Q) I’ve heard a lot of talk about all the kidney problems that the sugarcane workers in Central America have. Does anyone know why this is happening?
The unusually high rates of chronic kidney disease (CKD) among sugarcane workers in Central America have been a subject of great interest since National Public Radio (NPR) aired a special on this topic.3 There has been a rising epidemic of CKD in otherwise healthy male farm workers (ages 20 to 50), particularly those who harvest sugarcane.4,5 It has been hypothesized that recurrent episodes of acute kidney injury (AKI)—related to dehydration, volume depletion, pollutants, and rhabdomyolysis with inflammatory stress—are the underlying cause.5
Sugarcane harvesters typically work nine-hour days, six days per week, in extremely high temperatures and while wearing heavy, hot clothing. Each worker cuts approximately 10 tons of sugarcane daily, since they are paid based on cutting volume. Workers drink between five and 10 L of water during their shifts.
Santos et al designed a study to prospectively examine the effects of burnt sugarcane harvesting on renal function in healthy male farm workers. Twenty-eight men (ages 19 to 39) with no CKD risk factors (diabetes, smoking, obesity, hypertension, illicit drug or alcohol use) were followed for eight months from preharvest to postharvest. Blood samples were collected at the beginning and at the end of the workday and preharvest and postharvest season.5
Preseason lab values were normal in all 28 men. But postseason, all workers had elevated creatinine levels, with five meeting the criteria for AKI (see Table at left).5,6
Santos and colleagues identified potential causes for AKI in this population. These included
• Dehydration and volume depletion (episodes of tachycardia, increased urine density, lower urinary/serum sodium, higher hematocrit)
• Rhabdomyolysis (increased creatine kinase at the end of each workday)
• Systemic inflammation (increased white blood count, neutrophils, lymphocytes, and monocytes during the workday—possibly indicative of an inflammatory burst)
• Other factors (burning of the sugarcane releasing unknown nephrotoxic substances; unreported NSAIDs use)5
Compared to workers who showed early signs of CKD, those who developed frank AKI were more likely to have hyponatremia. Recommendations to reduce the problem include consumption of water/salt hydrating drinks, use of appropriate clothing, work-hour limitations, and changes to payment structures (ie, from a volume system to an hourly or daily system). Furthermore, education on the need to avoid alcohol, illicit drugs, and NSAIDs during the harvest season should help to decrease incidence of AKI among these workers.
Elizabeth C. Evans, RN, MSN, CNP, DNP
Renal Medicine Associates, Albuquerque, New Mexico
REFERENCES
1. Ayuk J, Gittoes N. Contemporary view of the clinical relevance of magnesium homeostasis. Ann Clin Biochem. 2014;51(Pt 2):179-188.
2. Firouzi A, Maadani M, Kiani R, et al. Intravenous magnesium sulfate: new method in prevention of contrast-induced nephropathy in primary percutaneous coronary intervention. Int Urol Nephrol. 2015;47(3):521-525.
3. Beaubien J. Mysterious kidney disease slays farm workers in central America. National Public Radio; 2014. www.npr.org/blogs/health/2014/04/30/306907097/mysterious-kidney-disease-slays-farmworkers-in-central-america. Accessed April 1, 2015.
4. Almaguer M, Herrera R, Orantes CM. Chronic kidney disease of unknown etiology in agricultural communities. MEDICC Rev. 2014;16(2):9-15.
5. Santos UP, Zanetta DMT, Burdmann EA. Burnt sugarcane harvesting is associated with acute renal dysfunction. Kidney Int. 2015;87(4):792-799.
6. Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney Int Suppl. 2012;2:1-138.