Endocrine Abstracts

Objective: Hashimoto’s thyroiditis (HT) is extremely common, particularly among women. Mean platelet volume (MPV) and platelet distribution width (PDW) are the measure of platelet size. We aimed to investigate MPV and PDW levels in euthyroid woman with HT.

Methods: This was a retrospective study in which the data were obtained from a computerized patient registry database. We evaluated 145 women with HT and 60 matched healty controls, who applied to our outpatient clinic of the internal medicine and endocrinology department. Anti-thyroid peroxidase (anti-TPO) and anti-tiroglobulin (anti-TG) antibody were positive in all patients. Serum thyroid-stimulating hormone (TSH),free thyroxine, free triiodothyronine, platelet count (PC),platelet mass (PM), MPV, and PDW were measured. PM was calculated by multiplying MPV and PLT. All subjects iron, total iron binding capacity, ferritin, vitamin B12 and folic acid were evaluated.

Results: There were no significant differences in age between the study and the control groups. Anti-TPO and anti-TG levels were significantly higher in the study group (P<0.001).Although serum TSH was within the reference value, which was higher in the HT (P<0.009).Mean MPV,PDW and PM were significantly higher in the HT (P<0.001).Analysis of subgroups indicated that TSH,MPV and PDW levels were significantly higher in the levothroxine replacement patients in the HT than no levothroxine replacement patients in the HT.There were positive corelation between PDW and anti-TPO levels (r=0.217, P=0.01). MPV was positive correlated with anti-TPO and anti-TG levels (r=0.175, P=0.03; r=0.407, P<0.001,respectively), also PM was positive correlated with anti-TPO and anti-TG levels (r=0.168, P=0.04; r=0.250, P=0.006, respectively).

Our results suggest that even if in euthyroid state, patients with HT have higher MPV, PDW,PC, and PM levels than the healthy controls. Even if in euthyroid state, HT patients with levothroxine replacement show higher MPV and PDW levels than those with no levothroxine replacement. MPV and PDW parameters are also positively correlated with serum TSH levels.

Conclusions: Because of have a higher risk of thyroid malignancies in HT patients,higher MPV and PDW levels may be associated with inflammation and thyroid malignancies.