SPONTANEOUS DIURNAL TSH SECRETION IS ENHANCED IN PROPORTION TO CIRCULATING LEPTIN IN OBESE PREMENOPAUSAL WOMEN
http://jcem.endojournals.org/cgi/content/short/jc.2005-0003v1
Context. Recent evidence implicates leptin as an important modulator of thyroid axis activity.
Objective. To study spontaneous 24 h TSH secretion and 24 h circulating leptin concentrations in obese and lean women.
Design. Prospective parallel study (2004).
Setting. Clinical Research Center LUMC.
Participants. 12 healthy obese premenopausal women (BMI 33.2 ± 0.9 kg/m2) and 11 lean controls (BMI 21.4 ± 0.5 kg/m2) were studied in the follicular phase of their menstrual cycle.
Intervention(s). None.
Main Outcome Measure(s). Spontaneous 24 h TSH concentrations (10 min time intervals) and secretion, calculated using waveform-independent deconvolution technique (Pulse). 24 h circulating leptin concentrations (20 min time intervals).
Results. Mean TSH concentration (obese 1.9 ± 0.2 vs. lean 1.1 ± 0.1 mU/L, P = 0.009) and secretion rate (obese 43.4 ± 5.5 vs. in lean 26.1 ± 2.2 mU/liter distribution volume. 24 h, P = 0.011) were substantially enhanced in obesity, whereas the fasting free thyroxine concentrations were similar (free T4 in obese 15.4 ± 1.5 vs. in lean 16.4 ± 1.5 pmol/L, P = 0.147). TSH secretion was positively related to 24 h leptin concentrations (R2 = 0.31, P = 0.007).
Conclusions. TSH release is enhanced in the face of normal plasma free thyroxine concentrations in obese premenopausal women and hyperleptinemia may well be involved in this neuroendocrine alteration.
Key words: Hormone Rhythms • Body Fat Distribution • Obesity • Circadian
tealady
Hi Bob,
I think (from memory only:-) that Larrian was of the belief that TSH was one of the things that controlled leptin. She never said it as much.. just it was important NOT to suppress TSH as that would interfere with leptin.
Above seems to be saying that TSH is greater in obese people.. and they have more leptin.. like maybe the obesity produced the leptin and this contls the TSH?
Jan