Decreased kidney function among agricultural workers in El Salvador.
BACKGROUND
An epidemic of chronic kidney disease of unknown cause has emerged along the Pacific coast of Central America, particularly in relatively young male sugarcane workers. In El Salvador, we examined residence and occupations at different altitudes as surrogate risk factors for heat stress.


METHODS
Cross-sectional population-based survey.


METHODS
Populations aged 20-60 years of 5 communities in El Salvador, 256 men and 408 women (participation, 73%): 2 coastal communities with current sugarcane and past cotton production and 3 communities above 500 m with sugarcane, coffee, and service-oriented economies.


METHODS
Participant sex, age, residence, occupation, agricultural history by crop and altitude, and traditional risk factors for CKD.


RESULTS
Serum creatinine (SCr) level greater than the normal laboratory range for sex, estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, and proteinuria categorized as low (protein excretion ≥ 30-< 300 mg/dL) and high grade (≥ 300 mg/dL).


RESULTS
Of the men in the coastal communities, 30% had elevated SCr levels and 18% had eGFR < 60 mL/min/1.73 m2 compared with 4% and 1%, respectively, in the communities above 500 m. For agricultural workers, prevalences of elevated SCr levels and eGFR < 60 mL/min/1.73 m2 were highest for coastal sugarcane and cotton plantation workers, but were not increased in sugarcane workers at 500 m or subsistence farmers. Women followed a weaker but similar pattern. Proteinuria was infrequent, of low grade, and not different among communities, occupations, or sexes. The adjusted ORs of decreased kidney function for 10-year increments of coastal sugarcane or cotton plantation work were 3.1 (95% CI, 2.0-5.0) in men and 2.3 (95% CI, 1.4-3.7) in women.


CONCLUSIONS
The cross-sectional nature of the study limits etiologic interpretations.


CONCLUSIONS
Agricultural work on lowland sugarcane and cotton plantations was associated with decreased kidney function in men and women, possibly related to strenuous work in hot environments with repeated volume depletion.
Faculty of Chemistry and Pharmacy, University of El Salvador, Ciudad Universitaria, San Salvador, El Salvador.
Sandra
S
Peraza
Catharina
C
Wesseling
Aurora
A
Aragon
Ricardo
R
Leiva
Ramón Antonio
RA
García-Trabanino
Cecilia
C
Torres
Kristina
K
Jakobsson
Carl Gustaf
CG
Elinder
Christer
C
Hogstedt
D000328:Adult; D000383:Agriculture; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D004544:El Salvador / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D018882:Heat Stress Disorders / Q000150:complications; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors
D003404:Creatinine