亚临床甲状腺功能减退与冠心病及其危险因素之间关系的研究进展

亚临床甲状腺功能减退症（subclinical hypothyroidism）是指血清促甲状腺激素（thyroid-stimulating hormone,TSH）水平升高,血清游离甲状腺素（free thyroxine,FT4）和游离三碘甲腺原氨酸（free triiodothyronine,FT3）水平正常,患者没有或几乎没有甲状腺功能减退的相应症状和体征的甲状腺疾病,简称亚临床甲减[1],好发于老年及女性[2,3],临床症状不典型或缺乏,诊断有赖于实验室检查.     

糖尿病性心脏病研究进展

近年糖尿病发病率急剧增高,成为仅次于心脑血管疾病和癌症的又一大疾病,严重危害人类健康。而在糖尿病当中,糖尿病性心脏病最严重,致死率极高。糖尿病可通过3种方式影响心脏:冠心病、糖尿病心肌病和心脏自主神经病变。不同糖尿病类型,发病情况不同。3种糖尿病性心脏病的发病机制有共同的地方,但在筛查及治疗的手段上又有所不同。本文整合相关的最新进展旨在分析阐明糖尿病性心脏病的机制、临床筛查和潜在治疗途径。     

亚临床甲状腺功能减退与心血管疾病的研究进展

亚临床甲状腺功能减退症(亚临床甲减)是一种常见、多发病,主要诊断依据是血清TSH水平增高,而游离甲状腺素(FT4)正常。其与心血管疾病的关系已成为当今研究的热点,目前认为亚临床甲减与高胆固醇血症、高血压、吸烟和糖尿病一样,构成动脉粥样硬化和心肌梗死的独立危险因素。本文综述了亚临床甲减与常见心血管疾病的关系及亚临床甲减的干预治疗等方面的进展。     

亚临床甲状腺功能异常与心血管疾病的关系

临床研究显示,亚临床甲状腺功能异常与心血管疾病之间存在密切的关系.亚临床甲状腺功能减退通常伴有血脂异常、高凝状态、纤维蛋白溶解活性减低等心血管疾病危险因素,其与动脉粥样硬化、冠心病和心血管死亡的风险显著相关.另一方面,亚临床甲状腺功能亢进与心房颤动发生风险显著相关,但与心血管死亡风险的相关性尚不清楚.对于亚临床甲状腺功能异常进行治疗是否能够带来心血管获益,目前尚无确切结论.     

亚临床期糖尿病性心脏病及相关因素的初探

目的探讨亚临床期糖尿病性心脏病相关因素，以采取有效的防治对策。方法（１）对２８８例无高血压、心脏病临床表现，并经有关检查基本除外冠心病及其它心脏病的糖尿病患者进行无创性心功能检查。（２）对亚临床期糖尿病性心脏病的相关因素进行单因素和多因素分析。结果（１）３３．６８％的糖尿病病人存在亚临床期糖尿病性心脏病变所导致的心功能异常。（２）年龄、病程、ＢＭＩ、代谢控制状况、微血管并发症与亚临床期糖尿病性心脏病的发生密切相关。结论年龄大、病程长、ＢＭＩ高、代谢控制不良及糖尿病其它微血管并发症是亚临床期糖尿病性心脏病的危险因素，对以上某些因素进行有效的控制，将可能预防和延缓糖尿病性心脏病的发生。     

亚临床甲状腺功能异常与心血管疾病的关系

临床研究显示,亚临床甲状腺功能异常与心血管疾病之间存在密切的关系.亚临床甲状腺功能减退通常伴有血脂异常、高凝状态、纤维蛋白溶解活性减低等心血管疾病危险因素,其与动脉粥样硬化、冠心病和心血管死亡的风险显著相关.另一方面,亚临床甲状腺功能亢进与心房颤动发生风险显著相关,但与心血管死亡风险的相关性尚不清楚.对于亚临床甲状腺功能异常进行治疗是否能够带来心血管获益,目前尚无确切结论.     

亚临床甲状腺功能异常与心血管疾病的关系

临床研究显示,亚临床甲状腺功能异常与心血管疾病之间存在密切的关系.亚临床甲状腺功能减退通常伴有血脂异常、高凝状态、纤维蛋白溶解活性减低等心血管疾病危险因素,其与动脉粥样硬化、冠心病和心血管死亡的风险显著相关.另一方面,亚临床甲状腺功能亢进与心房颤动发生风险显著相关,但与心血管死亡风险的相关性尚不清楚.对于亚临床甲状腺功能异常进行治疗是否能够带来心血管获益,目前尚无确切结论.     

Renal denervation prevents subclinical atrial fibrillation in patients with hypertensive heart disease: Randomized,sham-controlled trial

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Prognostic impact of subclinical thyroid dysfunction in heart failure

Background

Therapeutic and prognostic implications of subclinical thyroid dysfunction in patients with heart failure (HF) are unclear. We compared the prognostic impact of euthyroidism, subclinical thyroid dysfunction, and euthyroid sick syndrome (ESS) in systolic HF.

Methods

We included 1032 patients hospitalized for systolic HF (left ventricular ejection fraction [LVEF] ≤ 40%) who participated in a randomized trial assessing the effects of a HF disease management program. Patients with incomplete thyroid function tests or thyrotropic medication were excluded. In the remaining 758 subjects, the risk of all-cause death was estimated based on TSH only, or full thyroid function profile. Changes of thyroid function after six months were assessed in 451 subjects.

Results

Subclinical thyroid dysfunction was present in 103 patients at baseline (14%). No differences were found between groups regarding NYHA class (P = 0.29), and LVEF (P = 0.60). After a median follow-up of three years patients with ESS (n = 13) had a 3-fold age-adjusted increased risk of death compared to euthyroid patients (P = 0.001). However, neither subclinical hyperthyroidism (HR 1.18, 95%CI:0.82–1.70) nor hypothyroidism (HR 1.07, 95%CI:0.58–1.98) were associated with increased age-adjusted mortality risk. Subclinical thyroid dysfunction had normalized spontaneously at follow-up in 77% of patients. However, persistent subclinical thyroid dysfunction was also not associated with worse outcome.

Conclusions

In this large well-characterized HF cohort, subclinical thyroid dysfunction did not predict an increased mortality risk. Thus, in patients with moderate to severe HF, further diagnostic and therapeutic procedures for subclinical thyroid dysfunction appear dispensable. ESS was an infrequent but important indicator of a poor prognosis in HF.

Clinical trial registration

URL: http://www.controlled-trials.com. Unique identifier: ISRCTN23325295.     

Laboratory-based calculation of coronary heart disease risk in a hospital diabetic clinic.

AIMS: To develop an estimation of risk of coronary heart disease (CHD) based on the Framingham equation for use in a diabetes clinic, given concerns about the accuracy of the Sheffield risk tables in this setting. METHODS: A computer program using the Framingham equation based on patients' age, sex, systolic blood pressure, smoking history, presence of diabetes and left ventricular hypertrophy was applied to requests for lipid screening of patients attending the diabetes clinics of Birmingham Heartlands Hospital. The calculated risks for the population were compared with those estimated from the Sheffield tables. RESULTS: Of 1060 patients with diabetes mellitus, 215 (20%) had an annual CHD risk > or =3%, which is considered to be the threshold at which lipid-lowering drugs are cost-effective. Only 24 of these 215 patients (11%) were correctly identified by the Sheffield tables, which we conclude have an unacceptably low sensitivity in diabetes mellitus. CONCLUSIONS: A laboratory-based CHD risk calculation system is a practical alternative to the Sheffield system and may have a greater sensitivity in the diabetic clinic.     

微量清蛋白尿与2型糖尿病合并冠心病的关系

目的:探讨2型糖尿病患者微量清蛋白尿(MA)与冠心病的关系。方法:342例2型糖尿病患者根据冠状动脉(冠脉)造影结果分为合并冠心病组(106例)和不合并冠心病组(236例),测定2组24h尿清蛋白、血糖、糖化血红蛋白及血脂等相关指标;比较MA阳性组(139例)和MA阴性组(203例)冠心病的发病率及冠脉造影特点。采用多元Logistic回归方法分析2型糖尿病患者冠脉病变的危险因素。结果:糖尿病合并冠心病组MA水平明显高于不合并冠心病组(P<0.01),多元逐步回归分析也表明MA与糖尿病患者冠心病的发生显著相关(P<0.05);MA阳性组冠心病发病率明显高于MA阴性组(42.5%比23.2%,P<0.01);此外,与MA阴性组比较,MA阳性组重度血管狭窄、弥漫性和闭塞性病变更多(P0.05)。结论:MA是2型糖尿病患者冠脉病变的重要危险因素,且伴MA的2型糖尿病合并冠心病患者冠脉病变更严重。     

糖尿病与冠心病人QT间期及离散度变化的相关性研究

糖尿病和冠心病人的QTc和QTd明显长于非患病病者，町为预测心血管事件的发生提供依据。方法：采用病例一病例对照的研究方法，将130例糖尿病、冠心病病人分为冠心病组（G1）53例、糖尿病组（C2）47例、糖尿病合并冠心病组（G3）30例，对比QTc和QTd的变化及其与糖尿病和冠心病的相关性。结果：G3组病人的QTc和QTd较G1、G2组明显延长（P=0．010和0．017），相关分析结果显示QTd与QTc明显相关（R=0．252P=0．004），糖尿病或CHD病人的QTc与是否合并CHD或糖尿病独立相关（？=0．368和0．336P=0．007和0．046）。结论：糖尿病对心肌电活动的影响与心肌缺血引起的相近，二者合并出现后加重了心肌电活动的l不稳定性。     

Insulin resistance,haemostatic and inflammatory markers and coronary heart disease risk factors in Type 2 diabetic men with and without coronary heart disease

Aims/hypothesis We have examined markers of haemostasis and inflammation in men with diabetes, coronary heart disease (CHD) or both, and assessed their associations with insulin resistance in men with Type 2 diabetes.Methods The study was carried out in 4066 British men aged 60 to 79 years who were not on warfarin or insulin, of whom there were 426 men with prevalent Type 2 diabetes and 842 with prevalent CHD.Results Men with Type 2 diabetes were more likely to have multiple risk factors and higher levels of haemostatic and inflammatory markers than men without, irrespective of CHD status. Compared with men with CHD only, men with diabetes only showed increased levels of tissue plasminogen activator antigen, increased plasma and blood viscosity, and increased levels of coagulation factors VII, VIII and IX. They also had dyslipidaemia. In men with diabetes, increased insulin resistance (homeostasis model assessment, HOMA) was associated with increased levels of haemostatic markers and dyslipidaemia. The prevalence of CHD increased significantly with increasing tertiles of HOMA (adjusted odds ratio 1.32 [95% CI: 0.72–2.42] in the second, and 1.70 [95% CI: 0.92–3.44] in the third tertile; p=0.04 for trend).Conclusions/interpretation Increased insulin resistance among men with Type 2 diabetes is associated with increased prevalence of CHD and of activated haemostasis and dyslipidaemia. Reducing insulin resistance in men with diabetes may reduce their tendency to develop thrombosis and hence CHD risk.     

Abnormal right ventricular tissue velocities after repair of congenital heart disease--implications for late outcomes

BACKGROUND: Although repair of Tetralogy of Fallot (TOF) and transposition of the great arteries (TGA) has facilitated survival into adulthood, many survivors have residual haemodynamic abnormalities, including exercise intolerance and late right ventricular (RV) failure. METHODS: We studied 40 asymptomatic adult subjects (31.3+/-1.5 years) after congenital heart disease (CHD) surgery during childhood, using tissue Doppler echocardiography (TDE). We compared systolic (S') and diastolic (E' for early filling) RV and LV velocities, with 40 age matched controls (29.5+/-1.0 years). RESULTS: Both RV S' and E' velocities were significantly slower in the CHD group compared to controls (6.3+/-0.4 cm/s vs. 9.3+/-0.3 cm/s; 8.5+/-0.5 cm/s vs. 10.9+/-0.4 cm/s, respectively, p<0.001 for both). By contrast, LV S' and E' velocities were similar in both groups. Interestingly, in 50% of CHD subjects where RV function was reported as 'normal', both RV S' and E' velocities were significantly slower compared with controls (6.5+/-0.6 cm/s vs. 9.3+/-0.3 cm/s, p<0.0001 and 9.4+/-0.7 cm/s vs. 10.9+/-0.4 cm/s, p<0.05 respectively). CONCLUSIONS: RV S' and E' velocities are frequently abnormal in asymptomatic survivors of TOF and TGA repair, even where RV function appears 'normal'. Hence TDE during follow up may be a sensitive means of detecting pre-clinical abnormalities in RV performance.     

2型糖尿病患者血清胱抑素C与冠心病的关系

目的探讨2型糖尿病患者血清胱抑素C（CysC）与冠心病的相关性。方法行冠脉造影检查的106例2型糖尿病患者,根据有无并发冠心病分为糖尿病合并冠心病组（36例）和糖尿病无冠心病组（70例）,检测空腹血糖、餐后2小时血糖、糖化血红蛋白、三酰甘油、胆固醇、血肌酐、高敏C反应蛋白、CysC、同型半胱氨酸等。分析冠心病与CysC的相关性,并用二元Logistic回归方法分析CysC和其他相关因素与冠心病之间的相关性。结果糖尿病合并冠心病组CysC含量明显高于无冠心病组（P〈0．001）,应用二元Logistic回归方法进行分析,发现CysC、高敏C反应蛋白、餐后2小时血糖、收缩压、体重指数与冠心病相关。结论CysC是2型糖尿病患者发生冠心病的独立危险因素,检测CysC是预测2型糖尿病患者冠心病发病的有意义的指标。     

Impairment of diastolic function in middle-aged Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetic patients free of cardiovascular disease

Summary Left ventricular systolic and diastolic function was studied using systolic time intervals and echocardiography in 19 male and 17 female patients with Type 1 (insulin-dependent) diabetes, 24 male and 15 female patients with Type 2 (non-insulin-dependent) diabetes and 24 male and 24 female control subjects. The subjects for the present study were selected from a population based study in which 117 Type 1 and 510 Type 2 diabetic patients and 649 non-diabetic subjects were originally examined. After exclusions, none of the subjects had any evidence of coronary heart disease, hypertension or other diseases known to affect left ventricular function. There were no consistent differences in systolic time intervals or echocardiographic variables of systolic function between patients with Type 1 diabetes and non-diabetic control subjects; but patients with Type 2 diabetes showed an increased fractional shortening. Female patients with Type 2 diabetes showed an increased left ventricular mass not explicable by hypertension. Isovolumic relaxation period was longer in male (86±3 ms; mean±SEM) and female patients (84±6 ms) with Type 2 diabetes than in male (76±3 ms; p<0.05) and female (71±3 ms; p<0.05) control subjects. Peak diastolic filling rate was lower in female patients with Type 1 diabetes (12.8±0.8 cm/s, p<0.05) and in male (11.5±0.8 cm/s; p<0.01) and female patients (11.5±0.6 cm/s; p<0.001) with Type 2 diabetes as compared to male (14.4±0.7 cm/s) and female (14.9±0.5 cm/s) control subjects. In male patients with Type 1 diabetes the respective value (12.7±0.6 cm/s) did not differ significantly from that in male control subjects. Altogether 14 diabetic patients (26%) showed an abnormal low peak diastolic filling rate. The impaired diastolic filling among diabetic patients did not show any relationship to the duration and metabolic control of diabetes or the presence of microangiopathy, but a weak correlation was found between the peak diastolic filling rate and the diminution of heart rate variation suggestive of the presence of diabetic autonomic neuropathy.     

Coronary heart disease is associated with mean platelet volume in type 2 diabetic patients

Background: Mean platelet volume (MPV) is an indicator of platelet activation which is a central process in the pathophysiology of coronary heart disease (CHD). The aim of the study was twofold; first to determine whether MPV values is increased in patients with DM, and secondly to evaluate the relation between diabetic complications and MPV. Methods: The study population included 258 patients divided into two groups. Group A composed of 158 type 2 diabetic patients with coexistent coronary artery disease (stenotic lesions of 50%) (78 women, 80 men; mean age 53.9_10.8; mean diabetes duration 13.1_6.0). One hundred subjects (48 women, 52 men; mean age 53.9_11) without type 2 diabetes with normal coronary angiographies were taken as the control group (group B). To evaluate the extension of CHD, Gensini scoring system was used. Results: The MPV was significantly different in the patient group compared to the controls (9.79 ± 1.5 fl vs 8.3 ± 0.9 fl, P<0.001). The existence of CHD was associated with MPV with odds ratio (95% CI) of 2.31 (1.55–4.42, p50.001). Conclusion: We have found that diabetic patients with coronary heart disease have significantly higher MPV values compared to control subjects without diabetes and with angiographically normal coronary arteries.     

A six-month exercise intervention in subclinical diabetic heart disease: Effects on exercise capacity,autonomic and myocardial function

Objective

Autonomic dysfunction may contribute to the etiology and exercise intolerance of subclinical diabetic heart disease. This study sought the efficacy of exercise training for improvement of peak oxygen uptake (VO_2peak) and cardiac autonomic function in type 2 diabetic patients with non-ischemic subclinical left-ventricular (LV) dysfunction.

Materials/Methods

Forty-nine type 2 diabetic patients with early diastolic tissue Doppler velocity > 1 standard deviation below the age-based mean entered an exercise intervention (n = 24) or usual care (n = 25) for 6-months (controlled, pre-/post- design). Co-primary endpoints were treadmill VO_2peak and 5-min heart-rate variability (by the coefficient of variation of normal RR intervals [CVNN]). Autonomic function was additionally assessed by resting heart-rate (for sympathovagal balance estimation), baroreflex sensitivity, cardiac reflexes, and exercise/recovery heart-rate profiles. Echocardiography was performed for LV function (systolic/diastolic tissue velocities, myocardial deformation) and myocardial fibrosis (calibrated integrated backscatter).

Results

VO_2peak increased by 11% during the exercise intervention (p = 0.001 vs. − 1% in controls), but CVNN did not change (p = 0.23). Reduction of resting heart-rate in the intervention group (p < 0.05) was associated with an improvement in the secondary endpoint of heart-rate variability total spectral power (p < 0.05). However, baroreflex sensitivity, cardiac reflexes, and exercise/recovery heart-rate profiles showed no significant benefit. No effects on LV function were observed despite favorable reduction of calibrated integrated backscatter in the intervention group (p < 0.05).

Conclusions

The exercise intolerance of subclinical diabetic heart disease was amenable to improvement by exercise training. Despite a reduction in resting heart-rate and potential attenuation of myocardial fibrosis, no other cardiac autonomic or LV functional adaptations were detected.     

亚临床甲状腺功能减退症与冠心病的相关性研究

目的:探讨亚临床甲状腺功能减退症与冠心病(CHD)严重程度的相关性。方法:242例患者根据冠状动脉造影的结果分为正常对照组72例、单支病变组60例、多支病变组110例,检测超敏促甲状腺素(s-TSH)、游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、总胆固醇、三酰甘油、低密度脂蛋白、高密度脂蛋白、脂蛋白(a)、高敏C反应蛋白,凝血因子Ⅰ、计算体质指数。结果:多支病变组的亚临床甲状腺功能减退症发病率明显高于正常对照组与单支病变组(均P<0.05),亚临床甲状腺功能减退症与CHD多支病变具有相关性(OR=2.250,P<0.05)。结论:亚临床甲状腺功能减退症是CHD多支病变的危险因素之一。     

The relative myocardial blood volume differentiates between hypertensive heart disease and athlete's heart in humans.

AIMS: The adaptation of the myocardial microcirculation in humans to pathologic and physiologic stress has not been examined in vivo so far. We sought to test whether the relative blood volume (rBV) measured by myocardial contrast echocardiography (MCE) can differentiate between left ventricular (LV) hypertrophy (LVH) in hypertensive heart disease and athlete's heart. METHODS AND RESULTS: Four groups were investigated: hypertensive patients with LVH (n = 15), semi-professional triathletes with LVH (n = 15), professional football players (n = 15), and sedentary control individuals without cardiovascular disease (n = 15). MCE was performed at rest and during adenosine-induced hyperaemia. The rBV (mL mL(-1)), its exchange frequency (beta, min(-1)), and myocardial blood flow (mL min(-1) g(-1)) were derived from steady state and refill sequences of ultrasound contrast agent. Hypertensive patients had lower rBV (0.093 +/- 0.013 mL mL(-1)) than triathletes (0.141 +/- 0.012 mL mL(-1), P < 0.001), football players (0.129 +/- 0.014 mL mL(-1), P < 0.001), and sedentary individuals (0.126 +/- 0.018 mL mL(-1), P < 0.001). Conversely, the exchange frequency (beta) was significantly higher in hypertensive patients (11.3 +/- 3.8 min(-1)) than in triathletes (7.4 +/- 1.8 min(-1)), football players (7.7 +/- 2.3 min(-1)), and sedentary individuals (9.0+/-2.5 min(-1)). An rBV below 0.114 mL mL(-1) distinguished hypertensive patients and triathletes with a sensitivity of 93% and a specificity of 100%. CONCLUSION: Pathologic and physiologic LVH were differentiated non-invasively and accurately by rBV, a measure of vascularisation assessed by MCE.