Pediatric kidney dimensions and risk of persistent albuminuria in Mexican adolescents

In Mexico, chronic kidney disease of unknown origin is highly prevalent. Screening studies in adolescents have shown persistent microalbuminuria (pACR), adaptive podocytopathy and decreased kidney volume (KV). Here, we sought to develop normality tables of kidney dimensions by ultrasound in the Mexican state of Aguascalientes pediatric population (0 to 18y) and evaluate the relationship between the KV and pACR among the region's adolescents in a cross-sectional study. Kidney length (KL) and KV were determined by ultrasound. Our findings were compared with those in international literature of different populations where tables and graphs of normal kidney dimensions by ultrasound were reported. We compared organ dimensions in individuals above the age of 11 without albuminuria with those in patients with pACR recruited through screening studies in adolescents in Aguascalientes. This included 1068 individuals to construct percentile tables and graphs of the KL. Kidney dimensions were significantly lower when compared with all international comparisons. From a total 14,805 screen individuals, we compared 218 adolescents with pACR and 377 individuals without significant albuminuria. The Total KV adjusted to body surface (TKVBS) was significantly associated with pACR (odds ratio 1.03, 95% confidence interval 1.02-1.03). The upper quartile of TKVBS was highly associated with pACR (7.57, 4.13-13.87), hypertension (2.53, 1.66-3.86), and hyperfiltration (26 vs 11.5%). Thus, TKVBS is directly associated with pACR while greater KV, arterial hypertension, and hyperfiltration in patients with pACR suggest that the increase in volume is secondary to kidney hypertrophy. Additionally, the adaptative podocytopathy with low fibrosis seen on kidney biopsy which was performed in a subset of patients, and the smaller kidney dimensions in our population point to prenatal oligonephronia as the primary cause of the detected kidney disease.

High prevalence of end-stage renal disease of unknown origin in Aguascalientes Mexico: role of the registry of chronic kidney disease and renal biopsy in its approach and future directions

Background

Chronic kidney disease (CKD) is one of the pathologies with the greatest impact on the public health system. Over the last few decades, the relevance of CKD in Mexico has increased, with associated overwhelming costs for care of renal disease. There are no reliable CKD statistics in Mexico.

Methodology

In June 2018, the government of Aguascalientes called on all Health Institutions to create a state registry of treated end-stage renal disease (ESRD). In the same system, a renal biopsy result registry included all the native kidney biopsies obtained in the state of Aguascalientes since 2012. We herein describe the prevalence, incidence and characteristics of the patients included in the CKD and renal biopsy registry in the state of Aguascalientes.

Results

As of April 2020, the state has documented 2827 patients on renal replacement therapy (RRT), 1877 on dialysis and 950 that have been transplanted. The prevalence of patients on dialysis is 1326 per million population (p.m.p.), and if transplanted individuals are included, it is 1997 p.m.p. The incidence of treated ESRD in 2019 was 336 p.m.p. (n = 474) in individuals with an average age of 45.6 years (standard deviation ±18), and in a higher proportion of men (61%). There is a bimodal distribution of the age at which RRT was initiated. The first and the most significant peaks are between the ages of 20 and 40 years and are usually the result of CKD of unknown cause (73%). The second peak is between 50 and 70 years of age, and CKD is usually the result of diabetes mellitus and systemic arterial hypertension (59.6%). Since January 2012, 423 biopsies have been recorded. The patient’s ages were between 20 and 30 years (n = 112), and the most frequent diagnosis was focal segmental glomerulosclerosis (FSGS) (54%).

Conclusions

The prevalence of treated ESRD in the state of Aguascalientes is high. The disease mostly afflicts young people between 20 and 40 years of age, and there is a clear male predominance. In this age group, the main clinical diagnosis is CKD of unknown origin, and the most frequent biopsy diagnosis was FSGS.

Creatinine Fluctuations Forecast Cross-Harvest Kidney Function Decline Among Sugarcane Workers in Guatemala

Background

Chronic kidney disease of unknown origin (CKDu) is an epidemic that disproportionately affects young agriculture workers in hot regions. It has been hypothesized that repeated acute kidney injury (AKI) may play a role in the development of disease.

Methods

Latent class mixed models were used to identify groups of Guatemalan sugarcane harvesters based on their daily changes in creatinine over 6 consecutive days in 2018. Exponential smoothing state space models were used to forecast end-of-season creatinine between the identified groups. Percent change in estimated glomerular filtration rate (eGFR) across the harvest was compared between groups.

Results

Twenty-nine percent (n = 30) of the 103 workers experienced repeated severe fluctuations in creatinine across shift. The model with multiplicative error, multiplicative trend, and multiplicative seasonality was able to accurately forecast end-of-season creatinine in the severe group (mean percentage error [MPE]: −4.7%). eGFR of workers in the severe group on average decreased 20% across season compared to 11% decline for those in the moderate group (95% confidence interval for difference: −17% to 0%).

Conclusions

Daily fluctuations in creatinine can be used to forecast end-of-season creatinine in sugarcane harvesters. Workers who experience repeat severe daily fluctuations in creatinine, on average, experience a greater reduction in kidney function across the season.

Acute kidney injury and workload in a sample of California agricultural workers

BACKGROUND

Kidney damage is associated with an increased workload in high ambient temperatures and may represent a pathway to chronic kidney disease of unknown origin in agricultural workers. We tested the associations of workload and heat with acute kidney dysfunction in California agricultural workers.

METHODS

We recruited a convenience sample of 471 agricultural workers from 29 farms in California during two summer harvest seasons. The sustained 3-minute maximum workload was estimated using accelerometer data collected from Actical monitors and individual heat load through elevations in core body temperature. Acute kidney injury (AKI) was defined by a change in serum creatinine of ≥0.3 mg/dL or ≥1.5 times the preshift creatinine over the course of the work shift. Associations between AKI and workload were modeled using logistic regression, controlling for demographic, physiologic, and occupational variables.

RESULTS

Of the total, 357 workers (75.8%) had accelerometer readings in the moderate workload category, 93 (19.7%) had readings in the vigorous category. 177 (36%) had elevations of core body temperature ≥1°C; 72 workers (14.9%) demonstrated evidence of AKI after a single day of agricultural work. The workload category was associated with an increased adjusted odds of AKI (1.92; 95% confidence interval, 1.05-3.51). Piece-rate work was also associated with increased adjusted odds of AKI (3.02; 95% CI, 1.44-6.34).

CONCLUSIONS

Heavy occupational workload and piece-rate work were associated with acute effects on the renal health of agricultural workers. This indicates that occupations requiring high physical effort put workers at risk for AKI, possibly independent of ambient and core body temperature. Changes to agricultural practices may reduce the risk of renal disorders for these workers.

Expanding CAPD in Low-Resource Settings: A Distance Learning Approach

BACKGROUND

Despite growing need, treatment for end-stage renal disease is limited in low- and middle-income countries due to resource restraints. We describe the development of an educational curriculum and quality improvement program to support continuous ambulatory peritoneal dialysis (CAPD) performed primarily by non-nephrology providers in Sri Lanka.

METHODS

We developed a program of education, outcome tracking, and expert consultation to support providers in Kandy, Sri Lanka. Education included videos and in-person didactics covering core topics in CAPD. Event-tracking sheets recorded root causes and management of infections and hospitalizations. Conferences reviewed clinical cases and overall clinic management. We evaluated the patient census, peritonitis rates, and root causes and management of infections over 1 year.

RESULTS

The curriculum was published through the International Society of Nephrology online academy. High provider turnover limited curriculum assessments. The CAPD patient census rose from 63 to 116 during the year. The peritonitis rate declined significantly, from 0.8 episodes per patient-year in the first 6 months to 0.4 in the latter 6 months, though the most common root causes of peritonitis, related to contamination events and hygiene, persisted. The appropriate ascertainment of culture data and prescription of antibiotics also increased.

CONCLUSIONS

Our project supported the expansion of a CAPD program in a resource-limited setting, while also improving peritonitis outcomes. Ongoing challenges include ensuring a durable educational system for rotating providers, tracking outcomes beyond peritonitis, and formalizing management protocols. Our program can serve as an example of how established dialysis programs can support the burgeoning work of providers in resource-limited setting.