Diabetic nephropathy in the elderly

Chronic Kidney Disease in the Older Adult Patient with Diabetes

Diabetes mellitus (DM) and chronic kidney disease (CKD) are common in middle aged and older adult individuals. DM may accelerate the aging process, and the age-related declines in the estimated glomerular filtration rate (eGFR) can pose a challenge to diagnosing diabetic kidney disease (DKD) using standard diagnostic criteria especially with the absence of severe albuminuria among older adults. In the presence of CKD and DM, older adult patients may need multidisciplinary care due to susceptibility to various health issues, e.g., cognitive decline, auditory or visual impairment, various comorbidities, complex medical regimens, and increased sensitivity to medication adverse effects. As a result, it can be challenging to apply recent therapeutic advancements for the general population to older adults. We review the evidence that the benefits from these newer therapies apply equally to older and younger patients with CKD and diabetes type 2 and propose a comprehensive management. This framework will address nonpharmacological measures and pharmacological management with renin angiotensin system inhibitors (RASi), sodium glucose co-transporter 2 inhibitors (SGLT2i), non-steroidal mineralocorticoids receptor antagonists (MRAs), and glucagon like peptide 1 receptor agonists (GLP1-RAs).

Inequalities in end-stage renal disease: underprivileged and ethnic minority members are at higher risk

BACKGROUND

Incidence of end-stage renal disease (ESRD) is higher in Israel than the European average. Socio-economic differences in ESRD have been reported globally, but many countries lack a national register. Using national data, we assessed which socio-demographic factors are associated with 5-year incidence of ESRD in Israel, where there is universal access to renal replacement therapy (RRT).

METHODS

Data on all incident ESRD cases aged ≥20 years receiving chronic RRT between 1 January 2014 and 31 December 2018 (N = 7883) were collected from Israel's National Dialysis & Renal Transplant Register. Individual-level data on ESRD cases requiring RRT included residential area, age, gender, ethnicity (Jewish or Arab) and ESRD cause (diabetes, other, unknown/missing). Area-level data included age and sex distribution, socio-economic status (SES) and proportion of Arab population. The associations between individual-level socio-demographic characteristics and ESRD cause were tested in bivariate comparisons. The risk of developing ESRD during the study period (from all and specific causes) was estimated using multiple Poisson regression models with negative binomial distribution, using four parameters, namely sex, ethnicity, SES category and age strata, based on area-level distribution of these parameters, and with the whole population (aged ≥20 years) as the denominator.

RESULTS

A socio-economic gradient was seen for ESRD from all causes, more marked for diabetic aetiology [rate ratio (RR)=0.45, 95% CI: 0.39-0.52 highest vs lowest SES categories] than from other (RR = 0.64, 95% CI: 0.55-0.75) or unknown cause (RR = 0.79, 95% CI: 0. 62-0.99). Based on population area-level data, predominantly Arab neighbourhoods showed higher risk for ESRD requiring RRT for all causes, with the strongest association for diabetes (RR = 1.69, 95% CI: 1.53-1.86) adjusted for SES, age and sex.

CONCLUSIONS

A strong socio-economic gradient was demonstrated for ESRD requiring RRT. Arab ethnicity was associated with higher risk for ESRD, especially due to diabetes. Our findings suggest the need for allocation of health resources according to needs and culturally appropriate interventions for improving control of modifiable risk factors for chronic renal failure.

Effect of berberine in comparison to metformin on the biophysical and biochemical parameters in diabetic albino Wistar rats

Introduction: Diabetic endothelial dysfunction is accompanied by increased oxidative stress and upregulated proinflammatory and inflammatory mediators in the endothelial vasculature. Aim of this study is to investigate the effect of Berberine, a natural alkaloid, on the oxidative stress, inflammation and its anti-oxidant effect in streptozotocin diabetic rats and to compare the effectiveness of FF with that of Metformin (Met) Material & Methods: This experimental animal study was conducted at animal house. The sample size included 174 albino wistar rats divided into 3 Groups, one control groups (C) Diabetic and untreated and two test groups. T1 Diabetic and treated with metformin 75 mg/kgwt/day) and T2 (T – Diabetics treated with Berberine(Ber) 100 mg/kgwt/day), with 58 rats in each group (29 male & 29 female). All the rats were treated with streptozotocin intra peritoneally and the diabetic state was induced.  T1 group was treated with metformin 75 mg/kg/wt/day. The T2 group of rats were treated with Berberine at a dose of 100 mg/kgwt/day. Blood sample was drawn from retro orbital plexus of animals and the biophysical and biochemical parameters were tested at an interval of 3, 6 and 12-months duration.

Animal models of diabetic microvascular complications: Relevance to clinical features

Diabetes has become more common in recent years worldwide, and this growth is projected to continue in the future. The primary concern with diabetes is developing various complications, which significantly contribute to the disease's mortality and morbidity. Over time, the condition progresses from the pre-diabetic to the diabetic stage and then to the development of complications. Years and enormous resources are required to evaluate pharmacological interventions to prevent or delay the progression of disease or complications in humans. Appropriate screening models are required to gain a better understanding of both pathogenesis and potential therapeutic agents. Different species of animals are used to evaluate the pharmacological potentials and study the pathogenesis of the disease. Animal models are essential for research because they represent most of the structural, functional, and biochemical characteristics of human diseases. An ideal screening model should mimic the pathogenesis of the disease with identifiable characteristics. A thorough understanding of animal models is required for the experimental design to select an appropriate model. Each animal model has certain advantages and limitations. The present manuscript describes the animal models and their diagnostic characteristics to evaluate microvascular diabetic complications.

Medical treatments of elderly, French patients with type 2 diabetes: results at inclusion in the GERODIAB Cohort

Prevalence of diabetes in the elderly increases, and half of the French diabetics are over the age of 75 years. The GERODIAB study is the first French multicentre, prospective, observational study designed to analyse over 5 years the influence of glycaemic control on morbidity-mortality in type 2 diabetics patients 70 years old and over. This study analysed the diabetic and geriatric factors associated with the treatment modalities, particularly insulin, at inclusion in the cohort. The cohort of 987 type 2 diabetics was divided into three groups according to the method of treatment. Slightly fewer than one-third of these patients (26.4%) were treated with insulin alone, 31% received insulin and oral antidiabetic drugs, and 42.7% oral antidiabetic drugs alone. The patients that received insulin alone were significantly older, had poorer glycaemic control (HbA1c = 7.9 ± 1.4, 7.8 ± 1.0 and 7.1 ± 1.2%, respectively; P < 0.001) and had greater alterations of glomerular filtration rate (GFR). HbA1c was below 6.5% in 15% of patients and 37.3% of patients had a GFR below 60 mL/min. The patients treated with insulin alone had significantly more hypoglycaemic episodes (respectively 53.3, 36.3 and 19.5%, P < 0.001), retinopathy, cardiovascular involvement and more specific geriatric complications, such as cognitive disorders (respectively 34.1, 31.4 and 23.6%, P = 0.006). In this specific population of elderly type 2 diabetic patients, diabetic and geriatric conditions significantly differed between the types of drug treatments. Considering low values of HbA1c and GFR, some patients seemed overtreated and other patients received inappropriate drugs.

Renoprotective effect of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats

Proton pump inhibitors (PPIs) have exhibited glucose lowering action in animal models of diabetes; however, their potential in diabetes-related complications has not yet been evaluated. Hence, the present study has been undertaken to investigate the renoprotective potential of lansoprazole in streptozotocin-induced diabetic nephropathy in wistar rats. Diabetic nephropathy was induced with a single injection of streptozotocin (STZ, 45 mg/kg, i.p.). Lansoprazole (40 mg/kg; 80 mg/kg, p.o.; 4 weeks) was administered to diabetic rats after 4 weeks of STZ treatment. A battery of biochemical tests such as serum glucose, glycated hemoglobin, blood urea nitrogen (BUN), serum creatinine, albumin, and kidney weight/body weight (%) ratio were performed to evaluate the renal functions. Oxidative stress was determined by estimating renal thiobarbituric acid reactive species (TBARS) and reduced glutathione (GSH) levels. Lipid profile was assessed by determining serum cholesterol (TC), triglyceride (TG), and high-density lipoprotein (HDL). The STZ-treated rats demonstrated deleterious alterations in kidney functions, enhanced oxidative stress, and disturbed lipid profile. Administration of lansoprazole to diabetic rats significantly reduced serum glucose, glycated hemoglobin, BUN, creatinine, albumin levels, and oxidative stress. Serum lipids like TC and TG were decreased, and HDL was enhanced in lansoprazole-treated STZ rats. The findings of our study indicate that renoprotective effects of lansoprazole may be attributed to its glucose-lowering, lipid-lowering, and antioxidative potential.

Incretin therapies in the management of patients with type 2 diabetes mellitus and renal impairment

Renal impairment (RI) is common among patients with type 2 diabetes mellitus (T2DM), and these patients also experience an age-related decline in renal function. At the same time, treatment options are more limited and treatment is more complex, particularly in patients with moderate or severe RI due to contraindications, need for dose adjustment and/or regular monitoring, and side effects, such as fluid retention and hypoglycemia, which are a more serious concern in this patient population. Incretin therapies, consisting of the injectable glucagon-like peptide-1 (GLP-1) receptor agonists and the oral dipeptidyl peptidase-4 (DPP-4) inhibitors, are a promising new class of antihyperglycemic drugs. In the overall population, they improve glycemic control in a glucose-dependent manner and are not likely to cause hypoglycemia, representing a clear advantage in at-risk populations. Data regarding use of these agents in renally impaired patients have started to emerge, and the objective of this article is to provide an overview of the currently available data and the potential role of these novel agents in the management of patients with T2DM and RI. Data for the GLP-1 receptor agonists in patients with moderate or severe RI are still limited, with no trials dedicated to these populations currently published. In addition, their potential to cause gastrointestinal side effects may limit use in patients with RI due to the risk of dehydration and hypovolemia. The use of GLP-1 receptor agonists in patients with moderate or severe RI is therefore, at present, underlying caution and/or restrictions. On the other hand, data from specific trials in patients with moderate or severe RI are now becoming available for most of the DPP-4 inhibitors. These studies demonstrate good efficacy and tolerability of the DPP-4 inhibitors in patients with moderate or severe RI, thus opening a place for these therapies in the treatment of populations with T2DM and RI. Several of the DPP-4 inhibitors are already approved for use in patients with moderate or severe RI, including for those with end-stage renal disease. While discussing the advantages related to their common mechanism of action, this article also describes differences among the DPP-4 inhibitors (eg, related to their pharmacokinetic properties and the available clinical data). In conclusion, while initial data for these new therapies are promising, further experience is needed to fully assess the risk-benefit balance and clinical positioning of these agents in RI populations.

The spectrum of biopsy-proven kidney diseases in elderly Chinese patients

BACKGROUND

Studies on biopsy-proven renal disease in the elderly (age ≥65 years) are extremely limited in China. The aim of this study was to examine the spectrum of renal diseases and their clinical presentations in elderly patients undergoing renal biopsy.

METHODS

All native renal biopsies (n = 851) performed in patients aged ≥65 years from January 2003 to December 2012 were retrospectively analyzed. The results were compared with a control group of 28 574 patients aged 18-64 years undergoing renal biopsy over the same period.

RESULTS

These 851 patients included 549 males and 302 females. Primary glomerular diseases (53.94%) occurred more frequently than secondary glomerular diseases (36.49%). The clinical manifestations were nephrotic syndrome (NS) in 29.49% of the patients, chronic renal failure in 24.68%, proteinuria and hematuria in 13.28%, proteinuria in 10.93%, acute kidney injury (AKI) in 10.81% and AKI and NS in 8.93%. Membranous nephropathy (MN) was the most frequent diagnosis (28.79%), followed by diabetic nephropathy (DN, 9.75%), IgA nephropathy (IgAN, 9.64%) and vasculitis (6.82%). When compared with the control group, the results showed that MN (P < 0.0001), DN (P < 0.0001), vasculitis (P < 0.0001) and amyloidosis (P < 0.0001) occurred more frequently and IgAN (P < 0.0001), lupus nephritis (P < 0.0001) and minimal change disease (P < 0.0001) occurred less frequently in the elderly.

CONCLUSION

This study is the first and largest renal biopsy series to analyze patients aged ≥65 years in China, and the results obtained from this study may increase the knowledge of renal diseases in elderly patients.

Diagnosis and treatment of glomerular diseases in elderly patients

Glomerular diseases are common in elderly patients and are a major cause of kidney failure. Most glomerular diseases in the elderly are caused by chronic systemic diseases, including arterial hypertension, diabetes, and atherosclerotic vascular diseases, although acute systemic vasculitis, especially anti-neutrophil-cytoplamic-antibody-mediated vasculitis, and membranous nephropathy related to malignancy, drug toxicity, and idiopathic form also occur often. Complex age-related changes and sensitivity to drug toxicity can render diagnosis and treatment for elderly patients challenging. As the general population is aging and the rate of CKD rising, updating knowledge on managing these patients is critical for care providers. We provide a comprehensive review and update of the diagnosis and treatment of glomerular diseases in the elderly.

Cardiovascular events and geriatric scale scores in elderly (70 years old and above) type 2 diabetic patients at inclusion in the GERODIAB cohort

OBJECTIVE To analyze the relationships between cardiovascular complications and geriatric scale scores in French elderly (≥70 years of age) type 2 diabetic patients at inclusion in the GERODIAB cohort. RESEARCH DESIGN AND METHODS GERODIAB is the first French multicenter, prospective, observational survey designed to analyze the influence of glycemic control on morbidity/mortality in type 2 diabetic patients aged ≥70 years during a 5-year follow-up period. This study analyzed the relationships between classical macroangiopathic complications and geriatric scale scores in 987 patients at baseline, using bivariate and multivariate analyses. RESULTS Cardiac ischemia (31.2%) was significantly associated with impaired activities of daily living (ADL) scores (P < 0.001). Stepwise logistic regression included hypercholesterolemia, ADL, sex, and hypertension successively (70.3% concordance; P < 0.001). Heart failure (10.1%) was associated with impaired Mini Mental State Examination (MMSE), instrumental ADL (IADL) (P < 0.05), and ADL scores (P < 0.001). With the logistic model, waist circumference, age, and HDL cholesterol were significant factors (70.7% concordance; P < 0.001). Arterial disease of the lower limbs (25.6%) was associated with impaired IADL and ADL scores (P < 0.001). Significant factors using the logistic model were duration of diabetes, IADL score, hypertension, and sex (62.8% concordance; P < 0.001). Cerebral ischemia (15.8%) was associated with impaired MMSE, Mini Nutritional Assessment, ADL, and IADL scores (P < 0.01). IADL, sex, hypertension, and ADL were included in the logistic model successively (65.6% concordance; P < 0.001). CONCLUSIONS In this specific population, impaired geriatric scale scores were found to be associated with classical macrovascular complications, notably using multivariate analyses. This suggests the benefits of thorough screening and management of cognitive and functional decline in elderly type 2 diabetic patients.

Experience with vildagliptin in patients ≥75 years with type 2 diabetes and moderate or severe renal impairment

INTRODUCTION

Patients with type 2 diabetes (T2DM) are at increased risk for renal impairment (RI) and, in addition, there is an age-related decline in renal function. At the same time, T2DM treatment is more complex and treatment options are more limited in elderly patients as well as patients with RI, with the patient population ≥75 years with moderate or severe RI posing unique challenges, in particular, the high risk and more severe consequences of hypoglycemia. It was, therefore, of interest to assess the efficacy and tolerability of the dipeptidyl peptidase-4 inhibitor vildagliptin in patients with T2DM ≥75 years who also have moderate or severe RI.

METHODS

In this sub-analysis of data derived from a previously described randomized, double-blind, parallel-group, 24-week study, 105 patients (50 randomized to vildagliptin 50 mg qd and 55 to placebo) ≥75 years (mean age ~78 years) with T2DM and moderate or severe RI (mean baseline estimated glomerular filtration rate ~35 ml/min/1.73 m(2)) were included.

RESULTS

The adjusted mean change in glycated hemoglobin (HbA1c) with vildagliptin was -1.0% from a baseline of 7.8% (between-group difference -0.8%; p < 0.001). This improvement in glycemic control was not associated with an increased risk of hypoglycemia; the rate of confirmed hypoglycemia was 0.49 events per patient-year with vildagliptin and 0.96 events per patient-year with placebo (not significant). Weight remained stable with vildagliptin treatment. Adverse events (AEs) (58.0% vs. 72.7%), serious AEs (14.0% vs. 16.4%), discontinuations due to AEs (4.0% vs. 9.1%) and deaths (0% vs. 5.5%) were reported at a comparable or lower frequency in patients receiving vildagliptin versus patients receiving placebo.

CONCLUSION

In this uniquely fragile elderly population ≥75 years with T2DM and moderate or severe RI, vildagliptin was well tolerated and efficacious, with no increase in the rate of hypoglycemia compared to placebo despite the marked improvement in glycemic control.

GERODIAB: Glycaemic control and 5-year morbidity/mortality of type 2 diabetic patients aged 70 years and older: 1. Description of the population at inclusion

AIMS

The GERODIAB study is the first French multicentre, prospective, observational study that aims, through a 5-year cohort follow-up, to evaluate the link between glycaemic control and morbidity/mortality of type 2 diabetic (T2D) patients aged 70 years and older. This first report describes the study population at inclusion.

PATIENTS AND METHODS

A total of 987 T2D autonomous patients, aged ≥70 years, were recruited between June 2009 and July 2010 at 56 investigator centres. Their general parameters, diabetes characteristics and standard geriatric parameters were recorded.

RESULTS

The patients' mean age was 77±5 years, with 65.2% aged 75 years or more. The mean BMI was close to 30 kg/m(2). Hypertension was found in 89.7% of patients, and 85.0% had at least one cholesterol abnormality. The mean duration of the diabetes was around 18 years, and the mean HbA(1c) level was about 7.5%. During the previous six months, 33.6% of patients had experienced one or several hypoglycaemias. Also, 26% of patients presented with diabetic retinopathy, 37.3% had a GFR<60 mL/min, 31.2% had coronary insufficiency, 10.1% had heart failure, 15.8% had cerebrovascular involvement and 25.6% had peripheral vascular disease of the lower extremities. In addition, 30.5% of patients had orthostatic hypotension, 12.4% had malnutrition and 28.8% had cognitive impairment, all of which were often diagnosed at inclusion. Three-quarters of patients were taking an oral antidiabetic drug and nearly six in every 10 patients were using insulin.

CONCLUSION

This population can be considered representative of elderly, autonomous T2D patients, and its follow-up should clarify the link between glycaemic control and mortality/morbidity.

[Type 2 diabetes in the elderly, which specific features?]

Type 2 diabetes, whose prevalence has increased among elderly aged over 75 years, has a number of specific features which differ from that in young people: heterogeneous population, association with other cardiovascular risk factors and several comorbidities, different therapeutic constraints and risks, and lower life expectancy. By using a standardized geriatric assessment it is possible to determine therapeutic and glycemic goals for each patient. In the elderly, main complications of diabetes are hypoglycemia and foot lesions. In order to avoid malnutrition, lifestyle and dietary rules should not be too strict. Recommendations for the prescription of oral antidiabetic agents are the same for both elderly and young subjects, but with increased monitoring in the elderly because of the high risk of complications including iatrogenic hypoglycemia. Insulin therapy should be preferred.

Effects of Selected Anionic β-Cyclodextrins on Persistence of Blood Glucose Lowering by Insulin Glargine after Subcutaneous Injection to Rats

Insulin glargine is a synthetic long-acting insulin product used for patients with diabetes mellitus. In this study, to obtain the further desirable blood-glucose lowering profile of insulin glargine, we investigated the effects of β-cyclodextrin sulfate (Sul-β-CyD) and sulfobutylether β-cyclodextrin (SBE7-β-CyD) on physicochemical properties of insulin glargine and pharmacokinetics/pharmacodynamics of insulin glargine after subcutaneous injection to rats. Sul-β-CyD and SBE7-β-CyD increased solubility of insulin glargine. SBE7-β-CyD suppressed the formation of oligomer and enhanced the dissolution rate of insulin glargine from its precipitate, compared to that of Sul-β-CyD. Additionally, we revealed that after subcutaneous administration of an insulin glargine solution, SBE7-β-CyD, but not Sul-β-CyD, increased bioavailability and sustained the blood-glucose lowering effect, possibly due to the inhibitory effects of SBE7-β-CyD on the enzymatic degradation at the injection site. These results suggest that SBE7-β-CyD could be a useful excipient for sustained release of insulin glargine.

Proteolytic degradation by cathepsin D of glycated hemoglobin from diabetes patients gives rise to hemorphin-7 peptides

Previous studies showed a significantly reduced level of hemorphins in the serum of diabetes patients. In order to elucidate the biochemical mechanisms responsible for this anomaly, the influence of hemoglobin glycation on hemorphin generation was studied. The glycation of hemoglobin occurs in the blood of diabetes patients and this could modify its enzymatic digestion and the resulting proteolytic products. Several samples of hemoglobin were obtained from the blood of type 1 diabetes patients (n=8) and normal healthy control subjects (n=2). The glycated hemoglobin samples were classified on the basis of their HbA1c values expressed as a percentage of total hemoglobin. Four solutions of glycated hemoglobin characterized by HbA1c values of 6%, 9.1%, 10.7% and 12.1% were treated with cathepsin D and the hemorphins obtained following the proteolysis were compared to controls. It was found that hemorphins were produced whatever the level of glycation of hemoglobin and also that the degree of glycation had no effect on the quantity of hemorphins released. Thus the alteration of hemoglobin does not seem to be the essential reason for the decrease in hemorphin concentrations in the sera of diabetic patients.

Key priorities in managing glucose control in older people with diabetes

Older people with diabetes represent a major and increasing proportion of our elderly population and their care requires better organisation. Targets for risk factor control and pathways of care must be adjusted to the subject's general health status. It is thus advisable to screen for frailty. We have carried out a detailed literature review of the studies published on diabetes in older people since 1990. Studies were considered if they included groups or subgroups of diabetic patients > 65 years old. This review discusses the elaboration of general targets for care, the approach to risk factor control, the screening and the specific prevention or management of complications, the integration of geriatric concepts in diabetes care and the specificity of education with respect to frailty status.

Experimental models for nephropathy

Nephropathy is a leading cause of morbidity and mortality and its prevalence is continuously increasing in industrialised nations. Nephropathy is characterised to varying degrees by nodular glomerulosclerosis, glomerular basement membrane thickness and mesangial expansion, leading to a decline in glomerular filtration rate, persistent elevated albuminuria, elevated arterial blood pressure and fluid retention. Hyperglycaemia, hyperlipidaemia and hypertension are considered to be the major risk factors implicated in the progression of nephropathy.Various signalling systems, such as vasoconstrictor peptides, inflammatory mediators, growth factors and adhesion molecules, are involved in the pathogenesis of nephropathy.At present, no promising therapy is available to treat patients with nephropathy due to lack of understanding of signalling culprits involved in the pathogenesis of nephropathy. Animal models are being developed to better understand the disease pathogenesis and develop drugs for nephropathy. In the present review, we have discussed various animal models for nephropathy, which may open vistas for developing new drugs to treat nephropathy.