From the Guidelines
A TSH level of 1.455 in a 46-year-old male is generally considered acceptable and within the normal range. The typical reference range for TSH (thyroid-stimulating hormone) in adults is approximately 0.4 to 4.0 mIU/L, though exact ranges may vary slightly between different laboratories 1. A value of 1.455 falls comfortably within this normal range, suggesting proper thyroid function. Some key points to consider include:
- Values for serum TSH level below 0.1 mU/L are considered low and values above 6.5 mU/L are considered elevated 1.
- Subclinical hyperthyroidism has been associated with atrial fibrillation; dementia; and, less clearly, osteoporosis 1.
- Subclinical hypothyroidism is associated with poor obstetric outcomes and poor cognitive development in children 1. No medication or intervention is needed for this TSH level. TSH is produced by the pituitary gland and regulates the production of thyroid hormones (T3 and T4), which control metabolism throughout the body. When thyroid function is normal, TSH levels remain within this reference range. If you're experiencing symptoms that might suggest thyroid dysfunction despite this normal TSH (such as unexplained fatigue, weight changes, or mood disturbances), it might be worth discussing with your healthcare provider, as occasionally additional thyroid tests like free T4 or free T3 may provide more complete information about thyroid function.
From the Research
TSH Levels in a 46-Year-Old Male
- A TSH level of 1.455 in a 46-year-old male is within the normal range, as the normal range for TSH is typically between 0.5 and 4.5 mIU/L 2.
- The study by 2 suggests that the upper limit of the reference range for TSH should not be confused with a cut-off to define subclinical hypothyroidism.
- Another study by 3 found that within-person variation in serum TSH concentrations can be caused by multiple factors, including pulsatile secretion, circadian rhythm, seasonality, and ageing.
Clinical Implications
- The study by 4 states that symptom relief and normalized thyroid-stimulating hormone levels are achieved with levothyroxine replacement therapy, but it does not provide a specific TSH level for a 46-year-old male.
- The study by 5 found that nearly half of the hypothyroid patients had out-of-reference range serum TSH values, despite being under levothyroxine treatment.
- The study by 6 suggests that a low TSH level can be caused by various conditions and drugs, and that patience is a virtue when approaching a low TSH level.
Factors Affecting TSH Levels
- The study by 3 found that factors such as thyroid peroxidase (TPO)-antibody positivity, BMI, obesity, smoking, critical illness, and many xenobiotics can affect TSH levels.
- The same study also found that TSH levels can fluctuate over time due to within-person variation, and that it is important to take this into account when testing a patient in clinical practice.