Do Nondipping Pattern and Metabolic Syndrome Impact Left Ventricular Geometry and Global Function in Hypertensive Patients?

Left and right ventricular function by echocardiography, tissue Doppler imaging, carotid intima-media thickness, and asymmetric dimethyl arginine levels in obese adolescents with metabolic syndrome

PurposeThe aim of our study was to assess left ventricle and right ventricle systolic and diastolic functions in obese adolescents with metabolic syndrome using conventional echocardiography and pulsed-wave tissue Doppler imaging and to investigate carotis intima-media thickness, and asymmetric dimethyl arginine levels.

METHODS

A total of 198 obese adolescents were enrolled in the study. The obese patients were divided into metabolic syndrome group and non-metabolic syndrome group. All subjects underwent laboratory blood tests, including asymmetric dimethyl arginine, complete two-dimensional, pulsed, and tissue Doppler echocardiography, and measurement of the carotid intima-media thickness.

RESULTS

Obese adolescents were characterised by enlarged left end-diastolic, end-systolic and left atrial diameters, thicker left and right ventricular walls compared with non-obese adolescents. The metabolic syndrome group had normal left ventricle systolic function, impaired diastolic function, and altered global systolic and diastolic myocardial performance. In the metabolic syndrome obese group patients, left ventricle mass was found positively correlated with body mass index, waist and hip circumferences, diastolic blood pressure, age, and waist-to-hip circumference ratio. The carotid intima-media thickness was found positively correlated with waist and hip circumferences and total cholesterol levels. Asymmetric dimethyl arginine levels were found positively correlated with systolic blood pressure, waist-to-hip circumference ratio, and diastolic blood pressure.

CONCLUSIONS

The results of this study demonstrate that metabolic syndrome in adolescence is associated with significant changes in myocardial geometry and function. In addition, it has been associated with a high level of asymmetric dimethyl arginine concentration and thicker carotid intima-media thickness reflecting endothelial dysfunction.

Abdominal obesity and structure and function of the heart in healthy male Koreans: The ARIRANG study

Although central obesity is a more powerful predictor of cardiovascular disease (CVD) than general obesity, there is limited information on structural and functional changes of the heart in central obesity. Therefore, we evaluated the association between abdominal obesity and geometric and functional changes of the heart in healthy males. A total of 1460 healthy males aged 40 to 70 years without known CVD from the Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population were included. All individuals underwent conventional 2-dimensional echocardiography and tissue Doppler imaging to measure left atrial (LA) and left ventricle (LV) geometry and function. Increasing tertiles of waist circumference (WC) were associated with stepwise increases in LA volume, LV end-diastolic dimension, LV mass to height, deceleration time of E wave, and lower E/A ratio (all P trends <0.001). In multivariable logistic regression models, the odds ratios for LA enlargement, LV hypertrophy, LV enlargement, and diastolic dysfunction comparing the upper tertile of WC (>89 cm) to the lowest tertile (<82 cm) were 2.81 (95% confidence interval [CI] 2.24-3.54), 3.65 (95% CI 2.54-5.26), 4.23 (95% CI 2.61-6.87), and 1.75 (95% CI 1.37-2.22), respectively. LV ejection fraction and relative wall thickness were not increased with increasing WC. The association between WC and LA enlargement, LV enlargement, and diastolic dysfunction persisted after stratification by body mass index tertiles. Central obesity may be a stronger predictor than general obesity of geometric and functional changes in the LV and LA.

Does metabolic syndrome worsen systolic dysfunction in diabetes? The shortwave study

Patients with metabolic syndrome (MetS) have high cardiovascular event rates. The additional effect of MetS on left ventricular (LV) systolic function in patients with type 2 diabetes mellitus (T2DM) is unknown. We studied the relation between MetS and LV systolic function in T2DM patients without coronary artery disease (CAD). Clinical and echocardiographic data from 331 T2DM patients were analyzed. Prevalence of MetS was assessed based on NCEP ATPIII definition. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were analyzed as indexes of circumferential and longitudinal shortening, respectively. Sc-MS was impaired if <89 %, S' if <8.5 cm/s (10th percentile of healthy controls). MetS was diagnosed in 172 patients. Sc-MS and S' were similar in T2DM patients with and without MetS (91 ± 14 vs 92 ± 15 %; 9.8 ± 2.0 vs 9.5 ± 2.1 cm/s, respectively; p = ns) but significantly reduced comparing to controls (102 ± 11 % and 10.8 cm/s; p < 0.0001). Impairment of sc-MS and S' were detected in 37 vs 40 % and in 29 vs 32 % of T2DM patients with and without MetS (p = ns), respectively. LV systolic function measured as sc-MS and S' is frequently impaired in T2DM patients without CAD; however, the coexistence of MetS is not associated with more severe LV systolic dysfunction. Further pathological mechanisms have to be considered to explain the negative prognostic impact of MetS in T2DM patients.