Gut microbiota dysbiosis -associated obesity and its involvement in cardiovascular diseases and type 2 diabetes. A systematic review

INTRODUCTION

Obesity is a complex, multifactorial disease caused by various factors. Recently, the role of the gut microbiota in the development of obesity and its complications has attracted increasing interest.

PURPOSE

This article focuses on the mechanisms by which gut microbiota dysbiosis induces insulin resistance, type 2 diabetes, and cardiovascular diseases linked to obesity, highlighting the mechanisms explaining the role of gut microbiota dysbiosis-associated inflammation in the onset of these pathologies.

METHODS

A systematic study was carried out to understand and summarize the published results on this topic. More than 150 articles were included in this search, including different types of studies, consulted by an online search in English using various electronic search databases and predefined keywords related to the objectives of our study.

RESULTS

We have summarized the data from the articles consulted in this search, and we have found a major gut microbiota alteration in obesity, characterized by a specific decrease in butyrate-producing bacteria and the production of metabolites and components that lead to metabolic impairments and affect the progression of various diseases associated with obesity through distinct signaling pathways, including insulin resistance, type 2 diabetes, and cardiovascular diseases (CVD). We have also focused on the major role of inflammation as a link between gut microbiota dysbiosis and obesity-associated metabolic complications by explaining the mechanisms involved.

CONCLUSION

Gut microbiota dysbiosis plays a crucial role in the development of various obesity-related metabolic abnormalities, among them type 2 diabetes and CVD, and represents a major challenge for chronic disease prevention and health. Indeed, the intestinal microbiota appears to be a promising target for the nutritional or therapeutic management of these diseases.

Assessing the Burden of Kidney Disease among Type 2 Diabetic Subjects Attending a Semi-Urban Tertiary Health Facility in South-West Nigeria

BACKGROUND AND OBJECTIVES

Diabetes Mellitus (DM) remains an important public health issue and its complications are important causes of morbidity and mortality. Diabetic nephropathy (DN) is one of these complications and could be prevented/delayed by early detection. This study determined the burden of DN among patients with type 2 diabetes (T2DM).

METHODS

This cross-sectional, hospital-based study was conducted among 100 T2DM patients attending the medical outpatient clinics of a tertiary hospital in Nigeria and 100 age- and sex-matched healthy controls. The procedure included collection of sociodemographic parameters, urine for microalbuminuria and blood samples for estimation of fasting plasma glucose, glycated haemoglobin (HbA1c), and creatinine. Estimated creatinine clearance (eGFR) was derived from two formulae - Cockroft Gault formula, and Modification of Diet in Renal Disease study (MDRD) for staging chronic kidney disease. Data were analysed using the IBM SPSS version 23 software.

RESULTS

Participants' ages ranged from 28 years to 73 years [mean 53.0 (±10.7) years] with males accounting for 56% of the population and females 44%. Mean HbA1c was 7.6 (±1.8) % among the subjects; 59% had poor glycaemic control with HbA1c >7% (p-value <0.001). Overt proteinuria was present in 13% of T2DM participants while 48% had microalbuminuria compared to the non-diabetic group where 2% had overt proteinuria and 17% had microalbuminuria. Using the eGFR, chronic kidney disease was present in 14% of T2DM group and in 6% of the non-diabetic population. Increased age [OR= 1.09; 95%CI (1.03-1.14)], male sex [OR = 3.50; 95%CI (1.13 10.88)], and duration of diabetes [OR =1.01; 95%CI (1.00-1.01)] were associated with DN.

CONCLUSION

The burden of diabetic nephropathy is high in the T2DM patients attending our clinic and this is linked with advancing age.

Creatinine-to-cystatin C ratio as a marker of sarcopenia for identifying osteoporosis in male patients with type 2 diabetes mellitus

Background

Type 2 diabetes mellitus (T2DM) is associated with the increased incidence rate of sarcopenia and osteoporosis. Serum creatinine-to-cystatin C ratio (CCR) is a novel and simple tool which can be used as an index of sarcopenia. This study aims to investigate the association between CCR and osteoporosis as well as bone mineral density (BMD) in T2DM patients.

Methods

Four hundred eighteen T2DM patients were recruited, including 166 females and 252 males. General information, BMD data and laboratory data were collected. The correlation between CCR, BMD, bone metabolism markers and osteoporosis was explored by spearman correlation, receiver-operating characteristic (ROC) curve analysis and multiple regression analysis.

Results

Spearman correlation analysis showed that there was a positive correlation between CCR and BMD as well as serum calcium in male patients (r = 0.181–0.381, P < 0.01), but such correlation was not found in the female group. In multivariate regression analysis, it was found that there was a significant correlation between CCR and BMD of total lumbar spine, hip as well as femoral neck in male patients. ROC curve showed that the optimal cut-off value of CCR for predicting osteoporosis in male patients was 6.73 with the sensitivity of 88% and specificity of 63%.

Conclusion

In male T2DM patients, CCR was negatively correlated with osteoporosis and positively correlated with BMD.

Effect of Ramadan fasting on renal function of people with diabetes; a prospective longitudinal study

AIM

To observe the effect of Ramadan fasting on renal function of people with diabetes.

METHODS

This prospective, observational, and longitudinal study was conducted at Baqai Institute of Diabetology and Endocrinology, between April-July 2019. People with type2 diabetes mellitus were recruited using convenient sampling. Demographic data along with renal function were recorded before Ramadan. Kidney functions were assessed in those who came for follow up at 6 weeks, 3 months, and a year after Ramadan.

RESULTS

A total of seventy people with diabetes participated in this study with the mean age of 53.11 ± 8.70 years. A significant decline in eGFR was noted around six weeks post Ramadan with a significant improvement of eGFR at 3 months follow-up. The normalization of kidney functions among the study participants was observed even after one year of Ramadan.

CONCLUSION

In this study post Ramadan assessment of creatinine clearance showed a significant fall among fasting people with diabetes though remained with in normal limits. Significant improvement and reversal of kidney functions was noted in those who followed within three months' time.

Interpretation of clinical trials on the cardiovascular effects of hypoglycemic drugs in people with type2 diabetes

Randomized clinical trials on the cardiovascular effects of hypoglycemic drugs on people with type2 diabetes mellitus began more than fifty years ago. In the last decade, the emergence of new classes of hypoglycemic drugs has led to the development of randomized clinical trials to assess their cardiovascular safety. Known as Cardiovascular Outcome Trials, they have provided a lot of new information that needs to be critically appraised if the knowledge obtained is to be applicable in clinical practice. To this end, the current article first comments on the guidelines to which these trials have adhered, then reviews some concepts for improving their interpretation (such as different types of analyses, the definition of objectives and the evaluation of their results), and concludes by mentioning the new guidelines to which future trials designed to evaluate the safety of new hypoglycemic drugs should adhere.

Irs2 deficiency alters hippocampus-associated behaviors during young adulthood

Type 2 diabetes mellitus (T2DM), characterized by hyperglycemia and insulin resistance, has been recognized as a risk factor for cognitive impairment and dementia, including Alzheimer's disease (AD). Insulin receptor substrate2 (IRS2) is a major component of the insulin/insulin-like growth factor-1 signaling pathway. Irs2 deletion leads to life-threatening T2DM, promoting premature death in male mice regardless of their genetic background. Here, we showed for the first time that young adult male mice lacking Irs2 on a C57BL/6J genetic background (Irs2^-/-/6J) survived in different experimental environments and displayed hippocampus-associated behavioral alterations. Young adult male Irs2^-/-/6J mice also exhibit aberrant alterations in energy and nutrient sensors, such as AMP-activated protein kinase (AMPK) and glucose transporter3 (GLUT3), and reduced core body temperature accompanied by abnormal change in the temperature sensor in the brain. These results suggest that Irs2 deficiency-induced impairments of brain energy metabolism and thermoregulation contribute to hippocampus-associated behavioral changes in young adult male mice.

The KLF14 Variant is Associated with Type 2 Diabetes and HbA1C Level

The purpose of this study was to scan variants in coding region of Krȕppel like factor14 (KLF14) locus and assess association related to type 2 diabetes (T2D) in Iranian population. We sequenced the coding region of KLF14 to scan variants in case-sibling study (92 individuals with T2D and 92 healthy older siblings). To confirm, we analyzed rs76603546 association with T2D in a larger unrelated case-control study by PCR-RFLP (475 cases and 512 controls). We analyzed the association of rs76603546 with HbA_1C, BMI, fat mass, waist circumference, fasting glucose, cholesterol and HOMA-IR (Homeostatic Model Assessment for Insulin Resistance) using one-way ANOVA analysis. Also, association of genotypes with T2D adjusted for confounding variables was analyzed using logistic regression. HaploReg v 4.1 was used to predict rs76603546 possible function. Sequencing results analysis revealed the association of C allele of rs76603546, synonymous variant C>T, [OR 2.10 (1.38-3.20), P value < 0.001] and CC genotype of rs76603546 [OR 4.3 (1.79-10.23), P value = 0.001] with susceptibility to T2D. PCR-Restriction Fragment Length Polymorphism (RFLP) results analysis confirmed the association of rs76603546 with T2D [C allele, OR 1.91 (1.59-2.29), P value = 0.002, CC genotype, OR 3.27 (2.26-4.73), P value = 0.002 and TC genotype, OR 1.74 (1.31-2.31), P value = 0.001]. The CC genotype of rs76603546 is associated with HbA_1C level (P value < 0.001) and BMI (P value = 0.02). After adjustment with confounding variables, we observed association of CC genotype with T2D [OR 2.542 (1.25-3.77), P value = 0.03]. Among over 220 SNPs, rs76603546 was associated with T2D, HbA_1C and BMI in our study.

Evaluation of Relationship Between Arylesterase-Based Activity and Genetic Variants of Paraoxonase1 in T2DM Patients within Golestan Province

Arylesterase activity of Paraoxonase-1 (PON1) enzyme may be play important role in initiation and progression of several diseases. Activity or serum level of Arylesterase can be affected by many genetic alterations such as SNPs. The reduction in the activity and serum level of Arylesterase could be involved in Type2 diabetes mellitus (T2DM). The aim of this investigation is to examine the association between Arylesterase activity and promoter polymorphism (- 108C > T) of PON1gene in patients with T2DM in Golestan Province, northern area of Iran. Achievement of this purpose was due to DNA obtaining from blood then SNP determination using PCR-RFLP and Arylesterase activity measurement in the serum of 90 normal individuals and 90patients suffering diabetes. Data was processed by SPSS software version 16. The significant association was observed between the Arylesterase activity and three genotypes of PON1 gene such as CC, CT, and TT in subjects with T2DM. In the present study, it has been shown level of Arylestrase activity of PON1 in patients (117.33 ± 63.96) is lower than it in control group (289.33 ± 68.38); P < 0.05. Our results declared that activity of Arylesterase in diabetic patients was significantly lower than the healthy individuals.

Estimation of potential risk of allyl alcohol induced liver injury in diabetic patients using type 2 diabetes spontaneously diabetic Torii-Leprfa (SDT fatty) rats

In order to estimate the potential risk of chemicals including drug in patients with type 2 diabetes mellitus (T2DM), we investigated allyl alcohol induced liver injury using SD rats and Spontaneously Diabetic Torii-Lepr^fa (SDT fatty) rats as a model for human T2DM. The diabetic state is one of the risk factors for chemically induced liver injury because of lower levels of glutathione for detoxification by conjugation with chemicals and environmental pollutants and their reactive metabolites. Allyl alcohol is metabolized to a highly reactive unsaturated aldehyde, acrolein, which is detoxified by conjugation with glutathione. Therefore, we used allyl alcohol as a model compound. Our investigations showed that SDT fatty rats appropriately mimic the diabetic state in humans. The profiles of glucose metabolism, hepatic function tests and glutathione synthesis in the SDT fatty rats were similar to those in patients with T2DM. Five-week oral dosing with allyl alcohol to the SDT fatty rats revealed that the allyl alcohol induced liver injury was markedly enhanced in the SDT fatty rats when compared with the SD rats and the difference was considered to be due to lower hepatic detoxification of acrolein, the reactive metabolite of allyl alcohol, by depleted hepatic glutathione synthesis. Taking all the results of the present study into consideration, the potential for allyl alcohol to induce liver injury is considered to be higher in diabetic patients than in healthy humans.

Sitagliptin vs. pioglitazone as add-on treatments in patients with uncontrolled type 2 diabetes on the maximal dose of metformin plus sulfonylurea

AIMS

To compare the efficacy of sitagliptin versus pioglitazone as add-on drugs in patients with poorly controlled diabetes with metformin and sulfonylureas.

METHODS

This is a randomized, open-label, parallel assignment clinical trial. Patients who had inadequate glycemic control [7% (53 mmol/mol) ≤ A1C < 11% (97 mmol/mol)] despite a minimum 6-month period of active treatment with metformin 2000 mg/day plus gliclazide 240 mg/day were enrolled in the study. HbA1C, fasting blood glucose (FBG), fasting plasma lipid parameters [total cholesterol (TC0, low-density lipoprotein cholesterol (LDL-C), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C)], systolic and diastolic blood pressure (SBP, DBP), weight, waist circumference, and body mass index were measured at baseline and after 17, 34, and 52 weeks of treatment. Generalized estimating equation analysis was done to compare treatment groups for continuous efficacy parameters.

RESULTS

No significant difference in HbA1C reduction was observed between the treatment groups during the study course. (P = 0.149, adjusted P = 0.434; coefficient - 0.11 ± 0.08). The FBG (P = 0.032; coefficient 7.44 ± 3.48), HDL-C (P = 0.001; coefficient - 2.69 ± 0.83), TG (P = 0.027; coefficient 12.63 ± 5.71) and SBP (P < 0.001; coefficient 5.43 ± 1.26) changes from baseline, and weight gain were greater in the pioglitazone group. The mean changes in LDL-C and TC from baseline to week 52 were greater in the sitagliptin group (P = 0.034; coefficient - 7.40 ± 3.50, P = 0.013; coefficient - 7.16 ± 2.88, respectively).

CONCLUSION

Sitagliptin and pioglitazone were equally effective in improvement of HbA1C. There were some differences in terms of lipid indices, weight gain, and SBP. The current study confirmed that both sitagliptin and pioglitazone are effective treatment options and the decision should be made for each individual based on the baseline characteristics.

Inflammatory, oxidative stress and anti-oxidative markers in patients with endometrial carcinoma and diabetes

BACKGROUND

The role of chronic inflammation and oxidative stress in the development of diabetes and cancer has been established. In this study, we aimed to investigate inflammatory and oxidative stress markers in patients with diabetes (DM) and endometrial carcinoma (EC) separately and in combination.

METHODS

In a case-control study design, a total of 88 participants were enrolled including: 37 patients with EC (19 with DM and 18 without DM), 29 with type2 diabetes and 22 healthy controls. Cancer patients were sampled before treatment. Serum oxidative stress markers including: oxidized low density lipoprotein (ox-LDL,) nitric oxide (NO), advanced glycation end-products (AGEs) and advanced oxidation protein products (AOPP), malondialdehyde (MDA); ferric reducing ability of plasma (FRAP), as an antioxidant marker, and inflammatory markers including: Interleukin 6 (IL6), C reactive protein (CRP) and tumor necrosis factor alpha (TNFα) were measured.

RESULTS

Ox-LDL, NO, MDA, AOPP and AGE were increased in all patients either with endometrial carcinoma and/or diabetes compared to healthy controls (p < 0.05). Patients with both EC and DM had higher oxidative markers including: OX-LDL (17.47 ± 0.84 vs. 12.36 ± 0.91), NO (82.27 ± 5.75 vs. 76.34 ± 5.36), MDA (3.3 ± 0.1 vs. 2.75 ± 0.48) and AGE (73.89 ± 5.71 vs. 69.02 ± 3.14) compared to those with EC alone (ρ < 0.05). Levels of FRAP was lower in patients with both diabetes and cancer, cancer alone and diabetes alone compared to healthy controls (p < 0.05). Inflammatory markers, TNFα, IL6 and hs-CRP, were also significantly increased in patients with EC with and without DM compared to controls (ρ < 0.05). However, there were no significant differences between two groups of EC regarding to inflammatory markers (ρ > 0.05). Patients with DM had significantly higher levels of inflammatory markers compared to control group (all ρ < 0.05). In addition, significant subadditive interaction effect between EC and DM regarding levels of oxLDL, NO, AGE, AOPP and FRAP) was observed (p < 0.05).

CONCLUSION

Increased levels of chronic inflammatory and oxidative stress markers were observed in both endometrial carcinoma and diabetes. Additional effect of diabetes in patients with cancer was mediated more significantly via increase in oxidative stress rather than inflammatory markers.

Inflammation role in sensory neuropathy in Chinese patients with diabetes/prediabetes

OBJECTIVES

Prediabetes involves people with glucose-metabolism impairment, and is related to different diabetic complications, like peripheral neuropathy. We aimed to explore the relationship among inflammatory (tumor necrosis factor alpha [TNFα]) and antiinflammatory (interleukin 10 [IL10]) cytokines as well as neuropathy of very distal-sensory-nerves in Chinese patients with prediabetes/diabetes.

PATIENTS AND METHODS

In the present study, 55 patients having prediabetes, 55 patients having type 2 diabetes mellitus (DM), and 48 controls were included. TNFα, HbA1c, and IL10 plasma levels were measured. Electrodiagnosis was conducted on dorsal-sural/medial-plantar sensory nerve, that is most distal feet sensory-nerves.

RESULTS

Nerve conduction test (NCT) irregularities of dorsal-sural/medial-plantar sensory nerve were considerably greater in patients with prediabetes or diabetes. The means of TNFα levels demonstrated a significant increase in patients with diabetes when compared to prediabetes patients as well as controls showed a significant decrease in patients with prediabetes and diabetes contrasted with controls. No significant contrast with respect to serum biomarkers among patients having regular as well as irregular medial-plantar/dorsal-sural NCT was noted. Critical correlationship among TNFα as well as HbA1c with symptoms severity as well as disability while negative correlations of IL10 with neuropathy severity was noted. Biomarker levels of TNFα, IL10, and HbA1c were noted to differ significantly among patients without/with neuropathy.

CONCLUSION

All in all, the proinflammatory phase appears to start from initial pre-clinical phases, sometime prior to advancement of diabetes. The higher neuropathy frequency in patients with prediabetes indicates conceivable causative impact; although, the prospective part of inflammation in pathogenetics of peripheral neuropathy requires more elucidation.

Anti-islet Cell Antibodies in a Sample of Egyptian Females with Gestational Diabetes and its Relation to Development of Type 1 Diabetes Mellitus

BACKGROUND

Gestational diabetes mellitus is any degree of glucose intolerance with first diagnosis during pregnancy; it affects 3-10% of pregnancies. The presence of diabetes-related autoantibodies has shown to be able to predict the development of type 1 diabetes before hyperglycemia arises.

OBJECTIVE

To recognize the prevalence of islet cell antibodies among a sample of Egyptian females with gestational diabetes and its possible relation to development of Type 1 diabetes within one year postpartum.

METHODS

Our cross sectional study was conducted on 150 Egyptian pregnant females with gestational diabetes aged 19-39 years diagnosed by 75-g 2-hour oral glucose tolerance test. All females were subjected to full history, thorough clinical examination and laboratory measurement of anti-islet cell antibodies. Those females with positive antibodies were followed up six months and one year after delivery for their fasting insulin, fasting blood glucose and two hours post prandial glucose levels.

RESULTS

The prevalence of pregnant females with gestational diabetes having positive anti islet cell antibodies was (44%), the prevalence of females diagnosed to have diabetes mellitus was (37.88%) six months and (51.52%) one year postpartum.

CONCLUSION

The high prevalence of ICAs among pregnant Egyptian females with GDM and the risk of developing type 1diabetes later in life makes screening for ICA among women with GDM important to recognize those at risk of developing type 1 diabetes later in life.

Effects of Urtica dioica supplementation on blood lipids, hepatic enzymes and nitric oxide levels in type 2 diabetic patients: A double blind, randomized clinical trial

OBJECTIVE

Oxidative stress plays an important role in the development of diabetic complications including metabolic abnormality-induced diabetic micro-vascular and macro-vascular complications. Urtica dioica L. (U. dioica) has been traditionally used in Iranian medicine as an herbal remedy for hypoglycemic or due to its anti-inflammatory properties. The aim of the present study was to evaluate the effects of hydro-alcoholic extract of U. dioica on blood lipids, hepatic enzymes and nitric oxide levels in patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

50 women with type 2 diabetes participated in this study and were randomly divided into two groups namely, control and intervention groups. Control group received placebo and intervention group received hydro-alcoholic extract of U. dioica. Before and after 8 weeks of continuous treatment, some biochemical serum levels including FPG, TG, SGPT, SGOT, HDL, LDL, SOD and NO were measured.

RESULTS

The results indicated that after 8 weeks, in the intervention group, FPG, TG, and SGPT levels significantly decreased and HDL, NO and SOD levels significantly increased as compared to the control group.

CONCLUSION

Our results encourage the use of hydro-alcoholic extract of U. dioica as an antioxidant agent for additional therapy of diabetes as hydro-alcoholic extract of U. dioica may decrease risk factors of cardiovascular incidence and other complications in patients with diabetes mellitus.

[Morbidity and mortality cardiovascular risk in dependence of type 2 diabetes duration]

INTRODUCTION

This study was aimed to assess the prognostic importance of diabetes duration to predict cardiovascular risk in type 2 diabetic patients.

METHODS

Prospective cohort study with inclusion of type 2 diabetic patients. Follow-up lasted until the appearance of a cardiovascular event, until death or until 2012. Patients were classified into 5 groups in accordance to diabetes duration and baseline cardiovascular disease (CVD): group 1: ≤ 5 years without CVD; group 2: 6-10 years without CVD; group 3: 11-15 years without CVD; group 4: >15 years without CVD; group 5: baseline CVD independently of diabetes duration. CVD rates were expressed per 1000 patients-year and compared by Kaplan-Meier analysis and Log Rank Test. The predictive power of diabetes duration was evaluated by Cox regression.

RESULTS

457 patients, aged 64.9 (DE 9.3) years (38.9% males), were included. Diabetes duration was 10.5 (DE 7.6) years. 125 cardiovascular events occurred during 12.3 years follow-up. Cardiovascular event rates were progressively increased from groups 1 to 5 (group 1: 14.1; group 2: 18.3; group 3: 19.6; group 4: 32.9; group 5: 53.5; p<0.0001, linear tendency). Diabetes duration superior to 15 years significantly increased cardiovascular risk of the patients (HR=1.97; 95%CI: 1.23-3.15; P=.004).

CONCLUSIONS

It could be useful to consider diabetes duration in order to stratify cardiovascular risk of type 2 diabetic patients.