Role of sex hormones in diabetic nephropathy

Epidemiological trends in diabetic renal complications in United States adults: A center for disease control and prevention wide-ranging online data for epidemiologic research analysis (1999-2020)

BACKGROUND

Renal complications of diabetes mellitus pose a significant public health challenge, contributing to substantial morbidity and mortality globally. Understanding temporal trends and regional disparities in mortality related to diabetic nephropathy is crucial for guiding targeted interventions and policy decisions.

AIM

To display the trends and disparities of diabetic nephropathy related mortality.

METHODS

A retrospective analysis was conducted using death certificate data from the center for disease control and prevention (CDC) wide-ranging online data for epidemiologic research analysis (WONDER) database, spanning from 1999 to 2020, to investigate mortality related to renal complications of diabetes in adults aged 35 or above. Age-adjusted mortality rate (AAMR) per 100000 persons and annual percent change (APC) were computed, with stratification by year, sex, race/ethnicity, and geographic region.

RESULTS

Between 1999 and 2020, a total of 525804 deaths occurred among adults aged 35 to 85+ years due to renal-related issues associated with diabetes. AAMR for renal-related deaths in adult diabetic patients showed a consistent increase from 1.6 in 1999 to 34.9 in 2020 (average APC [AAPC]: 17.23; 95% confidence interval [CI]: 13.35-28.79). Throughout the study period, men consistently had higher AAMR (overall AAMR for men: 17.8; 95%CI: 17.7-17.9). In 1999, the AAMR for men was 1.8, increasing to 44.2 by 2020 (AAPC: 17.54; 95%CI: 13.09-29.53), while for women, it was 1.6 in 1999 and rose to 27.6 by 2020 (AAPC: 15.55; 95%CI: 13.35-21.10). American Indian/Alaska Native adults exhibited the highest overall AAMR (36.1; 95%CI: 35.2-36.9), followed by Black/African American (25.5; 95%CI: 25.3-25.7). The highest mortality was observed in the Western (AAMR: 16.6; 95%CI: 16.5-16.7), followed by the Midwestern region (AAMR: 14.4; 95%CI: 14.314.4). Significant variations in AAMR were observed among different states, with Oklahoma recording the highest (21.2) and Connecticut the lowest (7). The CDC WONDER database could potentially have omissions or inaccuracies. It does not provide data outside of the available variables. Furthermore, dataset after 2020 was not included in this study.

CONCLUSION

Our findings highlight an alarming rise in mortality related to renal complications of diabetes among United States adults over the past two decades, with concerning disparities across demographic and geographic factors. These results underscore the urgent need for targeted interventions, policies, and protocols to address the growing burden of diabetic nephropathy and substantially reduce mortality rates in the United States. This will help improve the overall health outcome in the United States by identifying communities at risk and implementing tailored assistance to them.

Urinary Fetuin-A with Specific Post-Translational Modification in Type 1 Diabetes Patients with Normoalbuminuria and Preserved Kidney Function

Background/Objectives: Post-translationally modified peptide fragments of fetuin-A (FetA) were identified as a potential biomarker of diabetic kidney disease (DKD). An independent association between urinary FetA-derived peptide levels (uPTM3-FetA) and DKD progression in patients with type 2 diabetes (T2D) was evidenced. This study aimed to explore uPTM3-FetA excretion and its associations with insulin resistance, inflammatory and metabolic biomarkers in patients with type 1 diabetes (T1D), and the normal albuminuria and estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2. Methods: uPTM3-FetA levels in aliquots of 24 h urine specimens, routine laboratory renal, metabolic and inflammatory tests, adipokines (leptin, adiponectin, resistin), and insulin resistance, assessed as the estimated glucose disposal rate (eGDR), were measured in a cohort of 169 adult T1D patients. To evaluate the changes in early renal dysfunction, the cohort was divided according to the median eGFR. Above- and below-median-eGFR groups were considered as having normal and declining kidney function, respectively. Results: The median (IQR) uPTM3-FetA level was 11.7 (8.43-16.65 µg/24 h), with no significant difference between males and females, as well as normal and declining kidney function patients. However, a sex-specific analysis revealed a significantly higher uPTM3-FetA excretion in male T1D patients with lower eGFRs, when compared to those with higher eGFRs, whereas no such difference was observed in female patients. BMI, hs-CRP, resistin and HDL-cholesterol were identified as independent predictors of uPTM3-FetA excretion. Conclusions: Our results implicate the potential role of uPTM3-FetA in the detection of an early renal dysfunction in male patients with T1DM and pinpoint the importance of a sex-specific approach in diabetes diagnostics and research.

Sexual Dimorphism in Impairment of Acetylcholine-Mediated Vasorelaxation in Zucker Diabetic Fatty (ZDF) Rat Aorta: A Monogenic Model of Obesity-Induced Type 2 Diabetes

Several reports, including our previous studies, indicate that hyperglycemia and diabetes mellitus exert differential effects on vascular function in males and females. This study examines sex differences in the vascular effects of type 2 diabetes (T2D) in an established monogenic model of obesity-induced T2D, Zucker Diabetic Fatty (ZDF) rats. Acetylcholine (ACh) responses were assessed in phenylephrine pre-contracted rings before and after apocynin, a NADPH oxidase (NOX) inhibitor. The mRNA expressions of aortic endothelial NOS (eNOS), and key NOX isoforms were also measured. We demonstrated the following: (1) diabetes had contrasting effects on aortic vasorelaxation in ZDF rats, impairing relaxation to ACh in females while enhancing it in male ZDF rats; (2) inhibition of NOX, a major source of superoxide in vasculature, restored aortic vasorelaxation in female ZDF rats; and (3) eNOS and NOX4 mRNA expressions were elevated in female (but not male) ZDF rat aortas compared to their respective leans. This study highlights sexual dimorphism in ACh-mediated vasorelaxation in the aorta of ZDF rats, suggesting that superoxide may play a role in the impaired vasorelaxation observed in female ZDF rats.

Sex Differences in Kidney Health and Disease

BACKGROUND

Sex differences exist in kidney physiology and disease which are underpinned by the biological actions of the sex hormones estrogen, progesterone and testosterone. In this review, we present an up-to-date discussion of the hormonal and molecular signalling pathways implicated in sex differences in kidney health and disease.

SUMMARY

Estrogen and progesterone have protective effects on renal blood flow, glomerular filtration rate and nephron ion and water reabsorptive processes, whereas testosterone tends to compromise these functions. The biological effects of estrogen appear to be the most important in reinforcing kidney function and protecting against kidney diseases in females. The actions of estrogen are myriad but all tend to bolster kidney physiology to maintain a steady-state and adaptable extracellular fluid volume (ECFV) and blood pressure. Estrogen safeguards ECFV homeostasis by stimulating renal epithelial sodium channel (ENaC) and water channel (AQP2) expression and transport function. Renal maintenance of ECFV within narrow physiological limits is a first-line of defense against hypertension and lowers the risk of cardiovascular disease in women. The estrogenic and XX chromosome basis for a female advantage are evident in a wide range of kidney diseases including acute kidney injury, chronic kidney disease, end-stage kidney disease, diabetic kidney disease, and polycystic kidney disease. The molecular mechanisms involve estrogen regulation of nephron ion and water transport, genetic immunogenic responses, activation of the protective arm of the renin angiotensin-aldosterone system and XX chromosome reinforcement of immune responses. Kidney disease can also predispose patients to cancer and women are protected in renal cancer with lower incidence, morbidity, and mortality than age-matched men with the disease.

KEY MESSAGES

This review underscores the importance of incorporating sex-specific considerations into clinical practice and basic research to bridge the gap in understanding and addressing biological sex disparities in kidney disease and renal cancer.

Testosterone deficiency and chronic kidney disease

Testosterone's biological functions are extensive, influencing reproductive and systemic health. It plays a vital role in sexual functions, muscle protein synthesis, bone metabolism, fat distribution, and cardiovascular health. The hormone also affects mood, cognitive function, and erythropoiesis, underscoring its importance in both physical and mental health. Testosterone deficiency, or male male hypogonadism, is increasingly recognized as a significant health issue affecting various bodily systems, also in the context of chronic kidney disease (CKD). Recent research indicates a complex interplay between testosterone levels and renal health, suggesting that male male hypogonadism may both impact and be impacted by CKD. The latter is characterized by a gradual loss of kidney function, affects millions globally and is often associated with diabetes mellitus, arterial hypertension, and autoimmune diseases. Men with CKD frequently experience lower testosterone levels, which can exacerbate muscle wasting, reduce quality of life, and increase cardiovascular risk. Overall, low testosterone levels in CKD patients are associated with increased morbidity and mortality. Several mechanisms explain the relationship between CKD and testosterone deficiency. The uremic environment in CKD disrupts the hypothalamic-pituitary-gonadal axis, impairing hormone production. Nutritional deficiencies and chronic inflammation common in CKD patients further suppress gonadal function. The consequences of low testosterone in CKD are profound, with studies suggesting that testosterone replacement therapy (TRT) might improve clinical outcomes, though the long-term effects and causal relationships remain under investigation. The potential benefits of TRT in CKD patients might be significant. TRT can enhance muscle mass and strength, address anemia by stimulating erythropoiesis, improve bone density, and possibly offer cardiovascular benefits by improving body composition and insulin sensitivity. General symptoms of male hypogonadism, such as deteriorated psychological, sexual and physical wellbeing, can be improved by TRT. However, these benefits must be weighed against potential risks. TRT may exacerbate fluid retention, arterial hypertension, or exacerbate existing heart failure, particularly in CKD patients with pre-existing cardiovascular comorbidities. Additionally, concerns about the progression of renal disease via several testosterone affected pathways involving renal tubular integrity exist, highlighting the need for careful patient selection and monitoring. Understanding this relationship is crucial for developing comprehensive treatment strategies that address both renal and endocrine dysfunctions, highlighting the need for integrated patient care, which means good collaboration between subspecialists like nephrologists, endocrinologists, urologists and primary care providers, aiming to improve outcomes and quality of life while mitigating adverse effects.

The Role of Estrogen across Multiple Disease Mechanisms

Estrogen is a significant hormone that is involved in a multitude of physiological and pathological processes. In addition to its pivotal role in the reproductive system, estrogen is also implicated in the pathogenesis of a multitude of diseases. Nevertheless, previous research on the role of estrogen in a multitude of diseases, including Alzheimer's disease, depression, cardiovascular disease, diabetes, osteoporosis, gastrointestinal diseases, and estrogen-dependent cancers, has concentrated on a single disease area, resulting in a lack of comprehensive understanding of cross-disease mechanisms. This has brought some challenges to the current treatment methods for these diseases, because estrogen as a potential therapeutic tool has not yet fully developed its potential. Therefore, this review aims to comprehensively explore the mechanism of estrogen in these seven types of diseases. The objective of this study is to describe the relationship between each disease and estrogen, including the ways in which estrogen participates in regulating disease mechanisms, and to outline the efficacy of estrogen in treating these diseases in clinical practice. By studying the role of estrogen in a variety of disease mechanisms, it is hoped that a more accurate theoretical basis and clinical guidance for future treatment strategies will be provided, thus promoting the effective management and treatment of these diseases.

Association between neutrophil-to-lymphocyte ratio and diabetic kidney disease in type 2 diabetes mellitus patients: a cross-sectional study

Aims

This investigation examined the possibility of a relationship between neutrophil-to-lymphocyte ratio (NLR) and diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM) patients.

Methods

Adults with T2DM who were included in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2020 were the subjects of the current cross-sectional investigation. Low estimated glomerular filtration rate (eGFR) (< 60 mL/min/1.73 m2) or albuminuria (urinary albumin-to-creatinine ratio (ACR) ≥ 30 mg/g) in T2DM patients were the diagnostic criteria for DKD. Weighted multivariable logistic regression models and generalized additive models were used to investigate the independent relationships between NLR levels with DKD, albuminuria, and low-eGFR. Additionally, we examined the relationships between DKD, albuminuria, and low-eGFR with other inflammatory markers, such as the aggregate index of systemic inflammation (AISI), systemic immune-inflammation index (SII), system inflammation response index (SIRI), and platelet-to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR). Their diagnostic capabilities were evaluated and contrasted using receiver operating characteristic (ROC) curves.

Results

44.65% of the 7,153 participants who were recruited for this study were males. DKD, albuminuria, and low-eGFR were prevalent in 31.76%, 23.08%, and 14.55% of cases, respectively. Positive correlations were seen between the NLR with the prevalences of DKD, albuminuria, and low-eGFR. Subgroup analysis and interaction tests revealed that the associations of NLR with DKD, albuminuria, and low-eGFR were not significantly different across populations. In addition, MLR, SII and SIRI showed positive associations with the prevalence of DKD. ROC analysis discovered that when compared to other inflammatory markers (MLR, PLR, SII, SIRI, and AISI), NLR may demonstrate more discriminatory power and accuracy in assessing the risk of DKD, albuminuria, and low-eGFR.

Conclusion

Compared to other inflammatory markers (MLR, PLR, SII, SIRI, and AISI), NLR may serve as the more effective potential inflammatory marker for identifying the risk of DKD, albuminuria, and low-eGFR in US T2DM patients. T2DM patients with elevated levels of NLR, MLR, SII, and SIRI should be closely monitored for their potential risk to renal function.

Factors affecting serum PFAS concentrations among US females with surgically and naturally induced menopause: data from NHANES 2003-2018

Sex hormones influence excretion of the biopersistent per-and polyfluoroalkyl substances (PFAS) in rodents, but such influences in human studies are less clear. Data from National Health and Nutrition Examination Survey (NHANES) for 2003-2018 for US females aged ≥ 20 years who reported having hysterectomy (HYST, N=1064) and who reported being in natural menopause (MENOP, N=1505) were analyzed for associations of ever use of birth control pills, past pregnancies, live births, and other factors with serum concentrations of six per- and polyfluoroalkyl substances (PFAS). For both HYST and MENOP, PFAS concentrations computed as adjusted geometric means (AGM) were higher among those who took female replacement hormone therapy (HRT) compared to nonusers in multivariable adjusted models, for example PFOS in HRT takers (10.70 ng/mL; 95% C.I. 9.46-12.11) vs. 8.70 ng/mL (95% C.I. 8.07-9.37) in nonusers (p<0.01), and PFOA in HRT users was 2.85 ng/mL (95% C.I. 2.53-3.21) vs. 2.44 ng/mL (95% C.I. 2.32-2.36) in nonusers (p=0.01), with similar findings across race/ethnicity stratifications. HYST participants with retained ovaries sometimes had higher serum PFAS than those without ovaries in post-HYST participants not taking HRT, but results had overlapping confidence intervals in all cases and were inconsistent. PFASs were inversely associated with obesity and directly associated with higher SES as reflected in poverty income ratio (PIR) in most cases, yet HRT results for the entire population are robust to adjustments for obesity and PIR. The results suggest the hypothesis that exogenous hormone use, and specifically estrogen hormones, are associated with higher serum PFAS in postmenopausal women. We discuss potential explanations for the findings, including data from other populations that estrogens may delay the onset of kidney disease, a finding which might paradoxically increase serum PFAS among the HRT population to explain some or all of our findings in a menopausal population.