Describing Natural History and Exploring Risk Factors for Kidney Function Decline in Persons With CKD of Uncertain Etiology in Sri Lanka

Introduction

Chronic kidney disease of uncertain etiology (CKDu) is a leading cause of death of adults in Sri Lanka's dry region.

Methods

We initiated the Kidney Progression Project (KiPP) to prospectively follow 292 persons with Chronic Kidney Disease Epidemiology Collaboration estimated glomerular filtration rate (eGFR) 20 to 60 ml/min per 1.73 m² living in a CKDu endemic area. Using data from 3-year follow-up, we assessed kidney function decline (>30% from baseline eGFR), and the composite outcome of >30% eGFR decline, eGFR <15 ml/min or death, and explored the association of the 2 outcomes with baseline demographic, residential, and clinical parameters accounting for baseline eGFR.

Results

Median eGFR at enrollment was 28 ml/min among 71 women; 30 ml/min among 221 men; 91% to 99% had trace or no proteinuria during follow-up. At enrollment, median serum sodium, uric acid, and potassium were 143 mmol/l, 6.3 mg/dl, 4.5 meq/l, respectively among women; and 143 mmol/l, 6.9 mg/dl, 4.3 meq/l among men. Mean slope of eGFR decline was -0.5 (SD 4.9) ml/min/yr. In exploratory analyses, men with greater years of education and those living in northern region of the study area experienced lower likelihood of disease progression (hazard ratios [HR] 0.87 [0.77-0.98] per additional year and 0.33 [0.12-0.89] for northern versus other subregions, respectively). There was a suggestion that men drinking well water had higher likelihood and men living further away from reservoirs had lower likelihood of >30% decline in eGFR (HR 2.07 [0.95-4.49] for drinking well water versus not, and HR 0.58 [0.32-1.05] per kilometer distance, respectively).

Conclusions

The overall rate of kidney function decline was slow in this CKDu cohort, similar to other nonalbuminuric CKD, and event rates were similar among men and women. Further etiologic investigations could focus on specific residence locale and water use.

MO388: A Critical Evaluation of Anthropological, Biological and Geo-Environmental Factors on Chronic Kidney Disease of unknown Aetiology in Affected Area Against Unaffected Area

BACKGROUND AND AIMS

Chronic kidney disease of unknown etiology (CKDu) has been a critical health issue among the farming communities of Sri Lanka for decades [1]. However, the distribution of CKDu in Sri Lanka is geographically significant by representing endemicity on its own [2]. This study was conducted to identify the anthropological and geo-environmental characteristics of CKDu, in relation to the biochemical profile between known CKDu endemic and non-endemic communities.

METHOD

A total of 214 male individuals from Wilgamuwa (endemic) and 102 male individuals from Mathurata (non-endemic) of 30–60 years were recruited. For each participant, blood pressure (BP), random blood sugar (RBS), serum creatinine (μmol/L) and serum cholesterol (mg/dL) were tested using standard methods. Anthropological data including population structure, farming behaviour and poverty statistics were obtained from the respective government officials. Geo climatic data including elevation, monthly average (Avg.) temperature (°C), monthly Avg. rainfall (mm), monthly Avg. humidity (%) and monthly Avg. UV intensity, monthly Avg. Sun hours (hrs.) were obtained for the two study areas.

RESULTS

Most striking difference between two communities is significantly high serum creatinine (t = 3.5175, P = 0.0005) in male individuals between the age category of 40 to 65 years in CKDu endemic area (M = 109.00, SD = 66.41) in comparison to non-endemic participants in the same age category from non-endemic area for CKDu (M = 85.41, SD = 18.78). The non-endemic area for CKDu, Maturata was colonized since the 16th century due to natural population migrations while the colonization of Wilgamuwa was implemented in a more drastic manner, parallel to the green revolution after the 1960s. Mathurata is located at a high elevation level of 976 m, whereas Wilgamuwa is located at an elevation level of 528 m. In comparison with meteorological variables for the year of 2019, monthly Avg. rainfall (mm) (P = 0.005), monthly Avg. temperature (°C) (P = 0.001), monthly Avg. cloud cover (%) (P = 0.004), monthly Avg. Humidity (%) (P = 0.007), monthly Avg. Sun hours (hrs) (P = 0.001) were highly significant between the two geographical areas.

CONCLUSION

We report comparably adverse weather conditions, higher exposure to natural and artificial toxic exposure in genetically and behaviourally vulnerable group in the CKDu endemic area in comparison with non-endemic area for CKDu.