Chronic kidney disease of unknown origin in agricultural communities: beyond tropical mist?

Environment and chronic kidney disease in farmers

The prevalence of chronic kidney disease (CKD) has been on the rise worldwide. Epidemiological studies performed primarily in Central America and South Asia have reported high prevalence of CKD among young and middle-aged men working in agricultural communities. The clinical features do not appear linked to any classical CKD risk factors, such as hypertension, diabetes, or chronic nephritis. The disease develops and progresses as interstitial nephritis, without showing noticeable symptoms or high levels of proteinuria. Pathologically, the disease essentially represents chronic interstitial nephritis and is termed chronic interstitial nephritis in agricultural communities (CINAC). The potential causes of CINAC include: (1) heat stress-related factors associated with increased ambient temperatures resulting from global warming; and (2) factors connected with exposure to agrochemicals and/or pesticides. Global warming and environmental pollution will undoubtedly pose a significant health risk to farmers, and heat stress during farm work could easily result in the development and progression of CKD. Japanese agricultural regions evidently will not be spared from global environmental changes. For future epidemiological studies, researchers should establish a more comprehensive analytical method that can incorporate additional risk-factor variables, such as occupational history (including agricultural work) and ambient temperature.