Sironi Anna Maria, Pingitore Alessandro, Ghione Sergio, De Marchi Daniele, Scattini Barbara, Positano Vincenzo, Muscelli Elza, Ciociaro Demetrio, Lombardi Massimo, Ferrannini Ele, Gastaldelli Amalia
Metabolism and MRI Laboratory, Consiglio Nazionale delle Ricerche Institute of Clinical Physiology, Via Moruzzi, 1-S Cataldo, 56124 Pisa, Italy.
Hypertension. 2008 Feb;51(2):282-8. doi: 10.1161/HYPERTENSIONAHA.107.098640. Epub 2008 Jan 2.
Mild-to-moderate hypertension is often associated with insulin resistance and visceral adiposity. Whether these metabolic abnormalities have an independent impact on regional cardiac function is not known. The goal of this study was to investigate the effects of increased blood pressure, insulin resistance, and ectopic fat accumulation on the changes in peak systolic circumferential strain. Thirty-five male subjects (age: 47+/-1 years; body mass index: 28.4+/-0.6 kg m(-2); mean+/-SEM) included 13 with normal blood pressure (BP: 113+/-5/67+/-2 mm Hg), 13 with prehypertension (BP: 130+/-1/76+/-2 mm Hg), and 9 newly diagnosed with essential hypertension (BP: 150+/-2/94+/-2 mm Hg) who underwent cardiac magnetic resonance tissue tagging (MRI) and MRI quantitation of abdominal visceral and epicardial fat. Glucose tolerance, on oral glucose tolerance test, and insulin resistance were assessed along with the serum lipid profile. All of the subjects had normal glucose tolerance, left- and right-ventricular volumes, and ejection fraction. Across the BP groups, left ventricular mass tended to increase, and circumferential shortening was progressively reduced at basal, midheart, and apical segments (on average, from -17.0+/-0.5% in normal blood pressure to -15.2+/-0.7% in prehypertension to -13.6+/-0.8% in those newly diagnosed with essential hypertension; P=0.004). Reduced circumferential strain was significantly associated with raised BP independent of age (r=0.41; P=0.01) and with epicardial and visceral fat, serum triglycerides, and insulin resistance independent of age and BP. In conclusion, regional left ventricular function is already reduced at the early stages of hypertension despite the normal global cardiac function. Insulin resistance, dyslipidemia, and ectopic fat accumulation are associated with reduced regional systolic function.
轻度至中度高血压常与胰岛素抵抗和内脏肥胖相关。这些代谢异常是否对局部心脏功能有独立影响尚不清楚。本研究的目的是调查血压升高、胰岛素抵抗和异位脂肪堆积对收缩期峰值圆周应变变化的影响。35名男性受试者（年龄：47±1岁；体重指数：28.4±0.6 kg/m²；均值±标准误）包括13名血压正常者（血压：113±5/67±2 mmHg）、13名高血压前期患者（血压：130±1/76±2 mmHg）和9名新诊断的原发性高血压患者（血压：150±2/94±2 mmHg），他们接受了心脏磁共振组织标记（MRI）以及腹部内脏和心外膜脂肪的MRI定量分析。通过口服葡萄糖耐量试验评估葡萄糖耐量、胰岛素抵抗以及血脂谱。所有受试者的葡萄糖耐量、左右心室容积和射血分数均正常。在各血压组中，左心室质量有增加趋势，基底段、心脏中部和心尖段的圆周缩短逐渐减少（平均而言，从血压正常者的-17.0±0.5%降至高血压前期患者的-15.2±.7%，再降至新诊断的原发性高血压患者的-13.6±0.8%；P=0.004）。圆周应变降低与血压升高显著相关，独立于年龄（r=0.41；P=0.01），并与心外膜和内脏脂肪、血清甘油三酯以及胰岛素抵抗相关，独立于年龄和血压。总之，尽管整体心脏功能正常，但在高血压早期局部左心室功能就已降低。胰岛素抵抗、血脂异常和异位脂肪堆积与局部收缩功能降低有关。
