High levels of thyroid-stimulating hormone are associated with aortic wall thickness in the general population.

OBJECTIVES: Our aim was to investigate the association of thyroid function defined by serum concentrations of thyroid-stimulating hormone (TSH) with thoracic aortic wall thickness (AWT) as a marker of atherosclerotic processes. METHODS: We pooled data of 2,679 individuals from two independent population-based surveys of the Study of Health in Pomerania. Aortic diameter and AWT measurements were performed on a 1.5-T MRI scanner at the concentration of the right pulmonary artery displaying the ascending and the descending aorta. RESULTS: TSH, treated as continuous variable, was significantly associated with descending AWT (ß = 0.11; 95 % confidence interval (CI) 0.02-0.21), while the association with ascending AWT was not statistically significant (ß = 0.20; 95 % CI -0.01-0.21). High TSH (>3.29 mIU/L) was significantly associated with ascending (ß = 0.12; 95 % CI 0.02-0.23) but not with descending AWT (ß = 0.06; 95 % CI -0.04-0.16). There was no consistent association between TSH and aortic diameters. CONCLUSIONS: Our study demonstrated that AWT values increase with increasing serum TSH concentrations. Thus, a hypothyroid state may be indicative for aortic atherosclerosis. These results fit very well to the findings of previous studies pointing towards increased atherosclerotic risk in the hypothyroid state. KEY POINTS: • Serum TSH concentrations are positively associated with aortic wall thickness. • Serum TSH concentrations are not associated with the aortic diameters. • Serum 3,5-diiodothyronine concentrations may be positively associated with aortic wall thickness.

Cardiovascular risk factors and thoracic aortic wall thickness in a general population.

PURPOSE: To evaluate the association of cardiovascular risk factors with wall thickness of the ascending and descending thoracic aorta in the general population. MATERIALS AND METHODS: The study included 1,176 individuals (523 women) 21-83 years old from the Study of Health in Pomerania without history of stroke or myocardial infarction. Aortic wall thickness (AWT) was determined by cine magnetic resonance imaging. The associations of AWT with the cardiovascular risk factors male sex, age, smoking, body mass index (BMI), systolic and diastolic blood pressure, hemoglobin A1c, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides were assessed by multivariable linear regression models, and interaction effects were tested. RESULTS: Male sex (ß = .086, P < .001), age (ß = .006, P < .001), and BMI (ß = .013, P < .001) were positively associated with the AWT of the ascending aorta. Male sex (ß = .105, P < .001), age (ß = .006, P < .001), current smoker (ß = .044, P = .010), BMI (ß = .013, P < .001), and HDL-C (ß = .057, P = .008) revealed a positive association with AWT of the descending aorta. LDL-C (ß = -.024, P = .009; ß = -.018, P = .010) was inversely associated with the AWT of the ascending and descending aorta, respectively. Triglyceride levels (ß = .024, P = .027; ß = .018, P = .024) showed a positive association with the AWT of the ascending and descending aorta, respectively, in men, but not in women. CONCLUSIONS: Established cardiovascular risk factors, including male sex, older age, smoking, high BMI, and high triglyceride levels, were associated with increasing thoracic AWT of the ascending and descending aorta. High HDL-C and low LDL-C levels were correlated with AWT.

MRI-based determination of reference values of thoracic aortic wall thickness in a general population.

OBJECTIVES: To provide age- and sex-specific reference values for MRI-derived wall thickness of the ascending and descending aorta in the general population. MATERIALS AND METHODS: Data of 753 subjects (311 females) aged 21-81 years were analysed. MRI was used to determine the aortic wall thickness (AWT). Equations for reference value calculation according to age were established for females and males. RESULTS: Median wall thickness of the ascending aorta was 1.46 mm (5th-95th range: 1.15-1.88 mm) for females and 1.56 mm (1.22-1.99 mm) for males. Median wall thickness of the descending aorta was 1.26 mm (0.97-1.58 mm) in females and 1.36 mm (1.04-1.75 mm) in males. While median and 5th and 95th percentiles for the ascending and descending aorta increased with age in both sexes, the association between age and median AWT was stronger in males than in females for both the ascending and descending aorta. CONCLUSIONS: Reference values for the ascending and descending AWT are provided. In a healthy sample from the general population, the wall of the ascending aorta is thicker than the wall of the descending aorta, and both walls are thicker in males than females. The increase in wall thickness with age is greater in males. KEY POINTS: Ascending aortic wall thickness is greater than descending aortic wall thickness. Ascending and descending aortic wall thickness is greater in males. Thoracic aortic wall thickness increases with age in both sexes. The age-related increase in aortic wall thickness is stronger in males.

Mean thoracic aortic wall thickness determination by cine MRI with steady-state free precession: validation with dark blood imaging.

RATIONALE AND OBJECTIVES: To assess the validity and reliability of measuring mean aortic wall thickness (MAWT) of the ascending and descending aorta using cine steady-state free precession (SSFP) imaging compared to dark blood (DB) imaging. MATERIALS AND METHODS: DB and SSFP images of the thoracic aorta acquired at 1.5 T in 50 volunteers (26 women, 24 men; mean age: 50.2 ± 13.1 years) were used. MAWT was calculated on DB and SSFP images for the ascending and descending aorta at the level of the right pulmonary artery by two independent observers. Validity was assessed using Bland-Altman analysis, Passing-Bablok regression, and Spearman correlation. Reliability was assessed using Bland-Altman analysis and intraclass coefficients (ICCs). RESULTS: The mean MAWT of the ascending aorta on DB and SSFP images was 1.89 ± 0.21 mm and 1.87 ± 0.20 mm. The measurements for the descending aorta were 1.60 ± 0.22 and 1.63 ± 0.20 mm, respectively. Comparison of DB and SSFP measurements revealed a mean bias of 1.3% (95% limits of agreement (LOA): -7.9, 10.5%) for the ascending and of -2.1% (LOA: -10.5, 6.3%) for the descending aorta. The corresponding regression equation was y = 0.042 + 0.960 × (r = 0.91; P < .0001) and y = 0.118 + 0.939 × (r = 0.95; P < .0001), respectively. Intra- and interobserver variability showed a mean bias of less than 2.0% and LOA of less than ±15.0%. ICCs were greater than or equal to 0.85. CONCLUSIONS: MAWT determination in the ascending and descending aorta using cine SSFP sequences is highly valid and reliable compared to DB imaging.