- People with overweight/obese or underweight body mass index (BMI) have altered levels of thyroid hormones, according to a study from China, with associated cardiovascular and metabolic differences.
Why this matters
- The relationship between thyroid hormone concentrations and body weight is unclear.
- Serum free triiodothyronine (fT3) levels and a high fT3/free thyroxine (fT4) ratio were positively associated with BMI, whereas serum fT4 levels were negatively associated with BMI (P<.001 for all in multivariate analysis>
- fT3 was positively associated with systolic blood pressure (P=.004) and low-density lipoprotein cholesterol (P=.009).
- fT4 was positively associated with diastolic blood pressure (P<.001 fasting blood glucose and high-density lipoprotein cholesterol negatively associated with hemoglobin a1c p=".017)" triglyceride>
- fT3/fT4 ratio was positively associated with HbA1c (P=.002) and triglyceride (P<.001 and negatively associated with fasting blood glucose hdl cholesterol>
- 16,975 euthyroid subjects admitted to the Health Management Center of Tongji Hospital of Wuhan, China, were analyzed for associations between thyroid function, BMI, and metabolic risk factors.
- Funding: None.
- Retrospective design.
- Some confounding factors (smoking, alcohol, diet, physical activity) not captured.