Kidneys are vital organs that help maintain stable composition of the blood. They prevent waste, toxins, and extra fluid from building up by filtering all of the blood in the body every 30 minutes. They also regulate levels of electrolytes and make important hormones that control blood pressure, make red blood cells, and keep bones strong.
When the kidneys are diseased or damaged, they can’t properly filter blood. This can lead to health consequences such as heart disease, stroke, anemia, or increased occurrence of infections.
More than one in seven American adults are estimated to have chronic kidney disease (CKD). Some of the main risk factors for CKD are hypertension, heart disease, infections, and diabetes, though genetics and family history can also play a role. However, these risk factors do not explain all cases of CKD.
NIEHS supports research on the environmental factors involved in CKD. These factors include exposure to potentially harmful chemicals, elevated temperatures, and infections.
NIEHS Grantees in this Area Study the Following Health Outcomes
- Chronic kidney disease
- Chronic kidney disease of unknown origin (CKDu)
- End stage renal disease (ESRD)
- Nonalcoholic steatohepatitis (NASH)
- Hepatic and renal injury
- Kidney fibrosis
What NIEHS is Doing
NIEHS-funded researchers are studying how environmental exposures in combination with other factors may affect kidney disease in the U.S. and around the world. Some are working to understand the underlying cellular mechanisms that lead to kidney disease and its progression. Others are following individuals over time, evaluating the potential risk factors associated with developing CKD. Other researchers assess how chemicals impact kidney function.
In addition, a unique epidemic of a type of chronic kidney disease is occurring that cannot be explained by traditional or known risk factors. Referred to here as chronic kidney disease of uncertain etiology (CKDu), it is also known as Mesoamerican Nephropathy (MeN), CKDnt (CKD of non-traditional etiology), CAN (chronic agricultural nephropathy), and CKD-mfo (CKD with multifactorial origin).
CKDu is a major public health problem. NIEHS currently funds research to understand how environmental factors, genetics, and other factors are involved in CKDu. In collaboration with other health organizations, NIEHS supported international workshops to bring experts together to discuss current knowledge and future research priorities to advance understanding of this disease.
Some key projects funded by NIEHS are:
- Cadmium Exposure and Chronic Kidney Disease in a Rural Population
Scientists are studying the association between metals, particularly cadmium, and chronic kidney disease. This study is unique in that the exposures are representative of a rural population without occupational exposure to cadmium, and researchers are building on an existing study so that exposure and disease outcomes can be evaluated over 15 years.
- Cohort Follow-up Study of Children Exposed to Arsenic in Utero and Early Childhood
Researchers are studying children exposed to arsenic early in development to identify biological markers of early life effects on kidneys, in addition to other important health outcomes.
- Etiologic and Mechanistic Factors Underlying Chronic Kidney Disease in Guatemalan Sugarcane Workers
Researchers are studying agricultural workers in Guatemala to identify occupational, environmental, and lifestyle factors that place them at risk for developing CKDu. They are also working to understand the underlying biological mechanisms by which dehydration may contribute to CKDu risk in addition to exposure to chemicals that are known to harm the kidneys.
- Longitudinal Study of Risk Factors for Mesoamerican Nephropathy among Agricultural Workers in El Salvador
A unique epidemic of CKDu disproportionately affects young male agricultural workers in El Salvador. Researchers are investigating the role of exposure to herbicides, metals, and heat stress on the risk of CKDu. This project also aims to identify biological markers of kidney injury that may be useful for early detection and treatment of kidney injury.
- Occupational Heat Exposure and Gene-Environment Interactions in Mesoamerican Nephropathy
Researchers are examining occupational heat exposure in a group of agricultural and non-agricultural workers. They are investigating the relationships between heat and both kidney injury and kidney function, and testing for potential interactions between underlying genetics and environment exposures. The findings will help identify individuals who are most at risk for the disease, which will inform strategies to prevent new cases.
- Role of SMOC2 in Kidney Fibrosis
Kidney fibrosis occurs when excess fiber-like connective tissue spreads over and through the kidneys, which can lead to scarring and ultimately renal failure. Scientists are studying how a gene found to be critically involved in kidney fibrosis, called SMOC2, regulates the initiation and progression of the disease. They are further investigating whether genetic or pharmacological therapies that target SMOC2 can improve health outcomes.
For additional information on what NIEHS grantees are doing, see our Kidney Disease Grantees webpage.
Bonnie R. Joubert, Ph.D.
Health Scientist Administrator
P.O. Box 12233Mail Drop K3-12Durham, N.C. 27709