[Proteinuria and chronic renal failure in the coast of El Salvador: detection with low cost methods and associated factors].

OBJECTIVES: El Salvador has high mortality rates from chronic kidney disease (CKD). The actual prevalence and causes remain unknown and local resources are scarce. Previous studies have suggested very high prevalence in specific populations: adult male farmers living in the coastlands, with high frequency of pesticides exposure and alcohol consumption. This population has low incomes and poor healthcare accessibility. Our aim was to detect CKD cases in this population using proteinuria as an inexpensive initial screening, investigating associations with those characteristics and comparing them with another population from the midlands.

METHODS: We performed a transversal study on volunteer men from both regions, taking into consideration the variables: age, farmer living, pesticides, exposure, alcohol consumption, medical past history, blood pressure level, glycemia and proteinuria in a random urine sample. Coastland men with proteinuria were additionally screened for CKD measuring hemoglobin and serum creatinine levels. Finally, we employed a logistic regression model, and Perason's Chi2 to investigate associations between those variables and the presence of proteinuria or CKD.

RESULTS: We included 291 men from the coastlands and 62 from the midlands: 35 and 16% off the total male population from their respective communities. Proteinuria (table I) was found in 133 (45.7%) and 8 cases (12.9%). CKD was diagnosed in 37 (12.7%) coastland men (table III), with mean creatinine 2.64 +/- 2.5 mg/dl, hemoglobin 12.32 +/- 1.9 g/dl and 81.1% with proteinuria 15-30 mg/l. Only 14 (37.8%) out of those 37 CKD patients featured diabetes or hypertension, while the remaining (62.2%) did not appear to have a clear-cut cause for CKD. Only one of them was formerly diagnosed with CKD. Farmer living, pesticides exposure and alcohol consumption were found to be very common characteristics in both populations, and were not associated to the presence of proteinuria or CKD (table II and III) DISCUSSION: The prevalence of CKD within the adult male farmers from the Salvadoran coastlands is remarkably high: at least 12.7%. There is a large number of undiagnosed cases, but they can be easily detected with inexpensive methods. This high prevalence is not completely explained by usual CKD causes like diabetes or hypertension. In addition, pesticides exposure and alcohol consumption may not be related, too. The disease is moderate, non symptomatic and has fairly mild proteinuria, possibly from interstitial origin. Further research is required to investigate environmental, occupational and hereditary factors, and to determine the real extent of the problem.