BASELINE CHARACTERISTICS OF THE CHILDHOOD KIDNEY HEALTH IN UDDANAM (CHIKU) COHORT

Introduction:

Chronic kidney disease of unknown etiology (CKDu) primarily affects young adult agricultural workers in specific geographic hotspots, including in the Uddanam region of Andhra Pradesh, India. In addition to unknown etiology, the timeframe of when CKDu-related kidney injury begins is also unknown and its identification is crucial for earlier, more effective medical management. The overall goal of the ChiKU cohort study is to evaluate whether CKDu-related kidney injury begins before adulthood. This ChiKU sub-study aims to assess the baseline characteristics of children living in Kaviti Mandal, which has the highest prevalence of adult CKD (25.4%; Gummidi et al 2020) within Uddanam.

Methods:

This is a cross-sectional sub-study of the school-based ChiKU cohort describing self-reported environmental exposures, anthropometrics, diet, family history, and 2 kidney health markers in children: blood pressure (BP) and first-morning urine protein levels. Right upper arm BP was measured on an oscillometric machine. Urine samples were kept on ice and dipped within 4 hours of collection. We included 8th and 9th graders who had lived in Kaviti Mandal for at least 5 years. Exclusion criteria were pre-existing diagnoses of CKD, diabetes, and hypertension. Written consent and assent were obtained from parents and students, respectively.

Results:

From July 1 to August 19, 2024, the ChiKU study enrolled 350 students living in Kaviti Mandal (Figure 1). This preliminary analysis includes the first 149 students enrolled: 75 boys and 74 girls with a mean age of 13.4 years (SD 1; Table 1). Fifty-one students (34%) had parents with occupations in farming or agriculture and on average spent 2 hours per week (SD 3.6) helping their parents in these occupations. Of these 51 children, 24 (47%) reported that their parents used pesticides. Reverse osmosis water was most commonly used for drinking water (40%). Public tap water (56%) was most commonly used for cooking water. Children had an average daily sun exposure of 50 minutes (SD 20). The children's diets included vegetables 2 days per week (SD 1), fruit 3 days per week (SD 1), and non-vegetarian food 4 days per week (SD 1). Twenty-four children (16%) had a parent, sibling, or grandparent with kidney disease. Twenty-seven children (18%) had a body mass index z-score more than -2 SDs from the mean (Figure 2). Five children (3%) had systolic blood pressure (SBP) >90th to 95th percentile, and 1 child (0.7%) had SBP >95th percentile but less than 95th percentile +12mmHg. Seven children (5%) had diastolic blood pressure (DBP) between 90th and 95th percentile (Figure 3). Twelve children (8%) had trace protein in the first morning urine, and 6 (4%) had 1+ protein. No children had +1 protein and SBP or DBP greater than 90th%ile.

Conclusions:

The incidence of elevated BP and proteinuria in this ChiKU subset analysis was low. However, given that the prevalence of childhood kidney impairment in Andhra Pradesh is reported to be 29.6% (Singh et al 2024), ongoing ChiKU work will focus specifically on measuring the kidney function of children. Our results show that children are exposed to suspected environmental risk factors for CKDu before entering the workforce, including pesticides, heat, and waterborne exposures, and suggest undernutrition as an additional risk factor for lifetime development and progression of CKD.

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.