Age, Gender, and Seasonal Effects on Thyroid Profile in Adults with Normal Thyroid Functions

Background: Thyroid hormone variations have been observed according to age and sex. Seasonal effects also induce in thyroid function even people with normal levels. The majority of clinical laboratories follow a single reference range without the consideration age, gender, especially seasonal tests.
 Objectives: To evaluate tests adults functions.
 Methodology: This cross sectional study was carried out at Pathology Department, Quaid-e-Azam Medical College, Bahawalpur. One year data from Jan 2018 2019 (TSH, T3 T4) demographic details were obtained for all those patients whose Stimulating Hormone (TSH) (0.5-4.5mU/L). We found 418 subjects 16 75 years among them 196 females 222 males.
 Results: Serum TSH levels higher (2.11mU/L ±1.54) than serum males (1.59mU/L ±1.2) p-value 0.0002. FT4 (normal range: 0.89-1.76ng/dL) significantly lower (p-value 0.0018) (1.33ng/dL ±0.50) as compared (1.48ng/dL ±0.48). In <20 group both genders, lowest levels, while highest 20-40 >60 females. mean high (2.98mU/L) winters it low (2.4mU/L) autumn. level (1.16ng/dL) (1.46ng/dL) summers. FT3 winter season other seasons.
 Conclusion: Age, affects hormones these factors should be considered interpreting lab results tests.