Prevalence of chronic kidney disease of unknown etiology (CKDU) and its association with exposure to Cadmium (Cd) in rural population in Monaragala District, Sri Lanka

During the past few decades, chronic kidney disease of uncertain etiology (CKDu) has become an emergent public health concern among dry climatic zone farming communities in Sri Lanka. Due to the highest Burden of CKDu, most of the epidemiological studies, have focused on paddy farming communities in North Central Province, and the burden of CKDu within the outskirts ofcharacteristicszone remains under-reported. Even though Moneragala  district is a highly agricultural region within the dry zone in Sri Lanka, to date no study has  performed a systematic evaluation of the prevalence of CKDu among the inhabitant farming  communities. Particularly this region resembles similar socioeconomic determinants and  agricultural practices as CKDu endemic regions, and the farming communities are likely to  have exposure to potential risk factors of CKDu that make them more susceptible to renal injury. Hence, the main focus of this study was to assess the prevalence of CKD/CKDu  among selected farming communities in Moneragala District, along with an assessment of the applicability of urinary β2 microglobulin (B2M) as a biomarker for early detection of CKDu susceptibility, and assessment of exposures to selected heavy metals and metalloids. A total of 647 individuals from six selected Grama niladhari divisions; Gonaganara (GA).  Kumaragama (KM), Yudaganawa (YU). Mahasenpura (MP), Rahatahangama (RH) and  Pelwatta (PL) participated in the study. The onsite medical examination was performed with  questionnaire-based data collection, and urine samples and blood samples were collected for the analysis. Serum creatinine (SCr), urinary albumin creatinine ratio (uACR), estimated glomerular filtration rate (eGFR, CKD EPI equation), and urinary B2M were used as the  markers of renal function. Determination of creatinine and albumin was performed using a clinical chemistry analyzer, while enzyme linked immunosorbent assay kits were used for  quantification of urinary B2M. Heavy metal analysis was performed with Inductive Coupled Plasma Mass Spectroscopy (ICP-MS).  Among the participants, 79% were farmers and 58% were males. The mean age was  44.1±0.7 years for males and 47±0.9 years for females. Cases with either eGFR