Ethnic/Race Diversity and Diabetic Kidney Disease

Multicentre, retrospective cohort study protocol to identify racial and ethnic differences in acute kidney injuries in children and adolescents with diabetic ketoacidosis

INTRODUCTION

Approximately 40% of children with diabetic ketoacidosis (DKA) develop acute kidney injury (AKI), which increases the risk of chronic kidney damage. At present, there is limited knowledge of racial or ethnic differences in diabetes-related kidney injury in children with diabetes. Understanding whether such differences exist will provide a foundation for addressing disparities in diabetes care that may continue into adulthood. Further, it is currently unclear which children are at risk to develop worsening or sustained DKA-related AKI. The primary aim is to determine whether race and ethnicity are associated with DKA-related AKI. The secondary aim is to determine factors associated with sustained AKI in children with DKA.

METHODS AND ANALYSIS

This retrospective, multicentre, cross-sectional study of children with type 1 or type 2 diabetes with DKA will be conducted through the Paediatric Emergency Medicine Collaborative Research Committee. Children aged 2-18 years who were treated in a participating emergency department between 1 January 2020 and 31 December 2023 will be included. Children with non-ketotic hyperglycaemic-hyperosmolar state or who were transferred from an outside facility will be excluded. The relevant predictor is race and ethnicity. The primary outcome is the presence of AKI, defined by Kidney Disease: Improving Global Outcomes criteria. The secondary outcome is 'sustained' AKI, defined as having AKI ≥48 hours, unresolved AKI at last creatinine measurement or need for renal replacement therapy. Statistical inference of the associations between predictors (ie, race and ethnicity) and outcomes (ie, AKI and sustained AKI) will use random effects regression models, accounting for hospital variation and clustering.

ETHICS AND DISSEMINATION

The Institutional Review Board of Children's Minnesota approved this study. 12 additional sites have obtained institutional review board approval, and all sites will obtain local approval prior to participation. Results will be presented at local or national conferences and for publication in peer-reviewed journals.

African Caribbean Ethnicity Is an Independent Predictor of Significant Decline in Kidney Function in People With Type 1 Diabetes

OBJECTIVE

The aim of the study was to identify the demographic and clinical features in an urban cohort of people with type 1 diabetes who developed a ≥50% decline in estimated glomerular filtration rate (eGFR).

RESEARCH DESIGN AND METHODS

We evaluated 5,261 people with type 1 diabetes (51% female, 13.4% African Caribbean) with baseline eGFR >45 mL/min/1.73 m2 between 2004 and 2018. The primary end point was an eGFR decline of ≥50% from baseline with a final eGFR <30 mL/min/1.73 m2. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

Of the cohort, 263 (5%) reached the primary end point. These individuals were more likely to be of African Caribbean ethnicity, be older, have a longer duration of diabetes, have higher systolic blood pressure and HbA1c, have more prevalent retinopathy, and have higher albuminuria (all P < 0.05). In multivariable Cox regression models, African Caribbean ethnicity emerged as a significant risk factor for the primary end point (hazard ratio 1.57, 95% CI 1.19, 2.08) compared with other ethnicities and independent of established risk factors (P < 0.01). The incidence rate for the primary end point in African Caribbean people was double that in non-African Caribbean people (16 vs. 7.7 per 1000 patient-years, P < 0.001). A similar significant independent impact of African Caribbean ethnicity for secondary end points (≥40% and ≥30% fall in eGFR) was observed.

CONCLUSIONS

We report a novel observation that African Caribbean ethnicity increased the risk of kidney function loss in people with type 1 diabetes, an effect that was independent of traditional risk factors. Further studies are needed to examine the associated pathophysiology that may explain this observation.

SNPs in PRKCA-HIF1A-GLUT1 are associated with diabetic kidney disease in a Chinese Han population with type 2 diabetes

OBJECTIVE

To explore the relationship between SNPs in PRKCA-HIF1A-GLUT1 and diabetic kidney disease in Chinese Han people.

MATERIALS AND METHODS

A total of 2552 participants from Shanghai Diabetes Institute Inpatient Database of Shanghai Jiao Tong University Affiliated Sixth People's Hospital were involved in the stage 1 cross-sectional population. A total of 6015 subjects from the Hong Kong Diabetes Register were included for validation. Genotyping of participants was conducted by the MassARRAY Compact Analyzer (Agena Bioscience). The data were analysed by plink, SAS, Haploview.

RESULTS

We identified variants associated with diabetic kidney disease in stage 1. Rs1681851 (P = .0105, OR = 1.331) in GLUT1 as well as rs2301108 (P = .0085, OR = 1.289) and rs79865957 (P = .0204, OR = 1.263) in HIF1A were significantly associated with diabetic kidney disease. Regarding DKD-related traits, rs1681851 was associated with plasma creatinine levels (P = .0169, β = 4.822) and eGFR (P = .0457, β = -6.956). Moreover, the results showed the interactions between PRKCA-GLUT1 in the occurrence of DKD. We further sought validation of the 17 SNPs in a prospective cohort and found that rs900836 and rs844501 were associated with the percentage change in eGFR slope. We performed a meta-analysis of case-control analysis data from the Hong Kong samples together with the stage 1 data from Shanghai. Rs9894851 showed significant correlation with the serum creatinine level as well as eGFR and no SNP showed association with DKD after meta-analysis.

CONCLUSIONS

Our results suggest potential association between SNPs in PRKCA-HIF1A-GLUT1 and diabetic kidney disease in Chinese Han people.

Racial Differences in the Effectiveness of a Multifactorial Telehealth Intervention to Slow Diabetic Kidney Disease

BACKGROUND

African Americans are significantly more likely than non-African Americans to have diabetes, chronic kidney disease, and uncontrolled hypertension, increasing their risk for kidney function decline.

OBJECTIVE

The objective of this study was to compare how African Americans and non-African Americans with diabetes responded to a multifactorial telehealth intervention designed to slow kidney function decline.

RESEARCH DESIGN

Secondary analysis of a randomized trial. Primary care patients (N=281, 56% African American) were allocated to either: (1) a multifactorial, pharmacist-delivered phone-based telehealth intervention focused on behavioral and medication management of diabetic kidney disease; or (2) an education control.

MEASURES

The primary study outcome was change in estimated glomerular filtration rate (eGFR). Linear mixed models were used to explore the moderating effect of race on the relationship between study arm and eGFR decline over time; the mean annual rate of eGFR decline was estimated by race and study arm.

RESULTS

Findings demonstrated a differential intervention effect on kidney function over time by race (Pinteraction=0.005). Among African Americans, the intervention arm had significantly greater preservation of eGFR over time than the control arm (difference in the annual rate of eGFR decline=1.5 mL/min/1.73 m; 95% confidence interval: 0.04, 3.02). For non-African Americans, the intervention arm had a faster decline in eGFR over time than the control arm (difference in the annual rate of eGFR decline=-1.7 mL/min/1.73 m; 95% confidence interval: -3.3, -0.02).

CONCLUSION

A multifactorial, pharmacist-delivered telehealth intervention for diabetic kidney disease may be more effective for slowing eGFR decline among African Americans than non-African Americans.

Clinical update: The important role of dual kidney function testing (ACR and eGFR) in primary care: Identification of risk and management in type 2 diabetes

Diabetic kidney disease (DKD) is common complication of type 1 and type 2 diabetes and may lead to progressive kidney dysfunction culminating in end-stage kidney disease. Kidney function is evaluated less frequently than other care procedures in patients with diabetes, even though the opportunity to identify DKD early and slow or even halt renal damage early in the disease progression represents a potentially important clinical opportunity for early intervention. The following review provides an overview of the under-recognised importance of kidney function in T2D and current best-practice to support the identification of DKD as part of primary care T2D management.

1,25(OH)2D3 provides protection against diabetic kidney disease by downregulating the TLR4-MyD88-NF-κB pathway

The over-activation of Toll-like receptors (TLRs) is a typical immune response to injury. Previous work has suggested that controlling the over-activation of TLR4-MyD88-NF-κB may represent a new therapeutic option for diabetic kidney disease (DKD). 1,25(OH)₂D₃ has also been shown to exert a protective effect on DKD, although the mechanism involved has yet to be elucidated. The aim of this study was to investigate whether 1,25(OH)₂D₃ protects against DKD by down-regulating the innate immune TLR-NF-κB pathway. NRK-52E cells were cultured under normal or high-glucose conditions. We then used siRNA to knock down TLR4 expression under high-glucose conditions. NRK-52E cells cultured under high-glucose conditions, and streptozotocin (STZ)-induced diabetic rats, were treated with different doses of 1,25(OH)₂D₃ and used as in vitro and in vivo models, respectively. Renal biochemical indicators were then measured to evaluate the influence of 1,25(OH)₂D₃ treatment on DKD in diabetic rats. Histological analysis was also performed to determine the extent of infiltration by inflammatory cells and tubulointerstitial fibrosis. Using RT-qPCR, western blotting, immunohistochemistry and immunofluorescence, we determined the expression levels of TLR4, MyD88, NF-κB p65, MCP-1 and α-SMA to investigate whether 1,25(OH)₂D₃ could reduce the development of tubulointerstitial fibrosis. Knocking down TLR4 abolished the tubulointerstitial fibrosis caused by high-glucose conditions. High doses of 1,25(OH)₂D₃ consistently reduced the expression of TLR4-MyD88-NF-κB in NRK-52E cells. Moreover, high doses of 1,25(OH)₂D₃ had an obvious protective effect on kidney injury and inhibited the infiltration of inflammatory cells and tubulointerstitial fibrosis in diabetic rats. In conclusion, high doses of 1,25(OH)₂D₃ protected against tubulointerstitial fibrosis both in vitro and in vivo by downregulating the expression of TLR4-MyD88-NF-κB.

Temporal trajectories of accompanying comorbidities in patients with type 2 diabetes: a Korean nationwide observational study

Type 2 diabetes mellitus is a major concern globally and well known for increasing risk of complications. However, diabetes complications often remain undiagnosed and untreated in a large number of high-risk patients. In this study based on claims data collected in South Korea, we aimed to explore the diagnostic progression and sex- and age-related differences among patients with type 2 diabetes using time-considered patterns of the incidence of comorbidities that evolved after a diagnosis of type 2 diabetes. This study compared 164,593 patients who met the full criteria for type 2 diabetes with age group-, sex-, encounter type-, and diagnosis date-matched controls who had not been diagnosed with type 2 diabetes. We identified 76,423 significant trajectories of four diagnoses from the dataset. The top 30 trajectories with the highest average relative risks comprised microvascular, macrovascular, and miscellaneous complications. Compared with the trajectories of male groups, those of female groups included relatively fewer second-order nodes and contained hubs. Moreover, the trajectories of male groups contained diagnoses belonging to various categories. Our trajectories provide additional information about sex- and age-related differences in the risks of complications and identifying sequential relationships between type 2 diabetes and potentially complications.

Genome-wide association study identifies new susceptibility loci for diabetic nephropathy in Korean patients with type 2 diabetes mellitus

Genetic factors are considered to be important in the pathogenesis of diabetic nephropathy (DN). Despite several genome-wide association studies (GWASs) demonstrating that specific polymorphisms of candidate genes were associated with DN, there were some limitations in previous studies. We conducted a GWAS using customized DNA chips to identify novel susceptibility loci for DN in Korean. We analyzed a total of 414 DN cases and 474 normoalbuminuric diabetic hyper-controls across two stages using customized DNA chips containing 98 667 single nucleotide polymorphisms (SNPs). We explored the associations between SNPs and DN in samples from 87 DN cases, mostly confirmed by renal biopsy, and 104 diabetic hyper-controls, and replicated these associations in independent cohort samples with 327 DN cases and 370 diabetic hyper-controls. The top significant SNPs from the discovery samples were selected for replication in the independent cohort. rs3765156 in PIK3C2B was significantly associated with DN in the replication cohort after multiple test. The SNPs identified in our study provide new insights into the pathogenesis of DN in the Korean population. Additional studies are needed to determine biological effects and clinical utility of our findings.

Prevalence and progression of diabetic nephropathy in South Asian, white European and African Caribbean people with type 2 diabetes: A systematic review and meta-analysis

AIMS

To conduct a systematic review and meta-analysis of published observational evidence to assess the difference in the prevalence and progression of diabetic nephropathy, and the development of end-stage renal disease (ESRD) in people from three different ethnic groups with type 2 diabetes (T2DM).

MATERIALS AND METHODS

Relevant studies were identified in a literature search of MEDLINE, EMBASE and reference lists of relevant studies published up to May 2018. We decided a priori that there were no differences in the prevalence and progression of diabetic nephropathy, and the development of ESRD in the three ethnicities with T2DM. Pooled relative risks of microalbuminuria by ethnicity were estimated by fitting three random effects meta-analyses models. A narrative synthesis of the nephropathy progression in the studies was carried out. The review was registered in PROSPERO (CRD42018107350).

RESULTS

Thirty-two studies with data on 153 827 unique participants were eligible for inclusion in the review. The pooled prevalence ratio of microalbuminuria in South Asian compared with white European participants was 1.14 (95% confidence interval [CI] 0.99, 1.32; P = 0.065), while for African Caribbean vs South Asian participants the pooled prevalence ratio was 1.08 (95% CI 0.93, 1.24; P = 0.327). Results for renal decline were inconsistent, with preponderance towards a high rate of disease progression in South Asian compared with white participants. The estimated pooled incidence rate ratio (IRR) for ESRD was significantly higher in African Caribbean vs white European participants: 2.75 (95% CI 2.01, 3.48; P < 0.001).

CONCLUSION

The results of this review did not show a significant link between ethnicity (South Asian, white European and African Caribbean) and the prevalence of microalbuminuria; however, the IRR for ESRD in African Caribbean compared with white European participants was significantly higher. Further research is needed to explore the potential non-albuminuric pathways of progression to ESRD.

Efficacy and safety of dapagliflozin in Asian patients: A pooled analysis

BACKGROUND

The efficacy and safety of dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, has been demonstrated predominantly in Western populations. This study examined the efficacy and safety of dapagliflozin in Asian patients with type 2 diabetes mellitus (T2DM) from eight Phase IIb/III double-blind trials of up to 24 weeks, treated with placebo (n = 497) or dapagliflozin 5 mg (n = 491) or 10 mg (n = 465).

METHODS

Efficacy was assessed in the pooled population receiving dapagliflozin 5, 10 mg or placebo over 24 weeks. Safety and tolerability were assessed by collating data for overall adverse events (AEs) and AEs of special interest over the 24-week period.

RESULTS

Demographic and baseline characteristics were comparable across treatment groups. Placebo-corrected adjusted mean changes from baseline at 24 weeks in the dapagliflozin 5 and 10 mg groups, respectively, were -0.52% and -0.58% for HbA1c and -1.34 and -1.80 kg for body weight. Modest reductions in blood pressure were also noted with dapagliflozin. Overall, 56.5%, 53.6%, and 58.7% of patients in the placebo and dapagliflozin 5 and 10 mg groups, respectively, experienced AEs, compared with 2.8%, 4.1%, and 2.4% experiencing serious AEs. Genital infections were more frequent with dapagliflozin 10 mg than placebo, whereas the pattern for urinary tract infections was less clear. A transient reduction in mean estimated glomerular filtration rate was noted with dapagliflozin, but was not associated with an increased frequency of serious renal AEs. In contrast, placebo-corrected reductions in urinary albumin : creatinine ratio in patients with albuminuria at baseline suggest a potential renoprotective effect of dapagliflozin.

CONCLUSION

Dapagliflozin was efficacious and well tolerated in Asian patients with T2DM.