#3096 Exploratory population-based screening of kidney function and heavy metal water source levels in a highly incident CKDu area in Guatemala

Abstract

Abstract Background and Aims Chronic kidney disease of unknown etiology (CKDu) has exponentially increased in the rural areas of the Pacific Coast in Central America. A multifactorial etiology has been postulated including exposure to environmental nephrotoxins such as heavy metals. The Pacific Coast of Guatemala has a volcanic topography with a high content of heavy metals, and the rural communities use ground water as their regular drinking consumption. Since the highest age group affected by CKDu are young adults, we postulated an exposure during childhood impacting later in life. We aim to identify changes in kidney function in children and adolescent healthy population from a highly incident CKDu area, and the heavy metal levels from water sources as a hypothesis generation exploratory study. Method We performed a population-based cross-sectional study of children and adolescents (below 17 y/o) from La Democracia municipality that were randomly chosen using Epidat software 3.1 from 10 different local schools from March 2019 to March 2020. The study was approved by external ethics board committee external-independent research ethics board committee. Subjects were excluded if they had known diagnosis of CKD, kidney replacement therapy or hypertension. The screening was performed in three different steps including a background assessment questionnaire, clinical assessment, and biochemical testing including creatinine from blood drop using StatSensor XpressTM to calculate estimated glomerular filtration rate (eGFR), urine dipstick, urinary creatinine, and protein. We measured arsenic (33As), cadmium (48Cd), mercury (80Hg), and lead (82Pb) in 21 water wells around the 10 screened schools, while only arsenic (33As), cadmium (48Cd) and mercury (80Hg) were measured in the urine of a small subset of the samples (data not shown in the results). Results A total of 508 randomly selected subjects’ and parents’ consent for screening but only 506 completed assessment. The median age was 14 y/o (IQR 11-17) 50% being female, with a close to 30% of the sample having obesity. The blood pressure was abnormal in 28% of the sample and at least 30% of them had an abnormal urine dipstick. The overall eGFR was 98, being the 25th%tile close to 83 ml/min/1.73 m2 BSA (Tables 1 and 2). Water sources showed higher than recommended levels of all heavy metals tested. Interestingly, the schools “Campiña” showed high levels of Arsenic and Cadmium in water sources, being the subjects tested coincidentally among the lowest eGFR of sample. Conclusion CKDu is an entity devastating low-resourced communities with young adults being the most affected. A likelihood for a link of early exposure needs to be further explored. Addressing the postulated hypothesis are key to implement preventive strategies, including screening earlier in life such as pediatric population.