Proteomic Analysis of Disease Stratified Human Pancreas Tissue Indicates Unique Signature of Type 1 Diabetes

Type 1 diabetes (T1D) and type 2 diabetes (T2D) are associated with functional beta cell loss due to ongoing inflammation. Despite shared similarities, T1D is an autoimmune disease with evidence of autoantibody production, as well as a role for exocrine pancreas involvement. Our hypothesis is that differential protein expression occurs in disease stratified pancreas tissues and regulated proteins from endocrine and exocrine tissues are potential markers of disease and potential therapeutic targets. The study objective was to identify novel proteins that distinguish the pancreas from donors with T1D from the pancreas from patients with T2D, or autoantibody positive non-diabetic donors. Detailed quantitative comprehensive proteomic analysis was applied to snap frozen human pancreatic tissue lysates from organ donors without diabetes, with T1D-associated autoantibodies in the absence of diabetes, with T1D, or with T2D. These disease-stratified human pancreas tissues contain exocrine and endocrine tissues (with dysfunctional islets) in the same microenvironment. The expression profiles of several of the proteins were further verified by western blot. We identified protein panels that are significantly and uniquely upregulated in the three disease-stratified pancreas tissues compared to non-disease control tissues. These proteins are involved in inflammation, metabolic regulation, and autoimmunity, all of which are pathways linked to, and likely involved in, T1 and T2 diabetes pathogenesis. Several new proteins were differentially upregulated in prediabetic, T1D, and T2D pancreas. The results identify proteins that could serve as novel prognostic, diagnostic, and therapeutic tools to preserve functional islet mass in Type 1 Diabetes.     

Absence of Diabetes and Pancreatic Exocrine Dysfunction in a Transgenic Model of Carboxyl-Ester Lipase-MODY (Maturity-Onset Diabetes of the Young)

Background

CEL-MODY is a monogenic form of diabetes with exocrine pancreatic insufficiency caused by mutations in CARBOXYL-ESTER LIPASE (CEL). The pathogenic processes underlying CEL-MODY are poorly understood, and the global knockout mouse model of the CEL gene (CELKO) did not recapitulate the disease. We therefore aimed to create and phenotype a mouse model specifically over-expressing mutated CEL in the pancreas.

Methods

We established a monotransgenic floxed (flanking LOX sequences) mouse line carrying the human CEL mutation c.1686delT and crossed it with an elastase-Cre mouse to derive a bitransgenic mouse line with pancreas-specific over-expression of CEL carrying this disease-associated mutation (TgCEL). Following confirmation of murine pancreatic expression of the human transgene by real-time quantitative PCR, we phenotyped the mouse model fed a normal chow and compared it with mice fed a 60% high fat diet (HFD) as well as the effects of short-term and long-term cerulein exposure.

Results

Pancreatic exocrine function was normal in TgCEL mice on normal chow as assessed by serum lipid and lipid-soluble vitamin levels, fecal elastase and fecal fat absorption, and the normoglycemic mice exhibited normal pancreatic morphology. On 60% HFD, the mice gained weight to the same extent as controls, had normal pancreatic exocrine function and comparable glucose tolerance even after resuming normal diet and follow up up to 22 months of age. The cerulein-exposed TgCEL mice gained weight and remained glucose tolerant, and there were no detectable mutation-specific differences in serum amylase, islet hormones or the extent of pancreatic tissue inflammation.

Conclusions

In this murine model of human CEL-MODY diabetes, we did not detect mutation-specific endocrine or exocrine pancreatic phenotypes, in response to altered diets or exposure to cerulein.     

Transient overexpression of cyclin D2/CDK4/GLP1 genes induces proliferation and differentiation of adult pancreatic progenitors and mediates islet regeneration

The molecular mechanism of β-cell regeneration remains poorly understood. Cyclin D2/CDK4 expresses in normal β cells and maintains adult β-cell growth. We hypothesized that gene therapy with cyclin D2/CDK4/GLP-1 plasmids targeted to the pancreas of STZ-treated rats by ultrasound-targeted microbubble destruction (UTMD) would force cell cycle re-entry of residual G₀-phase islet cells into G₁/S phase to regenerate β cells. A single UTMD treatment induced β-cell regeneration with reversal of diabetes for 6 mo without evidence of toxicity. We observed that this β-cell regeneration was not mediated by self-replication of pre-existing β cells. Instead, cyclin D2/CDK4/GLP-1 initiated robust proliferation of adult pancreatic progenitor cells that exist within islets and terminally differentiate to mature islets with β cells and α cells.     

The Clinical And Metabolic Characteristics Of Young-Onset Ketosis-Prone Type 2 Diabetes In China

Objective: To investigate the prevalence and clinical characteristics of ketosis-prone type 2 diabetes (KPD) in Chinese patients with young-onset diabetes.Methods: A total of 238 young diabetic patients were recruited from our inpatient department from January 1, 2012, to December 28, 2014. KPD was defined as diabetes without precipitating illness and with the presence of ketosis or diabetic ketoacidosis in the absence of autoantibodies at the time of diagnosis. We reviewed the clinical characteristics and disease progression of this group of patients.Results: Eighteen patients fulfilled the criteria for KPD, and the prevalence of patients with KPD was 7.6%. The mean (SD) age of the KPD group at the time of diagnosis of diabetes was 27.6 (4.85) years, and these patients were predominantly male (male to female ratio, 8:1) and had a high proportion of obesity and new-onset diabetes and a strong family history of diabetes. β-Cell function in the KPD group was intermediate between type 1 and type 2 diabetes. Patients with KPD had the highest levels of glycated hemoglobin, triglycerides, total cholesterol, and free fatty acids and the lowest levels of high-density lipoprotein. After 3 to 12 months of follow-up, 17 of 18 patients with KPD (94.4%) were able to discontinue insulin therapy, and 11 patients (61.1%) were managed with diet or exercise alone.Conclusion: KPD patients accounted for 7.6% of the diabetic patients requiring admission to a large urban hospital in China, with an age of onset of diabetes of ≤35 years. These patients are more likely to be male, have abnormal lipid metabolism, and have more reversible β-cell dysfunction.Abbreviations:BMI = body mass indexDKA = diabetic ketoacidosisGAD 65 = glutamate decarboxylase 65HbA _1c = glycated hemoglobinICAs = islet-cell antibodiesKPD = ketosis-prone type 2 diabetes mellitusLADA = latent autoimmune diabetes in an adultMIDD = maternally inherited diabetes and deafnessMODY = maturityonset diabetes of the youngT1DM = type 1 diabetes mellitusT2DM = type 2 diabetes mellitus     

Absence of spontaneous regeneration of endogenous pancreatic β-cells after chemical-induced diabetes and no effect of GABA on α-to-β cell transdifferentiation in rhesus monkeys

β-cell deficiency is common feature of type 1 and late-stage of type 2 diabetes mellitus. Thus, β?cell replacement therapy has been the focus of regenerative medicine past several decades. Particularly, evidences suggest that β?cell regeneration via transdifferentiation from sources including α-cells is promising. However, data using higher mammals besides rodents are scarce. Here, we examined whether endogenous pancreatic β-cells could regenerate spontaneously or under normoglycemia following porcine islet transplantation for varied periods up to 1197 days after streptozotocin-induced diabetes, and remaining α-cells transdifferentiate into β-cells by GABA treatment in vivo and in vitro. The results showed that endogenous β-cells rarely regenerate in both conditions as evidenced by stagnant serum C-peptide levels and β-cell number in the pancreas, and the remaining α-cells did not transdifferentiate into β-cells by GABA treatment. Collectively, we concluded that monkey β-cells had relatively low regenerative potential compared with rodent counterpart and GABA treatment could not induce α-to-β-cell transdifferentitation.     

miR-375, a microRNA related to diabetes

miR-375 is an important small non-coding RNA that is specifically expressed in islet cells of the pancreas. miR-375 is required for normal pancreatic genesis and influences not only β-cell mass but also α-cell mass. miR-375 is also important to glucose-regulated insulin secretion through the regulation of the expression of Mtpn and Pdk1 genes. When human embryonic stem cells (hESCs) differentiate into endodermal lineages, miR-375 is highly expressed in the definitive endoderm, which suggests that miR-375 may have a distinct role in early development. miR-375 plays an important role in the complex regulatory network of pancreatic development, which could be regulated by pancreatic genes, such as NeuroD1, Ngn3, Pdx1 and Hnf6; additionally, miR-375 regulates genes related to pancreas development, cell growth and proliferation and insulin secretion genes to exert its function. Because of the special role of miR-375, it may be a potential target to treat diabetes. Antagonising miR-375 may enhance the effects of exendin-4 in patients, and controlling the expression of miR-375 could assist mature hESCs-derived β-cells.     

Type 1 diabetes cadaveric human pancreata exhibit a unique exocrine tissue proteomic profile

Type 1 diabetes (T1D) is an autoimmune disorder resulting from a self‐destruction of pancreatic islet beta cells. The complete proteome of the human pancreas, where both the dysfunctional beta cells and their proximal environment co‐exist, remains unknown. Here, we used TMT10‐based isobaric labeling and multidimensional LC‐MS/MS to quantitatively profile the differences between pancreatic head region tissues from T1D (N = 5) and healthy subjects (N = 5). Among the 5357 (1% false discovery rate) confidently identified proteins, 145 showed statistically significant dysregulation between T1D and healthy subjects. The differentially expressed pancreatic proteome supports the growing notion of a potential role for exocrine pancreas involvement in T1D. This study also demonstrates the utility for this approach to analyze dysregulated proteins as a means to investigate islet biology, pancreatic pathology and T1D pathogenesis.     

Evaluation of 18F-labeled exendin(9-39) derivatives targeting glucagon-like peptide-1 receptor for pancreatic β-cell imaging

β-cell mass (BCM) is known to be decreased in subjects with type-2 diabetes (T2D). Quantitative analysis for BCM would be useful for understanding how T2D progresses and how BCM affects treatment efficacy and for earlier diagnosis of T2D and development of new therapeutic strategies. However, a noninvasive method to measure BCM has not yet been developed.We developed four ¹⁸F-labeled exendin(9-39) derivatives for β-cell imaging by PET: [¹⁸F]FB9-Ex(9-39), [¹⁸F]FB12-Ex(9-39), [¹⁸F]FB27-Ex(9-39), and [¹⁸F]FB40-Ex(9-39). Affinity to the glucagon-like peptide-1 receptor (GLP-1R) was evaluated with dispersed islet cells of ddY mice. Uptake of exendin(9-39) derivatives in the pancreas as well as in other organs was evaluated by a biodistribution study. Small-animal PET study was performed after injecting [¹⁸F]FB40-Ex(9-39).FB40-Ex(9-39) showed moderate affinity to the GLP-1R. Among all of the derivatives, [¹⁸F]FB40-Ex(9-39) resulted in the highest uptake of radioactivity in the pancreas 30?min after injection. Moreover, it showed significantly less radioactivity accumulated in the liver and kidney, resulting in an overall increase in the pancreas-to-organ ratio. In the PET imaging study, pancreas was visualized at 30?min after injection of [¹⁸F]FB40-Ex(9-39).[¹⁸F]FB40-Ex(9-39) met the basic requirements for an imaging probe for GLP-1R in pancreatic β-cells. Further enhancement of pancreatic uptake and specific binding to GLP-1R will lead to a clear visualization of pancreatic β-cells.     

Can pancreatic duct-derived progenitors be a source of islet regeneration?

The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing β-cells. The functional mass of β-cells is decreased in type 1 diabetes, so replacing missing β-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the β-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding β-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated.In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet β-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the “gold standard” of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal cells as an in vivo progenitor for pancreatic β-cells has implications for a potentially important, expandable source of new islets for diabetic replenishment therapy.     

Optimized Human Regular U-500 Insulin Treatment Improves β-Cell Function in Severely Insulin-Resistant Patients with Long-Standing Type 2 Diabetes and High Insulin Requirements

Objective: To assess β-cell function and insulin sensitivity following improvement in glycemic control in severely insulin-resistant patients with poorly controlled type 2 diabetes (T2D).Methods: A subset of patients in a 24-week, open-label, randomized trial comparing thrice-daily (n = 14/162) versus twice-daily (n = 11/163) human regular U-500 insulin (U-500R) underwent mixed meal tolerance testing at baseline and endpoint. Baseline characteristics were similar between treatment groups (combined means: age, 54.0 years; diabetes duration, 13.6 years; body mass index, 38.8 kg/m²; glycated hemoglobin [HbA_1c], 8.3%; U-100 insulin dose, 287.6 units/day, 2.6 units/kg/day). Primary outcome measure was ratio of area under the curve (AUC) for C-peptide to glucose (AUC_C-peptide/AUC_glucose) at 24-week endpoint.Results: Change from baseline HbA_1c, daily U-500R dose, and weight were -1.17% (P = .0002), +80.8 units (P = .0003), and +5.9 kg (P = .33), respectively. β-Cell function significantly improved after 24 weeks of U-500R therapy in combined treatment groups. The AUC_C-peptide/AUC_glucose increased 34.0% (ratio of least-squares geometric mean, 1.34; 95% confidence interval, 1.18 to 1.52; P = .0001). Integral of total insulin secretion rate increased from 27.0 to 33.7 nmol/m², and glucose sensitivity improved from 18.3 to 24.0 pmol/min/m²/mM (both, P = .02). Matsuda index improved from 0.8 to 1.3 (P = .008).Conclusion: Despite long-standing diabetes and poor glycemic control at baseline, functional recovery of β-cells was observed with improved glycemic control in these severely insulin-resistant patients with T2D, possibly due to alleviation of glucotoxicity.Abbreviations:AUC = area under the curveBID = twice dailyHbA_1c = glycated hemoglobinISR = insulin secretion rateLSM = least-squares meanMMTT = mixed meal tolerance testPG = plasma glucoseT2D = type 2 diabetesTDD = total daily doseTID = thrice dailyU-500R = human regular U-500 insulin     

Supplementation of pancreatic digestive enzymes alters the composition of intestinal microbiota in mice

Although pancreatic enzyme replacement therapy (PERT) is effective in the alleviation of pancreatic exocrine insufficiency (PEI)-related symptoms in patients with chronic pancreatitis, its mechanism of action is poorly understood. Recent studies suggest that the intestinal microbiota is associated with the pathogenesis of chronic pancreatitis. Therefore, we hypothesized that PERT exerts its effect by modifying the intestinal microbiota in addition to its presumed role in promoting fat and protein absorption. To explore the mechanism of action of PERT, we analyzed the intestinal microbiotas of two groups of mice treated with either pancrelipase or tap water by using 16S rRNA amplicon sequencing. The results revealed that the bacterial compositions of the pancrelipase-treated mice were significantly different from those of the control samples. Akkermansia muciniphila, a key beneficial bacterium in the intestinal tract, showed a higher relative abundance in the pancrelipase-treated samples than in the control samples. Lactobacillus reuteri, a widely used probiotic bacterium known to relieve intestinal inflammation, also showed a higher relative abundance in the pancrelipase-treated samples. These results suggested that PERT induces the colonization of beneficial bacteria, thereby contributing to the attenuation of PEI-associated symptoms in addition to improvement of the nutritional state.     

Caveolin-1 deficiency protects pancreatic β cells against palmitate-induced dysfunction and apoptosis

Lipotoxicity leads to insulin secretion deficiency, which is among the important causes for the onset of type 2 diabetes mellitus. Thus, the restoration of β-cell mass and preservation of its endocrine function are long-sought goals in diabetes research. Previous studies have suggested that the membrane protein caveolin-1 (Cav-1) is implicated in β-cell apoptosis and insulin secretion, however, the underlying mechanisms still remains unclear. Our objective is to explore whether Cav-1 depletion protects pancreatic β cells from lipotoxicity and what are the underlying mechanisms. In this study, we found that Cav-1 silencing significantly promoted β-cell proliferation, inhibited palmitate (PA)-induced pancreatic β-cell apoptosis and enhanced insulin production and secretion. These effects were associated with enhanced activities of Akt and ERK1/2, which in turn downregulated the expression of cell cycle inhibitors (FOXO1, GSK3β, P21, P27 and P53) and upregulated the expression of Cyclin D2 and Cyclin D3. Subsequent inhibition of PI3K/Akt and ERK/MAPK pathways abolished Cav-1 depletion induced β-cell mass protection. Furthermore, under PA induced endoplasmic reticulum (ER) stress, Cav-1 silencing significantly reduced eIF2α phosphorylation and the expression of ER stress-responsive markers BiP and CHOP, which are among the known sensitizers of lipotoxicity. Our findings suggest Cav-1 as potential target molecule in T2DM treatment via the preservation of lipotoxicity-induced β-cell mass reduction and the attenuation of insulin secretion dysfunction.     

Selective destruction of mouse islet beta cells by human T lymphocytes in a newly-established humanized type 1 diabetic model

Type 1 diabetes (T1D) is caused by a T cell-mediated autoimmune response that leads to the loss of insulin-producing β cells. The optimal preclinical testing of promising therapies would be aided by a humanized immune-mediated T1D model. We develop this model in NOD-scid IL2rγ^null mice. The selective destruction of pancreatic islet β cells was mediated by human T lymphocytes after an initial trigger was supplied by the injection of irradiated spleen mononuclear cells (SMC) from diabetic nonobese diabetic (NOD) mice. This resulted in severe insulitis, a marked loss of total β-cell mass, and other related phenotypes of T1D. The migration of human T cells to pancreatic islets was controlled by the β cell-produced highly conserved chemokine stromal cell-derived factor 1 (SDF-1) and its receptor C-X-C chemokine receptor (CXCR) 4, as demonstrated by in vivo blocking experiments using antibody to CXCR4. The specificity of humanized T cell-mediated immune responses against islet β cells was generated by the local inflammatory microenvironment in pancreatic islets including human CD4⁺ T cell infiltration and clonal expansion, and the mouse islet β-cell-derived CD1d-mediated human iNKT activation. The selective destruction of mouse islet β cells by a human T cell-mediated immune response in this humanized T1D model can mimic those observed in T1D patients. This model can provide a valuable tool for translational research into T1D.     

Acceleration of autoimmune diabetes in Rheb-congenic NOD mice with β-cell-specific mTORC1 activation

The protein Ras homolog enriched in brain (Rheb) is a Ras-like small GTPase that activates the mechanistic target of rapamycin complex 1 (mTORC1), which promotes cell growth. We previously generated transgenic C57BL/6 mice overexpressing Rheb in β-cells (B6^Rheb), which exhibited increased β-cell size and improved glucose tolerance with higher insulin secretion than wild type C57BL/6 mice. The mice also showed resistance to obesity-induced hyperglycemia, a model of type 2 diabetes, and to multiple low-dose-streptozotocin (MLDS)-induced hyperglycemia, a model of type 1 diabetes (T1D). To investigate whether the effects of mTORC1 activation by Rheb in B6^Rheb mice would also be evident in NOD mice, a spontaneous autoimmune T1D model, we created two NOD mouse lines overexpressing Rheb in their β-cells (NOD^Rheb; R3 and R20). We verified Rheb overexpression in β-cells, the relative activation of mTORC1 and β-cell enlargement. By 35 weeks of age, diabetes incidence was significantly greater in the R3 line and tended to be greater in the R20 line than in NOD mice. Histological analysis demonstrated that insulitis was significantly accelerated in 12-week-old R3 NOD^Rheb mice compared with NOD mice. Furthermore, serum insulin autoantibody (IAA) expression was significantly higher than that of NOD mice. We also examined whether complete Freund’s adjuvant (CFA) treatment alone or with glucagon-like peptide-1 (GLP-1) analog would reverse the hyperglycemia of NOD^Rheb mice; unexpectedly, almost none achieved normoglycemia. In summary, diabetes progression was significantly accelerated rather than prevented in NOD^Rheb mice. Our results suggest that the β-cell enlargement might merely enhance the autoimmunity of pathogenic T-cells against islets, leading to acceleration of autoimmune diabetes. We conclude that not only enlargement but also regeneration of β-cells in addition to the prevention of β-cell destruction will be required for the ideal therapy of autoimmune T1D.     

Dnmt1 activity is dispensable in δ-cells but is essential for α-cell homeostasis

In addition to β-cells, pancreatic islets contain α- and δ-cells, which respectively produce glucagon and somatostatin. The reprogramming of these two endocrine cell types into insulin producers, as observed after a massive β-cell ablation in mice, may help restoring a functional β-cell mass in type 1 diabetes. Yet, the spontaneous α-to-β and δ-to-β conversion processes are relatively inefficient in adult animals and the underlying epigenetic mechanisms remain unclear. Several studies indicate that the conserved chromatin modifiers DNA methyltransferase 1 (Dnmt1) and Enhancer of zeste homolog 2 (Ezh2) are important for pancreas development and restrict islet cell plasticity. Here, to investigate the role of these two enzymes in α- and δ-cell development and fate maintenance, we genetically inactivated them in each of these two cell types. We found that loss of Dnmt1 does not enhance the conversion of α- or δ-cells toward a β-like fate. In addition, while Dnmt1 was dispensable for the development of these two cell types, we noticed a gradual loss of α-, but not δ-cells in adult mice. Finally, we found that Ezh2 inactivation does not enhance α-cell plasticity, and, contrary to what is observed in β-cells, does not impair α-cell proliferation. Our results indicate that both Dnmt1 and Ezh2 play distinct roles in the different islet cell types.     

Apoptosis signal regulating kinase-1 and NADPH oxidase mediate human amylin evoked redox stress and apoptosis in pancreatic beta-cells

Misfolded toxic human islet amyloid polypeptide or amylin (hA) and plasma membrane-associated redox complex, NADPH oxidase (NOX), have been implicated in the islet β-cell demise associated with type-2 diabetes mellitus (T2DM). Studies show that hA accumulation is stressful to β-cells and that misfolding of human amylin evokes redox stress and activates mitogen activated protein (MAP) kinases, p38 MAPK and c-Jun N-terminal (JNK) kinase. However, the molecular link and causality between hA-evoked redox stress, NOX activity and MAP kinases signaling in pancreatic β-cells is incompletely understood. Here, we show that in the process of activating JNK, aggregation prone hA also activates an upstream apoptosis signal regulating kinase-1 (ASK1) with concomitant decrease in intracellular levels of reduced glutathione. Inhibition of ASK1 kinase activity, either by specific ASK1 inhibitor, NQDI1 or by thiol antioxidants reduces human amylin-evoked ASK1 and JNK activation and consequently human amylin toxicity in rat insulinoma Rin-m5F cells and human islets. β-cell specific overexpression of human amylin in mouse islets elicited ASK1 phosphorylation and activation in β-cells but not in other rodent's islet or exocrine cells. This ASK1 activation strongly correlated with islet amyloidosis and diabetes progression. Cytotoxic human amylin additionally stimulated pro-oxidative activity and expressions of plasma membrane bound NADPH oxidase (NOX) and its regulatory subunits. siRNA mediated NOX1 knockdown and selective NOX inhibitors, ML171 and apocynin, significantly reduced hA-induced mitochondrial stress in insulinoma beta-cells. However, NOX inhibitors were largely ineffective against hA-evoked redox stress and activation of cytotoxic ASK1/JNK signaling complex. Thus, our studies suggest that NOX1 and ASK1 autonomously mediate human amylin-evoked redox and mitochondrial stress in pancreatic β-cells.     

Impact of Family History of Diabetes on Diabetes Control and Complications

Objective: Our aim was to assess the impact of parental and sibling history of type 2 diabetes (T2D) on patient characteristics, glycemic control, and T2D complications.Methods: This cross-sectional study included adults with T2D. Type 1 diabetes and gestational diabetes patients were excluded. The laboratory data were retrieved from the patients' electronic files, and baseline measurements were obtained by the researchers.Results: The study included a total of 511 T2D patients, with a mean age of 60.1 ± 10.9 years and mean hemoglobin A1c of 8.94 ± 2.1% (74.2 ± 22.9 mmol/mol). Of these patients, 54% were male and 49.7% had a parental history of T2D. The patients with parental history of T2D were diagnosed at a younger age and had a higher body mass index (BMI) (P =.035) and higher waist circumference (WC) (P =.013) than those T2D patients with no parental history. Approximately 60% of the participants had siblings with a history of T2D, and in comparison with those with no sibling history, they had higher prevalence of cerebrovascular accidents (P =.02).Conclusion: Having a parental history of T2D is significantly associated with diagnosis at a younger age and a higher BMI and WC. Having a sibling history of T2D is significantly associated with worse cerebrovascular outcome.Abbreviations: ACR = albumin to creatinine ratio; BMI = body mass index; DBP = diastolic blood pressure; DM = diabetes mellitus; FBG = fasting blood glucose; GFR = glomerular filtration rate; HbA1c = hemoglobin A1c; LDL = low-density lipoprotein; SBP = systolic blood pressure; T2D = type 2 diabetes; TG = triglyceride; WC = waist circumference