In healthy euthyroid middle-aged men and women, higher fT3 levels, lower fT4 levels, and thus a higher fT3-to-fT4 ratio are consistently associated with various markers of unfavorable metabolic profile and cardiovascular risk.

Sex- and/or ethnic-appropriate echocardiographic reference values are indicated for many measurements of LA and LV size, LV mass, and EF. Reference values for LV volumes and mass also differ across the age range.

OBJECTIVEPulse pressure (PP), a strong predictor of cardiovascular events in type 2 diabetes, is a composite measure affected by several hemodynamic factors. Little is known about the hemodynamic determinants of central PP in type 2 diabetes or whether abnormalities in central pulsatile hemodynamics are already present in individuals with impaired fasting glucose (IFG). In a population-based study, we aimed to compare central PP and its hemodynamic determinants among adults with normal fasting glucose (n = 1654), IFG (n = 240), and type 2 diabetes (n = 33).RESEARCH DESIGN AND METHODSWe measured carotid pressure, left ventricular outflow, aortic root diameter, carotid artery flow, and distension in order to measure various structural and hemodynamic arterial parameters.RESULTSIFG was associated with a greater mean arterial pressure (MAP) but was not associated with intrinsic aortic stiffening or abnormal aortic pulsatile indices after adjustment for MAP. After adjustment for age, sex, and MAP, type 2 diabetes was associated with a higher aortic root characteristic impedance (Zc), aortic root elastance-thickness product (Eh), and aortic root pulse wave velocity (but not aortic root diameter), a greater carotid-femoral pulse wave velocity, and lower total arterial compliance and wave reflection magnitude. Carotid size, Zc, distensibility, or Eh did not significantly differ between the groups.CONCLUSIONSType 2 diabetes, but not IFG, is associated with greater large artery stiffness, without abnormalities in aortic root diameter or carotid stiffness. Subjects with type 2 diabetes demonstrate a decreased reflection magnitude, which may indicate an increased penetration of pulsatile energy to distal vascular beds.

Background: Triiodothyronine (T3) has many effects on the heart, and marked changes in cardiac function and structure occur in patients with (subclinical) thyroid disease. We investigated whether between-subject variation in thyroid hormone levels within the euthyroid range is also associated with heart rate and echocardiographic heart function and structure. Methods: Subjects were selected from the Asklepios study (n = 2524), a population-representative random sample of patients aged between 35 and 55 years, free from overt cardiovascular disease at baseline. Analyses were restricted to 2078 subjects (1013 women and 1065 men), not using antihypertensive or thyroid medication nor having antithyroperoxidase antibody levels above clinical cut-off or thyrotropin (TSH) levels outside the reference range. All subjects were phenotyped in-depth and underwent comprehensive echocardiography, including diastolic evaluation. Thyroid function parameters were determined by automated electrochemiluminescence. Results: Heart rate was robustly positively associated with (quartiles of) free T3 (FT3) and T3, both in subjects with TSH levels within reference (0.27-4.2 lU/L) and in narrow TSH range (0.5-2.5 lU/L; p <0.0001). FT3 and T3 were negatively associated with left ventricular (LV) end-diastolic volume but positively associated with relative wall thickness. Total T3 (TT3) was associated with enhanced ventricular contraction (as assessed by tissue Doppler imaging). Free thyroxine, FT3, and TT3 were positively associated with late ventricular filling, and TT3 was associated with early ventricular filling. Conclusion: We have demonstrated a strong positive association between thyroid hormone levels within the euthyroid range and heart rate, and more subtle effects on cardiac function and structure. More specifically, we suggest a smaller LV cavity size (with increased relative wall thickness), an enhanced atrial and ventricular contraction, and LV relaxation with higher circulating thyroid hormones. These results illustrate that variation in thyroid hormone levels, even within the reference range, exerts effects on the heart.

BackgroundSystemic telomere length has been associated with measures of diastolic function, vascular stiffness and left ventricular mass mainly in smaller, patient-specific settings and not in a general population. In this study we describe the applicability of these findings in a large, representative population.Methods and ResultsPeripheral blood leukocyte telomere length (PBL TL) was measured using telomere restriction fragment analysis in the young to middle-aged (>2500 volunteers, ∼35 to 55 years old) Asklepios study population, free from overt cardiovascular disease. Subjects underwent extensive echocardiographic, hemodynamic and biochemical phenotyping. After adjusting for relevant confounders (age, sex, systolic blood pressure, heart rate, body mass index and use of antihypertensive drugs) we found no associations between PBL TL and left ventricular mass index (P = 0.943), ejection fraction (P = 0.933), peak systolic septal annular motion (P = 0.238), pulse wave velocity (P = 0.971) or pulse pressure (P = 0.999). In contrast, our data showed positive associations between PBL TL and parameters of LV filling: the transmitral flow early (E) to late (A) velocity ratio (E/A-ratio; P<0.001), the ratio of early (e′) to late (a′) mitral annular velocities (e′/a′-ratio; P = 0.012) and isovolumic relaxation time (P = 0.015). Interestingly, these associations were stronger in women than in men and were driven by associations between PBL TL and the late diastolic components (A and a′).ConclusionsIn a generally healthy, young to middle-aged population, PBL TL is not related to LV mass or systolic function, but might be associated with an altered LV filling pattern, especially in women.