Biochemical Analysis of Liver Function in Individuals Affected and Unaffected by Dental Fluorosis in Endemic Fluoride Rural Areas of YSR Kadapa District, AP, India: A Cross-sectional Study

Abstract

Introduction: Fluoride is known to affect the nervous system, kidneys, liver, and gastrointestinal system, in addition to teeth and bones, when consumed in amounts exceeding 1 ppm per day over a prolonged period. YSR Kadapa district has been identified as one of the districts with endemic fluoride areas in Andhra Pradesh, India, by the Central Groundwater Board of India. Aim: To assess the toxic effects of fluoride on liver function in individuals affected and unaffected by dental fluorosis, who consume high levels of fluoride in water, in the endemic fluoride rural areas of YSR Kadapa district. Materials and Methods: A cross-sectional study was conducted in six villages of YSR Kadapa district, where the drinking water has elevated fluoride content. A total of 320 subjects were selected as study participants. The subjects were divided into two groups based on age and dental fluorosis: Group A, aged between 21 and 40 years, and Group B, aged between 41 and 60 years. Subjects of each group were further sub-grouped according to presence or absence of fluorosis. The selected subjects were screened for dental fluorosis, and Groups A and B were further divided into subgroups based on the presence or absence of dental fluorosis. Blood samples were collected from the participants to assess liver function using serum levels of liver function markers such as total bilirubin (direct and indirect), Serum Glutamic Oxaloacetic Transaminase (SGOT), Serum Glutamate Pyruvate Transaminase (SGPT), and Alkaline Phosphatase (ALP). Water and urine samples were also tested for fluoride levels using a fluoride ion meter. Statistical significance was determined using the t-test. Results: The mean fluoride levels in the water samples from the study areas ranged from 1.55±0.30 mg/L to 4.10±0.20 mg/L, and the urinary fluoride levels in the urine samples ranged from 0.54±0.46 mg/L to 2.13±0.845 mg/L. Among the study subjects, 60.6% (194) were affected by dental fluorosis, with 58.66% (88) belonging to Group A and 62.35% (106) belonging to Group B. There was no statistically significant difference in liver function markers in the serum between subjects with dental fluorosis and those without dental fluorosis in both groups (p>0.05), and the levels were within the normal reference range. Conclusion: This study found no impaired or altered liver function in adults affected by dental fluorosis and adults unaffected by dental fluorosis who consumed water with high levels of fluoride in the YSR Kadapa district.