Blood Cadmium Levels In Adolescents And Its Correlation With Renal Parameters

Abstract

Early-life exposure to low levels of heavy metals has far-reaching consequences later in life, including the development of hypertension, kidney disease, and renal dysfunction. Adolescents have heightened susceptibility to absorb heavy metals compared to adults which is attributed to biological and developmental factors. The highest concentrations of cadmium (Cd) are found in the kidneys, mainly in the proximal tubules, giving rise to dose-dependent toxicity by affecting cellular and functional integrity. Most of our knowledge concerning the health effects of toxic heavy metals largely stems from studies conducted on populations with relatively high exposure.

There is a paucity of data in India concerning chronic low environmental exposure to these metals and their effects on adolescent health. 116 adolescents aged 10 to 18 years were included, with consent and assent obtained from parents and adolescents. A cross-sectional study was conducted over 18 months. The questionnaire included information about demographics and exposure to risk factors of cadmium exposure. Blood samples were processed for cadmium levels and serum creatinine levels. Mid-stream urine samples were centrifuged and processed for urine retinol binding protein and albumin/creatinine ratio. All recruited adolescents were evaluated by a pediatrician and pediatric nephrologist.

Adolescents were sensitized about heavy metal exposure and prevention through the dissemination of pamphlets and counseling of parents and adolescents. In our study, among 116 participants, the blood cadmium level was found to be toxic in 4.31% (N=5) of cases. Cadmium levels were assessed in relation to serum creatinine (p = 0.387), urine albumin/creatinine ratio (p = 0.387), and urine retinol-binding protein (p=0.128). Risk factors in patients with toxic levels of cadmium included living near a factory (p=<0.001), with the most common type being a clothes factory (p=<0.001). No symptoms of cadmium toxicity were present. Among the 5 children with toxic levels of cadmium, the correlation between BMI and centile was between the 3rd to 50th centile (p=<0.036), which was significant. This study reveals that 4.31% of the study population had toxic levels of cadmium in their blood. All children with toxic levels of blood cadmium lived near a factory, with the majority being clothes factories. Most of the children with toxic levels of cadmium had a normal BMI. Cadmium levels did not show significant correlation with serum creatinine or urine albumin/creatinine ratio.