Comparison of the Average Dose of Thyroid Replacement Among Genders & Across Different Age Groups Tina Kochupurackal, D.O., Barry Hoffman, D.O. Rowan University SOM, Department of Family Medicine, Stratford, NJ 08084 ABSTRACT Comparison of Average Thyroid Dosing in Men & Women in Various Age Groups Background and Hypothesis: The objective of this study was to determine if patients truly required higher doses of thyroid repletion with increasing age. This study hypothesized that females require higher doses of thyroid repletion to reach euthyroid state. It was also hypothesized that females within older age brackets will require greater thyroid repletion with thyroid hormone supplementation than younger females or their male counterparts within similar age brackets.   Methods: An IRB-approved chart review was pursued using data from the electronic medical charts of patients seen within the past year at the four Rowan-SOM Family Medicine offices. Electronic charts of patients on thyroid hormone replacement were reviewed. Charts were chosen regardless of demographic characteristics such as age, gender, or ethnicity. However, charts of patients whose TSH levels were not within normal limits (0.4-4.0mIU/L) were excluded, as those patients had not reached a euthyroid state.   Results: Five hundred sixty-seven charts were reviewed after removing patients with TSH out of range or those that had not been checked within the past year. Four hundred fifty-eight female charts and 109 male charts were noted. Thyroid repletion dosing in females were noted to increase until age 40-50’s, and then subsequently decline. Conclusion: Data review revealed a bell shaped distribution in the thyroid replacement dosing among females – reaching its peak at an age range of approximately 40 to 50 years old. There was also a noted decrease in thyroid dosing in females beyond this age bracket, disproving our hypothesis. Results suggested that possible starting doses for thyroid medication repletion may follow a bell-shaped curve, with higher doses needed for females between 40-50 years old. This knowledge can lead to better patient care and surveillance of disease – allowing physicians to better understand TSH patterns over the course of a patient’s lifetime. BACKGROUND 567 charts were reviewed – consisting of 458 female patients & 109 male patients. Women appear to require higher thyroid dosing compared to their male counterparts in their 40s, 70s, 80s, and 90s. Average Thyroid Dosing in Women at Various Ages METHOD Thyroid repletion dosing in females are noted to increase until age 40-50s & then subsequently decline. This peak in thyroid dosing may very well represent premenopausal / menopausal ages in females. References Aoki Y, Belin RM, Clickner R, et al. Serum TSH and total T4 in the United States population and their association with participant characteristics: National Health and Nutrition Examination Survey (NHANES 1999-2002). Thyroid. 2007 Dec. 17 (12):1211-23. Devdhar, M., Drooger, R., Pehlivanova, M., Singh, G., & Jonklaas, J. (2011). Levothyroxine Replacement Doses Are Affected by Gender and Weight, But Not Age. Thyroid, 21(8), 821-827. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3148125/#B28 Jonklaas, J. (2010). Sex and Age Differences in Levothyroxine Dosage Requirement. Endocrine Practice, 16(1), 71-79. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/19833578 Orlander, P. R., MD. (n.d.). Hypothyroidism. Retrieved February 08, 2016, from http://emedicine.medscape.com/article/122393-overview#a5 Roth, D. S., MD. (2014). Diagnosis of and screening for hypothyroidism in nonpregnant adults. Retrieved February 08, 2016, from http://www.uptodate.com/contents/diagnosis-of-and-screening-for-hypothyroidism-in-nonpregnant-adults Sawin, C. T. (1985). The Aging Thyroid. Arch Intern Med Archives of Internal Medicine, 145(8), 1386. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/4026469 Wisse, B., MD. (2014, May 10). TSH test: MedlinePlus Medical Encyclopedia. Retrieved February 08, 2016, from https://www.nlm.nih.gov/medlineplus/ency/article/003684.htm Acknowledgement The authors want to acknowledge the Rowan IRB and the Department of Family Medicine for their support with the Research Project.