Monocytes Release Pro-Cathepsin D to Drive Blood-to-Brain Transcytosis in Diabetes.

BACKGROUND: Microvascular complications are the major outcome of type 2 diabetes progression, and the underlying mechanism remains to be determined. METHODS: High-throughput RNA sequencing was performed using human monocyte samples from controls and diabetes. The transgenic mice expressing human CTSD (cathepsin D) in the monocytes was constructed using CD68 promoter. In vivo 2-photon imaging, behavioral tests, immunofluorescence, transmission electron microscopy, Western blot analysis, vascular leakage assay, and single-cell RNA sequencing were performed to clarify the phenotype and elucidate the molecular mechanism. RESULTS: Monocytes expressed high-level CTSD in patients with type 2 diabetes. The transgenic mice expressing human CTSD in the monocytes showed increased brain microvascular permeability resembling the diabetic microvascular phenotype, accompanied by cognitive deficit. Mechanistically, the monocytes release nonenzymatic pro-CTSD to upregulate caveolin expression in brain endothelium triggering caveolae-mediated transcytosis, without affecting the paracellular route of brain microvasculature. The circulating pro-CTSD activated the caveolae-mediated transcytosis in brain endothelial cells via its binding with low-density LRP1 (lipoprotein receptor-related protein 1). Importantly, genetic ablation of CTSD in the monocytes exhibited a protective effect against the diabetes-enhanced brain microvascular transcytosis and the diabetes-induced cognitive impairment. CONCLUSIONS: These findings uncover the novel role of circulatory pro-CTSD from monocytes in the pathogenesis of cerebral microvascular lesions in diabetes. The circulatory pro-CTSD is a potential target for the intervention of microvascular complications in diabetes.

Maintenance of Enteral ACE2 Prevents Diabetic Retinopathy in Type 1 Diabetes.

BACKGROUND: We examined components of systemic and intestinal renin-angiotensin system on gut barrier permeability, glucose homeostasis, systemic inflammation, and progression of diabetic retinopathy (DR) in human subjects and mice with type 1 diabetes (T1D). METHODS: T1D individual with (n=18) and without (n=20) DR and controls (n=34) were examined for changes in gut-regulated components of the immune system, gut leakage markers (FABP2 [fatty acid binding protein 2] and peptidoglycan), and Ang II (angiotensin II); Akita mice were orally administered a Lactobacillus paracasei (LP) probiotic expressing humanized ACE2 (angiotensin-converting enzyme 2) protein (LP-ACE2) as either a prevention or an intervention. Akita mice with genetic overexpression of humanAce2 by small intestine epithelial cells (Vil-Cre.hAce2KI-Akita) were similarly examined. After 9 months of T1D, circulatory, enteral, and ocular end points were assessed. RESULTS: T1D subjects exhibit elevations in gut-derived circulating immune cells (ILC1 cells) and higher gut leakage markers, which were positively correlated with plasma Ang II and DR severity. The LP-ACE2 prevention cohort and genetic overexpression of intestinal ACE2 preserved barrier integrity, reduced inflammatory response, improved hyperglycemia, and delayed development of DR. Improvements in glucose homeostasis were due to intestinal MasR activation, resulting in a GSK-3ß (glycogen synthase kinase-3 beta)/c-Myc (cellular myelocytomatosis oncogene)-mediated decrease in intestinal glucose transporter expression. In the LP-ACE2 intervention cohort, gut barrier integrity was improved and DR reversed, but no improvement in hyperglycemia was observed. These data support that the beneficial effects of LP-ACE2 on DR are due to the action of ACE2, not improved glucose homeostasis. CONCLUSIONS: Dysregulated systemic and intestinal renin-angiotensin system was associated with worsening gut barrier permeability, gut-derived immune cell activation, systemic inflammation, and progression of DR in human subjects. In Akita mice, maintaining intestinal ACE2 expression prevented and reversed DR, emphasizing the multifaceted role of the intestinal renin-angiotensin system in diabetes and DR.

eNAMPT is a novel therapeutic target for mitigation of coronary microvascular disease in type 2 diabetes.

AIMS/HYPOTHESIS: Individuals with diabetes are at high risk of cardiovascular complications, which significantly increase morbidity/mortality. Coronary microvascular disease (CMD) is recognised as a critical contributor to the increased cardiac mortality observed in people with diabetes. Therefore, there is an urgent need for treatments that are specific to CMD. eNAMPT (extracellular nicotinamide phosphoribosyltransferase) is a damage-associated molecular pattern and TLR4 ligand, whose plasma levels are elevated in people with diabetes. This study was thus designed to investigate the pathogenic role of intracellular nicotinamide phosphoribosyltransferase (iNAMPT) and eNAMPT in promoting the development of CMD in a preclinical murine model of type 2 diabetes. METHODS: An inducible type 2 diabetic mouse model was generated by a single injection of low-dose streptozocin (75 mg/kg, i.p.) combined with a high-fat diet for 16 weeks. The in vivo effects of i/eNAMPT inhibition on cardiac endothelial cell (CEC) function were evaluated by using Nampt+/- heterozygous mice, chronic administration of eNAMPT-neutralising monoclonal antibody (mAb) or use of an NAMPT enzymatic inhibitor (FK866). RESULTS: As expected, diabetic wild-type mice exhibited significantly lower coronary flow velocity reserve (CFVR), a determinant of coronary microvascular function, compared with control wild-type mice. eNAMPT plasma levels or expression in CECs were significantly greater in diabetic mice than in control mice. Furthermore, in comparison with diabetic wild-type mice, diabetic Nampt+/- heterozygous mice showed markedly improved CFVR, accompanied by increased left ventricular capillary density and augmented endothelium-dependent relaxation (EDR) in the coronary artery. NAMPT inhibition by FK866 or an eNAMPT-neutralising mAb significantly increased CFVR in diabetic mice. Furthermore, administration of the eNAMPT mAb upregulated expression of angiogenesis- and EDR-related genes in CECs from diabetic mice. Treatment with either eNAMPT or NAD+ significantly decreased CEC migration and reduced EDR in coronary arteries, partly linked to increased production of mitochondrial reactive oxygen species. CONCLUSIONS/INTERPRETATION: These data indicate that increased i/eNAMPT expression contributes to the development of diabetic coronary microvascular dysfunction, and provide compelling support for eNAMPT inhibition as a novel and effective therapeutic strategy for CMD in diabetes.

The association of chronic complications with time in tight range and time in range in people with type 1 diabetes: a retrospective cross-sectional real-world study.

AIMS/HYPOTHESIS: The aim of this study was to evaluate the association of chronic complications with time in tight range (TITR: 3.9-7.8 mmol/l) and time in range (TIR: 3.9-10.0 mmol/l) in people with type 1 diabetes. METHODS: The prevalence of microvascular complications (diabetic retinopathy, diabetic nephropathy and diabetic peripheral neuropathy [DPN]) and macrovascular complications according to sensor-measured TITR/TIR was analysed cross-sectionally in 808 adults with type 1 diabetes. Binary logistic regression was used to evaluate the association between TITR/TIR and the presence of complications without adjustment, with adjustment for HbA1c, and with adjustment for HbA1c and other confounding factors (sex, age, diabetes duration, BMI, BP, lipid profile, smoking, and use of statins and renin-angiotensin-aldosterone system inhibitors). RESULTS: The mean TITR and TIR were 33.9 ± 12.8% and 52.5 ± 15.0%, respectively. Overall, 46.0% had any microvascular complication (34.5% diabetic retinopathy, 23.8% diabetic nephropathy, 16.0% DPN) and 16.3% suffered from any macrovascular complication. The prevalence of any microvascular complication, diabetic retinopathy, diabetic nephropathy and a cerebrovascular accident (CVA) decreased with increasing TITR/TIR quartiles (all ptrend<0.05). Each 10% increase in TITR was associated with a lower incidence of any microvascular complication (OR 0.762; 95% CI 0.679, 0.855; p<0.001), diabetic retinopathy (OR 0.757; 95% CI 0.670, 0.856; p<0.001), background diabetic retinopathy (OR 0.760; 95% CI 0.655, 0.882; p<0.001), severe diabetic retinopathy (OR 0.854; 95% CI 0.731, 0.998; p=0.048), diabetic nephropathy (OR 0.799; 95% CI 0.699, 0.915; p<0.001), DPN (OR 0.837; 95% CI 0.717, 0.977; p=0.026) and CVA (OR 0.651; 95% CI 0.470, 0.902; p=0.010). The independent association of TITR with any microvascular complication (OR 0.867; 95% CI 0.762, 0.988; p=0.032), diabetic retinopathy (OR 0.837; 95% CI 0.731, 0.959; p=0.010), background diabetic retinopathy (OR 0.831; 95% CI 0.705, 0.979; p=0.027) and CVA (OR 0.619; 95% CI 0.426, 0.899; p=0.012) persisted after adjustment for HbA1c. Similar results were obtained when controlling for HbA1c and other confounding factors. CONCLUSIONS/INTERPRETATION: TITR and TIR are inversely associated with the presence of microvascular complications and CVA in people with type 1 diabetes. Although this study was not designed to establish a causal relationship, this analysis adds validity to the use of TITR and TIR as key measures in glycaemic management. TRIAL REGISTRATION: ClinicalTrials.gov NCT02601729 and NCT02898714.

Adherence to a Mediterranean diet is associated with a lower risk of diabetic kidney disease among individuals with hyperglycemia: a prospective cohort study.

BACKGROUND: Type 2 diabetes is associated with a variety of complications, including micro- and macrovascular complications, neurological manifestations and poor wound healing. Adhering to a Mediterranean Diet (MED) is generally considered an effective intervention in individuals at risk for type 2 diabetes mellitus (T2DM). However, little is known about its effect with respect to the different specific manifestations of T2DM. This prompted us to explore the effect of MED on the three most significant microvascular complications of T2DM: diabetic retinopathy (DR), diabetic kidney disease (DKD), and vascular diabetic neuropathies (DN). METHODS: We examined the association between the MED and the incidence of these microvascular complications in a prospective cohort of 33,441 participants with hyperglycemia free of microvascular complications at baseline, identified in the UK Biobank. For each individual, we calculated the Alternate Mediterranean Diet (AMED) score, which yields a semi-continuous measure of the extent to which an individual's diet can be considered as MED. We used Cox proportional hazard models to analyze hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics, lifestyle factors, medical histories and cardiovascular risk factors. RESULTS: Over a median of 12.3 years of follow-up, 3,392 cases of microvascular complications occurred, including 1,084 cases of diabetic retinopathy (DR), 2,184 cases of diabetic kidney disease (DKD), and 632 cases of diabetic neuropathies (DN), with some patients having 2 or 3 microvascular complications simultaneously. After adjusting for confounders, we observed that higher AMED scores offer protection against DKD among participants with hyperglycemia (comparing the highest AMED scores to the lowest yielded an HR of 0.79 [95% CIs: 0.67, 0.94]). Additionally, the protective effect of AMED against DKD was more evident in the hyperglycemic participants with T2DM (HR, 0.64; 95% CI: 0.50, 0.83). No such effect, however, was seen for DR or DN. CONCLUSIONS: In this prospective cohort study, we have demonstrated that higher adherence to a MED is associated with a reduced risk of DKD among individuals with hyperglycemia. Our study emphasizes the necessity for continued research focusing on the benefits of the MED. Such efforts including the ongoing clinical trial will offer further insights into the role of MED in the clinical management of DKD.

Social Isolation, Loneliness, and Risk of Microvascular Complications Among Individuals With Type 2 Diabetes Mellitus.

RATIONALE & OBJECTIVE: Social disconnection has been associated with poor cardiometabolic health. This study sought to investigate the associations of social isolation and loneliness with diabetic microvascular complications (DMCs) among individuals with type 2 diabetes mellitus (T2DM) and compare these associations versus those related to traditional risk factors. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: A total of 24,297 UK Biobank participants with T2DM and no DMCs at baseline. EXPOSURE: Social isolation and loneliness were measured using self-reported questionnaires. OUTCOME: The incidence of DMCs defined as a composite of diabetic kidney disease, diabetic retinopathy, or diabetic neuropathy. ANALYTICAL APPROACH: Multivariable cause-specific hazards regression. To compare the relative importance of social disconnection with other established factors, the R2 values of the Cox models were calculated. RESULTS: During a median follow-up of 12.6 years, 5,530 patients were documented to experience DMCs (3,458 with diabetic kidney disease, 2,255 with diabetic retinopathy, and 1,146 with diabetic neuropathy). The highest level of social isolation was associated with an increased risk of any DMC component (most vs least: HR, 1.13; 95% CI, 1.05-1.22), especially diabetic kidney disease (HR, 1.14; 95% CI, 1.04-1.25) and neuropathy (HR, 1.31; 95% CI, 1.11-1.53). Any level of loneliness was associated with an increased risk of any DMC component (HR, 1.12; 95% CI, 1.02-1.23) and diabetic kidney disease (HR, 1.16; 95% CI, 1.03-1.30). Social isolation and loneliness exhibited associations with DMCs comparable to those of other conventional risk factors, including smoking, blood pressure, and physical activity. LIMITATIONS: Limited generalizability related to the composition of participants in the UK Biobank Study. CONCLUSIONS: Social isolation and loneliness were independently associated with a higher risk of incident DMCs among individuals with T2DM, with comparable importance to other traditional risk factors. These findings underscore social isolation and loneliness as novel and potentially modifiable risk factors for DMCs. PLAIN-LANGUAGE SUMMARY: Social isolation and loneliness are important social determinants that are associated with adverse cardiometabolic health. Individuals with diabetes are particularly vulnerable to social isolation and loneliness. However, the relationship of social isolation or loneliness with diabetic microvascular complications (DMCs) remains unclear. Our study used the UK Biobank study data to investigate the associations of social isolation and loneliness with the development of DMCs. We found that social isolation and loneliness were independently associated with a higher risk of incident DMCs. Remarkably, their association with DMCs was comparable to those of other lifestyle factors such as smoking, blood pressure, and physical activity. These findings collectively imply that social isolation and loneliness are 2 important potentially modifiable risk factors for DMCs among individuals with type 2 diabetes mellitus.

Clinically relevant stratification of patients with type 2 diabetes by using continuous glucose monitoring data.

AIM: The wealth of data generated by continuous glucose monitoring (CGM) provides new opportunities for revealing heterogeneities in patients with type 2 diabetes mellitus (T2DM). We aimed to develop a method using CGM data to discover T2DM subtypes and investigate their relationship with clinical phenotypes and microvascular complications. METHODS: The data from 3119 patients with T2DM who wore blinded CGM at an academic medical centre was collected, and a glucose symbolic pattern (GSP) metric was created that combined knowledge-based temporal abstraction with numerical vectorization. The k-means clustering was applied to GSP to obtain subgroups of patients with T2DM. Clinical characteristics and the presence of diabetic retinopathy and albuminuria were compared among the subgroups. The findings were validated in an independent population comprising 773 patients with T2DM. RESULTS: By using GSP, four subgroups were identified with distinct features in CGM profiles and parameters. Moreover, the clustered subgroups differed significantly in clinical phenotypes, including indices of pancreatic ß-cell function and insulin resistance (all p < .001). After adjusting for confounders, group C (the most insulin resistant) had a significantly higher risk of albuminuria (odds ratio = 1.24, 95% confidence interval: 1.03-1.39) relative to group D, which had the best glucose control. These findings were confirmed in the validation set. CONCLUSION: Subtyping patients with T2DM using CGM data may help identify high-risk patients for microvascular complications and provide insights into the underlying pathophysiology. This method may help refine clinically meaningful stratification of patients with T2DM and inform personalized diabetes care.

Investigating the causal association of generalized and abdominal obesity with microvascular complications in patients with type 2 diabetes: A community-based prospective study.

AIM: The paradoxical protective association between overweight/obesity and diabetic microvascular complications (DMC), a phenomenon well-known as the obesity paradox, has been considered a non-causal association based on methodological influences. We aimed to investigate the association of generalized and abdominal obesity, as measured by body mass index (BMI) and waist circumference (WC), respectively, with DMC in patients with type 2 diabetes (T2D), using a causal inference approach. MATERIALS AND METHODS: We enrolled 1436 patients with clinically diagnosed T2D but not DMC at baseline in a community-based prospective cohort in China between 2017 and 2019 and followed them annually until 2022 with new-onset DMC recorded. Marginal structural Cox models with inverse probability weighting were constructed to determine the causal association. Subgroup analyses were performed to identify potential effect modifiers. RESULTS: We observed 360 incident DMC cases, including 109 cases of diabetic nephropathy (DN) and 277 cases of diabetic retinopathy (DR) during four follow-up visits. Multivariable-adjusted hazard ratios (95% confidence intervals) for overall DMC, DN and DR were 1.037 (1.005-1.071), 1.117 (1.062-1.175) and 1.018 (0.980-1.059) for 1 kg/m2 increase in BMI, and 1.005 (0.994-1.017), 1.034 (1.018-1.051) and 1.000 (0.987-1.014) for 1 cm increase in WC, respectively. Similar patterns were observed across the BMI and WC categories, while the positive association appeared to be more pronounced in women. CONCLUSIONS: Generalized but not abdominal obesity was associated with an increased risk for the overall DMC, whereas both obesities were causally related to DN, albeit not DR, in T2D. Routine weight management should not be neglected in diabetes care, particularly in women.

Prevalence and associated factors of anaemia in patients with type 2 diabetes mellitus: a cross-sectional study in a tertiary care medical unit, Sri Lanka.

BACKGROUND: Anaemia is a global public health issue that impacts individuals of all ages in both developed and developing countries. Anaemia is common in patients with diabetes mellitus; however, it is often undiagnosed and untreated. The main aim of this study was to assess the prevalence and associated factors of anaemia in patients with type 2 diabetes mellitus admitting to a medical unit at National Hospital Kandy. METHODS: A descriptive, cross-sectional study was conducted in type 2 diabetes mellitus (T2DM) patients admitted to a medical ward at National Hospital Kandy (NHK). They were assessed with a pre-tested, interviewer-administered, structured questionnaire using consecutive sampling method. The data was entered and analyzed using SPSS 26. RESULTS: Total 252 patients with diabetes were included. The prevalence of anaemia in patients with T2DM was 31.3%. The corresponding values for males and females were 34.2% and 65.8% respectively. Independent predictors for anaemia among diabetic patients were older age, female gender, poor glycemic control, diabetes duration > 5 years, diabetic nephropathy, retinopathy, neuropathy, stage ≥ 3 chronic kidney disease (CKD), ischaemic heart disease (IHD), peripheral vascular disease (PVD), diabetic foot ulcers (DFU) and usage of aspirin. These were significantly associated with the prevalence anemia among patients with type 2 diabetes mellitus. Multivariate logistic regression analysis revealed that female gender, age ≥ 65 years, diabetic duration > 5 years, poor glycaemic control, stage ≥ 3 CKD, diabetic nephropathy and retinopathy were associated with greater odds for the presence of anaemia. CONCLUSION: We found that 31.3% T2DM patients in a medical ward at NHK had previously undiagnosed anaemia. Anaemia screening during diabetes diagnosis, maintaining glycaemic control and raising patient awareness can reduce anaemia prevalence, improve patient quality of life and potentially reduce microvascular complications.

Preventing diabetes complications.

The key aim of diabetes management is to prevent complications, which are a major cause of morbidity and mortality. At an individual level, people with diabetes are less likely than they were several decades ago to experience classical macrovascular and microvascular complications as a result of improvements in modifiable cardiovascular risk factors and preventive healthcare. However, a significant burden of diabetes complications persists at a population level because of the increasing incidence of diabetes, as well as longer lifetime exposure to diabetes because of younger diagnosis and increased life expectancy. Trials have shown that the most effective strategy for preventing complications of diabetes is a multifactorial approach focussing simultaneously on the management of diet, exercise, glucose levels, blood pressure and lipids. In addition to the cornerstone strategies of addressing diet, exercise and lifestyle measures, the introduction of newer glucose-lowering agents, including sodium-glucose transport protein 2 inhibitors and glucagon-like peptide-1 agonists, have brought about a paradigm shift in preventing the onset and progression of complications of type 2 diabetes, particularly cardiovascular and renal disease. The improvement in rates of classical complications of diabetes over time has been accompanied by a growing awareness of non-traditional complications, including non-alcoholic fatty liver disease. These emerging complications may not respond to a glycaemic-centred approach alone and highlight the importance of foundational strategies centred on lifestyle measures and supported by pharmaceutical therapy to achieve weight loss and reduce metabolic risk in patients living with diabetes.

Association between dipeptidyl peptidase-4 inhibitor use and diabetic retinopathy: a systematic review and meta-analysis of real-world studies.

BACKGROUND: The purpose of this review was to examine if dipeptidyl peptidase-4 inhibitor (DPP4i) use affects the risk of diabetic retinopathy (DR). METHODS: Cohort studies published up to 20th July 2023 in the databases of PubMed, CENTRAL, Embase, Scopus, and Web of Science were searched. The adjusted effect size was pooled to calculate the odds ratio (OR). RESULTS: Seven studies were included. Meta-analysis showed that the use of DPP4i was not associated with any significant change in the risk of DR (OR: 0.86 95% CI: 0.70, 1.06 I2 = 78%). The pooled analysis also found that DPP4i use was not associated with any significant risk of progression of DR (OR: 0.87 95% CI: 0.47, 1.59 I2 = 86%). The results did not change during sensitivity analysis. CONCLUSION: Present evidence from a limited number of real-world studies shows that DPP4i may not affect the incidence and progression of DR. There is a need for further studies from different countries using accurate definitions of DR and its progression to validate the current results.

Therapeutic Applications of Stem Cell-Derived Exosomes.

Exosomes are extracellular vesicles of endosomal origin, ranging from 30 to 150 nm in diameter, that mediate intercellular transfer of various biomolecules, such as proteins, lipids, nucleic acids, and metabolites. They modulate the functions of recipient cells and participate in diverse physiological and pathological processes, such as immune responses, cell-cell communication, carcinogenesis, and viral infection. Stem cells (SCs) are pluripotent or multipotent cells that can differentiate into various cell types. SCs can also secrete exosomes, which exhibit remarkable therapeutic potential for various diseases, especially in the field of regenerative medicine. For example, exosomes derived from mesenchymal stem cells (MSCs) contain proteins, lipids, and miRNAs that can ameliorate endocrine disorders, such as diabetes and cancer. Exosomes from SCs (sc-exos) may offer similar advantages as SCs, but with reduced risks and challenges. Sc-exos have lower tumorigenicity, immunogenicity, and infectivity. They can also deliver drugs more efficiently and penetrate deeper into tissues. In this review, we provide an overview of the recent advances in sc-exos and their therapeutic applications in various diseases, such as diabetes and cancer. We also elucidate how the biological effects of sc-exos depend on their molecular composition. We also address the current challenges and future directions of using sc-exos.

Correlation between plasma fibrinogen levels and microvascular complications in type 2 diabetes.

Objectives: To determine how plasma fibrinogen levels impact the severity of microvascular complications in people with type 2 diabetes while focussing on the molecular mechanisms of fibrinogen's role in such complications. METHODS: The analytical, cross-sectional study was conducted from September 2022 to March 2023 at the Department of Medicine, Mardan Medical Complex and Teaching Hospital, Khyber Pakhtunkhwa, Pakistan, and comprised adult patients of either gender who had been diagnosed with type 2 diabetes and microvascular complications. Each patient was subjected to an evaluation of microvascular complications, including diabetic retinopathy, nephropathy and neuropathy, using validated diagnostic criteria and clinical examinations. Data was analysed using SPSS 26. RESULTS: Of the 174 patients 97(%) were males and 77(%) were females. Retinopathy was found in 57(32.7) patients with median age 53 years (interquartile range: 46-63 years). Nephropathy was found in 55(31.6%) subjects with median age 54 years (interquartile range: 50-61 years). Neuropathy was found in 62(35.6%) patients with median age 53 years (interquartile range: 48-58 years). Diabetic neuropathy was significantly associated with elevated plasma fibrinogen levels and various biomarkers, such as creatinine, urea, fasting blood glucose, glycated haemoglobin and estimated average glucose (p<0.05). Diabetic retinopathy was significantly linked with higher levels of fibrinogen, which manifested through symptoms, like floaters or dark spots, impaired colour vision, difficulty seeing at night, blurred or fluctuating vision and vision loss (p<0.05). Diabetic nephropathy and the progression of its severity was significantly associated with increased fibrinogen levels, as well as markers, like albuminuria, creatinine, urea, fasting blood glucose, glycated haemoglobin and estimated average glucose (p<0.05). CONCLUSIONS: Elevated plasma fibrinogen levels in patients with type 2 diabetes significantly correlated with increased microvascular complications, underscoring the importance of monitoring and managing fibrinogen levels to mitigate diabetes-associated vascular pathologies.

Investigation of the Systemic Immune Inflammation (SII) Index as an Indicator of Morbidity and Mortality in Type 2 Diabetic Retinopathy Patients in a 4-Year Follow-Up Period.

Background and Objectives: This study aimed to investigate the relationship between the systemic immune inflammation (SII) index and the development of micro and macro complications and mortality within the first year and the following three years in type 2 diabetic retinopathy patients. Materials and Methods: The retrospective study included 523 type 2 diabetic retinopathy patients seen in the endocrinology outpatient clinic of our hospital between January and December 2019. Their demographic and clinical characteristics were analyzed using descriptive statistics. The normal distribution of quantitative data was assessed by the Shapiro-Wilk test. Mann-Whitney U, McNemar-Chi-square, and Cochran's Q tests were used to analyze the SII values and complication rates over time. An ROC analysis determined the sensitivity and specificity of SII. A multiple linear regression analysis examined the relationship between variables and SII, while Spearman's test assessed the correlation between CRP and SII. p < 0.05 was accepted as significant. Results: The mean age of patients was 63.5 ± 9.3 years, with mean SII values of 821.4 ± 1010.8. Higher SII values were significantly associated with acute-chronic renal failure, peripheral arterial disease, and hospitalization rates in both the first year and the following three years (p < 0.05 for all). Significant cut-off values for SII were found for micro- and macrovascular complications and death within the first year (p < 0.05 for all). The ROC curve analysis identified an optimal SII cut-off value of >594.0 for predicting near-term (1-year) complications and mortality, with a sensitivity of 73.8% and specificity of 49.4% (area under the ROC curve: 0.629, p = 0.001). Multiple linear regression indicated that smoking of at least 20 pack-years had a significant positive effect on SII. The Spearman test showed a weak positive correlation between SII and CRP. Conclusions: High SII values predict both early and late acute-chronic renal failure, peripheral arterial disease, and hospitalizations in patients with type 2 diabetic retinopathy. The study also shows that high SII values may predict microvascular and macrovascular complications of type 2 DM and mortality risk in the early period in patients with type 2 diabetic retinopathy. In addition, comorbidities and inflammatory habits, such as long-term smoking, should be considered in the clinical use of SII.

Sex differences in type 2 diabetes.

The prevalence of type 2 diabetes mellitus is increasing in both sexes, but men are usually diagnosed at a younger age and lower body fat mass than women. Worldwide, an estimated 17.7 million more men than women have diabetes mellitus. Women appear to bear a greater risk factor burden at the time of their type 2 diabetes diagnosis, especially obesity. Moreover, psychosocial stress might play a more prominent role in diabetes risk in women. Across their lifespan, women experience greater hormone fluctuations and body changes due to reproductive factors than men. Pregnancies can unmask pre-existing metabolic abnormalities, resulting in the diagnosis of gestational diabetes, which appears to be the most prominent risk factor for progression to type 2 diabetes in women. Additionally, menopause increases women's cardiometabolic risk profile. Due to the progressive rise in obesity, there is a global increase in women with pregestational type 2 diabetes, often with inadequate preconceptual care. There are differences between men and women regarding type 2 diabetes and other cardiovascular risk factors with respect to comorbidities, the manifestation of complications and the initiation of and adherence to therapy. Women with type 2 diabetes show greater relative risk of CVD and mortality than men. Moreover, young women with type 2 diabetes are currently less likely than men to receive the treatment and CVD risk reduction recommended by guidelines. Current medical recommendations do not provide information on sex-specific or gender-sensitive prevention strategies and management. Thus, more research on sex differences, including the underlying mechanisms, is necessary to increase the evidence in the future. Nonetheless, intensified efforts to screen for glucose metabolism disorders and other cardiovascular risk factors, as well as the early establishment of prophylactic measures and aggressive risk management strategies, are still required for both men and women at increased risk of type 2 diabetes. In this narrative review we aim to summarise sex-specific clinical features and differences between women and men with type 2 diabetes into risk factors, screening, diagnosis, complications and treatment.

Identification of genetic variants associated with diabetic kidney disease in multiple Korean cohorts via a genome-wide association study mega-analysis.

BACKGROUND: The pathogenesis of diabetic kidney disease (DKD) is complex, involving metabolic and hemodynamic factors. Although DKD has been established as a heritable disorder and several genetic studies have been conducted, the identification of unique genetic variants for DKD is limited by its multiplex classification based on the phenotypes of diabetes mellitus (DM) and chronic kidney disease (CKD). Thus, we aimed to identify the genetic variants related to DKD that differentiate it from type 2 DM and CKD. METHODS: We conducted a large-scale genome-wide association study mega-analysis, combining Korean multi-cohorts using multinomial logistic regression. A total of 33,879 patients were classified into four groups-normal, DM without CKD, CKD without DM, and DKD-and were further analyzed to identify novel single-nucleotide polymorphisms (SNPs) associated with DKD. Additionally, fine-mapping analysis was conducted to investigate whether the variants of interest contribute to a trait. Conditional analyses adjusting for the effect of type 1 DM (T1D)-associated HLA variants were also performed to remove confounding factors of genetic association with T1D. Moreover, analysis of expression quantitative trait loci (eQTL) was performed using the Genotype-Tissue Expression project. Differentially expressed genes (DEGs) were analyzed using the Gene Expression Omnibus database (GSE30529). The significant eQTL DEGs were used to explore the predicted interaction networks using search tools for the retrieval of interacting genes and proteins. RESULTS: We identified three novel SNPs [rs3128852 (P = 8.21×10-25), rs117744700 (P = 8.28×10-10), and rs28366355 (P = 2.04×10-8)] associated with DKD. Moreover, the fine-mapping study validated the causal relationship between rs3128852 and DKD. rs3128852 is an eQTL for TRIM27 in whole blood tissues and HLA-A in adipose-subcutaneous tissues. rs28366355 is an eQTL for HLA-group genes present in most tissues. CONCLUSIONS: We successfully identified SNPs (rs3128852, rs117744700, and rs28366355) associated with DKD and verified the causal association between rs3128852 and DKD. According to the in silico analysis, TRIM27 and HLA-A can define DKD pathophysiology and are associated with immune response and autophagy. However, further research is necessary to understand the mechanism of immunity and autophagy in the pathophysiology of DKD and to prevent and treat DKD.

Increased risk for microvascular outcomes in NAFLD-A nationwide, population-based cohort study.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) is considered a multisystem disease, as it is bidirectionally linked to other cardiometabolic disorders, such as type 2 diabetes (T2D). However, the long-term risk for microvascular outcomes in NAFLD is unclear. METHODS: Using the outpatient part of the nationwide Swedish Patient Register in the time period between 01/01/2002 and 12/31/2019, we identified all individuals with a first NAFLD diagnosis (N = 6785) and matched these (age, sex, and municipality) with up to 10 reference individuals from the general population (N = 61,136). Using population-based registers, we ascertained the development of microvascular diseases. The primary outcome was defined as a composite outcome of any diagnosis representative of microvascular disease (chronic kidney disease, retinopathy, or neuropathy). As secondary outcomes, we separately examined the risk of each specific microvascular outcome. Hazard ratios (aHR, adjusted for cirrhosis and time-varying T2D, hypertension, and hyperlipidemia) for the outcomes were calculated by Cox proportional-hazards models. RESULTS: Median follow-up was 5.7 years. The incidence rate of microvascular diseases was >twofold higher in patients with NAFLD (10.8 per 1000 person-years [95% confidence interval (CI) = 9.9-11.8]) versus reference individuals (4.7 per 1000 person-years [95%CI = 4.5-4.9]). NAFLD was independently and positively associated with the development of microvascular diseases compared to non-NAFLD subjects (aHR = 1.45 [95%CI = 1.28-1.63]). When stratifying the analysis by follow-up time, sex, or age categories, results remain virtually unchanged. CONCLUSIONS: NAFLD is positively and independently associated with the development of microvascular diseases. The risk for development of microvascular diseases should be taken into account in the personalized risk assessment of individuals with NAFLD.

miRNAs as cornerstones in diabetic microvascular complications.

Diabetes mellitus is usually accompanied by nephropathy, retinopathy, and neuropathy as microvascular complications. MicroRNAs (miRNAs) can affect the kidney, retina, and peripheral neurons through their implication in pathways involved in angiogenesis, inflammation, apoptosis, as well as fibrosis within these tissues and hence, play a crucial role in the pathogenesis of microvascular complications. In this review, the updated knowledge of the role of miRNAs in the pathogenesis of diabetic microvascular complications was summarized. PubMed Central was searched extensively to retrieve data from a wide range of reputable biomedical reports/articles published after the year 2000 to systematically collect and present a review of the key molecular pathways mediating the hyperglycemia-induced adverse effects on vascular tissues, particularly in persons with T2DM. In the present review, miR-126, miR-29b, and miR-125a are implicated in diabetes-induced microvascular complications, while miR-146a is found to be connected to all these complications. Also, vascular endothelial growth factors are noted to be the most impacted targets by miRNAs in all diabetic microvascular problems.

Both LDL and HDL particle concentrations associate positively with an increased risk of developing microvascular complications in patients with type 2 diabetes: lost protection by HDL (Zodiac-63).

BACKGROUND: Triglyceride-rich lipoproteins (TRL) and low-density lipoproteins (LDL) are associated positively whereas high-density lipoproteins (HDL) are associated inversely with the development of new-onset type 2 diabetes (T2D). Here we studied potential associations between these lipoprotein particle concentrations and the risk of developing microvascular complications in patients with established T2D. METHODS: Lipoprotein particle concentrations (TRLP, LDLP, and HDLP) were determined in 278 patients with T2D participating in a primary care-based longitudinal cohort study (Zwolle Outpatient Diabetes project Integrating Available Care [ZODIAC] study) leveraging the Vantera nuclear magnetic resonance (NMR) platform using the LP4 algorithm. Associations between lipoprotein particles and incident microvascular complications (nephropathy, neuropathy, and retinopathy) were assessed using Cox proportional hazards regression models. RESULTS: In total, 136 patients had microvascular complications at baseline. During a median follow-up of 3.2 years, 49 (34.5%) of 142 patients without microvascular complications at baseline developed new-onset microvascular complications. In multivariable Cox proportional hazards regression analyses, both total LDLP and HDLP concentrations, but not total TRLP concentrations, were positively associated with an increased risk of developing any microvascular complications after adjustment for potential confounding factors, including age, sex, disease duration, HbA1c levels, history of macrovascular complications, and statin use (adjusted hazard ratio [HR] per 1 SD increment: 1.70 [95% CI 1.24-2.34], P < 0.001 and 1.63 [95% CI 1.19-2.23], P = 0.002, respectively). When analyzing each microvascular complication individually, total LDLP concentrations were positively associated with retinopathy (adjusted HR 3.35, 95% CI 1.35-8.30, P = 0.009) and nephropathy (adjusted HR 2.13, 95% CI 1.27-3.35, P = 0.004), and total HDLP concentrations with neuropathy (adjusted HR 1.77, 95% CI 1.15-2.70, P = 0.009). No significant associations were observed for lipoprotein particle subfractions. CONCLUSIONS: Total lipoprotein particle concentrations of both LDL and HDL associate positively with an increased risk of developing microvascular complications in T2D. We propose that the protective role of HDL on the development of microvascular complications may be lost in established T2D.

Diabetic microvascular disease in non-classical beds: the hidden impact beyond the retina, the kidney, and the peripheral nerves.

Diabetes microangiopathy, a hallmark complication of diabetes, is characterised by structural and functional abnormalities within the intricate network of microvessels beyond well-known and documented target organs, i.e., the retina, kidney, and peripheral nerves. Indeed, an intact microvascular bed is crucial for preserving each organ's specific functions and achieving physiological balance to meet their respective metabolic demands. Therefore, diabetes-related microvascular dysfunction leads to widespread multiorgan consequences in still-overlooked non-traditional target organs such as the brain, the lung, the bone tissue, the skin, the arterial wall, the heart, or the musculoskeletal system. All these organs are vulnerable to the physiopathological mechanisms that cause microvascular damage in diabetes (i.e., hyperglycaemia-induced oxidative stress, inflammation, and endothelial dysfunction) and collectively contribute to abnormalities in the microvessels' structure and function, compromising blood flow and tissue perfusion. However, the microcirculatory networks differ between organs due to variations in haemodynamic, vascular architecture, and affected cells, resulting in a spectrum of clinical presentations. The aim of this review is to focus on the multifaceted nature of microvascular impairment in diabetes through available evidence of specific consequences in often overlooked organs. A better understanding of diabetes microangiopathy in non-target organs provides a broader perspective on the systemic nature of the disease, underscoring the importance of recognising the comprehensive range of complications beyond the classic target sites.