Sialic Acid Levels In Subclinical Hypothyroid And Subclinical Hyperthyroid Patients Of coastal Karnataka Region

INTRODUCTION: Sialic acid (SA) is a N- or O-substituted derivative of neuraminic acid, and it is found as a terminal component of glycolipids and glycoproteins. Excessive ROS can target oligosaccharides in protein structures and change their biological functions by breaking SAs located in the terminal position. Additionally, excessive levels of TSH, which can be seen in subclinical hypothyroidism, was shown to cause increased production of ROS which may further result in breaking of SA located in terminal position. Thus, this study is conducted to measure sialic acid level in patients with subclinical hypothyroidism and subclinical hyperthyroidism. OBJECTIVES: To estimate and compare sialic acid in normal, subclinical hypothyroidism and hyperthyroidism patients. MATERIALS AND METHODS: Total 60 serum samples were obtained and was divided into 3 groups(20 normal controls, 20 subclinical hypothyroidism and 20 subclinical hyperthyroidism). Sialic acid level was estimated by spectrophotometric method at 530nm. Statistical analysis was done using ANOVA and Pearson's correlation. RESULTS: Mean TSA was found to be highest in the patient group with subclinical hypothyroidism (87.2 [+ or -] 29.4) compared with the control group (77.5 [+ or -] 23.9) and patients with subclinical hyperthyroidism (61.2 [+ or -] 15.7), but statistically were not significant. Further a larger sample size may be required to obtain reliable results. CONCLUSION: Increased sialic acid in the serum indicates oxidative stress. The patients with subclinical hypothyroidism have the highest serum sialic acid levels, indicating greater oxidative stress in this group as compared to normal controls and subclinical hyperthyroidism patients. KEY WORDS: Sialic acid, glycolipids, glycoproteins, TSH