Relationship of thyroid function with body mass index, leptin, insulin sensitivity and adiponectin in euthyroid obese women.
BACKGROUND
A possible relationship between thyroid hormones and adipose tissue metabolism in humans has been suggested. Aim of the study We sought to evaluate thyroid function and its possible relationship with body mass index (BMI), leptin, adiponectin and insulin sensitivity in euthyroid obese women.


METHODS
Eighty-seven uncomplicated obese women (mean age 34.7 +/- 9 years, mean BMI 40.1 +/- 7 kg/m(2)) were studied. Levels of TSH, free thyroxine (FT4), free triiodothyronine (FT3), plasma adiponectin and leptin were evaluated. Insulin sensitivity was assessed by euglycaemic hyperinsulinaemic clamp (M index), fasting insulin and HOMA-IR.


RESULTS
Uncomplicated obese women with BMI > 40 kg/m(2) showed higher serum TSH than obese subjects with BMI < 40 kg/m(2) (P < 0.01). TSH was correlated with BMI (r = 0.44, P = 0.01) leptin (r = 0.41, P = 0.01), leptin/BMI ratio (r = 0.33, P = 0.03), body surface area (r = 0.26, P = 0.05), HOMA-IR (r = 0.245, P = 0.05) and inversely with adiponectin (r = -0.25, P = 0.05) and M index (r = -0.223 P = 0.05).


CONCLUSIONS
Our data show that, although thyroid function was normal in the studied obese population, TSH and BMI were positively related. TSH has been found to be correlated also with leptin adjusted for BMI. TSH could represent a marker of altered energy balance in severe, but uncomplicated obese women.
Iacobellis
Gianluca
G
Division of Endocrinology, Department of Clinical Sciences, La Sapienza University, Rome, Italy. gianluca.iaco@tin.it
Ribaudo
Maria Cristina
MC
Zappaterreno
Alessandra
A
Iannucci
Concetta Valeria
CV
Leonetti
Frida
F
D052242:Adiponectin; D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D020738:Leptin / Q000097:blood*; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D013961:Thyroid Gland / Q000378:metabolism / Q000503:physiopathology*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D052242:Adiponectin; D036341:Intercellular Signaling Peptides and Proteins; D020738:Leptin; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine