Natural History of Mild Subclinical Hypothyroidism: Prognostic Value of Ultrasound

Abstract

Most patients with SCH and TSH < or = 10 mIU/L do not progress to overt hypothyroidism. The presence of chronic thyroiditis as demonstrated by US increases the evolution of SH to overt hypothyroidism or more severe SCH and thus the need for L-T4 treatment. US findings are important in determining the prognosis of mild SCH.

Variation in thyroid function in subclinical hypothyroidism: importance of clinical follow-up and therapy

“…The causes of SCH resemble the causes of HYPO, where autoimmune thyroiditis is the most frequent cause (9). Table 1 lists studies of the natural history of SCH (10)(11)(12)(13)(14)(15)(16)(17)(18). Progression of SCH to HYPO is in the order of 5-8%/year.…”

Natural history of mild subclinical hypothyroidism in a middle-aged and elderly Chinese population: a prospective study

“…Furthermore, in addition to TSH and TPOAb status, lipid profiles and renal function may influence the course of the disease in some ways. A total of 505 mild SCH patients completed the present study, more than several previous studies on this topic [6][7][8][9][10][11]. Compared with other studies, we included individuals aged 40-years or older instead of only elderly people in both sexes [6][7][8][9][10][11].…”

“…However, we found that baseline characteristics were similar between subjects who accomplished the cohort and these 90 subjects, which meant that our results were representative to some extent. Finally, we did not perform ultrasound tests, which had been reported to have a considerable predictive value in outcomes of SCH, because of the lack of ultrasound scanners and experienced doctors [9].…”

“…The predictive value of TSH levels, TPOAb status and ultrasound for the natural history of the disease have been investigated [6][7][8][9][10][11][12]. However, important metabolic indices such as TC or creatinine (CR) have not been researched.…”

“…On the other hand, the proportion of patients with spontaneous normalization of thyroid function is 20%-53.5%. Age, sex, initial TSH levels and thyroid peroxidase antibodies (TPOAb) status may influence thyroid function [4,[6][7][8][9][10][11][12]. However, when referring to the natural history of "mild" SCH, only Rosário et al have focused on this topic in only the female population, and found the prognostic value of ultrasound [7,9].…”