Exp Clin Endocrinol Diabetes 2013; 121 - P92
DOI: 10.1055/s-0033-1336732

In euthyroidism, moderate weight reduction by lifestyle intervention is not reducing TSH levels

C Thätner 1, K Mai 1, T Bobbert 1, AM Arafat 1, S Ruhla 1, J Spranger 1, AFH Pfeiffer 1, 2, M Möhlig 1, 2
  • 1Charité University Medicine Berlin, Clinic of Endocrinology, Diabetes and Nutrition, Berlin, Germany
  • 2German Institute of Human Nutrition Potsdam-Rehbruecke, Clinical Nutrition, Nuthetal, Germany

Introduction: In euthyroidism, a positive correlation has been described between thyroid-stimulating hormone (TSH) and body mass index (BMI). The direction of this correlation, however, is still a matter of debate. Elevated TSH levels might be cause or consequence of adiposity.

Therefore, we investigated changes in TSH during a weight reduction program.

Methods: At baseline and after 6 months of a multi-modal lifestyle intervention program in overweight or obese subjects anthropometric measurements were performed and blood probes were collected. TSH and free thyroxine were measured by an ELISA (PerkinElmer, Rodgau, Germany), triiodothyronine was quantified by a RIA (Brahms, Hennigsdorf, Germany). Included were euthyroid subjects (TSH between 0.3 and 4.5 mU/l) not taking thyroid hormone or thyreostatic drugs. Differences were compared by Student's T-test for paired analysis using SPSS software package.

Results: 90 subjects completed the lifestyle intervention program. 60 subjects (11 males) fulfilled the inclusion criteria. The subjects were in mean 56.4 years old (SD 12.1) and their mean BMI was 34.43 kg/m2 (SD 6.3). As a consequence of the program, participants reduced significantly (p < 0.001) their BMI to 32.36 kg/m2 (SD 6.31). At baseline, TSH was 1.53 mU/l (SD 0.86), free thyroxine was 0.98 ng/dl (SD 0.16), and triiodothyronine was 1.32 ng/ml (SD 0.24). At the end of the program, TSH was slightly higher (1.56 mU/l (SD 0.81), p for difference = 0.61).

Discussion: Despite a modest weight reduction following a multi-modal lifestyle intervention program TSH levels remained unchanged in euthyroid subjects. These data, therefore, do no support the view that adiposity is affecting TSH levels. The degree of caloric restriction might explain differences to published data.