles of the IR indices. Receiver operating characteristic (ROC) curves were used to calculate the area under the ROC curve and predictability. The cutoff values for albuminuria detection were also computed.

Results

An increase in the quartiles of all three IR indices was associated with incident albuminuria, even after full adjustment for covariates (HOMA-IR: odds ratio [OR], 1.906; 95% confidence interval [CI], 1.311-2.772; P=0.006; METS-IR: OR, 2.236; 95% CI, 1.353-3.694; P=0.002; TyG index: OR, 1.757; 95% CI, 1.213-2.544; P=0.003). The area under the ROC curve for incident albuminuria based on the HOMA-IR, METS-IR, and TyG indices was 0.594 (95% CI, 0.568-0.619), 0.633 (95% CI, 0.607-0.659), and 0.631 (95% CI, 0.606-0.656), respectively. The optimal cutoff values for predicting albuminuria were 2.38, 35.38, and 8.72 for the HOMA-IR, METS-IR, and TyG indices, respectively.

Conclusion

The METS-IR and TyG indices outperformed HOMA-IR in predicting incident albuminuria.

Shared genetic architecture between periodontal disease and type 2 diabetes: a large scale genome-wide cross-trait analysis

PURPOSE

To investigate the relationship between abnormal glucose metabolism, type 2 diabetes (T2D), and periodontal disease (PER) independent of Body Mass Index (BMI), we employed a genome-wide cross-trait approach to clarify the association.

METHODS

Our study utilized the most extensive genome-wide association studies conducted for populations of European ancestry, including PER, T2D, fasting glucose, fasting insulin, 2-hour glucose after an oral glucose challenge, HOMA-β, HOMA-IR (unadjusted or adjusted for BMI) and HbA1c.

RESULTS

With this approach, we were able to identify pleiotropic loci, establish expression-trait associations, and quantify global and local genetic correlations. There was a significant positive global genetic correlation between T2D (rg = 0.261, p = 2.65 × 10-13), HbA1c (rg = 0.182, p = 4.14 × 10-6) and PER, as well as for T2D independent of BMI (rg = 0.158, p = 2.34 × 10-6). A significant local genetic correlation was also observed between PER and glycemic traits or T2D. We also identified 62 independent pleiotropic loci that impact both PER and glycemic traits, including T2D. Nine significant pathways were identified between the shared genes between T2D, glycemic traits and PER. Genetically liability of HOMA-βadjBMI was causally associated with the risk of PER.

CONCLUSION

Our research has revealed a genetic link between T2D, glycemic traits, and PER that is influenced by biological pleiotropy. Notably, some of these links are not related to BMI. Our research highlights an underlying link between patients with T2D and PER, regardless of their BMI.

Low Muscle Strength as Risk Factor for Non-Alcoholic Fatty Liver Disease in Different Metabolic Conditions

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) recently became a leading liver disease that threatens health worldwide. Low muscle strength, obesity, insulin resistance, and metabolic syndrome are recognized key factors for NAFLD. However, the impact of low muscle strength itself in different metabolic conditions has not been widely studied.

METHODS

A cross-sectional analysis was performed of a sample of 5,427 participants from the 2019 Korea National Health and Nutrition Examination Survey. Relative handgrip strength (rHGS, defined as handgrip strength/body mass index) was used to assess muscle strength. The cut-off values for a low rHGS were 1.405 for men and 0.850 for women. NAFLD was diagnosed if the Hepatic Steatosis Index was >36. Participants were stratified according to insulin resistance, metabolic syndrome, and central obesity for the subgroup analyses.

RESULTS

Complex sample multivariate logistic regression analysis revealed a significant association between low muscle strength and NAFLD after the adjustment for other confounders (odds ratio [OR], 1.92; P<0.001). In the insulin resistance, metabolic syndrome, and central obesity subgroups, a significant association between low muscle strength and NAFLD remained (OR, 1.66-4.19 depending on subgroup; all P<0.05), whereas it did not in the no central obesity group.

CONCLUSION

This study demonstrated that low muscle strength is correlated with a risk of NAFLD. This relationship was independent of insulin resistance and metabolic syndrome but was dependent on the presence of central obesity.

Brain insulin resistance and Alzheimer's disease: a systematic review

The disability of cells to react to insulin, causing glucose intolerance and hyperglycemia, is referred to as insulin resistance. This clinical condition, which has been well-researched in organs such as adipose tissue, muscle, and liver, has been linked to neurodegenerative diseases like Alzheimer's disease (AD) when it occurs in the brain.

Objective

The authors aimed to gather data from the current literature on brain insulin resistance (BIR) and its likely repercussions on neurodegenerative disorders, more specifically AD, through a systematic review.

Methods

A comprehensive search was conducted in multiple medical databases, including the Cochrane Central Register of Controlled Trials, EMBASE, Medical Literature Analysis and Retrieval System Online (Medline), and PubMed®, employing the descriptors: "insulin resistance", "brain insulin resistance", "Alzheimer's disease", "neurodegeneration", and "cognition". The authors focused their search on English-language studies published between 2000 and 2023 that investigated the influence of BIR on neurodegenerative disorders or offered insights into BIR's underlying mechanisms. Seventeen studies that met the inclusion criteria were selected.

Results

The results indicate that BIR is a phenomenon observed in a variety of neurodegenerative disorders, including AD. Studies suggest that impaired glucose utilization and uptake, reduced adenosine triphosphate (ATP) production, and synaptic plasticity changes caused by BIR are linked to cognitive problems. However, conflicting results were observed regarding the association between AD and BIR, with some studies suggesting no association.

Conclusion

Based on the evaluated studies, it can be concluded that the association between AD and BIR remains inconclusive, and additional research is needed to elucidate this relationship.

A Structure-function Analysis of Hepatocyte Arginase 2 Reveals Mitochondrial Ureahydrolysis as a Determinant of Glucose Oxidation

BACKGROUND & AIMS

Restoring hepatic and peripheral insulin sensitivity is critical to prevent or reverse metabolic syndrome and type 2 diabetes. Glucose homeostasis comprises in part the complex regulation of hepatic glucose production and insulin-mediated glucose uptake and oxidation in peripheral tissues. We previously identified hepatocyte arginase 2 (Arg2) as an inducible ureahydrolase that improves glucose homeostasis and enhances glucose oxidation in multiple obese, insulin-resistant models. We therefore examined structure-function determinants through which hepatocyte Arg2 governs systemic insulin action and glucose oxidation.

METHODS

To do this, we generated mice expressing wild-type murine Arg2, enzymatically inactive Arg2 (Arg2H160F) and Arg2 lacking its putative mitochondrial targeting sequence (Arg2Δ1-22). We expressed these hepatocyte-specific constructs in obese, diabetic (db/db) mice and performed genetic complementation analyses in hepatocyte-specific Arg2-deficent (Arg2LKO) mice.

RESULTS

We show that Arg2 attenuates hepatic steatosis, independent of mitochondrial localization or ureahydrolase activity, and that enzymatic arginase activity is dispensable for Arg2 to augment total body energy expenditure. In contrast, mitochondrial localization and ureahydrolase activity were required for Arg2-mediated reductions in fasting glucose and insulin resistance indices. Mechanistically, Arg2Δ1-22 and Arg2H160F failed to suppress glucose appearance during hyperinsulinemic-euglycemic clamping. Quantification of heavy-isotope-labeled glucose oxidation further revealed that mistargeting or ablating Arg2 enzymatic function abrogates Arg2-induced peripheral glucose oxidation.

CONCLUSION

We conclude that the metabolic effects of Arg2 extend beyond its enzymatic activity, yet hepatocyte mitochondrial ureahydrolysis drives hepatic and peripheral oxidative metabolism. The data define a structure-based mechanism mediating hepatocyte Arg2 function and nominate hepatocyte mitochondrial ureahydrolysis as a key determinant of glucose oxidative capacity in mammals.

Special features on insulin resistance, metabolic syndrome and vascular complications in hypopituitary patients

Pituitary hormone deficiency, hypopituitarism, is a dysfunction resulting from numerous etiologies, which can be complete or partial, and is therefore heterogeneous. This heterogeneity makes it difficult to interpret the results of scientific studies with these patients.Adequate treatment of etiologies and up-to-date hormone replacement have improved morbidity and mortality rates in patients with hypopituitarism. As GH replacement is not performed in a reasonable proportion of patients, especially in some countries, it is essential to understand the known consequences of GH replacement in each subgroup of patients with this heterogeneous dysfunction.In this review on hypopituitarism, we will address some particularities regarding insulin resistance, which is no longer common in these patients with hormone replacement therapy based on current guidelines, metabolic syndrome and its relationship with changes in BMI and body composition, and to vascular complications that need to be prevented taking into account the individual characteristics of each case to reduce mortality rates in these patients.

Determinants of Bone Mineral Density in Iranian Women with Polycystic Ovary Syndrome

Background

Whether the endocrine aberrations caused by polycystic ovary syndrome (PCOS) might influence bone density in women of reproductive age is controversial.

Objectives

The present study aimed to compare PCOS women to a control group matched in terms of age and body mass index (BMI) regarding bone indices and to clarify the potential relationship between their hormonal changes and bone density.

Methods

This case-control study consisted of 61 PCOS patients, and 35 women with normal ovulatory function served as controls. Bone parameters, including bone mineral content (BMC) and bone mineral density (BMD) in addition to T- and Z-scores, were measured at the lumbar vertebrae, neck of the left femur, hip, and distal part of the radial bone, using dual-energy X-ray absorptiometry. Blood samples were taken to be tested for biochemical parameters and serum concentrations of insulin, osteocalcin, parathyroid hormone (PTH), vitamin D, follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone, dehydroepiandrosterone sulfate (DHEAS), and estradiol were measured. Insulin resistance was evaluated through the homeostatic model assessment of insulin resistance (HOMA-IR).

Results

The results revealed greater levels of HOMA-IR and total testosterone in PCOS women than in controls. Nevertheless, the two groups were comparable in terms of bone parameters. In the control group, BMI was the only determinant of bone density at most of the skeletal sites. Nonetheless, BMI and HOMA-IR were independently and positively associated with bone indices at the femoral neck (FN) and total hip in the PCOS group. Parathyroid hormone and vitamin D concentrations were not different in the two groups. However, phosphate levels were higher in PCOS patients (P = 0.025). Osteocalcin was inversely correlated to BMI, and both groups had a negative correlation between DHEAS and PTH. Serum phosphate was inversely and independently associated with estrogen in the PCOS group (r = -0.377, P = 0.004).

Conclusions

Body mass index and HOMA-IR were independent and positive determinants of FN and total hip bone density in the PCOS subjects. Nonetheless, in the non-PCOS women, BMI was the only independent determinant of bone density at most of the skeletal sites. Additionally, osteocalcin was inversely correlated with BMI in both groups.

Reinstating acute-phase insulin release among sedentary adults at high risk for type 2 diabetes with Yoga and Walking based lifestyle modification

BACKGROUND

We compared the impact of 2 lifestyle modifying physical activities, yoga (YBLM) or walking (WBLM) on impaired beta cell function (IBF) or insulin resistance (IR) in restoring acute phase insulin release (APIR) among prediabetes at high risk for type 2 diabetes (HRDM).

METHOD

Male and female adults (N = 42, 38.1 ± 4.8 years) with abdominal obesity (Male:103 ± 8.1 cm) Female: 92 ± 11.1 cm), randomized into YBLM (n = 20) and WBLM (n = 22), were monitored for the practice of the intervention, 45 min a day/5 days a week for 12 weeks. Blood sample was collected at 0th minute to estimate the level of Fasting Blood Glucose (FBG), Sr. Insulin and lipid profile and at 10th minute (APIR). IBF, IR and sensitivity (IS) reading were checked in HOMA-2 calculator.

RESULT

Wilcoxon sign rank t-test denoted an improved APIR among the subjects with IBF (p = 0.008) and not among the subjects with IR (p = 0.332). However, regression analysis yielded an improved APIR among subjects with IBF (F(1,10) = 7.816, p = 0.002) with the management of body weight and lipid profile and IR (F(1,13) = 17.003, p = 0.001) being found influenced with selected lipid components. In all, during the post assessment period, an impressive boost in APIR was manifested among people shifted to Normoglycemia (n = 14, 35.9%).

CONCLUSION

Intriguingly, we postulate the potential role of YBLM over WBLM in the management of lipid profile and body weight on accelerating APIR either through improved Beta cell compensation or by sensitizing skeletal muscles regulating IR, helping improve glucose tolerance resulting in either remission or management of prediabetes.

Triglyceride-glucose index and cervical vascular function: outpatient-based cohort study

OBJECTIVES

The purpose of this study was to investigate the correlation between triglyceride-glucose (TyG) index and cervical vascular function parameters in the general population without cerebrovascular disease.

MATERIALS AND METHODS

This was a cross-sectional study that recruited a total of 1996 participants without cerebrovascular disease. TyG index was calculated based on fasting triglycerides and glucose. All patients were divided into two groups based on the median TyG index: the high TyG group and the low TyG group. The differences in basic clinical characteristics and neck vascular function parameters between the two groups of participants were compared, and then the correlation between TyG index and neck vascular function parameters was investigated.

RESULTS

Participants with a high TyG index had lower systolic, diastolic, and mean flow velocities in the basilar, vertebral, and internal carotid arteries compared with those with a low TyG index. Participants with a high TyG index had higher pulsatility index in the left vertebral artery and right internal carotid artery, but this difference was not observed in the basilar artery. In addition, TyG index was significantly negatively correlated with systolic, diastolic, and mean flow velocities in the basilar, vertebral, and internal carotid arteries, and the correlation remained after adjusting for confounding factors.

CONCLUSION

In the general population, there was a well-defined correlation between TyG index and cervical vascular function parameters, and increased TyG index was independently associated with reduced cervical vascular blood flow velocity.

Insulin resistance drives cognitive impairment in hypertensive pre-diabetic frail elders: the CENTENNIAL study

AIMS

Pre-diabetes is a condition that confers an increased cardiovascular risk. Frailty is very common in hypertensive patients, and insulin resistance has been linked to frailty in older adults with diabetes. On these grounds, our aim was to evaluate the association between insulin resistance and cognitive impairment in hypertensive and pre-diabetic and frail older adults.

METHODS AND RESULTS

We studied consecutive pre-diabetic and hypertensive elders with frailty presenting at the Avellino local health authority of the Italian Ministry of Health (ASL AV) from March 2021 to March 2022. All of them fulfilled the following inclusion criteria: a previous diagnosis of hypertension with no clinical or laboratory evidence of secondary causes, a confirmed diagnosis of pre-diabetes, age >65 years, Montreal Cognitive Assessment (MoCA) Score <26, and frailty. We enrolled 178 frail patients, of which 141 successfully completed the study. We observed a strong inverse correlation (r = -0.807; P < 0.001) between MoCA Score and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). The results were confirmed by a linear regression analysis using MoCA Score as dependent variable, after adjusting for several potential confounders.

CONCLUSION

Taken together, our data highlight for the first time the association between insulin resistance and global cognitive function in frail elders with hypertension and pre-diabetes.

Protective Effect of Tertiary Butylhydroquinone against Obesity-induced Skeletal Muscle Pathology in Post-weaning High Fat Diet Fed Rats

BACKGROUND

Obesity deleteriously affects skeletal muscle functionality starting from infancy to adulthood, leading to dysfunctional skeletal muscle.

OBJECTIVES

This study, therefore, evaluated the protective action of tert-butylhydroquinone (tBHQ) against obesity-induced skeletal muscle pathology in high-fat diet (HFD) fed rats.

METHODS

Twenty post-weaning male albino rats were randomized into four groups of five rats each as: Group 1 (control), Group 2 (HFD), Group 3 (orlistat) and Group 4 (tBHQ). Group one received rat pellets for 12 weeks, while groups 2 to 4 received HFD for 12 weeks. At the end of week 8, obesity was confirmed with Lee Obesity Index and body mass index values of ≥ 303 and ≥ 0.68 gcm2, respectively. Group 3 was given oral administration of orlistat (10 mg/kg, once daily), while group 4 was given oral administration of tBHQ (25 mg/kg, once daily). Administration of orlistat and tBHQ commenced from week 9 to the end of the experiment.

RESULTS

Chronic exposure of post-weaning rats to HFD led to their development of the metabolic syndrome phenotypes in adulthood, characterized by obesity, hyperglycemia, dyslipidaemia, hyperinsulinaemia, insulin resistance as well as induction of oxidative stress and alteration of skeletal muscle markers, which were mitigated following supplementation with orlistat and tBHQ.

CONCLUSION

The study showed the anti-obesity potentials of tBHQ and its protective action against HFD obesity-induced skeletal muscular pathology.

The acute effects of a DASH diet and whole food, plant-based diet on insulin requirements and related cardiometabolic markers in individuals with insulin-treated type 2 diabetes

AIMS

There is limited research regarding insulin dosing changes following adoption of plant-based diets. We conducted a nonrandomized crossover trial utilizing two plant-based diets (Dietary Approaches to Stop Hypertension, or DASH, and Whole Food, Plant-Based, or WFPB) to assess acute changes in insulin requirements and associated markers among individuals with insulin-treated type 2 diabetes.

METHODS

Participants (n = 15) enrolled in a 4-week trial with sequential, one-week phases: Baseline, DASH 1, WFPB, and DASH 2. Each diet was ad libitum and meals were provided.

RESULTS

Compared to baseline, daily insulin usage was 24%, 39%, and 30% lower after DASH 1, WFPB, and DASH 2 weeks respectively (all p < 0.01). Insulin resistance (HOMA-IR) was 49% lower (p < 0.01) and the insulin sensitivity index was 38% higher (p < 0.01) at the end of the WFPB week before regressing toward baseline during DASH 2. Total, LDL, and HDL cholesterol, leptin, urinary glucose, and hsCRP decreased to a nadir at the end of the WFPB week before increasing during DASH 2.

CONCLUSIONS

Adopting a DASH or WFPB diet can result in significant, rapid changes in insulin requirements, insulin sensitivity, and related markers among individuals with insulin-treated type 2 diabetes, with larger dietary changes producing larger benefits.

The Effect of Training Type on The Signaling P athway of Ceramide-Dependent Insulin Resistance in The Flexor Hallucis Longus Muscle of Streptozotocin-Induced Diabetic Rats

OBJECTIVE

This study aimed to compare the effect of different physical training on the mechanism of ceramidedependent insulin resistance in the flexor hallucis longus (FHL) muscle of diabetic rats.

MATERIALS AND METHODS

In this experimental study, 7 healthy as a healthy control (HC) group, and 21 diabetics (55 mg/ kg Streptozotocin) Wistar rats (200-220 g; 8-10 weeks old) divided into the diabetic control (DC), moderate continuous training (MCT), and moderate intensity interval training (MIIT) groups. Both MCT (55-70% of maximal oxygen uptake (VO2max), and MIIT (85% VO2max) groups trained for 10-25 minutes at a speed of 10-20 m/minutes. The changes in the expression of blood glucose, insulin, insulin resistance, lipid profile and total ceramide were measured as well as ceramide synthase-1, Glucose transporter type 4 (GLUT4), Protein kinase B known as Akt, phosphorylated protein kinase B known as pAkt, protein kinase C (PKC), and tumour necrosis factor α (TNFα).

RESULTS

Blood glucose, triglyceride (TG) and ceramide synthase-1 (CS1) expression levels in the MCT group decreased in comparison with the DC group. FHL protein expression of GLUT4 in the MCT group was higher than the DC group. FHL expression of GLUT4, pAKT, AKT/pAKT, PKC, CS1 and total ceramide in the MIIT group were higher than the DC group. Cholesterol, low-density lipoprotein (LDL), TG, and TNF-α protein expression in the MIIT group were lower than the DC group. GLUT4, PKC, pAKT, AKT/pAKT in the MIIT group were higher, and total ceramide and TNF-α were lower in the MIIT group than the MCT group.

CONCLUSION

It seems that both training plan MIIT and MCT have favorable effects on the metabolism of glucose, insulin, lipids, and the decrease of TNFα level in the diabetes, but in connection with the improvement of the ceramides mechanism, it seems that the MIIT training plan is more optimal than MCT training plan.

12-week combined strength and endurance exercise attenuates CD8+ T-cell differentiation and affects the kynurenine pathway in the elderly: a randomized controlled trial

BACKGROUND

Age-related accumulation of highly differentiated CD8⁺ effector memory re-expressing CD45RA (EMRA) T-cells and disruption of the kynurenine (KYN) pathway are associated with chronic inflammation and the development of insulin resistance. In this study the aim was to investigate the effects of 12-week combined strength and endurance exercise on CD8⁺ T-cell differentiation and KYN pathway metabolites. Ninety-six elderly subjects (f/m, aged 50-70) were randomized to a control (CON) or exercise (EX) group. The EX group completed combined strength and endurance training twice weekly for one hour each time at an intensity of 60% of the one-repetition maximum for strength exercises and a perceived exertion of 15/20 for endurance exercises. The EX group was also randomly subdivided into two groups with or without a concomitant balanced diet intervention in order to examine additional effects besides exercise alone. Before and after the intervention phase, the proportions of CD8⁺ T-cell subsets and levels of KYN pathway metabolites in peripheral blood were determined.

RESULTS

The CD8⁺ EMRA T-cell subsets increased in the CON group but remained almost unchanged in the EX group (p = .02). Plasma levels of kynurenic acid (KA) increased in the EX group and decreased in the CON group (p = .03). Concomitant nutritional intervention resulted in lower levels of quinolinic acid (QA) compared with exercise alone (p = .03). Overall, there was a slight increase in the QA/KA ratio in the CON group, whereas it decreased in the EX group (p > .05).

CONCLUSIONS

Combined strength and endurance training seems to be a suitable approach to attenuate CD8⁺ T-cell differentiation in the elderly and to redirect the KYN pathway towards KA. The clinical relevance of these effects needs further investigation.

Placental Fatty Acid Metabolism and Transport in a Rat Model of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a form of heightened insulin resistance triggered during gestation. This study examines how insulin resistance alters placental long-chain polyunsaturated fatty acid (LCPUFA) transport and metabolism in a rat model of lean GDM. Pregnant Sprague Dawley rats were administered with S961, an insulin receptor antagonist (30 nmol/kg s.c. daily), or vehicle from gestational day (GD) 7 to 20. Daily maternal body weight, food, and water intake were measured. Blood pressure assessment and glucose tolerance test were done on GD20. Fetal plasma and placenta were collected on GD20 and processed for fatty acid measurement using LC-mass spectrometry. The expression of fatty acid metabolism-related genes in the placenta was assessed using RT² Profiler PCR arrays. The results were validated by qRT-PCR. Blockade of insulin receptors with S961 in pregnant rats resulted in glucose intolerance with increased fasting glucose and insulin levels. Maternal body weight gain and food and water intake were not affected; however, S961 significantly increased maternal blood pressure and heart rate. The placenta n3 and n6 LCPUFA concentrations were significantly decreased by 8% and 11%, respectively, but their levels in the fetal plasma were increased by 15% and 4%. RT2 profiler arrays revealed that placental expressions of 10 genes related to fatty acid β-oxidation (Acaa1a, Acadm, Acot2, Acox2, Acsbg1, Acsl4, Acsm5, Cpt1b, Eci2, Ehhadh) and 3 genes related to fatty acid transport pathway (Fabp2, Fabp3, Slc27a3) were significantly upregulated. In summary, lack of insulin action increased the expression of genes related to placental fatty acid β-oxidation and transport with an increased transfer of LCPUFA to the fetus. The increased lipid levels routed toward the fetus may lead to fat adiposity and later-life metabolic dysfunction.

The Effect of the Saffron Intervention on NAFLD Status and Related Gene Expression in a Rat Model

Background

According to the worldwide increasing prevalence of non-alcoholic fatty liver disease (NAFLD), the present study aimed to investigate the mechanism effects of saffron consumption on preventing NAFLD in a rat model.

Methods

In an experimental study, 12 rats were randomly divided into 2 groups to be evaluated in the prevention phase for 7 weeks. In the prevention phase, the animals were randomly assigned to either fed HFHS + 250 mg/kg saffron (S) or fed with HFHS. Afterward, parts of the liver were excised for histopathologic examination. Plasma concentrations of ALT, AST, GGT, ALP, serum lipids, insulin concentrations, plasma glucose, hs-CRP, and TAC were measured. Moreover, Also, the gene expression of 6 target genes was evaluated, including FAS, ACC1, CPT1 ،PPARα ،DGAT2, and SREBP 1-c at the beginning and end of the study. Also, the differences among groups were evaluated by the Mann-Whitney test for non-normal data and the independent t test for normal data.

Results

The prevention phase groups have a significant elevation in body weight ( P = 0.034) and food intake (P = 0.001) of the HFHS group versus HFHS + 250 mg/kg S group. Also, there was a significant difference between groups 1 and 2 for ALT (P = 0.011) and AST (P = 0.010), and TG (P = 0.040). The HFHS group had higher plasma levels of FBS (P = 0.001), insulin (P = 0.035), HOMA-IR (P = 0.032), and lower TAC (P = 0.041) versus the HFHS+ S group. Also, the difference between HFHS + 250 mg/kg S and HFHS for PPARα gene expression was significant (P = 0.030).

Conclusion

The present study showed that consumption of saffron could prevent developing NAFLD in rats at least partially through modulation in gene expression of PPARα.

Is the Co-administration of Metformin and Clomiphene Superior to Induce Ovulation in Infertile Patients With Poly Cystic Ovary Syndrome and Confirmed Insulin-Resistance: A Double Blind Randomized Clinical Trial

Objective

This study aimed to compare the effects of clomiphene citrate (CC) combined with metformin or placebo on infertile patients with poly cystic ovary syndrome (PCOS) and insulin resistance (IR).

Materials and methods

We included 151 infertile women with PCOS and IR in a university hospital from November 2015 to April 2022 in this prospective, double-blind, randomized, placebo-controlled trial. Patients were randomized into two groups; group A: received CC plus metformin (n = 76) and group B: received CC plus placebo (n = 75). The ovulation rate was the main outcome measure. Clinical pregnancy, ongoing pregnancy, live birth and abortion rates were secondary outcome measures.

Results

There was no remarkable difference in ovulation rate in two groups. Moreover, no significant changes were observed in clinical pregnancy, ongoing pregnancy, live birth and abortion rates between two groups. A larger proportion of women in group A suffered from side effects of metformin (9.3% versus 1.4%; p=0.064), although this was not significant.

Conclusion

In IR infertile women with PCOS, metformin pre-treatment did not increase the ovulation, clinical pregnancy and live birth rates in patients on clomiphene citrate.

Association between integrase strand transfer inhibitor use with insulin resistance and incident diabetes mellitus in persons living with HIV: a systematic review and meta-analysis

Whether integrase strand transfer inhibitors (INSTIs) are associated with a higher risk of incident type 2 diabetes mellitus (DM) than other antiretroviral therapies (ART) needs to be established.MEDLINE, Embase, Web of Science, and ClinicalTrials.gov registries were searched for studies published between 1 January 2000 and 15 June 2022. Eligible studies reported incident DM or mean changes in insulin resistance measured by Homeostatic Model for Insulin Resistance (HOMA-IR) in patients on INSTIs compared with other ARTs. We performed random-effects meta-analyses to obtain pooled relative risks (RRs) with 95% CIs.A total of 16 studies were pooled: 13 studies meta-analyzed for incident diabetes with a patient population of 72 404 and 3 for changes in HOMA-IR. INSTI therapy was associated with a lower risk of incident diabetes in 13 studies (RR 0.80, 95% CI 0.67 to 0.96, I²=29%), of which 8 randomized controlled trials demonstrated a 22% reduced risk (RR 0.88, 95% CI 0.81 to 0.96, I²=0%). INSTIs had a lower risk compared with non-nucleoside reverse transcriptase inhibitors (RR 0.75, 95% CI 0.63 to 0.89, I²=0%) but similar to protease inhibitor-based therapy (RR 0.78, 95% CI 0.61 to 1.01, I²=27%). The risk was lower in studies with longer follow-up (RR 0.70, 95% CI 0.53 to 0.94, I²=24%) and among ART-naïve patients (RR 0.78, 95% CI 0.65 to 0.94, I²=3%) but increased in African populations (RR 2.99, 95% CI 2.53 to 3.54, I²=0%).In conclusion, exposure to INSTIs was not associated with increased risk of DM, except in the African population. Stratified analyses suggested reduced risk among ART-naïve patients and studies with longer follow-up.International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42021273040.

[Diagnostic performance of the FINDRISC questionnaire to identify insulin resistance in adults]

Background

Insulin resistance (IR) is a state prior to the development of type 2 diabetes (T2D) and it is reversible with lifestyle modification. However, it is underdiagnosed due to the difficulty in its measurement.

Objective

To evaluate the diagnostic performance of the FINDRISC questionnaire to identify IR.

Material and methods

An analytical cross-sectional study was performed in adults aged 20 to 60 years without previous diagnosis of T2D. Those using steroids and pregnant women were excluded. IR was diagnosed through the Triglycerides/glucose index. A ROC curve was used to establish the cut-off point for the diagnosis of IR. Sensitivity, specificity, predictive values and likelihood ratios were calculated. Risk measurement for IR was performed with the FINDRISC instrument.

Results

A total of 253 participants were included, with a prevalence of IR of 60.8%. The area under the curve of the FINDRISC instrument was 0.813 (95% confidence interval [95% CI] 0.759-0.865), with a cut-off point of 8. Sensitivity was 94.8% and specificity was 48.5%, positive predictive value was 74% and negative 86%, with a positive likelihood ratio of 1.84 and a negative of 0.11.

Conclusions

The FINDRISC instrument is a useful screening tool to identify subjects with IR at the first level of care. A score ≥ 8 identifies subjects with IR.

Association of short-term and long-term weight loss with the risk of major adverse cardiovascular disease: Community-based cohort study

BACKGROUND

This study evaluated temporal association of changes in BMI over time with major adverse cardiovascular event (MACE) in Korean middle-aged adults.

METHODS

Between 2001 and 2002, 6855 individuals from the Korean Genome and Epidemiology Study were included and followed up until 2014. The main predictor was the change in BMI determined using group-based trajectory modelling (decreasing, stable, and increasing) from the baseline to 4-, 6-, and 8-years of follow-up. The primary outcome was the occurrence of MACE.

RESULTS

During the mean 10.2 years follow-up, MACEs occurred in 350 (5.1 %) individuals. The median (interquartile rage) age of study population was 50 (44-59) years. In primary analysis with 4-year trajectory model, decreasing BMI trajectory was associated with a 1.41-fold higher risk of the MACEs (hazard ratio [HR], 1.41; 95 % confidence interval [CI], 1.06-1.91) compared with stable BMI trajectory. In secondary analyses with 6- and 8-year trajectory models, this association disappeared, and the corresponding HRs (95 % CIs) were 1.14 (0.81-1.61) and 0.98 (0.65-1.49), respectively. There were concomitant improvements in cardiometabolic risk factors in decreasing BMI group, but unfavorable risk burden remained up to 4 to 6 years.

CONCLUSIONS

The initial 4-year weight loss was paradoxically associated with a higher risk of MACEs, probably due to residual cardiovascular burden. However, this association became null in participants with sustained weight loss ≥ 6 years, suggesting a possible lag effect of weight loss on MACEs.

Hepatocyte Adenosine Kinase Promotes Excessive Fat Deposition and Liver Inflammation

BACKGROUND & AIMS

Nonalcoholic fatty liver disease is highly associated with obesity and progresses to nonalcoholic steatohepatitis when the liver develops overt inflammatory damage. While removing adenosine in the purine salvage pathway, adenosine kinase (ADK) regulates methylation reactions. We aimed to study whether hepatocyte ADK functions as an obesogenic gene/enzyme to promote excessive fat deposition and liver inflammation.

METHODS

Liver sections of human subjects were examined for ADK expression using immunohistochemistry. Mice with hepatocyte-specific ADK disruption or overexpression were examined for hepatic fat deposition and inflammation. Liver lipidomics, hepatocyte RNA sequencing (RNA-seq), and single-cell RNA-seq for liver nonparenchymal cells were performed to analyze ADK regulation of hepatocyte metabolic responses and hepatocyte-nonparenchymal cells crosstalk.

RESULTS

Whereas patients with nonalcoholic fatty liver disease had increased hepatic ADK levels, mice with hepatocyte-specific ADK disruption displayed decreased hepatic fat deposition on a chow diet and were protected from diet-induced excessive hepatic fat deposition and inflammation. In contrast, mice with hepatocyte-specific ADK overexpression displayed increased body weight and adiposity and elevated degrees of hepatic steatosis and inflammation compared with control mice. RNA-seq and epigenetic analyses indicated that ADK increased hepatic DNA methylation and decreased hepatic Ppara expression and fatty acid oxidation. Lipidomic and single-cell RNA-seq analyses indicated that ADK-driven hepatocyte factors, due to mitochondrial dysfunction, enhanced macrophage proinflammatory activation in manners involving increased expression of stimulator of interferon genes.

CONCLUSIONS

Hepatocyte ADK functions to promote excessive fat deposition and liver inflammation through suppressing hepatocyte fatty acid oxidation and producing hepatocyte-derived proinflammatory mediators. Therefore, hepatocyte ADK is a therapeutic target for managing obesity and nonalcoholic fatty liver disease.

Liver-specific FGFR4 knockdown in mice on an HFD increases bile acid synthesis and improves hepatic steatosis

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with increased risk in patients with metabolic syndrome. There are no FDA-approved treatments, but FXR agonists have shown promising results in clinical studies for NAFLD management. In addition to FXR, fibroblast growth factor receptor FGFR4 is a key mediator of hepatic bile acid synthesis. Using N-acetylgalactosamine-conjugated siRNA, we knocked down FGFR4 specifically in the liver of mice on chow or high-fat diet and in mouse primary hepatocytes to determine the role of FGFR4 in metabolic processes and hepatic steatosis. Liver-specific FGFR4 silencing increased bile acid production and lowered serum cholesterol. Additionally, we found that high-fat diet-induced liver steatosis and insulin resistance improved following FGFR4 knockdown. These improvements were associated with activation of the FXR-FGF15 axis in intestinal cells, but not in hepatocytes. We conclude that targeting FGFR4 in the liver to activate the intestinal FXR-FGF15 axis may be a promising strategy for the treatment of NAFLD and metabolic dysfunction.

Insulin resistance, autophagy and apoptosis in patients with polycystic ovary syndrome: Association with PI3K signaling pathway

Polycystic ovary syndrome (PCOS) is a disease in which endocrine metabolic abnormalities coexist with reproductive system abnormalities, with the main clinical manifestations including abnormal menstruation, hirsutism, acne, infertility, and obesity, and it is also a high risk for the development of many pregnancy complications, gynecological malignancies and other diseases. Therefore, timely intervention to prevent the progression of PCOS is of great significance for improving the quality of life of most female patients. Insulin resistance (IR) is one of the most common endocrine disorders in PCOS patients, with approximately 75% of PCOS patients experiencing varying degrees of IR. It is now believed that it is mainly related to the PI3K signaling pathway. The role of autophagy and apoptosis of ovarian granulosa cells (GCs) in the pathogenesis of PCOS has also been gradually verified in recent years. Coincidentally, it also seems to be associated with the PI3K signaling pathway. Our aim is to review these relevant studies, to explore the association between the IR, cellular autophagy and apoptosis in PCOS patients and the PI3K pathway. We summarize some of the drug studies that have improved PCOS as well. We have also found that proteomics holds great promise in exploring the pathogenesis of PCOS, and we have published our views on this.

Changes in hyperglycaemia-related testing for prediabetes and type 2 diabetes mellitus management: a prospective, cross-sectional survey of 16 years of general practice data from Australia

BACKGROUND

The rising prevalence of prediabetes increases the population risk of type 2 diabetes mellitus (T2DM), metabolic syndrome and cardiovascular disease. Early identification by General Practitioners (GPs) provides opportunities for lifestyle modifications that can lower these risks.

METHODS

This study examined 16 years of hyperglycaemia-related testing for patients in Australia aged 13 years or older with, or at risk of a diagnosis of T2DM. The Bettering the Evaluation and Care of Health (BEACH) study is a national cross-sectional survey, with a single-stage, cluster sampling design. Approximately 1,000 GPs were randomly selected annually (2000/01-20,015/16) from across Australia, who each recorded details of 100 consecutive clinical encounters with consenting patients. Point estimates were adjusted for intracluster correlation and GP characteristics.

RESULTS

Fifteen thousand six hundred seventy nine GPs recorded details of 1,387,190 clinical encounters with patients aged 13 + years. Prediabetes and T2DM were managed at 0.25% (95% CI: 0.24-0.27%) and 3.68% (95% CI: 3.62-3.73%) of encounters respectively. By the end of the study, the proportion of encounters where prediabetes was managed was 2.3 times higher and for T2DM, 1.5 times higher. The proportion of prediabetes (55.9%, 95% CI: 53.9-57.8%) and T2DM (27.3%, 95% CI: 26.7-27.9%) management occasions where one or more hyperglycaemia-related tests were requested were relatively stable. However, differences in the types of tests were observed. For prediabetes, glucose tolerance tests were most common but from 2014/15, requests for HbA1c tests began to increase. For T2DM, HbA1c tests were most common, and requests for one or more glucose tests gradually declined.

CONCLUSION

The observed 16-year annual trends align with the rising incidence of prediabetes and T2DM. GPs appeared to be strongly influenced by changes to the national insurance scheme and clinical guidelines for hyperglycaemia-related pathology testing. However, some GPs may have been pre-empting policy changes as there was also evidence of 'unendorsed' testing, notably for prediabetes, that warrants further investigation. The increasing proportion of encounters for prediabetes, coupled with a high proportion of management occasions where pathology was requested have substantial resource implications. Calls to lower the risk threshold for prediabetes screening therefore warrant an economic analysis. Ongoing, reliable, up-to-date data is needed to inform clinical practice guidelines and policy in Australia.

Does oxidative DNA damage trigger histotoxic hypoxia via PARP1/AMP-driven mitochondrial ADP depletion-induced ATP synthase inhibition in Alzheimer's disease?

The low cerebral metabolic rate of oxygen despite the relatively preserved perfusion in Alzheimer's disease (AD) patients' medial temporal lobes suggest histotoxic hypoxia due to mitochondrial dysfunction that is independent of, but could precede, insulin resistance. Neuropathological, metabolomic, and preclinical evidence are consistent with the notion that this mitochondrial dysfunction may be contributed to by oxidative stress and DNA damage, leading to poly-(ADP-ribose)-polymerase-1 (PARP1) activation and consequent AMP accumulation, clogging of mitochondrial adenine nucleotide transporters (ANTs), matrix ADP deprivation, and ATP synthase inhibition. Complementary mechanisms may include mitochondrial-protein poly-ADP-ribosylation and mitochondrial-biogenesis suppression via PARPs outcompeting Sirtuin-1 (SIRT1) for nicotinamide-adenine-dinucleotide (NAD⁺).

AGA Clinical Practice Guideline on Pharmacological Interventions for Adults With Obesity

BACKGROUND & AIMS

Pharmacological management of obesity improves outcomes and decreases the risk of obesity-related complications. This American Gastroenterological Association guideline is intended to support practitioners in decisions about pharmacological interventions for overweight and obesity.

METHODS

A multidisciplinary panel of content experts and guideline methodologists used the Grading of Recommendations Assessment, Development and Evaluation framework to prioritize clinical questions, identify patient-centered outcomes, and conduct an evidence synthesis of the following agents: semaglutide 2.4 mg, liraglutide 3.0 mg, phentermine-topiramate extended-release (ER), naltrexone-bupropion ER, orlistat, phentermine, diethylpropion, and Gelesis100 oral superabsorbent hydrogel. The guideline panel used the evidence-to-decision framework to develop recommendations for the pharmacological management of obesity and provided implementation considerations for clinical practice.

RESULTS

The guideline panel made 9 recommendations. The panel strongly recommended the use of pharmacotherapy in addition to lifestyle intervention in adults with overweight and obesity (body mass index ≥30 kg/m2, or ≥27 kg/m2 with weight-related complications) who have an inadequate response to lifestyle interventions. The panel suggested the use of semaglutide 2.4 mg, liraglutide 3.0 mg, phentermine-topiramate ER, and naltrexone-bupropion ER (based on moderate certainty evidence), and phentermine and diethylpropion (based on low certainty evidence), for long-term management of overweight and obesity. The guideline panel suggested against the use of orlistat. The panel identified the use of Gelesis100 oral superabsorbent hydrogel as a knowledge gap.

CONCLUSIONS

In adults with overweight and obesity who have an inadequate response to lifestyle interventions alone, long-term pharmacological therapy is recommended, with multiple effective and safe treatment options.

Vitamin D, parathyroid hormone, glucose metabolism and incident diabetes in the multiethnic study of atherosclerosis

INTRODUCTION

Higher concentrations of serum 25-hydroxyvitamin D (25(OH)D) and lower concentrations of parathyroid hormone (PTH) are associated with lower insulin resistance and incident diabetes in non-Hispanic White and Hispanic Americans. Results are mixed in other populations, with no observational studies in a large multiethnic cohort. The association of serum 25(OH)D with diabetes may vary by adiposity level.

RESEARCH DESIGN AND METHODS

Among 5611 participants in the Multi-Ethnic Study of Atherosclerosis without diabetes at baseline, cross-sectional associations of serum 25(OH)D with homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA-β were examined using linear regressions. The association of 25(OH)D with incident diabetes over 9 years was examined using Cox proportional hazard regression.

RESULTS

Black Americans had the highest proportion of individuals with 25(OH)D<20 ng/mL (61%) and White Americans had the least (17%). Serum 25(OH)D was inversely associated with HOMA-IR in fully adjusted models (-0.34% difference in HOMA-IR per ng/mL higher 25(OH)D, p<0.0001). Longitudinally, a 1 ng/mL higher serum 25(OH)D was associated with 2% lower risk of incident diabetes (HR 0.982, CI 0.974 to 0.991), and a 1 pg/mL higher serum PTH was associated with 1% higher risk of incident diabetes (HR 1.007, CI 1.004 to 1.010), both prior to adjustment for waist circumference. After adjusting for waist circumference, a 1 ng/mL higher 25(OH)D was associated with 1% lower risk of incident diabetes (HR 0.991, CI 0.983 to 1.000). The magnitude of association of serum 25(OH)D with incident diabetes was largest at lower waist circumference (p for interaction=0.025). There was no heterogeneity by race/ethnicity (p=0.317).

CONCLUSIONS

Serum 25(OH)D is inversely associated with insulin resistance and incident diabetes in a diverse cohort, including non-Hispanic White, Black, Hispanic and Chinese Americans. Future research should explore mechanisms for the interaction between serum 25(OH)D and adiposity in this relationship.

Ameliorating Inflammation in Insulin-resistant Rat Adipose Tissue with Abdominal Massage Regulates SIRT1/NF-κB Signaling

It was the aim of this study to determine whether abdominal massage reverses high-fat diet-induced insulin resistance compared with RSV treatment. A total of sixty male Sprague-Dawley rats were randomly placed in one of four groups:the non-fat diet (NFD), the high-fat diet (HFD), the HFD with abdominal massage (HFD+ AM), and the HFD plus resveratrol (HFD+ RSV). For eight weeks, rats were fed high-fat diets to create insulin resistance, followed by six weeks of either AM or RSV. Molecular mechanisms of adipogenesis and cytokine production in rats with high-fat diets were investigated. The model rat adipose tissue showed significant improvements in obesity, glucose intolerance, and the accumulation of lipid in the body [the total cholesterol level (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)], metabolic effects of glucose [The fasting blood glucose (FBG), Fasting insulin levels (FINS)], inflammatory status [interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α, C-reactive protein (CRP)], and macrophage polarization after AM or RSV treatment. Further, AM increased SIRT1/NF-κB signaling in rat adipose tissue. Accordingly, in rat adipose tissue, our results indicate that AM regulates the secretion of proinflammatory cytokines, blood sugar levels, and related signaling pathways, contributing to improvement of IR, which may serves as a new therapeutic approach for the treatment for IR.

Serum isthmin-1 levels are positively and independently correlated with albuminuria in patients with type 2 diabetes mellitus

INTRODUCTION

Isthmin-1 (Ism-1), as a novel adipokine, plays a role in glucose homeostasis and lipid metabolism. However, the relationship between Ism-1 and type 2 diabetes mellitus (T2DM) remains unclear. This study aims to investigate the association of serum Ism-1 levels with albuminuria and insulin resistance in patients with T2DM and preserved renal function.

RESEARCH DESIGN AND METHODS

A total of 150 patients with T2DM were recruited. The presence of albuminuria was evaluated by urinary albumin:creatinine ratio (UACR) in first morning urine sample. Serum Ism-1 levels were tested by ELISA. Homeostasis model assessments were used to evaluate insulin resistance. Binary logistic regression and multivariable linear regression analyses were used to assess the association of serum Ism-1 levels with albuminuria. Multivariable linear regression analyses were performed to explore the correlation of serum Ism-1 levels with insulin resistance.

RESULTS

Compared with the normal-albuminuria and microalbuminuria groups, serum Ism-1 levels were significantly higher in the macroalbuminuria group (p<0.01). Binary logistic regression analyses showed that serum Ism-1 was positively associated with odds of albuminuria even after multiple adjustments (OR=4.766, p=0.013). Serum Ism-1 was positively associated with log10-transformed UACR (β=0.625, p<0.001). However, the associations between serum Ism-1 levels and insulin resistance were not observed in patients with T2DM.

CONCLUSIONS

Serum Ism-1 levels were positively and independently correlated with the severity of albuminuria in patients with T2DM but not with insulin resistance.

Metabolic and Genetic Risk Factors Are the Strongest Predictors of Severity of Alcohol-Related Liver Fibrosis

BACKGROUND & AIMS

Individual risk for developing alcohol-related liver disease (ALD) varies greatly. We hypothesized that metabolic risk factors and genetic polymorphisms predict severity of ALD.

METHODS

Biopsy-controlled, cross-sectional study in patients with a history of excessive drinking. We measured the homeostatic model assessment of insulin resistance (HOMA-IR), plasma triglycerides, high- and low-density lipoproteins (HDL, LDL), and total cholesterol. Moreover, we genotyped four single nucleotide polymorphisms in PNPLA3 (rs738409C>G), TM6SF2 (rs58542926C>T), MBOAT7 (rs641738C>T), and HSD17B13 (rs72613567T>TA). We assessed predictors of higher fibrosis stage using multivariable ordered logistic regression.

RESULTS

Of 325 included patients, 25% had severe fibrosis or cirrhosis and 59% had HOMA-IR ≥2.5. HOMA-IR increased for each fibrosis stage, while there was a similar decrease in LDL and total cholesterol. Individuals with risk variant PNPLA3 rs738409-G or TM6SF2 rs58542926-T had higher fibrosis stage. In multivariable regression, HOMA-IR ≥2.5 (OR = 3.04, 95% CI 1.90-4.87), LDL <2.60 mmol/L (OR = 2.05, 95% CI 1.33-3.16), TM6SF2 rs58542926-T (OR = 1.99, 95% CI 1.17-3.37), age above 50 years (OR = 1.66, 95% CI 1.03-2.70), and PNPLA3 rs738409-G (OR = 1.54, 95% CI 1.11-2.12) independently predicted higher fibrosis stage. Independent predictors of hepatic inflammatory activity were HOMA-IR, active drinking, age, and PNPLA3 risk variant. Active drinking, elevated triglycerides, and PNPLA3 risk variant predicted steatosis.

CONCLUSIONS

Insulin resistance is the strongest predictor of liver fibrosis stage and hepatic inflammation in patients with alcohol-related liver disease. Genetic susceptibility further aggravates this risk. These data highlight the clinical value of detailed metabolic and genetic profiling of patients with excessive alcohol use.

Lipocalin-Type Prostaglandin D2 Synthase Protein- A Central Player in Metabolism

Lipocalin-type prostaglandin D synthase was previously known as β-trace protein (BTP), a low-molecular-weight glycoprotein that is heavily expressed in human cerebrospinal fluid. Nevertheless, it is also seen to be expressed in numerous other tissues including the kidney, liver, lung, heart, adipose, muscle, and pancreas. Functionally, L-PGDS behaves like a lipocalin type protein where it helps in binding and transportation of small lipophilic substances, such as steroids, retinoids, and other lipophilic ligands. Enzymatically, L-PGDS functions as a prostaglandin synthase where it helps in the production of PGD₂ by catalyzing the isomerization of PGH₂, a common precursor of the two series of prostaglandins. PGD₂ regulates its physiological function through two individual receptors named DP1 and DP2. L-PGDS has been a central player in many diseases, its role in metabolism including diabetes, fatty liver disease, and obesity has gathered a large attention. In this review, we summarize the current state of knowledge about L-PGDS and it's signaling in adipose, hepatic, skeletal muscle, and pancreas tissues, which are core targets for metabolic studies. Modulation of L-PGDS signaling can be considered as a potential future therapeutic target for the treatment of insulin resistance as well as fatty liver disease.

Physical behaviors and their association with type 2 diabetes mellitus risk markers in urban South African middle-aged adults: an isotemporal substitutionapproach

INTRODUCTION

To examine the associations between physical behaviors and type 2 diabetes mellitus (T2DM) risk markers in middle-aged South African men and women.

RESEARCH DESIGN AND METHODS

This cross-sectional study included middle-aged men (n=403; age: median (IQR), 53.0 (47.8-58.8) years) and women (n=324; 53.4 (49.1-58.1) years) from Soweto, South Africa. Total movement volume (average movement in milli-g) and time (minutes/day) spent in different physical behaviors, including awake sitting/lying, standing, light intensity physical activity (LPA) and moderate-to-vigorous intensity physical activity (MVPA), were determined by combining the signals from two triaxial accelerometers worn simultaneously on the hip and thigh. All participants completed an oral glucose tolerance test, from which indicators of diabetes risk were derived. Associations between physical behaviors and T2DM risk were adjusted for sociodemographic factors and body composition.

RESULTS

Total movement volume was inversely associated with measures of fasting and 2-hour glucose and directly associated with insulin sensitivity, basal insulin clearance, and beta-cell function, but these associations were not independent of fat mass, except for basal insulin clearance in women. In men, replacing 30 min of sitting/lying, standing or LPA with the same amount of MVPA time was associated with 1.2-1.4 mmol/L lower fasting glucose and 12.3-13.4 mgl2/mUmin higher insulin sensitivity. In women, substituting sitting/lying with the same amount of standing time or LPA was associated with 0.5-0.8 mmol/L lower fasting glucose. Substituting 30 min sitting/lying with the same amount of standing time was also associated with 3.2 mgl2/mUmin higher insulin sensitivity, and substituting 30 min of sitting/lying, standing or LPA with the same amount of MVPA time was associated with 0.25-0.29 ng/mIU higher basal insulin clearance in women.

CONCLUSION

MVPA is important in reducing T2DM risk in men and women, but LPA appears to be important in women only. Longitudinal and intervention studies warranted to provide more specific PA recommendations.

Triglyceride-to-glucose index to detect a non-dipping circadian pattern in newly diagnosed hypertensive patients

Introduction: In this investigation, we aimed to explore the relationship between the triglyceride-glucose (TyG) index and the non-dipping blood pressure (BP) pattern in newly diagnosed hypertensive patients. Methods: In this retrospective study, 216 consecutive newly diagnosed hypertensive patients who had undergone 24-hour ambulatory blood pressure (ABPM) monitoring and had not received anti-hypertensive drugs were included. Non-dipping status was evaluated by a 24-h ABPM monitoring in all patients. We categorized the patients into two groups as; dippers (n=104 cases) and non-dippers (n=112 cases). The TyG index was derived from the fasting triglyceride and fasting glucose levels using the formula; ln[fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Results: Non-dipper group had a higher TyG index than the dipper group. The TyG was an independent predictor of non-dipping BP in hypertensive individuals, according to multivariable analysis. The TyG index was negatively associated with a decrease in both systolic and diastolic BP during the nighttime. The ideal cutoff value of the TyG index in detecting non-dipping status was≥9.01 with 74.1% sensitivity and 71.2% specificity. A ROC comparison indicated that the area under the curve value of TyG index was superior to fasting triglyceride, fasting glucose, and homeostasis model assessment of IR (HOMA-IR) in detecting non-dipping BP. Conclusion: The TyG index was an independent predictor of non-dipping status in newly diagnosed hypertensive patients who had undergone 24-hour ABPM monitoring and had not received anti-hypertensive drugs. As a simple and easily obtained parameter, the TyG index can be used to detect such pattern among these patients.

Insulin use in type II diabetic patients: a predictive of mortality in covid-19 infection

INTRODUCTION

Starting December 2019, the world has been devastated by the rapid spread of coronavirus disease 2019 (Covid-19). Many risk factors have been associated with worse outcomes and death from Covid-19 pneumonia including having diabetes mellitus. To date, it is not clear if all group of diabetics share the same risk of complications with COVID-19 infection. This study aims to compare disease severity and mortality rate in insulin users versus non-insulin users.

METHODS

In this retrospective case-control study conducted at the largest health care network in New York state, we included adult, diabetic patients admitted from March 2020 to October 2020 with Covid-19 pneumonia. We compared the baseline characteristics in addition to outcomes of diabetic patients on home insulin (cases) and non-insulin user diabetics (controls). In addition, to determine if home insulin use is associated with an increased mortality, we conducted a cox regression analysis.

RESULTS

We included 696 patients in the study period with a median age of 57 years, interquartile range [IQR] 51-62, and median body mass index 29.9 (IQR: 26-34.7). The majority (476 [68%]) were males. We identified 227 cases (33%) and 469 controls (67%). More cases than controls were hypertensive (74% vs 67%, p = 0.03), on ACE/ARB (50% vs 42%, p = 0.05), and had a hemoglobin A1c > 8.1 (71% vs 44%, p < 0.001). More cases had AKI (52% vs 38%, p < 0.001), however no significant differences were found in intubation rates (26% vs 24%, p = 0.54), detection of pulmonary embolism (4% vs 6%, p = 0.19) or death rate (15% vs 11%, p = 0.22) comparing cases and controls. In a multivariate analysis, we found that home insulin use was independently associated with increased risk of death: Hazard ratio: 1.92, 95% confidence interval (1.13-3.23).

CONCLUSION

We showed herein that diabetic patients on home insulin with COVID-19 pneumonia, have worse outcomes and increased mortality compared to diabetics on oral antihyperglycemic agents. Close monitoring of insulin-dependent type II diabetic patients is needed in the current pandemic.

Prevalence rates of metabolic health and body size phenotypes by different criteria and association with insulin resistance in a Maltese Caucasian population

INTRODUCTION

Hyperinsulinemia and insulin resistance are known to be associated with increased cardiovascular morbidity and mortality. A metabolically unhealthy phenotype is frequently used as a surrogate marker for insulin resistance. The aims of the current study were to compare the prevalence of the body size phenotypes using different definitions of metabolic health and to investigate which one of them is most strongly associated with insulin resistance in men and women.

METHODS

We conducted a cross-sectional study in a middle-aged cohort of Maltese Caucasian non-institutionalized population. Metabolic health was defined using the various currently used definitions.

RESULTS

There were significant differences in the prevalence of body size phenotypes according to the different definitions. We also found significant sex differences in the predictive value of the various definitions of the metabolically unhealthy phenotype to predict insulin resistance. The strongest association was for the definition of having >2 NCEP-ATPIII criteria to characterize the metabolic unhealthy phenotype in women (odds ratio of 19.7). On the other hand, the Aguilar-Salinas et al. definition had the strongest association in men (odds ratio of 18.7).

CONCLUSIONS

We found large differences in the prevalence of the various body size phenotypes when using different definitions, highlighting the need for having standard criteria. Our data also suggest the need for sex-specific definitions of metabolic health.

Dipeptidyl peptidase 4 inhibitor improves insulin resistance in Japanese patients with type 2 diabetes: a single-arm study, a brief report

BACKGROUND

Dipeptidyl peptidase 4 inhibitor (DPP4i) is an effective medicine for type 2 diabetes mellitus (T2DM). Some articles reported DPP4i improves insulin secretion and insulin resistance. However, these effects are not well established by glucose clamp test and test meal in Japanese. We investigated the effect of DPP4i on insulin resistance and insulin secretion by using the glucose clamp test and meal tolerance test (MTT).

METHODS

We performed a MTT, and the hyperinsulinemic-euglycemic clamp in 8 Japanese patients with T2DM. This study was a single-arm study. We measured fasting and postprandial glucose, insulin, incretins, and glucagon levels. We also measured serum adiponectin levels.

RESULTS

HbA1c was significantly decreased after 3 months. The fasting and postprandial glucose levels were significantly decreased. Fasting and postprandial insulin levels were not changed. The insulin resistance derived from the glucose clamp test was significantly improved. HOMA-IR was not significantly changed. GLP-1 and GIP were significantly increased but glucagon did not change. Adiponectin was not significantly changed.

CONCLUSIONS

Although the number of patients was very small, these results suggested that DPP4i treatment might improve insulin resistance without changing insulin secretion.

Metabolic syndrome; Definition, Pathogenesis, Elements, and the Effects of medicinal plants on it's elements

Introduction

Metabolic syndrome (MetS) is a cluster of metabolic risk factors that include central obesity, hypertension, insulin resistance, and atherogenic dyslipidemia and is strongly associated with a greater risk for developing cardiovascular disease and type 2 diabetes mellitus.

Methods

A literature search was conducted using the words metabolic syndrome, definition and pathogenesis in Scopus, and PubMed. The search also extended to cover medicinal plants and their role as a potential treatment of the metabolic syndrome. The search based on studies published in the English language from 1st of January 2000 to 30th of May 2021. The abstracts and the articles were then screened. Articles were scanned and read; further relevant references in the reference lists are also included.

Results

Both lifestyle factors and genetic factors are involved in the pathogenesis of the metabolic syndrome. Recently, MetS have gained significant attention due to the high prevalence of obesity worldwide. Diagnosis of patients with MetS is important to improve the outcomes of the disease by employing lifestyle and risk factors modifications. Currently, there is a rising interest in medicinal plants and their extracts because the medicinal plants have minimal side effects. Here we review the history, definitions, pathogenesis, management of metabolic syndrome and summarize the beneficial effects of some medicinal plants and their extracts on MetS.

Conclusion

Further research and clinical studies are needed to establish whether medicinal plants can be safely given as potential therapy for metabolic syndrome and whether this can be beneficial in low resources setting countries.

Association between Relative Handgrip Strength and Insulin Resistance in Korean Elderly Men without Diabetes: Findings of the 2015 Korea National Health Nutrition Examination Survey

BACKGROUND

Evidence regarding the association between handgrip strength (HGS) and insulin resistance in a non-diabetic population is scarce. This study aimed to investigate the association between relative HGS and insulin resistance in older men without diabetes, using a representative sample of the Korean male population.

METHODS

The study population comprised 206 participants aged 65-80 years, selected from the 2015 Korea National Health and Nutrition Examination Survey. Insulin resistance was defined as the upper tertile of the homeostatic model assessment of insulin resistance (HOMA-IR). Odds ratios and 95% confidence intervals for insulin resistance were assessed using multiple logistic regression analyses after adjusting for confounding variables.

RESULTS

The prevalence of insulin resistance decreased with increasing relative HGS. The prevalence in the T1, T2, and T3 groups was 46.0%, 32.2%, and 26.4%, respectively. Compared with the individuals in the highest tertile of relative HGS, the odds ratio (95% confidence interval) for insulin resistance in individuals in the lowest quartile was 2.82 (1.10-7.21) after adjusting for age, smoking, alcohol consumption, aerobic exercise, resistance exercise, systolic blood pressure, total cholesterol, residential area, household income, and education level.

CONCLUSION

Lower relative HGS was inversely associated with an increased risk of insulin resistance in older Korean men without diabetes. In clinical practice, relative HGS, which is a simple and inexpensive tool, could be a useful measure for identifying older men with insulin resistance. Moreover, these findings suggest that muscle strengthening exercises should be considered to reduce insulin resistance and increase insulin sensitivity.

Ameliorative Effects of Malonyl Ginsenoside from Panax ginseng on Glucose-Lipid Metabolism and Insulin Resistance via IRS1/PI3K/Akt and AMPK Signaling Pathways in Type 2 Diabetic Mice

Our previous study has revealed that malonyl-ginsenosides from Panax ginseng (PG-MGR) play a crucial role in the treatment of T2DM. However, its potential mechanism was still unclear. In this study, we investigated the anti-diabetic mechanisms of action of PG-MGR in high fat diet-fed (HFD) and streptozotocin-induced diabetic mice and determined the main constituents of PG-MGR responsible for its anti-diabetic effects. Our results showed that 16 malonyl ginsenosides were identified in PG-MGR by HPLC-ESI-MS/MS. PG-MGR treatment significantly reduced fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels and improved insulin resistance and glucose tolerance. Simultaneously, PG-MGR treatment improved liver injury by decreasing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) expression. Furthermore, Western blot analysis demonstrated that the protein expression levels of p-PI3K/PI3K, p-AKT/AKT, p-AMPK/AMPK, p-ACC/ACC and GLUT4 in liver and skeletal muscle were significantly up-regulated after PG-MGR treatment, and the protein expression levels of p-IRS-1/IRS-1, Fas and SREBP-1c were significantly reduced. These findings revealed that PG-MGR has the potential to improve glucose and lipid metabolism and insulin resistance by activating the IRS-1/PI3K/AKT and AMPK signal pathways.

Effect of Endoscopic Bariatric and Metabolic Therapies on Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Weight loss via lifestyle intervention remains the mainstay of treatment for nonalcoholic fatty liver disease (NAFLD). Endoscopic bariatric and metabolic therapies (EBMTs) have recently been developed as an alternative treatment option for obesity. This study aimed to assess the effect of FDA-approved EBMTs on NAFLD.

METHODS

We searched MEDLINE, EMBASE, Web of Science and Cochrane Central through December 2020 for studies that assessed changes in liver outcomes following EBMT. Primary Outcomes: Liver fibrosis.

SECONDARY OUTCOMES

Liver biochemistry, steatosis, NAFLD histological changes and insulin sensitivity. The Grading of Recommendations, Assessment, Development, and Evidence (GRADE) approach was conducted to assess quality of evidence.

RESULTS

Of 4994 potential studies, 18 studies with 863 patients were included. Average weight loss was 14.5% of initial weight at a 6-month follow-up. Primary outcomes: Following EBMT, liver fibrosis significantly reduced by standardized mean difference (SMD) of 0.7 (95% CI, 0.1, 1.3; P = .02).

SECONDARY OUTCOMES

There were significant improvements in other NAFLD surrogates including alanine aminotransferase (-9.0 U/L; 95% CI, -11.6, -6.4; P < .0001), hepatic steatosis (SMD: -1.0; 95% CI, -1.2, -0.8; P < .0001) and histologic NAFLD activity score (-2.50; 95% CI, -3.5, -1.5; P < .0001). Other metabolic parameters including insulin resistance and waist circumference also significantly improved. The overall quality of the evidence for primary outcomes was low to very low.

CONCLUSIONS

EBMTs appear effective at treating NAFLD with significant improvement in liver fibrosis. Given the worsening NAFLD pandemic and limitations of currently available therapies, EBMTs should be further investigated as a potential treatment option for this patient population.

Inositols in the ovaries: activities and potential therapeutic applications

INTRODUCTION

Myo-inositol (MI) and d-chiro-inositol (DCI) play a key role in ovarian physiology, as they are second messengers of insulin and gonadotropins. Ex-vivo and in-vitro experiments demonstrate that both isomers are deeply involved in steroid biosynthesis, and that reduced MI-to-DCI ratios are associated with pathological imbalance of sex hormones.

AREAS COVERED

This expert opinion provides an overview of the physiological distribution of MI and DCI in the ovarian tissues, and a thorough insight of their involvement into ovarian steroidogenesis. Insulin resistance and compensatory hyperinsulinemia dramatically reduce the MI-to-DCI ratio in the ovaries, leading to gynecological disorders characterized by hyperandrogenism, altered menstrual cycle and infertility.

EXPERT OPINION

Available evidence indicates that MI and DCI have very specific physiological roles and, seemingly, physiological MI-to-DCI ratios in the ovaries are crucial to maintain the correct homeostasis of steroids. Inositol treatments should be evaluated on the patients' specific conditions and needs, as long-term supplementation of high doses of DCI may cause detrimental effects on the ovarian functionality. In addition, the effects of inositol therapy on the different PCOS phenotypes should be further investigated in order to better tailor the supplementation.

Latent Autoimmune Diabetes in Adults and Metabolic Syndrome-A Mini Review

Latent autoimmune diabetes in adults (LADA) is a heterogeneous subtype of diabetes characterized by islet cell destruction mediated by islet autoimmunity and insulin resistance. Metabolic syndrome (MetS) is a state in which many risk factors for metabolic and cardiovascular diseases accumulate in an individual. Based on clinical data, this review covers the prevalence of MetS in LADA, focusing on the risk associated with and the role of insulin resistance in the development of LADA from the perspective of inflammatory factors, environmental factors, and the gut microbiota, aiming to improve our understanding of this condition.

Ocimum gratissimum enhances insulin sensitivity in male Wistar rats with dexamethasone-induced insulin resistance

Purpose

The antidiabetic activities of Ocimum gratissimum (OG) leaf extract are well documented in experimental diabetes induced by beta cell destruction resulting in hypoinsulinemia. There is however paucity of data on its effect in conditions characterized by hyperinsulinemia. This study therefore investigated the effect of OG on insulin resistance induced by dexamethasone in male Wistar rats.

Method

Twenty male Wistar rats grouped as control, normal + OG, Dex and Dex + OG were used. Control and normal + OG received normal saline while Dex and Dex + OG received dexamethasone (1 mg/kg, i.p) followed by distilled water or OG (400 mg/kg) for 10 days. Levels of fasting blood glucose (FBG), insulin, HOMA-IR, liver and muscle glycogen, hexokinase activities, hepatic HMG CoA reductase activity were obtained. Histopathology of pancreas and liver tissues was carried out using standard procedures.

Results

Body weight reduced significantly in the Dex and Dex + OG groups compared with the control. FBG (147.8 ± 9.93 mg/dL), insulin (2.98 ± 0.49 µIU/ml) and HOMA-IR (1.11 ± 0.22) of Dex animals were higher than the control (FBG = 89.22 ± 6.53 mg/dL; insulin = 1.70 ± 0.49 µIU/ml; HOMA-IR = 0.37 ± 0.04). These were significantly reduced in the Dex + OG (FBG = 115.31 ± 5.93 mg/dL; insulin = 1.85 ± 0.11µIU/ml; HOMA-IR = 0.53 ± 0.08) compared with Dex. Glycogen content and hexokinase activities were increased in the Dex + OG. Increased pancreatic islet size, hepatic steatosis and HMG Co A reductase activity were observed in the Dex but reduced in Dex + OG.

Conclusion

OG promotes cellular glucose utilization and reduces hepatic fat accumulation in Wistar rats with insulin resistance induced by dexamethasone. Further study to identify the involved signal transduction will throw more light on the observed effects.

Transient Insulin Resistance in Propionic Acidaemia: Knowing is half the battle

Propionic acidaemia (PPA) is a disorder of amino acid and odd-chain fatty acid metabolism. Hypoglycaemia is a more commonly described finding rather than hyperglycaemia during metabolic decompensation of PPA. There is a high mortality rate in patients with organic acidaemias having severe insulin-resistant hyperglycaemia. We report a nine-month-old boy with PPA who was admitted to tertiary care hospital in Muscat, Oman, in 2018 with metabolic decompensation, persistent hyperglycaemia and transient insulin resistance. Hyperglycaemia did not respond to high insulin infusion. Plasma glucose only improved when glucose infusion rate (GIR) reached 7 mg/kg/min. The patient has full recovery and was discharged, with follow up plan. It is important to balance the GIR to achieve the targeted insulin level, beyond which the risks of hyperglycaemia start to outweigh the potential anabolic benefits of additional insulin secretion. Timely clinical attention should be given to achieve adequate caloric delivery through alternative sources other than high GIR to permit better glycaemic control, especially when insulin-resistant hyperglycaemia is present.