Cross-sectional study examining the accuracy of self-reported smoking status as compared to urinary cotinine levels among workers at risk for chronic kidney disease of unknown origin in Guatemala

Exposome and Metabolome Analysis of Sugarcane Workers Reveals Predictors of Kidney Injury

Introduction

Sugarcane workers are exposed to potentially hazardous agrochemicals, including pesticides, heavy metals, and silica. Such occupational exposures present health risks and have been implicated in a high rate of kidney disease seen in these workers.

Methods

To investigate potential biomarkers and mechanisms that could explain chronic kidney disease (CKD) among this worker population, paired urine samples were collected from sugarcane cutters at the beginning and end of a harvest season in Guatemala. Workers were then separated into 2 groups, namely those with or without kidney function decline (KFD) across the harvest season. Urine samples from these 2 groups underwent elemental analysis and untargeted metabolomics.

Results

Urine profiles demonstrated increases in silicon, certain pesticides, and phosphorus levels in all workers, whereas heavy metals remained low. The KFD group had a reduction in estimated glomerular filtration rate (eGFR) across the harvest season; however, kidney injury marker 1 did not significantly change. Cross-harvest metabolomic analysis found trends of fatty acid accumulation, perturbed amino acid metabolism, presence of pesticides, and other known signs of impaired kidney function.

Conclusion

Silica and certain pesticides were significantly elevated in the urine of sugarcane workers with or without KFD. Future work should determine whether long-term occupational exposure to silica and pesticides across multiple seasons contributes to CKD in these workers. Overall, these results confirmed that multiple exposures are occurring in sugarcane workers and may provide insight into early warning signs of kidney injury and may help explain the increased incidence of CKD among agricultural workers.

Prevalence of kidney disease of unknown etiology in agricultural workers, Guatemala

Objectives

To determine the prevalence of kidney disease of unknown etiology in banana, melon, and tomato workers in north-eastern Guatemala, and to evaluate the usefulness of a cystatin C blood test for early detection of renal disease.

Methods

This was a cross-sectional, farm-based study of 462 agricultural workers conducted from June to September 2021. Epidemiological and demographic characteristics of the workers were collected through a self-administered questionnaire. Blood samples were obtained to determine glucose, creatinine and cystatin C levels. Anthropometric and clinical data were also recorded.

Results

The prevalence of kidney disease of unknown etiology was 3.03% (95% confidence interval (CI): 1.36-4.70%) based on glomerular filtration rate (GFR-EPI) < 60 mL/min/1.73 m², with a significantly higher prevalence in banana workers (5.67%; 95% CI: 2.16-9.18%) than melon workers (p = 0.009) and tomato workers (p = 0.044). Ten workers (2.16%) had reduced kidney function (GFR-EPI 60-90 mL/min/1.73 m²). The levels of cystatin C showed less variability (coefficient of variation 46.4%) than those of creatinine (coefficient of variation 67.0%), and cystatin C levels in cases with abnormal and reduced kidney function were significantly different from cases with normal kidney function (p < 0.001).

Conclusions

Surveillance of the health of active farm workers and improvement of working conditions, such as sun protection, adequate hydration, and sufficient breaks, are recommended. The significant differences in cystatin C levels between cases with abnormal and reduced kidney function and those with normal kidney function suggest that cystatin C could be a useful measure for early detection of renal disease.

Urinary concentrations of metals before and after volcanic eruption: a natural experiment surrounding the eruption of Volcán de Fuego, 2018

Volcanic eruptions increase environmental heavy metal concentrations, yet little research has been performed on their extrapulmonary human health effects. We fortuitously collected biological samples in a cohort of Guatemalan sugarcane cutters in the area surrounding Volcán de Fuego before and after the June 2018 eruption. We sought to determine whether stratovolcanic activity was associated with changes in urinary concentrations of heavy metals in a cohort of sugarcane workers. In this exploratory analysis, we found significant increases in urinary arsenic, (β = 1.46, P < 0.0001), cadmium (β = 1.03, P < 0.0001), and lead (β = 0.87, P = 0.003) in participants with residential proximity to Volcán de Fuego as compared to participants farther away, suggesting that volcanic activity could be associated with acute heavy metal exposures. This natural experiment is, to our knowledge, the first of its kind and suggests a need for more research into heavy metal exposure-related health impacts of volcanic eruptions.

Prevalence of Hypertension, Diabetes, and Other Cardiovascular Disease Risk Factors in Two Indigenous Municipalities in Rural Guatemala: A Population-Representative Survey

Background

Nearly 50% of Guatemalans are Indigenous Maya, yet few studies have examined the prevalence of modifiable cardiovascular disease (CVD) risk factors in Indigenous Maya populations. Therefore, we sought to estimate the prevalence of modifiable CVD risk factors in two Indigenous Maya areas in Guatemala.

Methods

We conducted, between June 2018 and October 2019, a population-representative survey of adults aged 18 years and older in two rural Indigenous Maya municipalities in Guatemala. Our primary outcomes were five modifiable CVD risk factors: diabetes, hypertension, obesity, smoking, and alcohol use. We estimated the crude and age-standardized prevalence of each outcome. We also constructed multivariable logistic regression models to assess prevalence over covariates including age, sex, education level, ethnicity, and poverty. Sampling weights adjusted for nonresponse, and appropriate survey commands were used in all analyses.

Results

The crude prevalence of diabetes was 12.5% (95% confidence Interval [CI] 9.6% to 16.1%), hypertension 20.3% (95% CI 17.1% to 23.9%), obesity 23.7% (95% CI 19.4% to 28.6%), smoking 10.7% (95% CI 7.8% to 14.5%), and high alcohol use 0.9% (95% CI 0.5% to 1.6%). Age-standardized prevalence of each outcome was similar to the crude prevalence. The prevalence of multiple CVD risk factors increased between the age groups 18-29 years and 50-59 years before decreasing among older age groups. Men had twenty-fold higher smoking prevalence than women (20.5% vs. 1.2%, respectively) and women had nearly double the age-adjusted prevalence of obesity as men (30.1% vs. 17.0%, respectively).

Conclusion

There is a substantial prevalence of modifiable CVD risk factors in rural, Indigenous populations in Guatemala, in particular hypertension, diabetes, obesity (among women), and smoking (among men). These findings can help catalyze policy and clinical investments to improve the prevention, management, and control of CVD risk factors in these historically marginalized communities.

Where do you live and what do you do? Two questions that might impact your kidney health

In many cases the social determinants of health need to be assessed through their interaction with environmental factors. This review looks at the impact of physical location and occupation of individuals on their kidney health. It examines the effect of living at high altitude on kidney function and the relationship between extreme cold or hot temperatures and the incidence of kidney injury. It reviews as well the many occupations that have been linked to kidney disease in high-income and low-and-middle-income countries. As a conclusion, this overview proposes preventive recommendations that could be individualized based on weather, altitude, socio-economic level of the country and occupation of the individual.