Thyroxine requirements in autoimmune gastritis

[Guest guest]

This article says LT4 needs are greater in some people even if TSH is

normal (0.3–3.0 µU/ml) .

L-Thyroxine Requirement in Patients with Autoimmune Hypothyroidism

and Parietal Cell Antibodies

Serenella Checchi, lisa Montanaro, Letizia Pasqui, Cristina

Ciuoli, Valentina De Palo, Celeste Chiappetta and Furio Pacini

Section of Endocrinology and Metabolism, Department of Internal

Medicine, Endocrinology and Metabolism and Biochemistry, University

of Siena, 53100 Siena, Italy

Background: Hypothyroid patients on L-T4 therapy may require

replacement doses exceeding the theoretical needs to normalize serum

TSH due to low patient compliance, drugs interference, and

malabsorption.

Objective: We examined whether autoimmune gastritis might cause

increased L-T4 requirement in patients with autoimmune thyroiditis

receiving L-T4 replacement.

Patients: We studied 391 patients with clinical or subclinical

hypothyroidism from autoimmune thyroiditis who had achieved normal

serum TSH concentration (0.3–3.0 µU/ml) under L-T4 for at least 6

months. Patients were screened for serum parietal cell antibodies

(PCA) as a marker of autoimmune gastritis, and the PCA status was

correlated with the L-T4 dose. We also studied a group of 60 patients

receiving L-T4 replacement after total thyroidectomy.

Results: PCA-positive (155 of 391) and PCA-negative (236 of 391)

patients did not differ for pretherapy serum TSH levels and thyroid

volume. The L-T4 requirement was significantly (P = 0.002) higher in

PCA-positive (1.24 ± 0.40 µg/kg · d) than in PCA-negative patients

(1.06 ± 0.36 µg/kg · d), and a significant positive correlation was

found between L-T4 requirement and serum PCA levels.

Among PCA-positive patients, L-T4 requirement was even higher in

those with proven gastritis (1.52 ± 0.40 µg/kg · d) compared with

those without gastric damage (1.15 ± 0.33 µg/kg · d) (P < 0.0001).

The increased L-T4 requirement was confirmed also in PCA-positive

thyroidectomized patients (1.81 ± 0.27 µg/kg · d) compared with PCA-

negative thyroidectomized patients (1.52 ± 0.24 µg/kg · d).

Independent variables affecting L-T4 requirement were PCA and serum

TSH at diagnosis.

Conclusions: Autoimmune gastritis is an additional factor affecting L-

T4 requirement in patients with autoimmune thyroiditis. Serum PCA

measurement should be considered in patients with an unexplained high

requirement of L-T4.

[Guest guest]

What is LT4?

sol

boatkitten wrote:

> This article says LT4 needs are greater in some people even if TSH is

> normal (0.3–3.0 µU/ml) .

>

>