The thyroid regulates the body s metabolism the rate at which the body produces energy from nutrients and affects heart rate, energy and mood. Signs and symptoms of an underactive thyroid include fatigue, depression, forgetfulness, unexplained weight gain, and menstrual irregularities. If left untreated, thyroid disease may lead to an increased risk for heart disease, osteoporosis and infertility. Thyroid disease can strike anyone at any time, but is more common in women, Dr. Canaris said. One woman in eight will develop a thyroid disorder during her lifetime, Dr. Canaris said.
Incidence also increases with age.
By age 60, more than 20 percent of American women will have a thyroid disorder. The study, one of the largest patient populations ever evaluated, found that of the 25,862 participants, 11.7 percent had abnormal serum TSH levels. The study also found that even the slightest decrease in thyroid function may increase cholesterol levels, possibly increasing a patient s risk for cardiovascular disease. This link between the early stages of underactive thyroid and cholesterol levels provides evidence that untreated patients may experience serious negative health consequences. While it has been known for decades that overt hypothyroidism contributes to elevated cholesterol levels, this is the largest study to show that the cholesterol levels among patients with mildly decreased thyroid function were significantly higher than the cholesterol levels in people with normal thyroid function.