Τίτλος:
Studies of insulin resistance in patients with clinical and subclinical hypothyroidism
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Objective: Although clinical hypothyroidism (HO) is associated with insulin resistance, there is no information on insulin action in subclinical hypothyroidism (SHO). Design and methods: To investigate this, we assessed the sensitivity of glucose metabolism to insulin both in vivo (by an oral glucose tolerance test) and in vitro (by measuring insulin-stimulated rates of glucose transport in isolated monocytes with flow cytometry) in 21 euthyroid subjects (EU), 12 patients with HO, and 13 patients with SHO. Results: All three groups had comparable plasma glucose levels, with the HO and SHO having higher plasma insulin than the EU (P<0.05). Homeostasis model assessment index was increased in HO (1.97±0.22) and SHO (1.99±0.13) versus EU (1.27±0.16, P<0.05), while Matsuda index was decreased in HO (3.89±0.36) and SHO (4.26±0.48) versus EU (7.76±0.87, P<0.001), suggesting insulin resistance in both fasting and post-glucose state. At 100 μU/ml insulin: i) GLUT4 levels on the monocyte plasma membrane were decreased in both HO (215±19 mean fluorescence intensity, MFI) and SHO (218±24 MFI) versus EU (270±25 MFI, P=0.03 and 0.04 respectively), and ii) glucose transport rates in monocytes from HO (481±30 MFI) and SHO (462±19 MFI) were decreased versus EU (571±15 MFI, P=0.04 and 0.004 respectively). Conclusions: In patients with HO and SHO: i) insulin resistance was comparable; ii) insulin-stimulated rates of glucose transport in isolated monocytes were decreased due to impaired translocation of GLUT4 glucose transporters on the plasma membrane; iii) these findings could justify the increased risk for insulin resistance-associated disorders, such as cardiovascular disease, observed in patients with HO or SHO. © 2009 European Society of Endocrinology.
Συγγραφείς:
Maratou, E.
Hadjidakis, D.J.
Kollias, A.
Tsegka, K.
Peppa, M.
Alevizaki, M.
Mitrou, P.
Lambadiari, V.
Boutati, E.
Nikzas, D.
Tountas, N.
Economopoulos, T.
Raptis, S.A.
Dimitriadis, G.
Περιοδικό:
European Journal of Endocrinology
Λέξεις-κλειδιά:
glucose; glucose transporter 3; glucose transporter 4; insulin; liothyronine; prolactin; thyroxine; glucose transporter 3; glucose transporter 4; insulin; SLC2A3 protein, human; SLC2A4 protein, human, adult; article; cell membrane; clinical article; clinical hypothyroidism; controlled study; euthyroidism; flow cytometry; glucose blood level; glucose metabolism; glucose transport; human; hypothyroidism; in vitro study; in vivo study; insulin blood level; insulin resistance; liothyronine blood level; monocyte; oral glucose tolerance test; priority journal; prolactin blood level; subclinical hypothyroidism; thyroxine blood level; blood; cell culture; comparative study; diet restriction; glucose tolerance test; metabolism; middle aged; pathology; physiology; thyroid function test, Adult; Blood Glucose; Cell Membrane; Cells, Cultured; Fasting; Glucose Tolerance Test; Glucose Transporter Type 3; Glucose Transporter Type 4; Humans; Hypothyroidism; Insulin; Insulin Resistance; Middle Aged; Monocytes; Thyroid Function Tests
