"Revaluation of cut off values of TSH based on correlation of biochemical and clinical parameters in Hypothyroid and Biochemically Thyroid patients attending the tertiary care hospital of Bihar-A cross sectional study."

Hypothyroidism is one amongst the most mainstream endocrine disorders worldwide. The prevalence of hypothyroidism in India is 10-11%. The recent studies reflect the significant burden of over 42 million population in INDIA alone suffering from thyroid disease. Hypothyroidism is a common cause of secondary dyslipidaemia and subsequent cardiovascular risk. These patients exhibit significantly high serum total Cholesterol, LDL-C and Triglyceride. Studies done in patients of subclinical hypothyroidism (SCH) have shown a similar picture though less pronounced. Studies in the past have shown serum TSH above 1.5 or 2 mIU/L (Biochemically euthyroid- BET) linked with increased hypothyroid associated lipid and inflammatory pathologies thus increasing the morbidity and mortality. 

Subclinical hypothyroidism (SCH) suggests mild thyroid failure with raised TSH in combination with serum free T3 and T4 within normal reference range. The prevalence of SCH is 4-15% depending on the population under study. SCH is more rampant than frank hypothyroidism. Moreover, the conversion rate of SCH with positive TPO antibody is around 6% per year, hence early screening and diagnosis of the concerned populations is the prime need of the hour to prevent further elevation in serum TSH and the clinical implications that follows.

The most common cause of SCH is autoimmune thyroiditis with raised anti-TPO abs. Controversially high biochemically euthyroid (high BET) subjects with serum TSH>3.01-<5.0 mIU/L were found to have high anti-TPO ab titres and higher rates of progression to overt hypothyroidism in spite of TSH being within normal cut offs. Thus, the core of the debate is to trail down the upper limit of TSH reference range. The aim of the present study is to see if biochemically euthyroid, subclinical hypothyroid and overt hypothyroid differ significantly with respect to their lipid profile, anti-TPO, anti-TG, hsCRP levels in conjugation with TSH ranges. And if yes, the addition of above tests for early diagnosis and prompt initiation of thyroid hormone replacement in such patients could possibly save extra expenditures on long-term diseases and it’s attending morbidities. Study design:  A Hospital based cross-sectional study. An informed consent would  be taken from all the participants of this study after they have been briefed about information pertaining to this study. The study population will be recruited from the Dept. of Medicine, AIIMS, Patna. The study will be carried out in the Dept. of Biochemistry, AIIMS, Patna. Data shall be collected from untreated patients of age group 18-65 years, presenting to the hospital with non-specific symptoms suggestive of hypothyroidism. They would be advised thyroid and lipid profile, hsCRP, anti-TPO, anti-TG apart from routine filling of questionnaires. The study group will be classified as HT(HYPOTHYROID), SCH and BET ( BIOCHEMICALLY EUTHYROID)based on the thyroid profile. After data collection , the results will be statistically analysed.