“There is a lot of controversy over whether these minimally raised levels of TSH affect anyone badly,” Dr. Surks added. “They may even be beneficial,” one published study suggests. “Nobody knows.”
Three meta-analyses published this year reached divergent conclusions, with two saying mildly elevated TSH levels increased the risk of cardiac complications, and one reporting no increased risks. “That tells you the data are no good,” Dr. Surks said.
He and his associates will publish a new analysis of the NHANES III data this fall concluding that a significant share of the elderly people whose TSH levels were designated as elevated were inappropriately classified.
As for setting the upper limits on TSH low, Dr. Shireen Fatemi, director of endocrinology at the Panorama City (Calif.) Kaiser Permanente Medical Center, said that it's important to treat case by case. “You can't make a strong case either way” to treat or not treat mildly elevated TSH levels, she said. “Take the whole patient into consideration.”
'You can't make a strong case either way' to treat or not treat mildly elevated TSH levels. DR. FATEMI