Evaluation of the Chronic Kidney Disease Epidemiology Collaboration equation for estimating the glomerular filtration rate in multiple ethnicities

Prevalence and prognosis of malignancy in THSD7A-associated membranous nephropathy: a systematic literature review and clinical case study

BACKGROUND

This study aims to investigate the incidence and prognosis of malignancy in individuals with thrombospondin type-1 domain-containing 7A (THSD7A)-associated membranous nephropathy (MN).

METHODS

First, we performed a systematic literature review of prevalence of malignancy in THSD7A-associated MN. Then, we conducted a retrospective analysis of 454 patients diagnosed with MN through renal biopsy at our hospital between January 2016 and December 2020. We assessed the presence of serum anti-THSD7A antibodies and performed immunohistochemical staining of renal tissue for THSD7A. Subsequently, we followed patients with THSD7A-associated MN for a minimum of 3-5 years, collecting their clinical, pathological characteristics, and prognosis. Additionally, we conducted a literature review on patients with THSD7A-associated MN in conjunction with malignancy.

RESULTS

We identified a total of nine articles containing comprehensive data on THSD7A-associated MN and malignancy. Among 235 patients with THSD7A-positive MN, 36 individuals had concurrent malignancies, resulting in a malignancy prevalence of 13.3% (95% CI: 8.9-17.7%). In our center, we followed up with 15 patients diagnosed with THSD7A-associated MN and observed three cases of concomitant tumors: two cases of lung adenocarcinoma and one case of small cell lung cancer with multiple metastases. The prevalence of malignancy in our cohort was 20%. Notably, we detected positive THSD7A staining in both renal and lung cancer tissues in one patient with small cell lung cancer.

CONCLUSIONS

Patients with THSD7A-associated MN should undergo vigilant follow-up assessments, with a particular focus on actively seeking potential tumorigenic lesions to prevent misdiagnosis or oversight.

The effects of Tripterygium wilfordii Hook F on renal outcomes in type 2 diabetic kidney disease patients with severe proteinuria: a single-center cohort study

AIM

Tripterygium wilfordii Hook F (TwHF) has been shown to substantially reduce proteinuria in patients with diabetic kidney disease (DKD); however, the effect of TwHF on renal outcomes in DKD remains unknown. Accordingly, we aimed to establish the effects of TwHF on renal outcomes in patients with DKD.

METHODS

Overall, 124 patients with DKD, induced by type 2 diabetes mellitus, with 24-h proteinuria > 2 g, and an estimated glomerular filtration rate > 30 mL/min/1.73 m2 were retrospectively investigated. The renal outcomes were defined as doubling serum creatinine levels or end-stage kidney disease. Kaplan-Meier curves and Cox regression analyses were performed to analyze prognostic factors for renal outcomes.

RESULTS

By the end of the follow-up, renal outcomes were observed in 23 and 11 patients in the non-TwHF and TwHF groups, respectively (p = 0.006). TwHF significantly reduced the risk of renal outcomes (adjusted hazard ratio [HR] 0.271, 95% confidence interval [CI] 0.111-0.660, p = 0.004) in patients with chronic kidney disease (CKD) G3 (adjusted HR 0.274, 95%CI 0.081-0.932, p = 0.039). Based on the Kaplan-Meier analysis, 1- and 3-year proportions of patients without renal outcomes were significantly lower in the non-TwHF group than those in the TwHF group (92.8% vs. 95.5% and 47.2% vs. 76.8%, respectively; p = 0.0018).

CONCLUSION

In DKD patients with severe proteinuria, TwHF could prevent DKD progression, especially in patients with CKD G3. A randomized clinical trial is needed to elucidate the benefits of TwHF on renal outcomes in patients with DKD.

Prevalence and immunopathologic characteristics of seropositive and seronegative hepatitis B virus-associated membranous nephropathy: a retrospective study of 420 biopsy-proven cases

BACKGROUND

This retrospective study aims to investigate the prevalence and immunopathologic characteristics of seropositive and seronegative hepatitis B virus-associated membranous nephropathy (HBV-MN).

METHODS

Clinicopathologic and serologic records of 420 patients with histologically confirmed HBV-MN between January 2014 and July 2021 were examined to determine the prevalence of seropositive and seronegative HBV-MN. Serum anti-PLA2R antibody testing was conducted on 280 patients with HBV-associated membranous nephropathy (HBV-MN) from August 2018 to July 2021. Immunopathologic characteristics of HBV-MN patients and anti-PLA2R antibody positivity were analyzed.

RESULTS

Among 420 pathologically confirmed HBV-MN patients, 230 (54.8%) were seropositive for HBV. The seropositive group exhibited higher blood creatinine values and incidence of liver function abnormalities than the seronegative group (p < .05). Serum anti-PLA2R antibody testing on 280 HBV-MN patients revealed a total positive rate of 44.6%, with the seronegative group showing a significantly higher rate (62.6%) compared to the seropositive group (32.1%) (p < .01). The anti-PLA2R antibody-positive group displayed higher levels of urine protein (p < .05), serum cholesterol (p < .01), and IgG4 subtypes (p < .05) compared to the negative group. Additionally, the positive group had significantly lower levels of serum albumin and IgG than the negative group (p < .01).

CONCLUSIONS

This comprehensive study reveals a significantly higher prevalence of seronegative HBV-MN than previously thought. The blood creatinine values and incidence of liver function abnormalities was higher in the serology-positive group than in the serology-negative group. Notably, the seronegative group displayed a higher positive rate of anti-PLA2R antibodies compared to the seropositive group, indicating distinctive clinical and immunopathologic features.

Investigating the causal association of generalized and abdominal obesity with microvascular complications in patients with type 2 diabetes: A community-based prospective study

AIM

The paradoxical protective association between overweight/obesity and diabetic microvascular complications (DMC), a phenomenon well-known as the obesity paradox, has been considered a non-causal association based on methodological influences. We aimed to investigate the association of generalized and abdominal obesity, as measured by body mass index (BMI) and waist circumference (WC), respectively, with DMC in patients with type 2 diabetes (T2D), using a causal inference approach.

MATERIALS AND METHODS

We enrolled 1436 patients with clinically diagnosed T2D but not DMC at baseline in a community-based prospective cohort in China between 2017 and 2019 and followed them annually until 2022 with new-onset DMC recorded. Marginal structural Cox models with inverse probability weighting were constructed to determine the causal association. Subgroup analyses were performed to identify potential effect modifiers.

RESULTS

We observed 360 incident DMC cases, including 109 cases of diabetic nephropathy (DN) and 277 cases of diabetic retinopathy (DR) during four follow-up visits. Multivariable-adjusted hazard ratios (95% confidence intervals) for overall DMC, DN and DR were 1.037 (1.005-1.071), 1.117 (1.062-1.175) and 1.018 (0.980-1.059) for 1 kg/m2 increase in BMI, and 1.005 (0.994-1.017), 1.034 (1.018-1.051) and 1.000 (0.987-1.014) for 1 cm increase in WC, respectively. Similar patterns were observed across the BMI and WC categories, while the positive association appeared to be more pronounced in women.

CONCLUSIONS

Generalized but not abdominal obesity was associated with an increased risk for the overall DMC, whereas both obesities were causally related to DN, albeit not DR, in T2D. Routine weight management should not be neglected in diabetes care, particularly in women.

Assessing bias in GFR estimating equations: improper GFR stratification can yield misleading results

BACKGROUND

Assessing bias (estimated - measured) is key to evaluating glomerular filtration rate (GFR). Stratification by subgroups can indicate where equations perform differently. However, there is a fallacy in the assessment of two instruments (e.g., eGFR and mGFR) when stratifying on the level of only one of those instruments. Here, we present statistical aspects of the problem and a solution for GFR stratification along with an empirical investigation using data from the CKiD study.

METHODS

Compared and contrasted biases (eGFR relative to mGFR) with 95% confidence intervals within strata of mGFR only, eGFR only, and the average of mGFR and eGFR using data from the Chronic Kidney Disease in Children (CKiD) study.

RESULTS

A total of 304 participants contributed 843 GFR studies with a mean mGFR of 48.46 (SD = 22.72) and mean eGFR of 48.67 (SD = 22.32) and correlation of 0.904. Despite strong agreement, eGFR significantly overestimated mGFR when mGFR < 30 (+ 6.2%; 95%CI + 2.9%, + 9.7%) and significantly underestimated when mGFR > 90 (-12.2%; 95%CI - 17.3%, - 7.0%). Significant biases in opposite direction were present when stratifying by eGFR only. In contrast, when stratifying by the average of eGFR and mGFR, biases were not significant (+ 1.3% and - 1.0%, respectively) congruent with strong agreement.

CONCLUSIONS

Stratifying by either mGFR or eGFR only to assess eGFR biases is ubiquitous but can lead to inappropriate inference due to intrinsic statistical issues that we characterize and empirically illustrate using data from the CKiD study. Using the average of eGFR and mGFR is recommended for valid inferences in evaluations of eGFR biases.

Early life exposure to Chinese famine and risk of digestive system cancer in midlife

To investigate whether early-life exposure to the Great Famine of 1959-1961 in China was associated with the risk of digestive system cancer. The prospective cohort study involved 17 997 participants from the Kailuan Study (Tangshan, China) that began in 2006. All participants were divided into three groups based on their date of birth. The unexposed group (born from 1 October 1962 to 30 September 1964), fetal-exposed group (born from 1 October 1959 to 30 December 1961), and early-childhood-exposed group (born from 1 October 1956 to 30 December 1958). The Cox proportional hazards model was used to analyze the association between early famine exposure and digestive system cancer. During the mean follow-up period of (10.4 ± 2.2) years, a total of 223 digestive system cancer events occurred. Including 54 cases in the unexposed group (62.14/100 000 person-years), 57 cases in the fetal-exposed group (114.8/100 000 person-years), and 112 cases in the early-childhood-exposure group (122.2/100 000 person-years). After adjusting covariates, compared with the unexposed group, the HR and 95% CI were 1.85 (1.28, 2.69) for participants in the fetal-exposed group and 1.92 (1.38, 2.66) for participants in the early-childhood-exposed group. No interactions were observed in our study. After classifying digestive system cancers, the HR and 95% CI were 2.02 (1.03, 3.97) for colorectal cancer for participants in the fetal-exposed group and 2.55 (1.43, 4.55) for participants in the early-childhood-exposed group. The HR and 95% CI were (1.13, 3.83) of liver cancer for participants in the fetal-exposed group and 1.15 (0.63, 2.10) for participants in the early-childhood-exposed group. Early-life famine exposure was associated with a higher risk of digestive system cancer in adulthood. Fetal-exposed individuals might increase the risk of colorectal cancer and liver cancer, and early childhood-exposed might increase the risk of colorectal cancer.

Seasonal variation in ambulatory blood pressure control in patients on clinic blood pressure-guided antihypertensive treatment

BACKGROUND

We investigated seasonal variation in ambulatory blood pressure control in hypertensive patients on clinic blood pressure-guided antihypertensive treatment.

METHODS

The study participants were hypertensive patients enrolled in an 8-week therapeutic study. Antihypertensive treatment was initiated with long-acting dihydropyridine calcium channel blockers amlodipine 5 mg/day or the gastrointestinal therapeutic system (GITS) formulation of nifedipine 30 mg/day, with the possible up-titration to amlodipine 10 mg/day or nifedipine-GITS 60 mg/day at 4 weeks of follow-up.

RESULTS

The proportion of up-titration to higher dosages of antihypertensive drugs at 4 weeks of follow-up was higher in patients who commenced treatment in autumn/winter ( n  = 302) than those who commenced treatment in spring/summer ( n  = 199, 24.5 vs. 12.0%, P  < 0.001). The control rate of clinic blood pressure, however, was lower in autumn/winter than in spring/summer at 4 (56.7 vs. 70.7%, P  = 0.003) and 8 weeks of follow-up (52.5 vs. 74.9%, P  < 0.001). At 8 weeks, patients who commenced treatment in autumn/winter, compared with those who commenced treatment in spring/summer, had a significantly ( P ≤0.03) smaller daytime (mean between-season difference -3.2/-2.8 mmHg) but greater nighttime SBP/DBP reduction (3.6/1.6 mmHg). Accordingly, at 8 weeks, the prevalence of nondippers was significantly ( P  < 0.001) higher in spring/summer than in autumn/winter for both SBP (54.8 vs. 30.0%) and DBP (53.4 vs. 28.8%).

CONCLUSION

Clinic blood pressure-guided antihypertensive treatment requires a higher dosage of medication in cold than warm seasons, which may have led to over- and under-treatment of nighttime blood pressure, respectively.

Hypertension-specific association of cardio-ankle vascular index with subclinical left ventricular function in a Chinese population: Danyang study

The association of cardio-ankle vascular index (CAVI), with subclinical cardiac dysfunction in hypertensive patients is unclear. We aim to examine their relationship in hypertensive patients compared with that in normotensive subjects. Our study included 1887 subjects enrolled from Danyang between 2018 and 2019. CAVI was measured using VaSera VS-1500A device. We performed conventional echocardiography to measure ejection fraction (EF) and E/A, tissue Doppler to measure mitral annular early diastolic velocities (e'), and speckle-tracking to estimate left ventricular (LV) global longitudinal strain (GLS). LV mass index (76.3, 80.0, and 84.0 g/m2), and E/e' (7.6, 8.2, and 8.8) were increased and GLS (21.1, 21.0, and 20.4%), E/A (1.2, 1.0, and 0.8) and e' velocity (11.2, 9.4, and 8.2 cm/s) was decreased from tertiles 1-3 of CAVI on unadjusted analyses (P < .001). After adjustment for covariates, GLS, E/A, and e' were still significantly decreased from tertiles 1-3 of CAVI (P ≤ .04). Further sensitive analyses revealed a similar association pattern for diastolic function but not systolic function. Compared with the lowest tertile, subjects with a top tertile of CAVI were at higher risk of subclinical LV systolic dysfunction in hypertensive patients (OR = 2.61; P = .005). Increased CAVI is associated with worse subclinical diastolic function. However, this relationship of CAVI to subclinical systolic function was more prominent in hypertensive patients.

Tophi and carotid atherosclerosis in gout patients: Role of insulin resistance

BACKGROUND AND AIM

Gout and cardiovascular disease are closely related, but the mechanism linking them is still unknown. Gout may affect the insulin signaling pathway inducing insulin resistance (IR). The study aims to evaluate the association between tophi and carotid atherosclerosis, considering the potential role of IR.

METHODS AND RESULTS

A total of 595 patients with gout aged 18 to 80 were enrolled in this study. Carotid intima-media thickness, plaques and tophi were evaluated by B-mode ultrasonography. IR was assessed by the HOMA index (hepatic IR) and Gutt index (peripheral IR). Multivariable logistic regression and interaction analysis were used to examine the association between tophi and IR and its impact on carotid atherosclerosis. Among these participants, the average age was 55.4 (±12.54) years, and 94.6 % were male. Tophi were associated with increased odds of carotid atherosclerosis and burden after adjustment for confounders (P < 0.05). Tophi and IR synergically interacted for inducing carotid atherosclerosis. The interaction between peripheral IR with tophi was more pronounced than hepatic IR with tophi.

CONCLUSIONS

Tophi were independently associated with carotid atherosclerosis risk. IR mediated a significant amount of the effect of tophi on the development of carotid atherosclerosis. Peripheral IR probably plays a more important role than hepatic IR does.

Associations between cardiometabolic indices and the risk of diabetic kidney disease in patients with type 2 diabetes

BACKGROUND

This study was designed to assess the associations between emerging cardiometabolic indices-the atherogenic index of plasma (AIP), the stress hyperglycemia ratio (SHR), the triglyceride-glucose (TyG) index, and the homeostasis model assessment of insulin resistance (HOMA-IR)-and the incidence of diabetic kidney disease (DKD) in type 2 diabetes (T2D) patients.

METHODS

We consecutively enrolled 4351 T2D patients. The AIP, SHR, TyG index, and HOMA-IR were calculated from baseline parameters. DKD was defined as a urine albumin/creatinine ratio > 30 mg/g or an eGFR < 60 mL/min per 1.73 m. All participants were categorized into tertiles based on the cardiometabolic indices. Multivariate logistic regression models, restricted cubic splines, and receiver operating characteristic (ROC) curves were used for analysis.

RESULTS

A total of 1371 (31.5%) patients were diagnosed with DKD. A restricted cubic spline showed a J-shaped association of the AIP and TyG index with DKD, a log-shaped association between HOMA-IR and DKD, and a U-shaped association between the SHR and DKD incidence. Multivariate logistic regression revealed that individuals in the highest tertile of the four cardiometabolic indices had a significantly greater risk of DKD than did those in the lowest tertile (AIP: OR = 1.08, 95% CI = 1.02-1.14, P = 0.005; SHR: OR = 1.42, 95% CI = 1.12-1.81, P = 0.004; TyG index: OR = 1.86, 95% CI = 1.42-2.45, P < 0.001; HOMA-IR: OR = 2.24, 95% CI = 1.52-3.30, P < 0.001). The receiver operating characteristic curves showed that the HOMA-IR score was better than other indices at predicting the risk of DKD, with an optimal cutoff of 3.532.

CONCLUSIONS

Elevated AIP, SHR, TyG index and HOMA-IR are associated with a greater risk of DKD in patients with T2D. Among these indices, the HOMA-IR score demonstrated the strongest association with and predictive value for DKD incidence.

Urate-lowering therapy, serum urate, inflammatory biomarkers, and renal function in patients with gout following pegloticase discontinuation

BACKGROUND/PURPOSE

Little is known about long-term clinical outcomes or urate-lowering (ULT) therapy use following pegloticase discontinuation. We examined ULT use, serum urate (SU), inflammatory biomarkers, and renal function following pegloticase discontinuation.

METHODS

We conducted a retrospective analysis of gout patients who discontinued pegloticase using the Rheumatology Informatics System for Effectiveness (RISE) registry from 1/2016 to 6/2022. We defined discontinuation as a gap ≥ 12 weeks after last infusion. We examined outcomes beginning two weeks after last dose and identified ULT therapy following pegloticase discontinuation. We evaluated changes in lab values (SU, eGFR, CRP and ESR), comparing on- treatment (≤ 15 days of the second pegloticase dose) to post-treatment.

RESULTS

Of the 375 gout patients discontinuing pegloticase, median (IQR) laboratory changes following discontinuation were: SU: +2.4 mg/dL (0.0,6.3); eGFR: -1.9 mL/min (- 8.7,3.7); CRP: -0.8 mg/L (-12.8,0.0); and ESR: -4.0 mm/hr (-13.0,0.0). Therapy post-discontinuation included oral ULTs (86.0%), restarting pegloticase (4.5%), and no documentation of ULT (9.5%), excluding patients with multiple same-day prescriptions (n = 17). Oral ULTs following pegloticase were: 62.7% allopurinol, 34.1% febuxostat. The median (IQR) time to starting/restarting ULT was 92.0 days (55.0,173.0). Following ULT prescribing (≥ 30 days), only 51.0% of patients had SU < 6 mg/dL. Patients restarting pegloticase achieved a median SU of 0.9 mg/dL (IQR:0.2,9.7) and 58.3% had an SU < 6 mg/dL.

CONCLUSION

Pegloticase treats uncontrolled gout in patients with failed response to xanthine oxidase inhibitors, but among patients who discontinue, optimal treatment is unclear. Based on this analysis, only half of those starting another ULT achieved target SU. Close follow-up is needed to optimize outcomes after pegloticase discontinuation.

Correlation Between C4/IgG with Macroproteinuria in Chronic Kidney Disease: A Pilot Study

Background and Objectives

Loss of immunoglobulin G (IgG) is accompanied with proteinuria, especially macroproteinuria. The complement system participates kidney disease resulting in proteinuria. Whether the ratio of complement and IgG is associated with macroproteinuria remains unknown.

Design Setting Participants and Measurements

A total of 1013 non-dialysis chronic kidney disease (CKD) patients were recruited according to the electrical case records system with 268 patients who endured kidney biopsy. Patients were grouped via the estimated glomerular filtration rate or the levels of proteinuria determination. Biomarkers in different CKD groups or proteinuria groups were compared by one-way ANOVA or independent samples t-test. Pearson or spearman analysis was employed to analyze correlation between clinical indexes. Further, influence factor of macroproteinuria was studied by using binary logistic regression. The ROC curve was performed to explore probable predictive biomarker for macroproteinuria.

Results

No significant difference of complement C3 and C4 among CKD1 to CKD5 stages, while higher level of complement C4 in patients with macroproteinuria. Further, C4 had a positive correlation with proteinuria (r=0.255, p=0.006). After adjusted for age, IgA, IgM, triglyceride and HDL, a binary logistic regression model showed lnC4/IgG (OR=3.561, 95% CI 2.196-5.773, p<0.01), gender (OR=1.737, 95% CI 1.116-2.702, p=0.014), age (OR=0.983, 95% CI 0.969-0.997, p=0.014), and history of diabetes (OR=0.405, 95% CI 0.235-0.699, p<0.01) were independent influence factors of macroproteinuria. The area under the ROC curve was 0.77 (95% CI: 0.75-0.82, p<0.001) for C4/IgG. The analysis of ROC curves revealed a best cut-off for complement C4 was 0.024 and yielded a sensitivity of 71% and a specificity of 71%. The area under the ROC curve was 0.841 (95% CI: 0.735-0.946, p < 0.001) for C4/IgG in IgA nephropathy patients. The analysis of ROC curves revealed a best cut-off for complement C4/IgG was 0.026 and yielded a sensitivity of 75% and a specificity of 81.2%. The area under the ROC curve for C4/IgG in CKD1-5 stages were 0.772, 0.811, 0.785, 0.835, 0.674.

Conclusion

Complement C4/IgG could be used to predict macroproteinuria.

Long-term exposure to fine particulate matter constituents in relation to chronic kidney disease: evidence from a large population-based study in China

The effects of long-term exposure to fine particulate matter (PM2.5) constituents on chronic kidney disease (CKD) are not fully known. This study sought to examine the association between long-term exposure to major PM2.5 constituents and CKD and look for potential constituents contributing substantially to CKD. This study included 81,137 adults from the 2018 to 2019 baseline survey of China Multi-Ethnic Cohort. CKD was defined by the estimated glomerular filtration rate. Exposure concentration data of 7 major PM2.5 constituents were assessed by satellite remote sensing. Logistic regression models were used to estimate the effect of each PM2.5 constituent exposure on CKD. The weighted quantile sum regression was used to estimate the effect of mixed exposure to all constituents. PM2.5 constituents had positive correlations with CKD (per standard deviation increase), with ORs (95% CIs) of 1.20 (1.02-1.41) for black carbon, 1.27 (1.07-1.51) for ammonium, 1.29 (1.08-1.55) for nitrate, 1.20 (1.01-1.43) for organic matter, 1.25 (1.06-1.46) for sulfate, 1.30 (1.11-1.54) for soil particles, and 1.63 (1.39-1.91) for sea salt. Mixed exposure to all constituents was positively associated with CKD (1.68, 1.32-2.11). Sea salt was the constituent with the largest weight (0.36), which suggested its importance in the PM2.5-CKD association, followed by nitrate (0.32), organic matter (0.18), soil particles (0.10), ammonium (0.03), BC (0.01). Sulfate had the least weight (< 0.01). Long-term exposure to PM2.5 sea salt and nitrate may contribute more than other constituents in increasing CKD risk, providing new evidence and insights for PM2.5-CKD mechanism research and air pollution control strategy.

Low platelet count at diagnosis of anti-neutrophil cytoplasmic antibody-associated vasculitis is correlated with the severity of disease and renal prognosis

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is an autoimmune disease that involves inflammation of blood vessels. There is increasing evidence that platelets play a crucial role not only in hemostasis but also in inflammation and innate immunity. In this study, we explored the relationship between platelet count, clinical characteristics, and the prognosis of patients with AAV. We divided 187 patients into two groups based on their platelet count. Clinicopathological data and prognostic information were retrospectively gathered from medical records. Univariate and multivariate regression analyses were used to identify risk factors for prognosis, including end-stage renal disease (ESRD) and mortality. The cutoff point for platelet count was set at 264.5 × 109/L, as determined by the receiver operating characteristic (ROC) curve for predicting progression to ESRD in patients with AAV. We observed patients with low platelet count (platelets < 264.5 × 109/L) had lower leukocytes, hemoglobin, complement, acute reactants, and worse renal function (P for eGFR < 0.001). They were also more likely to progress to ESRD or death compared to the high platelet count group (platelets > 264.5 × 109/L) (P < 0.0001, P = 0.0338, respectively). Low platelet count was potentially an independent predictor of poor renal prognosis in the multivariate regression analysis [HR 1.670 (95% CI 1.019-2.515), P = 0.014]. Lower platelet count at diagnosis is associated with more severe clinical characteristics and impaired renal function. Therefore, platelet count may be an accessible prognostic indicator for renal outcomes in patients with AAV.

Nonlinear relationship between body mass index and serum uric acid: An observational and Mendelian randomization study among Chinese adults

BACKGROUND AND AIMS

Conflicting evidence exists on the relationship between body mass index (BMI) and serum uric acid (SUA), and importantly, the causal role of BMI in SUA remains unclear. We aimed to evaluate the BMI-SUA relationship and its causality among Chinese adults using observational and Mendelian randomization (MR) analyses.

METHODS AND RESULTS

Study included 6641 adults from East China. A genetic risk score based on 14 BMI-associated East Asian variants was formulated. One-sample MR and non-linear MR analyses assessed the causal link between BMI_GRS and SUA levels. Mean BMI levels were 24.8 (SD 3.4) and 24.3 (SD 3.6) kg/m2 in men and women, respectively. Spline models revealed gender-specific BMI-SUA associations: a reverse J-shape for men and a J-shape for women (P-values for nonlinearity <0.05). In men, BMI showed a positive correlation with SUA levels when BMI was below 29.6 kg/m2 (beta coefficient 19.1 [95 % CI 15.1, 23.0] μmol/L per 1-SD increase in BMI), while in women, BMI exhibited a negative correlation with SUA levels when the BMI was less than 21.7 kg/m2 (beta coefficient -12.9 [95 % CI -21.6, -4.1] μmol/L) and a positive correlation when BMI exceeded 21.7 kg/m2 (beta coefficient 13.3 [95 % CI 10.9, 15.8] μmol/L). Furthermore, MR analysis suggested non-linear BMI-SUA link in women but not men.

CONCLUSION

Our study indicates a non-linear correlation between BMI and SUA in both genders. It is noteworthy that in women, this correlation may have a causal nature. Nevertheless, further longitudinal investigations are required to authenticate our findings.

Comparison of EKFC, Pakistani CKD-EPI and 2021 Race-Free CKD-EPI creatinine equations in South Asian CKD population: A study from Pakistani CKD community cohort

INTRODUCTION

South Asian individuals possess a high risk of chronic kidney disease. There is a need to study, evaluate, and compare the newly suggested glomerular filtration rate (eGFR) equations for accurate CKD diagnosis, staging, and drug dosing. This study aimed to (1) evaluate the European Kidney Function Consortium (EKFC), Pakistani CKD-EPI, and 2021 Race-Free CKD-EPI creatinine equation in the South Asian population with CKD and (2) to examine the expected implications on both CKD classification as well as End Stage Renal Disease (ESRD) prevalence across these equations in South Asian population.

METHODS

We carried out a cross-sectional investigation on 385 participants, a CKD cohort ≥ 18 years, at Allama Iqbal Medical College, Jinnah Hospital, Lahore. Serum creatinine was measured by Jaffe's method and rGFR was measured by inulin clearance.

RESULTS

Pakistani CKD-EPI has a lower median difference at -1.33 ml/min/1.73m2 elevated precision (IQR) at 2.33 (-2.36, -0.03) and higher P30 value at 89.35% than 2021 CKD-EPI and EKFC equations. The mean difference (ml/min/1.73m2), 95% agreement limits (ml/min/1.73m2) of CKD-EPI PK: -1.18, -6.14, 2021 CKD-EPI: -5.98, -13.24 and EKFC: -5.62, -13.01 (P <0.001). These equations highly correlated to rGFR (P <0.001). An upward re-classification in GFR categories was shown by 2021 CKD-EPI and EKFC compared to the Pakistani CKD-EPI equation. However, there was an exception regarding the G5 category, where an elevated count of 217 (56.36%) was shown for CKD-EPI PK. The prevalence of ESRD was seen in entire age groups and prevailed among females more than in males overall equations.

CONCLUSIONS

Pakistani CKD-EPI exhibited outstanding performance, while 2021 CKD-EPI and EKFC demonstrated poor performances and could not show an adequate advantage for both CKD classification and prevalence of ESRD compared to Pakistani CKD-EPI. Therefore, Pakistani CKD-EPI appears optimal for this region and warrants future validation in other South Asian countries. In contrast, suitable measures must be implemented in Pakistani laboratories.

Prevalence and Risk Factors for Renal Insufficiency among Adults Living with HIV in Tanzania: Results from a Cross-Sectional Study in 2020-2021

With improved survival, adults living with HIV (ALHIV) are increasingly likely to experience age-related and HIV-related comorbidities, including renal insufficiency. Other risk factors for renal insufficiency (high blood pressure (BP), obesity, diabetes, and dyslipidemia) are also growing more common among ALHIV. To determine the prevalence of renal insufficiency (defined as an eGFR < 60 mL/min/1.73 m2) and factors associated with reduced eGFR, we conducted a cross-sectional study at six HIV clinics in Dar-es-Salaam, Tanzania. We applied multivariable (MV) ordinal logistic regression models to identify factors associated with reduced eGFR and examined the interaction of age with BP levels. Among the 450 ALHIV on ART analyzed [26% males; median age 43 (IQR: 18-72) years; 89% on tenofovir-containing ART; 88% HIV viral load ≤50 copies/mL], 34 (7.5%) had renal insufficiency. Prevalence was higher among males (12%) vs. females (6%), p = 0.03; ALHIV ≥50 (21%) vs. <50 years (2.5%), p < 0.001; those with high [≥130/80 mmHg (15%)] vs. normal [<120/80 mmHg (4%)] BP, p < 0.01 and those with dyslipidemia (10%) vs. those without (4.5%), p < 0.03. After adjusting for covariates, age (in years) was the only covariate with a statistically significant association with reduced eGFR (OR = 1.09 (1.07-1.12), p < 0.001). No significant interaction between age and BP was found. Interventions to increase routine screening for renal insufficiency, especially among older ALHIV, and improve BP control are critical to reducing kidney disease-related morbidity and mortality.

Association between famine exposure during infancy and childhood and the risk of chronic kidney disease in adulthood

BACKGROUND

Famine exposure in childhood is proven to be associated with multiple chornic disease in adult but has not been studied with chronic kidney disease (CKD).

AIMS

This study was conducted to identify the relationship between famine exposure during infancy and childhood - specifically, the Chinese famine of 1959-1961 - and the risk of adult-onset chronic kidney disease (CKD) among Chinese individuals.

METHODS

This study included 2937 individuals from the Qingdao Diabetes Prevention Program. They were stratified by birth year into infancy-exposed (1956-1958), childhood-exposed (1950-1955) and unexposed (1963-1971) groups. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. CKD was defined as an eGFR of <90 mL/min/1.73 m2 .

RESULTS

The mean eGFR values for the infancy-exposed and childhood-exposed groups were 107.23 ± 12.53 and 103.23 ± 12.44 mL/min/1.73 m2 , respectively, both of which were lower than that of the unexposed group (114.82 ± 13.39 mL/min/1.73 m2 ; P < 0.05). In the crude model, the odds ratio (OR) for CKD was 2.00 (95% confidence interval (CI): 1.39-2.88) in the infancy-exposed group and 2.92 (95% CI: 2.17-3.93) in the childhood-exposed group. Further adjustments for urban/rural residence, body mass index, age, current smoking, type 2 diabetes, systolic blood pressure, diastolic blood pressure and total cholesterol did not significantly alter the association between famine exposure and CKD. The corresponding ORs were 1.71 (95% CI: 1.17-2.50) and 2.48 (95% CI: 1.81-3.40) for the infancy-exposed and childhood-exposed groups respectively.

CONCLUSIONS

Famine exposure during infancy and childhood is associated with a long-term decline in eGFR and an increased adult-onset CKD risk. Early intervention for high-risk individuals may mitigate the risk of adult-onset CKD.

Bias and Accuracy of Glomerular Filtration Rate Estimating Equations in the US: A Systematic Review and Meta-Analysis

Importance

There is increasing concern that continued use of a glomerular filtration rate (GFR) estimating equation adjusted for a single racial group could exacerbate chronic kidney disease-related disparities and inequalities.

Objective

To assess the performance of GFR estimating equations across varied patient populations.

Data Sources

PubMed, Embase, Web of Science, ClinicalTrials.gov, and Scopus databases were systematically searched from January 2012 to February 2023.

Study Selection

Inclusion criteria were studies that compared measured GFR with estimated GFR in adults using established reference standards and methods. A total of 6663 studies were initially identified for screening and review.

Data Extraction and Synthesis

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 2 authors independently extracted data on studies that examined the bias and accuracy of GFR estimating equations. For each outcome, a random-effects model was used to calculate pooled estimates. Data analysis was conducted from March to December 2023.

Main Outcomes and Measures

The primary outcomes were bias and accuracy of estimated GFRs in Black vs non-Black patients, as well as in individuals with chronic conditions. Bias was defined as the median difference between the measured GFR and the estimated GFR. Accuracy was assessed with P30 (the proportion of persons in a data set whose estimated GFR values were within 30% of measured GFR values) and measures of heterogeneity.

Results

A total of 12 studies with a combined 44 721 patients were included. Significant heterogeneity was found in the bias of various GFR estimation equations. Race-corrected equations and creatinine-based equations tended to overestimate GFR in Black populations and showed mixed results in non-Black populations. For creatinine-based equations, the mean bias in subgroup analysis was 2.1 mL/min/1.73 m2 (95% CI, -0.2 mL/min/1.73 m2 to 4.4 mL/min/1.73 m2) in Black persons and 1.3 mL/min/1.73 m2 (95% CI, 0.0 mL/min/1.73 m2 to 2.5 mL/min/1.73 m2) in non-Black persons. Equations using only cystatin C had small biases. Regarding accuracy, heterogeneity was high in both groups. The overall P30 was 84.5% in Black persons and 87.8% in non-Black persons. Creatinine-based equations were more accurate in non-Black persons than in Black persons. For creatinine-cystatin C equations, the P30 was higher in non-Black persons. There was no significant P30 difference in cystatin C-only equations between the 2 groups. In patients with chronic conditions, P30 values were generally less than 85%, and the biases varied widely.

Conclusions and Relevance

This systematic review and meta-analysis of GFR estimating equations suggests that there is bias in race-based GFR estimating equations, which exacerbates kidney disease disparities. Development of a GFR equation independent of race is a crucial starting point, but not the sole solution. Addressing the disproportionate burden of kidney failure on Black individuals in the US requires an enduring, multifaceted approach that should include improving diagnostics, tackling social determinants of health, confronting systemic racism, and using effective disease prevention and management strategies.

Evaluation of novel candidate filtration markers from a global metabolomic discovery for glomerular filtration rate estimation

Creatinine and cystatin-C are recommended for estimating glomerular filtration rate (eGFR) but accuracy is suboptimal. Here, using untargeted metabolomics data, we sought to identify candidate filtration markers for a new targeted assay using a novel approach based on their maximal joint association with measured GFR (mGFR) and with flexibility to consider their biological properties. We analyzed metabolites measured in seven diverse studies encompasing 2,851 participants on the Metabolon H4 platform that had Pearson correlations with log mGFR and used a stepwise approach to develop models to < -0.5 estimate mGFR with and without inclusion of creatinine that enabled selection of candidate markers. In total, 456 identified metabolites were present in all studies, and 36 had correlations with mGFR < -0.5. A total of 2,225 models were developed that included these metabolites; all with lower root mean square errors and smaller coefficients for demographic variables compared to estimates using untargeted creatinine. Seventeen metabolites were chosen, including 12 new candidate filtration markers. The selected metabolites had strong associations with mGFR and little dependence on demographic factors. Candidate metabolites were identified with maximal joint association with mGFR and minimal dependence on demographic variables across many varied clinical settings. These metabolites are excreted in urine and represent diverse metabolic pathways and tubular handling. Thus, our data can be used to select metabolites for a multi-analyte eGFR determination assay using mass spectrometry that potentially offers better accuracy and is less prone to non-GFR determinants than the current eGFR biomarkers.

Sweetened Beverages, Genetic Susceptibility, and Incident Atrial Fibrillation: A Prospective Cohort Study

BACKGROUND

An association between sweetened beverages and several cardiometabolic diseases has been reported, but their association with atrial fibrillation (AF) is unclear. We aimed to investigate the associations between consumption of sugar-sweetened beverages (SSB), artificially sweetened beverages (ASB), and pure fruit juice (PJ) and risk of consumption with AF risk and further evaluate whether genetic susceptibility modifies these associations.

METHODS

A total of 201 856 participants who were free of baseline AF, had genetic data available, and completed a 24-hour diet questionnaire were included. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up of 9.9 years, 9362 incident AF cases were documented. Compared with nonconsumers, individuals who consumed >2 L/wk of SSB or ASB had an increased risk of AF (HR, 1.10 [95% CI, 1.01-1.20] and HR, 1.20 [95% CI, 1.10-1.31]) in the multivariable-adjusted model. A negative association was observed between the consumption of ≤1 L/wk of PJ and the risk of AF (HR, 0.92 [95% CI, 0.87-0.97]). The highest HRs (95% CIs) of AF were observed for participants at high genetic risk who consumed >2 L/wk of ASB (HR, 3.51 [95% CI, 2.94-4.19]), and the lowest HR were observed for those at low genetic risk who consumed ≤1 L/wk of PJ (HR, 0.77 [95% CI, 0.65-0.92]). No significant interactions were observed between the consumption of SSB, ASB, or PJ and genetic predisposition to AF.

CONCLUSIONS

Consumption of SSB and ASB at >2 L/wk was associated with an increased risk for AF. PJ consumption ≤1 L/wk was associated with a modestly lower risk for AF. The association between sweetened beverages and AF risk persisted after adjustment for genetic susceptibility to AF. This study does not demonstrate that consumption of SSB and ASB alters AF risk but rather that the consumption of SSB and ASB may predict AF risk beyond traditional risk factors.

Model-Based Dose Selection of Subcutaneous Nivolumab in Patients with Advanced Solid Tumors

The pharmacokinetics (PK) of intravenous (i.v.) nivolumab is well characterized. A subcutaneous (s.c.) nivolumab formulation with and without recombinant human hyaluronidase PH20 enzyme is being evaluated in CheckMate 8KX (NCT03656718). A model-based analysis was conducted to characterize the PK of nivolumab s.c. and predict systemic exposures after i.v. and s.c. administration to guide dosing regimen selection for nivolumab s.c. A prior i.v. model was modified to incorporate an s.c. extravascular compartment and estimate the absorption rate constant and bioavailability of nivolumab s.c. Serum concentration-time data from 82 patients treated with nivolumab s.c. 720, 960, or 1,200 mg were pooled with existing i.v. data from multiple studies for model development. Prediction-corrected visual predictive check (pcVPC) plots assessed the model's performance. Stochastic simulations were conducted to predict exposures for i.v. and s.c. administration. The data were described by a two-compartment model with time-varying clearance, zero-order infusion into the central compartment after i.v. dosing, and first-order absorption from the extravascular compartment after s.c. dosing. The pcVPC suggested that the model adequately described the observed nivolumab s.c. data. Predicted nivolumab exposures at 1,200 mg s.c. every 4 weeks (q4w) were higher than those at the approved dose of 3 mg/kg i.v. q2w and lower than those at the highest tested safe dose of 10 mg/kg i.v. q2w. Nivolumab PK is well-characterized using the combined s.c./i.v. population PK model. The model-based analysis facilitated a comprehensive benefit-risk assessment of nivolumab s.c. and informed selection of 1,200 mg s.c. q4w for phase III evaluation.

Association between estimated glomerular filtration rate and reversion to normoglycemia in people with impaired fasting glucose: a 5-year retrospective cohort study

OBJECTIVES

The present body of evidence regarding the correlation between the estimated glomerular filtration rate (eGFR) and the reversal of impaired fasting glucose (IFG) to normoglycemia remains constrained. Consequently, the objective of our study is to examine the relationship between eGFR and the restoration of normoglycemia in individuals with IFG.

METHODS

This retrospective cohort study consecutively collected data from 24,541 non-selective participants with IFG at Rich Healthcare Group in China from January 2010 to 2016. We aimed to investigate the association between baseline eGFR and reversion to normoglycemia using the Cox proportional-hazards regression model. Through the utilization of a Cox proportional hazards regression model featuring cubical spline smoothing, we were able to ascertain the non-linear correlation between eGFR and the return to normoglycemia. Furthermore, various sensitivity and subgroup analyses were carried out, and a competing risk multivariate Cox regression was employed to examine the progression to diabetes as a competing risk for the reversal of normoglycemic events.

RESULTS

In our study, comprising 24,541 participants, the average age was 49.25 ± 13.77 years, with 66.28% being male. The baseline eGFR mean was 104.16 ± 15.78 ml/min per 1.73 m2. During a median follow-up period of 2.89 years, we observed a reversion rate to normoglycemia of 45.50%. Upon controlling for covariates, our findings indicated a positive correlation between eGFR and the probability of returning to normoglycemia (HR = 1.008, 95% CI 1.006-1.009). In addition, a non-linear association was observed between eGFR and the likelihood of transitioning from IFG to normoglycemia. The inflection point of eGFR was found to be 111.962 ml/min per 1.73 m2, with HRs of 1.003 (95% CI 1.001, 1.005) on the left side of the point and 1.019 (95% CI 1.015, 1.022) on the right side. Our robust results were supported by competing risks multivariate Cox's regression and sensitivity analysis.

CONCLUSIONS

The findings of our investigation indicate a favorable and non-linear correlation between eGFR and the restoration of normoglycemia in Chinese individuals with IFG. Specifically, a reduction in renal function at an early stage in these patients may considerably diminish the likelihood of attaining normoglycemia.

Distinct characteristics and prognosis of IgA nephropathy patients with nephrotic syndrome: a propensity score-matched cohort study

Introduction

IgA nephropathy (IgAN) is the most prevalent primary glomerulonephritis globally. While nephrotic syndrome (NS) is uncommon in IgAN, its significance remains unclear.

Methods

We conducted a retrospective analysis of 170 IgAN patients, classifying them into NS (n = 85) and non-NS (n = 5) groups. Our study aims to compare their clinical characteristics, treatment responses, and prognoses. Patients were selected based on renal biopsy from 2003 to 2020. Propensity score matching ensured comparability. Clinical, pathological, and immunological data were analyzed. Composite endpoints were defined as end-stage kidney disease (ESKD) or a 30% decline in estimated glomerular filtration rate (eGFR).

Results

NS patients showed higher eGFR (74.3 ± 36.8 vs. 61.5 ± 33.6 mL/min.1.73 m2, p = 0.02), severe hematuria (35.0 (4.7,147.5) vs. 4.0 (1.8,45,0) cells/μl, p < 0.001), severe foot process effacement (p = 0.01), and lower C3 levels (1.0 ± 0.3 vs. 1.1 ± 0.2 g/L, p = 0.03). In contrast, the non-NS group had higher BMI (24.3 ± 4.0 vs. 26.8 ± 3.7 kg/m2, p < 0.001) and elevated serum uric acid levels (376 (316,417) vs. 400 (362, 501) mmol/L, p = 0.001), suggesting metabolic factors might contribute to their condition. Both groups exhibited similar MESTC scores. NS patients had higher complete remission rates (26.2% vs. 14.1%, p = 0.04). Cox regression revealed NS independently associated with a higher risk of composite endpoints (HR = 1.97, 95% CI 1.05-3.72, p = 0.04). Linear mixed models did not show significant eGFR trajectory differences.

Discussion

This study has established that IgAN patients with NS exhibit distinct characteristics, including active disease and increased complement activation. NS is independently associated with a poorer prognosis, emphasizing the need for targeted interventions in this subgroup.

Association of Visceral Obesity Indices With Incident Diabetic Retinopathy in Patients With Diabetes: Prospective Cohort Study

BACKGROUND

Visceral adipose tissue plays an active role in the pathogenesis of type 2 diabetes and vascular dysfunction. The lipid accumulation product (LAP), visceral adiposity index (VAI), and Chinese VAI (CVAI) have been proposed as simple and validated surrogate indices for measuring visceral adipose tissue. However, the evidence from prospective studies on the associations between these novel indices of visceral obesity and diabetic retinopathy (DR) remains scant.

OBJECTIVE

This study aimed to investigate the longitudinal associations of LAP, VAI, and CVAI with incident DR in Chinese patients with diabetes.

METHODS

This was a prospective cohort study conducted in Guangzhou in southern China. We collected baseline data between November 2017 and July 2020, while on-site follow-up visits were conducted annually until January 2022. The study participants consisted of 1403 patients with a clinical diagnosis of diabetes, referred from primary care, who were free of DR at baseline. The LAP, VAI, and CVAI levels were calculated by sex-specific equations based on anthropometric and biochemical parameters. DR was assessed using 7-field color stereoscopic fundus photographs and graded according to the modified Airlie House Classification scheme. Time-dependent Cox proportional hazard models were constructed to estimate the hazard ratios with 95% CIs. Restricted cubic spline curves were fitted to examine the dose-response relationship between the 3 indices of visceral obesity and new-onset DR. Subgroup analyses were performed to investigate the potential effect modifiers.

RESULTS

The mean age of study participants was 64.5 (SD 7.6) years, and over half (816/1403, 58.2%) were female. During a median follow-up of 2.13 years, 406 DR events were observed. A 1-SD increment in LAP, VAI, or CVAI was consistently associated with increased risk for new-onset DR, with a multivariable‑adjusted hazard ratio of 1.24 (95% CI 1.09-1.41; P=.001), 1.22 (95% CI 1.09-1.36; P<.001), and 1.48 (95% CI 1.19-1.85; P=.001), respectively. Similar patterns were observed across tertiles in LAP (P for trend=.001), VAI (P for trend<.001), and CVAI (P for trend=.009). Patients in the highest tertile of LAP, VAI, and CVAI had an 84%, 86%, and 82% higher hazard of DR, respectively, compared to those in the lowest tertile. A nonlinear dose-response relationship with incident DR was noted for LAP and VAI (both P for nonlinearity<.05), but not for CVAI (P for nonlinearity=.51). We did not detect the presence of effect modification by age, sex, duration of diabetes, BMI, or comorbidity (all P for interaction>.10).

CONCLUSIONS

Visceral obesity, as measured by LAP, VAI, or CVAI, is independently associated with increased risk for new-onset DR in Chinese patients with diabetes. Our findings may suggest the necessity of incorporating regular monitoring of visceral obesity indices into routine clinical practice to enhance population-based prevention for DR.

Application of creatinine-based eGFR equations in Chinese septuagenarians and octogenarians

PURPOSE

The utilization of creatinine-based estimated glomerular filtration rate (eGFR) equations in the adult population is acknowledged. Nevertheless, the appropriateness of creatinine-based eGFR in septuagenarians and octogenarians is debatable. This study evaluates the creatinine-based equations in Chinese septuagenarians and octogenarians cohorts.

PATIENTS AND METHODS

This study employed a retrospective design, utilizing a review of the hospital medical records system to identify 347 hospitalized participants within the Division of Geriatrics or the Division of Nephrology. These participants underwent renal dynamic imaging with 99 m Tc-DTPA and serum creatinine testing. Comparison of the equations was performed, including the full age-spectrum equation (FAS-Cr equation), European Kidney Function Consortium equation (EKFC equation), Chronic Kidney Disease Epidemiology Collaboration equation for Asian (Asian CKD-EPI equation), Xiangya equation, and Lund-Malmö revised equation (LMR equation).

RESULTS

Most equations tended to underestimate GFR. The FAS-Cr equation had the smallest interquartile range (IQR), while the Asian CKD-EPI equation (mGFR ≥ 30) and Xiangya equation (mGFR < 30) had the biggest IQRs. The FAS-Cr equation had the highest overall P30 of 63.98%, while the Asian CKD-EPI equation had the highest P30 of 75.64% in mGFR ≥ 60. The Xiangya equation, on the other hand, reported the lowest P30 of 36.36% in mGFR < 30. We discovered similar patterns in root-mean-square error (RMSE) as P30. GFR category misclassification rates in the entire cohort ranged from 46.11 to 49.86% for all equations. The FAS-Cr equation exhibited an advantage in octogenarians over other equations in the GFR category misclassification with mGFR lower than 60 ml/min/1.73 m2.

CONCLUSION

None of the creatinine-based equations in this study could perform well regarding precision, accuracy, and CKD stages' classification for the Chinese elderly. Nevertheless, the FAS-Cr equation should be suitable for octogenarians with mGFR lower than 60 ml/min/1.73 m2.

Metabolomic Insights on Potassium Excretion, Blood Pressure, and Glucose Homeostasis: The African-PREDICT Study

BACKGROUND

Low-potassium intake is associated with a higher risk of type 2 diabetes and hypertension. Both conditions occur more frequently in Black populations, who also consume less potassium-rich foods.

OBJECTIVES

Using metabolomics to identify dysregulated metabolic pathways associated with low-potassium excretion may procure more accurate entry points for nutritional prevention and intervention for type 2 diabetes and hypertension.

METHODS

A total of 440 White and 350 Black adults from the African-PREDICT study (aged 20-30 y) were included. Twenty-four-hour blood pressure (BP) was measured. Potassium, sodium, and fasting glucose concentrations were analyzed in 24-h urine and plasma samples. Liquid chromatography-tandem mass spectrometry-based metabolomics included the analyses of amino acids and acylcarnitines in spot urine samples.

RESULTS

Black participants had lower urinary potassium concentrations than Whites (36.6 compared with 51.1 mmol/d; P < 0.001). In White but not Black adults, urinary potassium correlated positively with 2-aminoadipic acid (2-AAA) (r = 0.176), C3-[propionyl]carnitine (r = 0.137), C4-[butyryl]carnitine (r = 0.169) and C5-[isovaleryl]carnitine (r = 0.167) in unadjusted and 2-AAA (r = 0.158) and C4-carnitine (r = 0.160) in adjusted analyses (all P < 0.05 and q < 0.05). Elevated C0-, C3-, and C5-carnitine in turn were positively associated with systolic BP (Black and White groups), diastolic BP (Black group), and glucose (White group) (all P < 0.05).

CONCLUSIONS

Racial differences are an important consideration when investigating nutrient-metabolite relationships and the role thereof in cardiovascular disease. Only in White adults did urinary potassium associate with 2-AAA and short-chain acylcarnitines. These metabolites were positively related to BP and fasting plasma glucose concentrations. In White adults, the metabolomic profiles related to potassium excretion may contribute to BP regulation and glucose homeostasis. This trial was registered at clinicaltrials.gov as NCT03292094.

Alcohol Consumption and Antihypertensive Treatment Effect in Male Patients With Hypertension

BACKGROUND

Alcohol consumption is a proven risk factor of hypertension. In the present analysis, we investigated the use of antihypertensive medications and blood pressure control in male alcohol drinkers and non-drinkers with hypertension (systolic/diastolic blood pressure 160-199/100-119 mm Hg).

METHODS

The study participants were patients enrolled in a 12-week therapeutic study and treated with the irbesartan/hydrochlorothiazide combination 150/12.5 mg once daily, with the possible up-titration to 300/12.5 mg/day and 300/25 mg/day at 4 and 8 weeks of follow-up, respectively, for blood pressure control of <140/90 mm Hg or <130/80 mm Hg in patients with diabetes mellitus. Alcohol consumption was classified as non-drinkers and drinkers.

RESULTS

The 68 alcohol drinkers and 168 non-drinkers had similar systolic/diastolic blood pressure at baseline (160.8 ± 12.1/99.8 ± 8.6 vs. 161.8 ± 11.0/99.2 ± 8.6, P ≥ 0.55) and other characteristics except for current smoking (80.9% vs. 47.6%, P < 0.0001). In patients who completed the 12-week follow-up (n = 215), the use of higher dosages of antihypertensive drugs was similar at 4 weeks of follow-up in drinkers and non-drinkers (10.6% vs. 12.4%, P = 0.70), but increased to a significantly higher proportion in drinkers than non-drinkers at 12 weeks of follow-up (54.7% vs. 36.6%, P = 0.01). The control rate of hypertension tended to be lower in alcohol drinkers, compared with non-drinkers, at 4 weeks of follow-up (45.6% vs. 58.9%, P = 0.06), but became similar at 12 weeks of follow-up (51.5% vs. 54.8%, P = 0.65).

CONCLUSION

Alcohol drinkers compared with non-drinkers required a higher dosage of antihypertensive drug treatment to achieve similar blood pressure control.

CLINICAL TRIAL REGISTRY NUMBER

NCT00670566 at www.clinicaltrials.gov.

Determining the Risk of Elevated Digoxin Concentrations Following Loading Dose in Patients With Acute and Chronic Kidney Disease

BACKGROUND

The optimal loading dose of digoxin in patients with reduced kidney function is unknown. Tertiary references recommend reduced loading doses; however, these recommendations are based on immunoassays that are falsely elevated by the presence of digoxin-like immunoreactive substances, a problem that is minimized in modern assays.

OBJECTIVE

To determine whether chronic kidney disease (CKD) or acute kidney injury (AKI) is associated with supratherapeutic digoxin concentrations after a digoxin loading dose.

METHODS

A retrospective analysis on patients who received an intravenous loading dose of digoxin with a digoxin concentration collected 6 to 24 hours after the end of the dose. Patients were stratified into 3 groups: AKI, CKD, and non-AKI/CKD (NKI) based on glomerular filtration rate and serum creatinine. The primary outcome was frequency of supratherapeutic digoxin concentrations (>2 ng/mL) and secondary outcomes included frequency of adverse events.

RESULTS

A total of 146 digoxin concentrations were included (AKI = 59, CKD = 16, NKI = 71). Frequencies of supratherapeutic concentrations were similar between groups (AKI: 10.2%, CKD: 18.8%, NKI: 11.3%; P = 0.61). Pre-planned logistic regression demonstrated no significant relationship between kidney function group and the development of a supratherapeutic concentration (AKI: odds ratio [OR]: 1.3, 95% confidence interval [CI]: 0.4-4.5; CKD: OR 4.3, 95% CI: 0.7-23).

CONCLUSION AND RELEVANCE

This is the first study in routine clinical practice evaluating the relationship between kidney function and digoxin peak concentrations that differentiates AKI from CKD. We did not find a relationship between kidney function and peak concentrations; however, the group with CKD was underpowered.

Comparison of Pakistani CKD-EPI, new Asian-modified CKD-EPI and revised Lund-Malmö study equations in a South Asian CKD population: a study from a Pakistani CKD cohort

BACKGROUND

Newly proposed estimating glomerular filtration rate equations need to be studied, evaluated and compared for chronic kidney disease staging, diagnosis and medication dosing in South Asians. The objectives of the study were (1) to assess the performance of the CKD-EPIPK, CKD-EPIAsian-Modified, and LMRevised equations in the Pakistani chronic kidney disease population, and (2) to investigate prospective implications on chronic kidney disease classification and end-stage kidney disease prevalence.

METHODS

We conducted a cross-sectional analysis on a chronic kidney disease cohort of 385 participants 18 years of age or above.

RESULTS

CKD-EPIPK showed the lowest bias (- 1.33 ml/min/1.73 m2), highest precision [IQR, 2.33 (- 2.36, - 0.03)] and enhanced P30 accuracy (89.35%) compared to the CKD-EPIAsian-Modified and LMRevised equations. The mean difference (ml/min/1.73 m2), 95% limit of agreement (ml/min/1.73 m2) of the equations were; CKD-EPIAsian-Modified: - 5.98, - 13.03, LMRevised: - 4.06, - 8.13 and CKD-EPIPK: - 1.18, - 6.14 (P < 0.001). CKD-EPIAsian-Modified and LMRevised showed upward re-classification of the GFR categories compared to the CKD-EPIPK equation except in the G5 category where the highest count (217, 56.36%) was noted for the CKD-EPIPK equation. End-stage kidney disease prevailed in all age groups according to all equations, and the prevalence was high in females in all equations.

CONCLUSION

CKD-EPIPK showed the best performance, whereas both CKD-EPIAsian-Modified and LMRevised showed poor performance and did not offer a sufficient advantage in chronic kidney disease classification and end-stage kidney disease prevalence estimation over CKD-EPIPK. Hence, CKD-EPIPK seems ideal for South Asians, thus appropriate measures should be taken for its implementation, at least in Pakistani laboratories.

Muscle Mass and Serum Creatinine Concentration by Race and Ethnicity among Hemodialysis Patients

SIGNIFICANCE STATEMENT

Serum creatinine is a product of skeletal muscle metabolism. Differences in serum creatinine concentration between Black and non-Black individuals have been attributed to differences in muscle mass but have not been thoroughly examined. Furthermore, other race and ethnic groups have not been considered. If differences in body composition explain differences in serum concentration by race or ethnicity, then estimates of body composition could be used in eGFR equations rather than race. Adjustment for intracellular water (ICW) as a proxy of muscle mass among patients with kidney failure in whom creatinine clearance should minimally influence serum concentration does not explain race- and ethnicity-dependent differences.

BACKGROUND

Differences in serum creatinine concentration among groups defined by race and ethnicity have been ascribed to differences in muscle mass. We examined differences in serum creatinine by race and ethnicity in a cohort of patients receiving hemodialysis in whom creatinine elimination by the kidney should have little or no effect on serum creatinine concentration and considered whether these differences persisted after adjustment for proxies of muscle mass.

METHODS

We analyzed data from 501 participants in the A Cohort Study to Investigate the Value of Exercise in ESKD/Analyses Designed to Investigate the Paradox of Obesity and Survival in ESKD study who had been receiving hemodialysis for >1 year. We examined the independent associations among race and ethnicity (Black, Asian, non-Hispanic White, and Hispanic), serum creatinine, and ICW (L/m 2 ), a proxy for muscle mass, derived by whole-body multifrequency bioimpedance spectroscopy, using multivariable linear regression with adjustment for several demographic, clinical, and laboratory characteristics. We examined the association of race and ethnicity with serum creatinine concentration with and without adjustment for ICW.

RESULTS

Black, Asian, and Hispanic patients had higher serum creatinine concentrations (+1.68 mg/dl [95% confidence interval (CI), 1.09 to 2.27], +1.61 mg/dl [95% CI, 0.90 to 2.32], and +0.83 [95% CI, 0.08 to 1.57], respectively) than non-Hispanic White patients. Overall, ICW was associated with serum creatinine concentration (0.26 mg/dl per L/m 2 ICW; 95% CI, 0.006 to 0.51) but was not statistically significantly different by race and ethnicity. Black, Asian, and Hispanic race and ethnicity remained significantly associated with serum creatinine concentration after adjustment for ICW.

CONCLUSION

Among patients receiving dialysis, serum creatinine was higher in Black, Asian, and Hispanic patients than in non-Hispanic White patients. Differences in ICW did not explain the differences in serum creatinine concentration across race groups.

Novel model predicts diastolic cardiac dysfunction in type 2 diabetes

OBJECTIVE

Diabetes mellitus complicated with heart failure has high mortality and morbidity, but no reliable diagnoses and treatments are available. This study aimed to develop and verify a new model nomogram based on clinical parameters to predict diastolic cardiac dysfunction in patients with Type 2 diabetes mellitus (T2DM).

METHODS

3030 patients with T2DM underwent Doppler echocardiography at the First Affiliated Hospital of Shenzhen University between January 2014 and December 2021. The patients were divided into the training dataset (n = 1701) and the verification dataset (n = 1329). In this study, a predictive diastolic cardiac dysfunction nomogram is developed using multivariable logical regression analysis, which contains the candidates selected in a minor absolute shrinkage and selection operator regression model. Discrimination in the prediction model was assessed using the area under the receiver operating characteristic curve (AUC-ROC). The calibration curve was applied to evaluate the calibration of the alignment nomogram, and the clinical decision curve was used to determine the clinical practicability of the alignment map. The verification dataset was used to evaluate the prediction model's performance.

RESULTS

A multivariable model that included age, body mass index (BMI), triglyceride (TG), creatine phosphokinase isoenzyme (CK-MB), serum sodium (Na), and urinary albumin/creatinine ratio (UACR) was presented as the nomogram. We obtained the model for estimating diastolic cardiac dysfunction in patients with T2DM. The AUC-ROC of the training dataset in our model was 0.8307, with 95% CI of 0.8109-0.8505. Similar to the results obtained with the training dataset, the AUC-ROC of the verification dataset in our model was 0.8083, with 95% CI of 0.7843-0.8324, thus demonstrating robust. The function of the predictive model was as follows: Diastolic Dysfunction = -4.41303 + 0.14100*Age(year)+0.10491*BMI (kg/m2) +0.12902*TG (mmol/L) +0.03970*CK-MB (ng/mL) -0.03988*Na(mmol/L) +0.65395 * (UACR > 30 mg/g) + 1.10837 * (UACR > 300 mg/g). The calibration plot diagram of predicted probabilities against observed DCM rates indicated excellent concordance. Decision curve analysis demonstrated that the novel nomogram was clinically useful.

CONCLUSION

Diastolic cardiac dysfunction in patients with T2DM can be predicted by clinical parameters. Our prediction model may represent an effective tool for large-scale epidemiological study of diastolic cardiac dysfunction in T2DM patients and provide a reliable method for early screening of T2DM patients with cardiac complications.KEY MESSAGESThis study used clinical parameters to predict diastolic cardiac dysfunction in patients with T2DM. This study established a nomogram for predicting diastolic cardiac dysfunction by multivariate logical regression analysis. Our predictive model can be used as an effective tool for large-scale epidemiological study of diastolic cardiac dysfunction in patients with T2DM and provides a reliable method for early screening of cardiac complications in patients with T2DM.

Validation of the EKFC equation for glomerular filtration rate estimation and comparison with the Asian-modified CKD-EPI equation in Chinese chronic kidney disease patients in an external study

OBJECTIVES

The aim of this study is to determine whether new European Kidney Function Consortium (EKFC) equation is more applicable than Asian-modified CKD-EPI equation in clinical practice, having a higher accuracy in estimating GFR in our external CKD population.

METHODS

We calculated estimated GFR_EKFC and GFR_CKD-EPI independently using the EKFC and Asian-modified CKD-EPI formulas, respectively. The clinical diagnostic performance of the two equations was assessed and compared by median bias, precision, accuracy (P₃₀) and so on, using ^99mTc-DTPA dual plasma sample clearance method as a reference method for GFR measurement (mGFR). The equation that met the following targets was superior: (1) median bias within ± 3 mL/min/1.73 m²; (2) P₃₀ > 75%; and (3) better precision and 95% limits of agreement in Bland-Altman analysis.

RESULTS

Totally, 160 CKD patients were recruited in our external cohort. GFR_EKFC was highly related to mGFR, with a regression equation of GFR_EKFC=mGFR × 0.87 + 5.27. Compared with the Asian-modified CKD-EPI equation, EKFC equation demonstrated a wider median bias (-1.64 vs. 0.84 mL/min/1.73 m², p < 0.01) that was within 3 mL/min/1.73 m² and not clinically meaningful. Furthermore, the precision (12.69 vs. 12.72 mL/min/1.73 m², p = 0.42), 95% limits of agreement in Bland-Altman analysis (42.4 vs. 44.4 mL/min/1.73 m²) and incorrect reclassification index of the two target equations were almost identical. Although, EKFC equation had a slightly better P₃₀ (80.0% vs. 74.4%, p = 0.01).

CONCLUSIONS

The overall performance of EKFC equation is acceptable. There is no clinically meaningful difference in the performance of the Asian-modified CKD-EPI and EKFC equations within the limits imposed by the small sample size.

Risk prediction of the progression of chronic kidney disease stage 1 based on peripheral blood samples: construction and internal validation of a nomogram

Patients with chronic kidney disease (CKD) have high morbidity and mortality, and the disease progression has a significant impact on their survival and living standards. This research aims to analyze risk factors for CKD stage 1 and provide a reference for clinical decision making. The clinical data and peripheral blood samples of 300 patients with CKD stage 1 were collected retrospectively. Patients were randomly assigned into a training set (n = 210) and a validation set (n = 90). Patients' baseline characteristic levels were subjected to statistical tests for difference. Univariate and multivariate Cox regression analyses were utilized to identify risk factors influencing disease progression. Subsequently, a prediction model for disease progression was developed using a nomogram, and the model's accuracy was assessed using the C-index and calibration curve. The results revealed that hypertension, diabetes, and urinary albumin were essential factors in the progression of CKD stage 1. The nomogram was constructed and then the C-index was calculated. The calibration curve was utilized to assess the risk model. The C-index of the training set was 0.75, and the C-index of the validation set was 0.73, suggesting a good predictive ability of the model. The risk model accurately predicted the progression of CKD stage 1, which is of great significance to developing personalized treatment for patients in clinical practice.

Association of eGFR and mortality with use of a joint model: results of a nationwide study in Iceland

OBJECTIVES

Prior studies on the association of estimated glomerular filtration rate (eGFR) and mortality have failed to include methods to account for repeated eGFR determinations. The aim of this study was to estimate the association between eGFR and mortality in the general population in Iceland employing a joint model.

METHODS

We obtained all serum creatinine and urine protein measurements from all clinical laboratories in Iceland in the years 2008-16. Clinical data were obtained from nationwide electronic medical records. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation and categorized as follows: 0-29, 30-44, 45-59, 60-74, 75-89, 90-104 and >104 mL/min/1.73 m2. A multiple imputation method was used to account for missing urine protein data. A joint model was used to assess risk of all-cause mortality.

RESULTS

We obtained 2 120 147 creatinine values for 218 437 individuals, of whom 84 364 (39%) had proteinuria measurements available. Median age was 46 (range 18-106) years and 47% were men. Proteinuria associated with increased risk of death for all eGFR categories in persons of all ages. In persons ≤65 years, the lowest risk was observed for eGFR of 75-89 mL/min/1.73 m2 without proteinuria. For persons aged >65 years, the lowest risk was observed for eGFR of 60-74 mL/min/1.73 m2 without proteinuria. eGFR of 45-59 mL/min/1.73 m2 without proteinuria did not associate with increased mortality risk in this age group. eGFR >104 mL/min/1.73 m2 associated with increased mortality.

CONCLUSIONS

These results lend further support to the use of age-adapted eGFR thresholds for defining chronic kidney disease. Very high eGFR needs to be studied in more detail with regard to mortality.

Novel Associations of Dyslipidaemia with Vitamin D and Bone Metabolism in Elderly Patients with Diabetes: A Cross-Sectional Study

Objective

Little is known about whether diabetic dyslipidaemia contributes to increased bone fragility in patients with diabetes. This study aimed to explore the potential effects of dyslipidaemia on vitamin D and bone metabolism in elderly subjects with type 2 diabetes (T2D).

Methods

A total of 1479 male patients and 1356 female patients 50 years or older with T2D were included in Shanghai, China. Lipid profiles, 25-hydroxyvitamin D (25(OH)D), serum procollagen type I N-terminal propeptide (P1NP), β-C-terminal telopeptide (β-CTX) and other parameters were measured. Principal component regression (PCR) and mediation analysis were used to estimate the associations of lipid profile, 25(OH)D and bone turnover levels.

Results

Female patients presented with higher blood lipids, lower 25(OH)D, and higher P1NP and β-CTX levels than male patients with T2D. TC was associated with P1NP in males and females (β=0.056, P<0.05; β=0.095, P<0.01, respectively), and 25(OH)D fully mediated the associations in males and mediated approximately 17.89% of the effects in females. LDL-C was associated with P1NP in males and females (β=0.072 and 0.105 respectively, all P<0.01), and 25(OH)D mediated the relationships approximately 20.83% in males and 14.29% in females. TG was negatively associated with P1NP (in males, β= -0.063, P<0.05; in females, β= -0.100, P<0.01) and β-CTX (in males, β= -0.108; in females, β= -0.128, all P<0.01) independent of 25(OH)D, while HDL-C was not associated with P1NP or β-CTX in diabetic patients.

Conclusion

Hypercholesterolemia and hypertriglyceridaemia might affect bone metabolism by distinguishing pathways in diabetes patients. Ameliorating lipid control in elderly diabetes patients, especially female patients, will benefit both vitamin D and bone metabolism.

Plasma D-dimer as a potential predictor of progression in IgA nephropathy: a cohort study

INTRODUCTION

Coagulation disorders play a key role in chronic kidney disease, and the formation or elevation of plasma D-dimer levels reflects activation of the coagulation system. However, its relationship with the severity and progression of kidney disease in IgA nephropathy (IgAN) remains unclear.

METHODS

We assessed 1818 patients with IgAN diagnosed between 2002 and 2019 at the First Affiliated Hospital, Zhejiang University School of Medicine. Plasma D-dimer levels were measured at the time of the renal biopsy. The association between plasma D-dimer levels and kidney disease progression events, defined as a 50% decline in eGFR and end-stage kidney disease (ESKD), was tested using restricted cubic splines and Cox proportional hazard models.

RESULTS

The median plasma D-dimer level was 220 (170-388.5) µg/L FEU, which was significantly higher than healthy controls 170 (170-202) µg/L FEU. Plasma D-dimer levels were positively correlated with proteinuria (r = 0.211, p < 0.001) and serum galactose-deficient IgA1 (r = 0.226, p = 0.004) and negatively correlated with eGFR (r=-0.127, p < 0.001) and Oxford T (p < 0.001) and C (p = 0.004) scores. After a median follow-up of 25.67 (13.03-47.44) months, 126 (6.93%) patients experienced composite kidney disease progression events. Higher plasma D-dimer levels were associated with an increased risk of kidney disease progression events (hazard ratio, 1.73; 95% confidence interval [95% CI], 1.40-2.23) per ln-transformed plasma D-dimer (p < 0.001), after adjustment for sex, age, proteinuria, Mean arterial pressure (MAP) and Oxford classification scores. In reference to the first tertile of plasma D-dimer, hazard ratios were 1.48 (95% CI, 0.76-2.88) for the second tertile, 3.03 (95% CI, 1.58-5.82) for the third tertile.

CONCLUSIONS

High plasma D-dimer levels were associated with the progression of kidney disease severity in IgA nephropathy.

Nomogram for the prediction of crescent formation in IgA nephropathy patients: a retrospective study

BACKGROUND

The 2017 Oxford classification of immunoglobulin A nephropathy (IgAN) recently reported that crescents could predict a worse renal outcome. Early prediction of crescent formation can help physicians determine the appropriate intervention, and thus, improve the outcomes. Therefore, we aimed to establish a nomogram model for the prediction of crescent formation in IgA nephropathy patients.

METHODS

We retrospectively analyzed 200 cases of biopsy-proven IgAN patients. Least absolute shrinkage and selection operator(LASSO) regression and multivariate logistic regression was applied to screen for influencing factors of crescent formation in IgAN patients. The performance of the proposed nomogram was evaluated based on Harrell's concordance index (C-index), calibration plot, and decision curve analysis.

RESULTS

Multivariate logistic analysis showed that urinary protein ≥ 1 g (OR = 3.129, 95%CI = 1.454-6.732), urinary red blood cell (URBC) counts ≥ 30/ul (OR = 3.190, 95%CI = 1.590-6.402), mALBU ≥ 1500 mg/L(OR = 2.330, 95%CI = 1.008-5.386), eGFR < 60ml/min/1.73m2(OR = 2.295, 95%CI = 1.016-5.187), Serum IgA/C3 ratio ≥ 2.59 (OR = 2.505, 95%CI = 1.241-5.057), were independent risk factors for crescent formation. Incorporating these factors, our model achieved well-fitted calibration curves and a good C-index of 0.776 (95%CI [0.711-0.840]) in predicting crescent formation.

CONCLUSIONS

Our nomogram showed good calibration and was effective in predicting crescent formation risk in IgAN patients.

Important Factors to Expect the Outcome After Intracerebral Hemorrhage: An Observational Study From a University Hospital in Saudi Arabia

BACKGROUND

Intracerebral hemorrhage (ICH) has worse clinical outcomes than other stroke types. The risk factors contributing to ICH outcomes are not entirely understood, and published literature from Saudi Arabia on ICH outcomes is limited. Our goal was to study the specific clinical and imaging determinants of ICH outcomes.

METHODS

We retrospectively retrieved all patients with spontaneous ICH (SICH) from a prospective King Fahd Hospital University registry between 2017 and 2019. The clinical characteristics of ICH events and data on clinical outcomes (6 to 12 mo) were recorded. Groups of patients with a favorable modified Rankin Scale of 0 to 2 and nonfavorable outcomes of a modified Rankin Scale of 3 to 6 were investigated. The relationship between the clinical characteristics of the SICH event and its outcomes was assessed using linear and logistic regression analyses.

RESULTS

A total of 148 patients with a mean age of 60.3 years (±15.2) and a median follow-up of 9 months were included. Unfavorable outcomes were reported in 98 patients (66.2%). The ICH event variables associated with unfavorable outcomes were impaired renal function, Glasgow Coma Score <8, hematoma volume, hematoma expansion, and intraventricular extension (IVE).

CONCLUSIONS

Our study demonstrated important clinical and radiologic features in patients with ICH that may affect their clinical long-term functional outcomes. A larger multicenter study is required to validate our results and evaluate the methods to improve health care in patients with SICH.

Prognostic role of the neutrophil-to-lymphocyte ratio in patients with chronic kidney disease

BACKGROUND/AIMS

The neutrophil-to-lymphocyte ratio (NLR) has a prognostic value in cardiovascular disease, infection, inflammatory disease, and several malignancies. Therefore, the NLR has a possible predictive value in patients with chronic kidney disease (CKD), but this predictive value has not been validated. Here, we aimed to investigate the possibility of NLR as a predictor of CKD progression.

METHODS

This retrospective observational study included 141 patients with non-dialysis CKD. The participants were divided into terciles (T1, T2, and T3) according to NLR. The primary outcome was defined as a composite kidney event, which included a decline in the estimated glomerular filtration rate (eGFR) of at least 50% or initiation of renal replacement therapy during the follow-up period.

RESULTS

The mean follow-up duration was 5.45 ± 2.11 years. The mean NLRs were 1.35 ± 0.05 in T1 (n = 47), 2.16 ± 0.04 in T2 (n = 47), and 4.29 ± 0.73 in T3 (n = 47). The group with the highest NLR (T3) had higher baseline CKD and serum creatinine and lower eGFR levels than the group with the lowest NLR (T1). The cumulative incidence rate of composite kidney events was significantly higher in T3 compared with T1 (p < 0.001, log-rank test). Cox regression analysis revealed that high NLR was associated with the risk of composite kidney events (adjusted hazard ratio, 3.33; 95% confidence interval, 1.43-7.76).

CONCLUSION

A higher NLR reflects the more advanced stage of CKD and suggests a role for NLR as a biomarker for predicting CKD progression.

Incidence and clinical relevance of paraneoplastic syndromes in patients with renal cell carcinoma

BACKGROUND

Paraneoplastic syndromes (PNS) are defined as the signs and symptoms attributed to cytokines or hormones released from a tumor or a patient's immune system. PNS have been reported with many cancers for decades and data supporting their relevance in renal cell carcinoma (RCC) are largely historical. The widespread use of electronic medical record (EMR) systems provides a more robust method to capture data. The objective of this study was to establish contemporary data regarding the incidence and relevance of PNS in patients undergoing nephrectomy for suspected RCC.

METHODS

In this retrospective single-institution study, 851 patients undergoing nephrectomy for suspected RCC between 2011 and 2018 were assessed for the presence or absence of PNS as defined by laboratory abnormalities. Factors associated with PNS and with all-cause mortality were examined.

RESULTS

The incidence of PNS was 33.1% among 851 patients prior to nephrectomy. The most prevalent PNS were anemia (22.4%), thrombocytosis (7.5%), and elevated C-reactive protein (CRP) (7.4%). PNS were more common in women (39.2% vs. 29.4%, p = 0.0032) and higher stage RCC (31.1% of stage I vs. 54.2% of stage IV, p = 0.0036). Factors associated with the presence of PNS in multivariable analysis included female gender, high comorbidity, and stage IV RCC. Prenephrectomy PNS were associated with poorer survival in multivariable analysis (HR: 2.12, p = 0.0002). Resolution of PNS occurred in 52.1% of patients after nephrectomy, including 55.2% with stage I to III and 38.5% with stage IV RCC (p = 0.10).

CONCLUSIONS

Using EMR data, laboratory evidence of PNS was present in one-third of a contemporary cohort of patients undergoing nephrectomy, with >50% of PNS resolving after surgery. Consistent with prior reports, PNS are more common in higher-stage RCC and are associated with poorer survival in RCC patients.

No impact of a high-fat meal coupled with intermittent hypoxemia on acute kidney injury biomarkers in adults with and without obstructive sleep apnea

Obstructive sleep apnea (OSA) is characterized by chronic intermittent hypoxemia, which is associated with progressive loss of kidney function, where postprandial fluctuations in renal physiology may further compromise oxygen supply and kidney function. Therefore, we measured biomarkers of acute kidney injury (AKI) following a high-fat meal with and without intermittent hypoxemia. Eighteen healthy young men (mean age [SD]: 22.7 years [3.1]) and seven middle-aged to older individuals with OSA (54.4 years [6.4]) consumed a high-fat meal during normoxia or intermittent hypoxemia (~15 hypoxic cycles per hour, ~85% oxyhemoglobin saturation) for 6 h. We observed no changes in estimated glomerular filtration rate and plasma concentrations of creatinine, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) at any measured time points. In both groups, plasma concentrations of interleukin-18 (IL-18) increased after 6 h during normoxia only (p = 0.033, ηp 2  = 0.122), and plasma concentrations of liver-type fatty acid-binding protein (L-FABP) transiently decreased after 3 h in both conditions (p = 0.008, ηp 2  = 0.152). These findings indicate that AKI biomarkers are not acutely elevated during the postprandial state with or without intermittent hypoxemia, suggesting that other mechanisms may play more important roles in the progression of kidney disease in OSA.

Different associations of anthropometric indices with diabetic retinopathy and diabetic kidney disease in chinese patients with type 2 diabetes mellitus

AIMS

To investigate the associations of anthropometric indices, including body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist circumference (WC) and hip circumference (HC), with diabetic retinopathy (DR) and diabetic kidney disease (DKD) in Chinese patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

This cross-sectional study evaluated 5226 Chinese participants with T2DM at three hospitals between 2005 and 2016. Logistic regression models and restricted cubic spline analysis were used to assess the associations of anthropometric indices with DR and DKD.

RESULTS

A BMI of around 25 kg/m2 was related to a low risk of DR (OR based on the third fifth: 0.752, 95%CI: 0.615-0.920). Besides, HC had an inverse association with DR in men independently of BMI (OR based on the highest fifth: 0.495, 95%CI: 0.350-0.697). In the restricted cubic spline models, BMI, WHtR, WC, and HC showed J-shaped associations with DKD, while WHR showed an S-shaped association with DKD. Compared to the lowest fifth, the odds ratios (OR) based on the highest fifth of BMI, WHR, WHtR, WC and HC for DKD were 1.927 (1.572-2.366), 1.566 (1.277-1.923), 1.910 (1.554-2.351), 1.624 (1.312-2.012) and 1.585 (1.300-1.937) respectively in multivariable models.

CONCLUSIONS

A median BMI and a large hip might be related to a low risk of DR, while lower levels of all the anthropometric indices were associated with a lower risk of DKD. Our findings suggested maintain a median BMI, a low WHR, a low WHtR and a large hip for prevention of DR and DKD.

Association of Hyper-Triglyceridemic Waist Phenotype and Diabetic Vascular Complication in the Chinese Population

Background

Diabetic vascular complications are the leading cause of crippling and death of diabetic patients and seriously affect patients' quality of life. It is essential to control the risk factors contributing to vascular complications in patients with Type 2 diabetes (T2DM). This study aimed to examine the association between hyper-triglyceridemic waist phenotype (HWP) and the risk of vascular complication index of diabetes in T2DM patients.

Methods

The participants with type 2 diabetes mellitus in this study registered at the National Metabolic Management Center (MMC) of Beijing Luhe Hospital from June 2017 to June 2021. Data were collected by trained personnel according to the protocol. The questionnaire containing information on demographic characteristics and lifestyle factors (including alcohol drinking and cigarette smoking et al) was administered by trained interviewers. Logistic regression analysis assessing the associations between the hyper-triglyceridemic waist phenotype and vascular complication index of diabetes. In addition, the subgroup analysis was performed by age, sex, HbA1c, hypertension or not, and education level.

Results

After data cleaning, a total of 3221 participants with T2DM were enrolled. The median (IQR) duration of diabetes was 47.00 (3.00, 125.00) months. Compared to the participants in the Normal triglycerides level and Normal waist circumference group (NTNW), those in the Elevated triglycerides level and Enlarged waist circumference group (HTGW) have a higher risk of CKD-related vascular complications; the OR of decreased estimated glomerular filtration rate (GFR) and elevated urinary albumin creatinine ratio (UACR) were 2.21 (95% CI:1.32-3.82) and 2.18 (95% CI:1.69-2.81), respectively. Moreover, compared to the participants in the NTNW group, the ORs of the decreased ankle-brachial index (ABI) and elevated Brachial-ankle pulse wave velocity (baPWV) were 2.24 (95% CI:1.38-3.80) and 1.63 (95% CI:1.28-2.06) in the HTGW group.

Conclusion

In summary, there was an association between hyper-triglyceridemic waist phenotype and diabetic vascular complications in the Chinese population.

Thyroid Dysfunction at Different Stages of Chronic Kidney Disease: A Cross-Sectional Study at a Rural Teaching College in Central India

Background The high prevalence of thyroid dysfunction in patients with chronic kidney disease (CKD) indicates a major correlation between the progression of CKD and thyroid dysfunction. In this study, we highlighted thyroid dysfunction and its relation to the severity and different stages of CKDs. Materials and methods From October 2018 to September 2020, 200 cases with CKD, admitted under the Department of Medicine at a rural teaching hospital in central India, were selected for the study. The collected data was analyzed and correlated using the Chi-square test, and the parameters suggested the presence or absence of low T3 syndrome, low T4 syndrome, and primary hypothyroidism. Results Out of 200 patients enrolled, 181 (91.5%) had thyroid abnormalities. Among these patients, the presence of low T3 syndrome was 57%, low T4 syndrome was 23%, and primary hypothyroidism was 10.5%. It was reported that as the CKD stages advanced, TSH levels increased with a statistically significant difference (p=0.04). Conclusions As kidney function progressively deteriorated, specifically in stage five, the chances of occurrence of hypothyroidism increased.

Predictive performance of the new race-free Chronic Kidney Disease Epidemiology Collaboration equations for kidney outcome in Korean patients with chronic kidney disease

BACKGROUND

The new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations without a race coefficient have gained recognition across the United States. We aimed to test whether these new equations performed well in Korean patients with chronic kidney disease (CKD).

METHODS

This study included 2,149 patients with CKD G1-G5 without kidney replacement therapy from the Korean Cohort Study for Outcome in Patients with CKD (KNOW-CKD). The estimated glomerular filtration rate (eGFR) was calculated using the new CKD-EPI equations with serum creatinine and cystatin C. The primary outcome was 5-year risk of kidney failure with replacement therapy (KFRT).

RESULTS

When we adopted the new creatinine equation [eGFRcr (NEW)], 81 patients (23.1%) with CKD G3a based on the current creatinine equation (eGFRcr) were reclassified as CKD G2. Accordingly, the number of patients with eGFR of <60 mL/min/1.73 m2 decreased from 1,393 (64.8%) to 1,312 (61.1%). The time-dependent area under the receiver operating characteristic curve for 5-year KFRT risk was comparable between the eGFRcr (NEW) (0.941; 95% confidence interval [CI], 0.922-0.960) and eGFRcr (0.941; 95% CI, 0.922-0.961). The eGFRcr (NEW) showed slightly better discrimination and reclassification than the eGFRcr. However, the new creatinine and cystatin C equation [eGFRcr-cys (NEW)] performed similarly to the current creatinine and cystatin C equation. Furthermore, eGFRcr-cys (NEW) did not show better performance for KFRT risk than eGFRcr (NEW).

CONCLUSION

Both the current and the new CKD-EPI equations showed excellent predictive performance for 5-year KFRT risk in Korean patients with CKD. These new equations need to be further tested for other clinical outcomes in Koreans.

Prevalence and predictors of chronic kidney disease of undetermined causes (CKDu) in Western Kenya's "sugar belt": a cross-sectional study

BACKGROUND

Epidemics of chronic kidney disease of undetermined causes (CKDu) among young male agricultural workers have been observed in many tropical regions. Western Kenya has similar climatic and occupational characteristics as many of those areas. The study objectives were to characterize prevalence and predictors of CKDu, such as, HIV, a known cause of CKD, in a sugarcane growing region of Kenya; and to estimate prevalence of CKDu across occupational categories and evaluate if physically demanding work or sugarcane work are associated with reduced eGFR.

METHODS

The Disadvantaged Populations eGFR Epidemiology Study (DEGREE) protocol was followed in a cross-sectional study conducted in Kisumu County, Western Kenya. Multivariate logistic regression was performed to identify predictors of reduced eGFR.

RESULTS

Among 782 adults the prevalence of eGFR < 90 was 9.85%. Among the 612 participants without diabetes, hypertension, and heavy proteinuria the prevalence of eGFR < 90 was 8.99% (95%CI 6.8%, 11.5%) and 0.33% (95%CI 0.04%, 1.2%) had eGFR < 60. Among the 508 participants without known risk factors for reduced eGFR (including HIV), the prevalence of eGFR < 90 was 5.12% (95%CI 3.4%, 7.4%); none had eGFR < 60. Significant risk factors for reduced eGFR were sublocation, age, body mass index, and HIV. No association was found between reduced eGFR and work in the sugarcane industry, as a cane cutter, or in physically demanding occupations.

CONCLUSION

CKDu is not a common public health problem in this population, and possibly this region. We recommend that future studies should consider HIV to be a known cause of reduced eGFR. Factors other than equatorial climate and work in agriculture may be important determinants of CKDu epidemics.

Performance and pitfalls of the tools for measuring glomerular filtration rate to guide chronic kidney disease diagnosis and assessment

Accurate diagnosis, classification and risk stratification for chronic kidney disease (CKD) allow for early recognition and delivering optimal care. Creatinine-based glomerular filtration rate (GFR), urinary albumin: creatinine ratio (UACR) and the kidney failure risk equation (KFRE) are important tools to achieve this, but understanding their limitations is important for optimal implementation.When accurate GFR is required (eg, chemotherapy dosing), GFR is measured using an exogenous filtration marker. In routine clinical practice, in contrast, estimated GFR (eGFR) from serum creatinine (SCr), calculated using the enzymatic method±UACR, is recommended. Limitations of SCr include non-GFR determinants such as muscle mass, diet and tubular handling. An alternative or additional endogenous filtration marker is cystatin C, which can be used alongside SCr for confirmatory testing of CKD. However, its role in the UK is more limited due to concerns regarding false positive results.The recommended creatinine-based eGFR equation in the UK is the CKD Epidemiology Collaboration 2009 equation. This was recently updated to a race-neutral 2021 version and demonstrated reduced bias in people of Black ethnicity, but has not been validated in the UK. Limitations are extremes of age, inaccuracy at greater GFRs and reduced generalisability to under-represented ethnicity groups.The KFRE (based on age, sex, SCr and UACR) has recently been developed to help determine 2-year and 5-year risk of progression to end-stage kidney disease. It has been validated in over 30 countries and provides meaningful quantitative information to patients. However, supporting evidence for their performance in ethnic minority groups and kidney diseases such as glomerulonephritis remains modest.In conclusion, early identification, risk stratification of kidney disease and timely intervention are important to impact kidney disease progression. However, clinician awareness of the limitations and variability of creatinine, cystatin C and the eGFR equations, is key to appropriate interpretation of results.

Cardiovascular risk and kidney function profiling using conventional and novel biomarkers in young adults: the African-PREDICT study

BACKGROUND

Low- and middle-income countries experience an increasing burden of chronic kidney disease. Cardiovascular risk factors, including advancing age, may contribute to this phenomenon. We (i) profiled cardiovascular risk factors and different biomarkers of subclinical kidney function and (ii) investigated the relationship between these variables.

METHODS

We cross-sectionally analysed 956 apparently healthy adults between 20 and 30 years of age. Cardiovascular risk factors such as high adiposity, blood pressure, glucose levels, adverse lipid profiles and lifestyle factors were measured. Various biomarkers were used to assess subclinical kidney function, including estimated glomerular filtration rate (eGFR), urinary albumin, uromodulin and the CKD273 urinary proteomics classifier. These biomarkers were used to divide the total population into quartiles to compare extremes (25th percentiles) on the normal kidney function continuum. The lower 25th percentiles of eGFR and uromodulin and the upper 25th percentiles of urinary albumin and the CKD273 classifier represented the more unfavourable kidney function groups.

RESULTS

In the lower 25th percentiles of eGFR and uromodulin and the upper 25th percentile of the CKD273 classifier, more adverse cardiovascular profiles were observed. In multi-variable adjusted regression analyses performed in the total group, eGFR associated negatively with HDL-C (β= -0.44; p < 0.001) and GGT (β= -0.24; p < 0.001), while the CKD273 classifier associated positively with age and these same risk factors (age: β = 0.10; p = 0.021, HDL-C: β = 0.23; p < 0.001, GGT: β = 0.14; p = 0.002).

CONCLUSION

Age, lifestyle and health measures impact kidney health even in the third decade.

The prognostic value of monocyte-to-lymphocyte ratio in peritoneal dialysis patients

BACKGROUND

The monocyte-to-lymphocyte ratio (MLR) is considered as a new inflammation marker. This study was aimed to investigate the prognostic value of MLR for all-cause mortality and new-onset cardiovascular disease (CVD) events in peritoneal dialysis (PD) patients.

METHODS

This study enrolled patients receiving PD treatment for  ≥ 3 months. Baseline characteristics were obtained within 1 week before PD catheterization. The receiver operating characteristic curve analysis was conducted to determine the optimal cut-off value of MLR. The Kaplan-Meier curve estimated the cumulative survival rate and new CVD free survival rate. Univariate and multivariate Cox regression models were preformed to investigate the association between MLR and clinical outcomes.

RESULTS

A total of 369 PD patients participated in this study. During a median follow-up period of 32.83 months, 65 patients (24.2%) died, and 141 patients (52.4%) occurred new-onset CVD events. The Kaplan-Meier curve revealed that survival rate in high MLR group (MLR  > 0.2168) was significantly lower than in low MLR group (P = 0.008). Patients in high MLR group were more likely to experience CVD events (P = 0.002). Even after adjustment of traditional risk factors, including age, diabetes mellitus, CVD history, smoking, hyperlipidemia, high MLR remained an independent predictor of all-cause mortality [hazard ration (HR) = 2.518, 95% confidence intervals (CI) = 1.020-6.214, P = 0.045] and new-onset CVD events (HR = 1.815, 95% CI = 1.157-2.849, P = 0.010).

CONCLUSIONS

This study suggested that high MLR was significantly and independently associated with all-cause mortality and CVD events in PD patients. The MLR is an inexpensive and straightforward indicator to reflect systemic inflammation status and help clinicians improve PD management.