Figure 3.

Relationships between TSH and FT4 or FT3 at symptomatic versus asymptomatic presentations.

The main panel shows the crude relationships obtained by locally weighted scatterplot smoothing in each group over the full range. The inserts are restricted to the nonhypothyroid range, fitted by a mixed model adjusted for FT4/FT3, gender, age and BMI. Responses in symptomatic patients were significantly shifted to the right (FT4: p = 0.03, FT3: p = 0.007).

BMI, body mass index; FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid stimulating hormone.