Chronic interstitial nephritis of nontraditional causes in Salvadoran agricultural communities.

In El Salvador, a form of chronic kidney disease (CKD) of nontraditional causes (CKDnt) affecting farmers is being reported. Its behavior has been epidemic and is responsible for tens of thousands of deaths. This article summarizes the results obtained from a series of studies conducted to identify the epidemiology and clinical behavior of this disease, proposing a case definition and an etiopathogenic hypothesis. Methods included a survey of CKD in agricultural communities studying 2,388 people ≥ 18 years and 1,755 < 18, a descriptive clinical study followed by histopathological assessment conducted in 46 possible cases of CKDnt ≥ 18 years, and a national survey to study the prevalence of CKD and associated risk factors in 4,817 participants ≥ 20 years followed by a nested case-control study. In the agricultural communities, the prevalence of CKD in adults was 18% (men: 23.9%, women: 13.9%), 26.8% in agricultural workers (non-agricultural 13.8%), CKDnt accounted for 51.9% of cases. CKD in the population < 18 years was 3.9% (mean estimated glomerular filtration rate > 160 mL/1.73m2). The national CKD prevalence was 12.6% (urban: 11.3%; rural: 14.4%; males: 17.8%, females 8.5%), and CKDnt was only 3.8%; with associations between CKD and exposure to agrochemicals. The clinical study revealed the presence of markers of kidney damage (A3 albuminuria: 80.4%; ß2-microglobulin: 78.2%), urine electrolyte anomalies (100% hypermagnesuria, 45.7% hypernatriuria, 43.5% osmotic polyuria), abnormal osteotendinous reflexes (45.7%), sensorineural hearing loss (56.5%), and damage of the tibial arteries by Doppler imaging (66.7%). Biopsies revealed a chronic tubulointerstitial nephropathy. The etiopathogenesis of CKDnt is possibly multifactorial, including environmental contamination by agrochemicals, heat stress, and dehydration.

Epidemiological characteristics of chronic kidney disease of non-traditional causes in women of agricultural communities of El Salvador.

INTRODUCTION: In El Salvador end-stage renal disease (ESRD) was the first cause of hospital mortality overall, the first cause of hospital deaths in men, and the fifth cause of hospital mortality in women in 2013. In agricultural communities, chronic kidney disease (CKD) occurs predominantly in male agricultural workers, but it also affects women to a lesser degree, even those who are not involved in agricultural work. Internationally, most epidemiological CKD studies emphasize men and no epidemiological studies focused exclusively on women. OBJECTIVE: To describe the epidemiological characteristics of CKD in females in agricultural communities of El Salvador. METHODS: A cross-sectional epidemiological study was carried out in 2009 - 2011 based on active screening for CKD and risk factors in women aged ≥ 18 years in 3 disadvantaged populations of El Salvador: Bajo Lempa (Usulután Department), Guayapa Abajo (Ahuachapán Department), and Las Brisas (San Miguel Department). Epidemiological and clinical data were gathered through personal history, as well as urinalysis for renal damage markers, determinations of serum creatinine and glucose, and estimation of glomerular filtration rates. CKD cases were confirmed at 3 months. RESULTS: Prevalence of CKD was 13.9% in 1,412 women from 1,306 families studied. Chronic kidney disease of nontraditional causes (CKDu), not attributed to diabetes mellitus, hypertension, or proteinuric primary glomerulopathy (proteinuria > 1 g/L) was 6.6%. Prevalence of chronic renal failure was 6.8%. Prevalence of renal damage markers was 9.8% (microalbuminuria (30 - 300 mg/L) 5.7%; macroalbuminuria (> 300 mg/L) 2%; and hematuria, 2.1%. Prevalence of chronic kidney disease risk factors was: diabetes mellitus, 9.3%; hypertension, 23%; family history of CKD, 16%; family history of diabetes mellitus (DM), 18.7%; family history of hypertension (HT), 31.9%; obesity, 21%; central obesity, 30.7%; NSAID use, 84.3%; agricultural occupation, 15.2%; and contact with agrochemicals, 33.1%. CONCLUSIONS: CKD in women of Salvadoran agricultural communities is associated with disadvantaged populations, traditional (DM, HT, obesity) and non-traditional causes (environmental and occupational exposure to toxic agents and inadequate working conditions). Our results reinforce the hypotheses emerging from other studies, suggesting a multifactorial etiopathology including environmental and occupational nephrotoxic exposure.