Hyperthyroidism increases AF risk

Patients with thyroid disease should be screened for AF, the researchers said in the wake of their study, the first to assess AF risk across the whole spectrum of thyroid disease.

The Danish investigators identified more than 586,000 patients presenting for evaluation of their thyroid function and followed them up for an average of five and a half years.

Some 3% were diagnosed with their first episode of AF during that period. Patients with overt hyperthyroidism were 42% more likely to be diagnosed with AF , compared to those with normal thyroid function.

But the study found an “almost linear” relationship between TSH levels and AF risk, with a 31% increased risk among patients having subclinical hyperthyroidism.

Overt and subclinical hypothyroidism were associated with a 33% and 13% lower risk of AF respectively.

Medication prescribed to people with hypothyroidism may reduce AF risk, the researchers said.