Association factors of target organ damage: analysis of 17,682 elderly hypertensive patients in China.

BACKGROUND: Hypertensive target organ damage (TOD) is the main reason for mortality or disability in elderly hypertensive patients. The studies on TOD of hypertension in Asia, especially in Chinese elderly hypertensive patients, are very limited. The aim of this study was to evaluate the prevalence and correlative factors of TOD in older Chinese hypertensive inpatients. METHODS: This is a retrospective survey and data were collected from the computerized medical files of hypertensive inpatients from January of 1993 to December of 2008. The analysis was done on 17 682 inpatients, aged 60 years or older, with a diagnosis of essential hypertension (EH). The evidence of hypertensive TOD and associated factors with TOD were collected. RESULTS: The prevalence of any hypertensive target organ involvement among these subjects was high. In multivariable Logistic regressions adjusted for potentially confounding factors, older age, male gender, diabetes, EH grade 3, systolic blood pressure (SBP), and low-density lipoprotein cholesterol (LDL-C), were independently associated with coronary artery disease. Age, duration of EH, EH grade 3, SBP, pulse pressure (PP), and homocysteine (Hcy) were independently associated with cerebrovascular disease. Age, diabetes, duration of EH, EH grade 3, SBP, PP and estimated glomerular filtration rate (eGFR) were independently associated with chronic kidney disease. Male gender, EH grade 3 and SBP were independently associated with aortic dissection. CONCLUSIONS: The prevalence of hypertensive TOD is high in older Chinese hypertensive inpatients. Various cardiovascular risk factors are associated with hypertensive TOD. The level of SBP and severe hypertension (grade 3 hypertension) are common independent risk factors of TOD.

Effects of autoantibodies against M2 muscarinic acetylcholine receptors on rabbit atria in vivo.

BACKGROUND: Evidence has shown that autoantibodies against M2 muscarinic acetylcholine receptors may play a role in the development of atrial fibrillation. The goal of this study was to evaluate the effects of anti-M2 receptor autoantibodies on rabbit atria in vivo. METHODS: Rabbits were immunized monthly with a synthetic peptide corresponding to the M2 receptor. The atrial electrophysiology of the isolated perfused rabbit hearts was studied. Western blots and RT-PCR were performed to determine the expression of the atrial muscarinic receptor and the acetylcholine-activated potassium channel. Atrial tissue was stained with Masson's trichrome stain for fibrosis detection. RESULTS: Autoantibodies were persistently detected in immunized rabbits. M2 rabbits showed a significantly shorter atrial effective refractory period and a longer intra-atrial activation time than control rabbits. Electrical stimuli induced a significantly larger number of repetitive atrial responses in M2 rabbits. The protein levels of the M2 receptor and GIRK4 were upregulated in M2 rabbits. The mRNA levels of GIRK1 and GIRK4 were also upregulated. Histological examination revealed significantly increased diffuse fibrotic deposition in M2 rabbit atria compared with control rabbits. CONCLUSION: The M2 receptor autoantibody-positive rabbits showed altered atrial electrophysiology, overexpression of the M2 receptor-I(K,ACh) pathway and atrial fibrosis, which indicates that the autoantibodies against M2 receptors may participate in the induction and perpetuation of atrial fibrillation.