Thyroid peroxidase Antibody (TPO Ab) Can Be Used As a Marker For Persistence of Symptoms of Hypothyroidism in Patients with Primary Hypothyroidism Despite Normal TSH Level: Cross-Sectional Study

Background Primary hypothyroidism is one of the most prevalent endocrine conditions. Some hypothyroid patients treated with an acceptable dose of levothyroxine report continuing symptoms including fatigue, depression, and weight gain, despite having a TSH level in the lower half of the normal range. Aim to evaluate why some hypothyroid patients on levothyroxine continue to have residual symptoms despite apparently adequate replacement& laboratory euthyroid status? Patients and methods 111 Adult male and female ranging from (18-65) years with primary hypothyroidism and normal TSH taking adequate levothyroxine dose were divided into 2 groups. Group1: Hypothyroid patients with persistent symptoms despite normal TSH level and Group2: Hypothyroid patients which are clinically free with normal TSH level (Control). Complete full history taking, including: (Age, Sex, Marital status, smoking, income, education, and employment) Symptoms of hypothyroidism (weight gain –poor concentration –general fatigue –mood changes -Infertility –Hair falling –Puffiness of eyelid –Cold Intolerance. Venous blood was withdrawn from all patients for: FT3, FT4, TSH, TPO Abs, CBC, Vitamin D3 Results There was a statistically significantly higher female participants, and anti-TPO by both published cutoff values (≥121 and ≥35) in group (1) vs. group (2). Family history, vit D3 category, age, BMI, treatment duration, TSH, FT4, TPO, Hemoglobin, platelet count, and WBCs count were non-significant different between group 1 and group 2. The most frequent symptoms were fatigue (62.2%), weight gain (62.2%), and poor concentration (61.1%). There was a statistically significant negative correlation between Total symptom score (TSS) and treatment duration, age and FT4 and a statistically significant positive correlation between TSS and FT3. TPO at cutoff ≥35, poor concentration and hair fall can be predicted. Participants with TPO ≥ 35 has 3 times higher odds to exhibit poor concentration and 2.6 times higher odds to exhibit hair falling. Conclusion In patients with hypothyroidism on adequate replacement therapy we cannot realize only on the level of TSH to explain the persistence of symptomatology. TPO ≥ 35 has 3 times associated with persistent of symptomatology like menstrual irregularity, hair loss and poor concentration.