There have also been arguments that treating subclinical hypothyroidism could lower cholesterol levels. Ms. C started on a statin in 2003 when her TSH was 3.5 and thus euthyroid. Any efforts to lower cholesterol might be done by adjusting her statin dose rather than adding levothyroxine.
Both over- and undertreatment with thyroid hormone replacement are common, she pointed out, and overtreatment has been associated with an increased risk for hip and major osteoporotic fracture, as well as increasing the risk for atrial fibrillation. She also noted that there is harm in medicalizing a normal condition, as the upper range of TSH is arbitrarily set based upon population data.
In the case of Mrs. C, Dr. Bates would explain that there is no risk for heart disease given the degree of thyroid dysfunction and, especially, that her goal of weight loss and symptom relief likely won’t happen.
If she did wish to be treated, Dr. Bates would also start her on a low dose. “If she were to embark on treatment, I would suggest monitoring her weight and symptoms,” she wrote. “While many authorities would recommend treatment at a calculated full replacement dose, my experience suggests that this risks overtreatment, and I would recommend starting at 25 to 50 mcg.”