Linagliptin alleviates fatty liver disease in diabetic db/db mice

AIM To study the effects of linagliptin on the structural signs of non-alcoholic fatty liver disease(NAFLD) in db/db mice. METHODS Male diabetic db /db mice(BKS.Cg-Dock7m+/+Leprdb/J) aged 10 wk received the dipeptidyl peptidase 4(DPP4) inhibitor linagliptin(10 mg/kg) or saline as a placebo once per day by gavage for 8 wk. Intact db/db mice served as controls. Structural changes in the liver were analyzed from light and electron microscopic images of sections from intact, placebo-treated and linagliptin-treated animals. We estimated the changes in hepatocytes, sinusoidal cells, liver microvasculature and lymphatic roots. Hepatic staining for lymphatic vessel endothelial hyaluronan receptor-1(LYVE-1) was assessed by immunohistochemistry. RESULTS In 18-wk-old diabetic mice, liver steatosis(predominantly microvesicular and mediovesicular steatosis) was accompanied by dilation of the roots of the lymphatic system, interlobular blood vessels and bile canaliculi. Compared to saline-treated mice, linagliptin-treated mice exhibited a reduction in the mean numeral densities of hepatocytes with lipid droplets(92.4% ± 1.7% vs 64.9% ± 5.8% per field of view, P = 0.0002) and a lower proportion of hepatocytes with a high density of lipid droplets(20.7% ± 3.6% vs 50.4% ± 3.1%, P = 0.0007). We observed heterogeneous hepatocytes and relatively preserved cell structures in the linagliptin group. Dilation of blood and lymphatic vessels, as well as ultrastructural changes in the hepatocyte endoplasmic reticulum and mitochondria, were alleviated by linagliptin treatment. In intact and placebo-treated mice, immunohistochemical staining for LYVE-1 was observed in the endothelial cells of interlobular lymphatic vessels and on the membranes of some endothelial sinusoidal cells. We observed an enlarged LYVE-1 reaction area in linagliptin-treated mice compared to intact and placebo-treated mice. The improvement in the structural parameters of the liver in linagliptin-treated mice was independent to changes in the plasma glucose levels. CONCLUSION The DPP4 inhibitor linagliptin alleviates liver steatosis and structural changes in the hepatic microvasculature and lymphatic roots in a model of NAFLD in diabetic db/db mice.

Empagliflozin alleviates podocytopathy and enhances glomerular nephrin expression in db/db diabetic mice

BACKGROUND Modern guidelines recommend sodium-glucose cotransporter-2(SGLT2)inhibitors as the preferred antihyperglycemic agents for patients with type 2 diabetes and chronic kidney disease.However,the mechanisms underlying the renal protective effect of SGLT2 inhibitors are not fully understood.structure of podocytes and nephrin expression in glomeruli in db/db diabetic mice.METHODS We treated 8-wk-old male db/db mice with EMPA(10 mg/kg/d)or vehicle for 8 wk.Age-matched male db/+mice were included as non-diabetic controls.Parameters of body composition,glycemic and lipid control,and plasma concentrations of leptin,insulin and glucagon were assessed.We evaluated renal hypertrophy as kidney weight adjusted to lean mass,renal function as plasma levels of creatinine,and albuminuria as the urinary albumin-to-creatinine ratio(UACR).Renal structures were studied by light and transmission electron microscopy with a focus on mesangial volume and podocyte structure,respectively.Glomerular nephrin and transforming growth factor beta(TGF-β)were assessed by immunohistochemistry.RESULTS Severe obesity and hyperglycemia developed in db/db mice prior to the start of the experiment;increased plasma concentrations of fructosamine,glycated albumin,cholesterol,leptin,and insulin,and elevated UACR were detected.Mesangial expansion,glomerular basement membrane thickening,and increased area of TGF-βstaining in glomeruli were revealed in vehicle-treated mice.Podocytopathy was manifested by effacement of foot processes;nephrin-positive areas in glomeruli were reduced.EMPA decreased the levels of glucose,fructosamine and glycated albumin,UACR,kidney hypertrophy,mesangial expansion,glomerular basement membrane thickening,and glomerular TGF-βstaining,alleviated podocytopathy and restored glomerular staining of nephrin.CONCLUSION These data indicate that EMPA attenuates podocytopathy in experimental diabetic kidney disease.The anti-albuminuric effect of EMPA could be attributed to mitigation of podocyte injury and enhancement of nephrin expression.

Risk factors and urinary biomarkers of non-albuminuric and albuminuric chronic kidney disease in patients with type 2 diabetes

BACKGROUND A number of recent studies indicate a transformation in the natural course of chronic kidney disease(CKD)in type 2 diabetes(T2D)patients:an increasing prevalence of declined renal function without proceeding to the accompanying elevation of albuminuria.It has been suggested that albuminuric and nonalbuminuric CKD patterns could be different in their phenotypes and pathogenic mechanisms.AIM To identify the risk factors and biomarkers of albuminuric and non-albuminuric patterns of CKD in patients with T2D.METHODS Three hundred sixty patients with T2D duration≥10 years were included in this observational cross-sectional study.The associations of a panel of demographic and clinical characteristics,complications,comorbidities,and metabolic and hematology parameters with albuminuric and non-albuminuric CKD patterns were analyzed.The urinary excretion of nephrin and podocin,two podocytespecific markers,and WAP-four-disulfide core domain protein 2(WFDC-2),a marker of tubulointerstitial fibrosis,was determined by ELISA in comparison with healthy controls.RESULTS Non-albuminuric CKD was associated with age≥65 years(P=0.0001),female sex(P=0.04),diabetes duration≥15 years(P=0.0009),and the use of diuretics(P=0.0005).Male sex(P=0.01),smoking(P=0.01),waist-to-hip ratio>1.0(P=0.01)and hemoglobin A1c(HbA1c)>8.0%(P=0.005)were risk factors for elevated albuminuria not accompanied by a decrease in estimated glomerular filtration rate(eGFR).Duration of diabetes≥15 years and the use of calcium channel blockers were risk factors for albuminuria with decreased eGFR(both P=0.01).In multivariate logistic regression analysis,age,HbA1c,female sex and diuretics were significant predictors for reduced eGFR,while waist-to-hip ratio,HbA1c and male sex were associated with elevated urinary albumin-to-creatinine ratio(UACR).Excretion of nephrin and podocin was increased in patients with albuminuria,regardless of decline in renal function(P<0.001),correlating positively with UACR.The urinary excretion of WFDC-2 was markedly higher in men than in women(P<0.000001).Men with T2D demonstrated increased WFDC-2 levels independently of the CKD pattern(all P<0.05).In T2D women,WFDC-2 excretion was increased in those with reduced renal function(P≤0.01),correlating negatively with eGFR.CONCLUSION The data provide further evidence that albuminuric and non-albuminuric CKD phenotypes correspond to different pathways of diabetic kidney disease progression.

Factors associated with trabecular bone score in postmenopausal women with type 2 diabetes and normal bone mineral density

BACKGROUND Osteoporosis and type 2 diabetes(T2D)have been recognized as a widespread comorbidity leading to excess mortality and an enormous healthcare burden.In T2D,bone mineral density(BMD)may underestimate the risk of low-energy fractures as bone quality is reduced.It was hypothesized that a decrease in the trabecular bone score(TBS),a parameter assessing bone microarchitecture,may be an early marker of impaired bone health in women with T2D.AIM To identify clinical and body composition parameters that affect TBS in postmenopausal women with T2D and normal BMD.METHODS A non-interventional cross-sectional comparative study was conducted.Potentially eligible subjects were screened at tertiary referral center.Postmenopausal women with T2D,aged 50-75 years,with no established risk factors for secondary osteoporosis,were included.BMD,TBS and body composition parameters were assessed by dual-energy X-ray absorptiometry.In women with normal BMD,a wide range of anthropometric,general and diabetes-related clinical and laboratory parameters were evaluated as risk factors for TBS decrease using univariate and multivariate regression analysis and analysis of receiver operating characteristic(ROC)curves.RESULTS Three hundred twelve women were initially screened,176 of them met the inclusion criteria and underwent dual X-ray absorptiometry.Those with reduced BMD were subsequently excluded;96 women with normal BMD were included in final analysis.Among them,43 women(44.8%)showed decreased TBS values(≤1.31).Women with TBS≤1.31 were taller and had a lower body mass index(BMI)when compared to those with normal TBS(Р=0.008 and P=0.007 respectively).No significant differences in HbA1c,renal function,calcium,phosphorus,alkaline phosphatase,PTH and 25(ОН)D levels were found.In a model of multivariate linear regression analysis,TBS was positively associated with gynoid fat mass,whereas the height and androgen fat mass were associated negatively(all P<0.001).In a multiple logistic regression,TBS≤1.31 was associated with lower gynoid fat mass(adjusted odd ratio[OR],0.9,95%confidence interval[CI],0.85-0.94,P<0.001),higher android fat mass(adjusted OR,1.13,95%CI,1.03-1.24,P=0.008)and height(adjusted OR,1.13,95%CI,1.05-1.20,P<0.001).In ROC-curve analysis,height≥162.5 cm(P=0.04),body mass index≤33.85 kg/m2(P=0.002),gynoid fat mass≤5.41 kg(P=0.03)and android/gynoid fat mass ratio≥1.145(P<0.001)were identified as the risk factors for TBS reduction.CONCLUSION In postmenopausal women with T2D and normal BMD,greater height and central adiposity are associated with impaired bone microarchitecture.