Jostel's TSH index

Jostel's TSH index (also known as TSHI or Jostel's index) is a thyroid function test used to assess the thyroid gland's function. It is named after Dr. G. Jostel, who first proposed the index in 2009. The index is calculated by dividing the thyroid-stimulating hormone (TSH) level by the upper limit of the normal range, then multiplying by 100.

Overview

The TSH index is used to evaluate the severity of thyroid disease, particularly in cases of thyrotoxicosis (an excess of thyroid hormone) and hypothyroidism (a deficiency of thyroid hormone). It can also be used to monitor the effectiveness of treatment for these conditions.

Calculation

The TSH index is calculated using the following formula:

TSHI = (TSH / upper limit of normal) x 100

The upper limit of normal for TSH is typically around 4.0 mIU/L, but this can vary depending on the laboratory and the individual's age and health status.

Clinical use

The TSH index can be used to differentiate between different types of thyrotoxicosis, such as Graves' disease and toxic multinodular goitre. It can also help to determine the severity of hypothyroidism and monitor the response to treatment.

Limitations

While the TSH index is a useful tool in the diagnosis and management of thyroid disease, it is not without limitations. It is dependent on the accuracy of the TSH assay, and it may not be reliable in cases of pituitary disease or other conditions that affect TSH secretion.

See also

• Thyroid function tests
• Thyroid-stimulating hormone
• Thyroid disease

Jostel's TSH index

• Reference ranges for TSH, FT4, JTI and SPINA-GT
  Reference ranges for TSH, FT4, JTI and SPINA-GT
• JTI percentiles
  JTI percentiles