Structural basis of ethnic-specific variants of PAX4 associated with type 2 diabetes

Genome-Wide Association Studies for Albuminuria of Nondiabetic Taiwanese Population

INTRODUCTION

Chronic kidney disease, which is defined by a reduced estimated glomerular filtration rate and albuminuria, imposes a large health burden worldwide. Ethnicity-specific associations are frequently observed in genome-wide association studies (GWAS). This study conducts a GWAS of albuminuria in the nondiabetic population of Taiwan.

METHODS

Nondiabetic individuals aged 30-70 years without a history of cancer were enrolled from the Taiwan Biobank. A total of 6,768 subjects were subjected to a spot urine examination. After quality control using PLINK and imputation using SHAPEIT and IMPUTE2, a total of 3,638,350 single-nucleotide polymorphisms (SNPs) remained for testing. SNPs with a minor allele frequency of less than 0.1% were excluded. Linear regression was used to determine the relationship between SNPs and log urine albumin-to-creatinine ratio.

RESULTS

Six suggestive loci are identified in or near the FCRL3 (p = 2.56 × 10-6), TMEM161 (p = 4.43 × 10-6), EFCAB1 (p = 2.03 × 10-6), ELMOD1 (p = 2.97 × 10-6), RYR3 (p = 1.34 × 10-6), and PIEZO2 (p = 2.19 × 10-7). Genetic variants in the FCRL3 gene that encode a secretory IgA receptor are found to be associated with IgA nephropathy, which can manifest as proteinuria. The PIEZO2 gene encodes a sensor for mechanical forces in mesangial cells and renin-producing cells. Five SNPs with a p-value between 5 × 10-6 and 5 × 10-5 are also identified in five genes that may have a biological role in the development of albuminuria.

CONCLUSION

Five new loci and one known suggestive locus for albuminuria are identified in the nondiabetic Taiwanese population.

Interconnection between cardiovascular, renal and metabolic disorders: A narrative review with a focus on Japan

Insights from epidemiological, clinical and basic research are illuminating the interplay between metabolic disorders, cardiovascular disease (CVD) and kidney dysfunction, termed cardio-renal-metabolic (CRM) disease. Broadly defined, CRM disease involves multidirectional interactions between metabolic diseases such as type 2 diabetes (T2D), various types of CVD and chronic kidney disease (CKD). T2D confers increased risk for heart failure, which-although well known-has only recently come into focus for treatment, and may differ by ethnicity, whereas atherosclerotic heart disease is a well-established complication of T2D. Many people with T2D also have CKD, with a higher risk in Asians than their Western counterparts. Furthermore, CVD increases the risk of CKD and vice versa, with heart failure, notably, present in approximately half of CKD patients. Molecular mechanisms involved in CRM disease include hyperglycaemia, insulin resistance, hyperactivity of the renin-angiotensin-aldosterone system, production of advanced glycation end-products, oxidative stress, lipotoxicity, endoplasmic reticulum stress, calcium-handling abnormalities, mitochondrial malfunction and deficient energy production, and chronic inflammation. Pathophysiological manifestations of these processes include diabetic cardiomyopathy, vascular endothelial dysfunction, cardiac and renal fibrosis, glomerular hyperfiltration, renal hypoperfusion and venous congestion, reduced exercise tolerance leading to metabolic dysfunction, and calcification of atherosclerotic plaque. Importantly, recognition of the interaction between CRM diseases would enable a more holistic approach to CRM care, rather than isolated treatment of individual conditions, which may improve patient outcomes. Finally, aspects of CRM diseases may differ between Western and East Asian countries such as Japan, a super-ageing country, with potential differences in epidemiology, complications and prognosis that represent an important avenue for future research.

Relationship between Ultra-Processed Food Consumption and Risk of Diabetes Mellitus: A Mini-Review

Studying the factors that cause diabetes and conducting clinical trials has become a priority, particularly raising awareness of the dangers of the disease and how to overcome it. Diet habits are one of the most important risks that must be understood and carefully applied to reduce the risk of diabetes. Nowadays, consuming enough home-cooked food has become a challenge, particularly with modern life performance, pushing people to use processed foods. Ultra-processed food (UPF) consumption has grown dramatically over the last few decades worldwide. This growth is accompanied by the increasing prevalence of non-communicable diseases (NCDs) such as cardiovascular diseases, hypertension, and type 2 diabetes. UPFs represent three main health concerns: (i) they are generally high in non-nutritive compounds such as sugars, sodium, and trans fat and low in nutritional compounds such as proteins and fibers, (ii) they contain different types of additives that may cause severe health issues, and (iii) they are presented in packages made of synthetic materials that may also cause undesirable health side-effects. The association between the consumption of UPF and the risk of developing diabetes was discussed in this review. The high consumption of UPF, almost more than 10% of the diet proportion, could increase the risk of developing type 2 diabetes in adult individuals. In addition, UPF may slightly increase the risk of developing gestational diabetes. Further efforts are needed to confirm this association; studies such as randomized clinical trials and prospective cohorts in different populations and settings are highly recommended. Moreover, massive improvement in foods' dietary guidelines to increase the awareness of UPF and their health concerns is highly recommended.

Ethnic-Specific Type 2 Diabetes Risk Factor PAX4 R192H Is Associated with Attention-Specific Cognitive Impairment in Chinese with Type 2 Diabetes

Background: Type 2 diabetes mellitus (T2DM) has been shown to increase the risks of cognitive decline and dementia. Paired box gene 4 (PAX4), a transcription factor for beta cell development and function, has recently been implicated in pathways intersecting Alzheimer’s disease and T2DM. Objective: In this report, we evaluated the association of the ethnic-specific PAX4 R192H variant, a T2DM risk factor for East Asians which contributes to earlier diabetes onset, and cognitive function of Chinese T2DM patients. Methods: 590 Chinese patients aged 45–86 from the SMART2D study were genotyped for PAX4 R192H variation using Illumina OmniExpress-24 Array. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) which had been validated in the Singapore population was administered to assess five cognitive domains: immediate memory, visuospatial/constructional, language, attention, and delayed memory. Multiple linear regression was used to assess the association of the R192H risk allele and cognitive domains. Results: Patients with two PAX4 R192H risk alleles showed significantly lower attention index score (β= –8.46, 95% CI [–13.71, –3.21], p = 0.002) than patients with wild-type alleles after adjusting for age, gender, diabetes onset age, HbA1c, body-mass index, renal function, lipid profiles, systolic blood pressure, metformin usage, smoking history, education level, Geriatric Depression Scale score, and presence of APOE ɛ4 allele. Conclusion: Ethnic-specific R192H variation in PAX4 is associated with attention-specific cognitive impairment in Chinese with T2DM. Pending further validation studies, determining PAX4 R192H genotype may be helpful for early risk assessment of early-onset T2DM and cognitive impairment to improve diabetes care.