[Proliferation kinetics of human anagen hair in hyper- and hypothyroidism: DNA flow cytometry studies].

Disorders of the thyroid function and abnormalities of the scalp hair growth are frequently associated. Former studies were based on clinical findings and trichorhizogram evaluation. Our present study making use of DNA-flow cytometry demonstrates the influence of thyroid hormones on the proliferative activity of anagen hair bulbs in patients suffering from disorders of the thyroid function. In comparison with a healthy control group (n = 20), the mean proliferative activity (S- and G2+M-%) was found 15% lower in hypothyroid patients (n = 6), whereas in hyperthyroidism (n = 6) we observed an increase of the corresponding values of about 30%. Our data might suggest a direct correlation between S-phase percentages and plasma T3 levels, but this assumption could not be proved by statistical methods.