Morphometry of the Thyroid Gland and its Correlation with Various Anthropometric Parameters in Asymptomatic Indian Young Adults- A Cross-sectional Study

Abstract

Introduction: The volume, shape and size of the thyroid gland varies with age and sex. Morphometry of the thyroid with particular emphasis on its volume is an essential and most important parameter which must be evaluated. It is helpful in the diagnosis and monitoring of various thyroid diseases. Aim: To evaluate the volume of the normal thyroid gland and thickness of thyroid isthmus by ultrasonography and to observe its correlation with sex, height, weight, Body Mass Index (BMI), Neck Circumference (NC), Body Surface Area (BSA) and Lean Body Mass (LBM) in asymptomatic subjects. Materials and Methods: This was a cross-sectional study which included 100 volunteers (50 males and 50 females) from among 1st year MBBS/BDS students, who were attending classes in the Department of Anatomy, King George’s Medical University, UP, Lucknow during April 2019-March 2020. Detailed information (sex, height, weight, NC) was recorded for every subject. Also, BMI, BSA and LBM were calculated for each. Thereafter, ultrasound was performed to measure the dimensions of the thyroid gland. The statistical analysis was done using Statistical Package for Social Sciences (SPSS) version 24. Student t-test (to test the significance of two means), Analysis of Variance (ANOVA) and bivariate correlation using Karl Pearson correlation coefficient (r) were used as statistical tests; and p-value <0.05 was regarded as statistically significant. Results: The mean volume of the right lobe of the thyroid gland was found to be 3.89±1.28 mL and of left side was 3.59±1.09 mL. The mean total volume of thyroid gland was 7.48±2.22 mL. In males, it was found to be 8.32±2.30 mL and in females, it was 6.63±1.78 mL. The mean thickness of thyroid isthmus was 2.09±0.66 mm. The correlation of total thyroid volume with all the anthropometric parameters was significant, while correlation of isthmus thickness was statistically significant with LBM and NC only. Conclusion: Presentstudy provides a normative reference data for the physicians and surgeons to consider while dealing with everyday cases of thyroid hypoplasia or goiter in their Outpatient Department (OPD)/Inpatient Departments (IPDs).