Prevalence of CKD of Unknown Etiology and its Potential Risk Factors in a Rural Population in Sri Lanka

Abstract

Chronic kidney disease of unknown etiology (CKDu) is an emerging form of CKD that predominantly affects working-age adults belonging to agricultural communities living in discrete geographic areas. Disease hotspots have been identified in several countries, including El Salvador, Nicaragua, Guatemala, Mexico, India, Egypt, and Sri Lanka.1 Despite its widespread distribution, the main clinicopathological features of the disease are similar among the different communities.2

In Sri Lanka, CKDu is prevalent in the north-central region and the most affected communities are involved in paddy farming. The prevalence of the disease in this region range from 6% to 15%.3,4 Similar environmental, socioeconomic, and occupational risk factors for CKDu are prevalent in other areas of Sri Lanka, specifically among the sugarcane and paddy-farming communities living in the south-eastern dry zone. Nevertheless, these populations have not been a common focus of epidemiological studies on CKDu.

Although the exact etiology of CKDu is yet to be explained, it is considered a disease of multifactorial origin primarily resulting from environmental factors.5 Renal damage can progress even in the absence of continuous exposure to the risk factors. Therefore, community screening is of utmost importance in the detection and management of CKDu. The conventional markers, serum creatinine (sCr), and urine albumin creatinine ratio (uACR), are not sensitive and specific enough for the diagnosis of CKD or CKDu in their asymptotic early stages. On the contrary, novel markers such as urinary β2 microglobulin (uβ2M), could provide better specificity and sensitivity in the early diagnosis.

A cross sectional study was conducted in 6 selected Grama Niladhari divisions located within the Buttala Divisional Secretariat in Moneragala district in Sri Lanka (Supplementary Figure S1 and S2) (Supplementary Methods) to assess the prevalence of CKD and CKDu, the value of uβ2M as a biomarker in the early diagnosis of CKD or CKDu, and to investigate the association of heavy metals such as cadmium, lead, and arsenic with CKD or CKDu.