The effect of levothyroxine on arterial stiffness and lipid profile in patients with subclinical hypothyroidism.
BACKGROUND
The influence of treatment for subclinical hypothyroidism (SCH) on cardiovascular morbidity and mortality, arterial stiffness, and lipid profile has not been elucidated yet. The aim of this study was to evaluate the effect of levothyroxine on arterial stiffness, lipid profile, and inflammation.


METHODS
The study included 30 patients with SCH. Patients were treated with levothyroxine and were assessed at baseline and at 1, 4, and 7 months. Blood samples were taken for lipid profile and highly sensitive C-reactive protein (hs-CRP). Arterial stiffness was evaluated by augmentation index (AIx). In conditions that cause arterial stiffness, the pulse wave traveling from the periphery to the heart reaches the heart during systole, resulting in augmentation of the central pressure. This increase, calculated as the AIx, is a good expression of central aortic pressure.


RESULTS
After accomplishing euthyroidism, the AIx decreased from 17.2 +/- 8.3 to 14.3 +/- 6.5 (p < 0.01) and AIx percentage decreased from 36.2 +/- 11.5 to 33.2 +/- 9.1 (p = 0.03). Systolic blood pressure (SBP) decreased from 134.7 +/- 20 to 127.6 +/- 13.7 mmHg (p < 0.01). In those patients whose AIx decreased, low-density lipoprotein (LDL) levels decreased by 0.4 +/- 0.96 mmol/L compared to the patients whose AIx did not decrease and LDL increased by 0.62 +/- 1.48 mmol/L (p = 0.057). Total cholesterol decreased by 0.72 +/- 1.64 mmol/L in the patients whose AIx decreased and increased by 1 +/- 2.53 mg/dL in the patients whose AIx did not improve (p = 0.06).


CONCLUSIONS
In patients with SCH, treatment with levothyroxine had a significant beneficial effect on arterial stiffness and SBP, and no effect on lipid profile or hs-CRP.
Peleg
Ronit Koren
RK
Department of Internal Medicine A, Assaf Harofeh Medical Center, Zerifin, Israel. ronitkoren@gmail.com
Efrati
Shai
S
Benbassat
Carlos
C
Fygenzo
Marina
M
Golik
Ahuva
A
D000328:Adult; D000368:Aged; D001158:Arteries / Q000187:drug effects* / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D002097:C-Reactive Protein / Q000187:drug effects* / Q000378:metabolism; D004548:Elasticity / Q000187:drug effects; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy*; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000187:drug effects; D013974:Thyroxine / Q000494:pharmacology* / Q000627:therapeutic use
D015415:Biomarkers; D008055:Lipids; D002097:C-Reactive Protein; D013974:Thyroxine