Genetically predicted testosterone and electrocardiographic QT interval duration in Chinese: a Mendelian randomization analysis in the Guangzhou Biobank Cohort Study.

BACKGROUND: QT interval prolongation, a predictor of cardiac arrhythmias, and elevated heart rate are associated with higher risk of cardiovascular mortality. Observationally testosterone is associated with shorter corrected QT interval and slower heart rate; however, the evidence is open to residual confounding and reverse causality. We examined the association of testosterone with electrocardiogram (ECG) parameters using a separate-sample instrumental variable (SSIV) estimator. METHODS: To minimize reverse causality, a genetic score predicting testosterone was developed in 289 young Chinese men from Hong Kong, based on a parsimonious set of single nuclear polymorphisms (rs10046, rs1008805 and rs1256031). Linear regression was used to examine the association of genetically predicted testosterone with QT interval, corrected QT interval [using the Framingham formula (QTf) and Bazett formula (QTb)] and heart rate in 4212 older (50+ years) Chinese men from the Guangzhou Biobank Cohort Study. RESULTS: Predicted testosterone was not associated with QT interval [-0.08 ms per nmol/l testosterone, 95% confidence interval (CI) -0.81 to 0.65], QTf interval (0.40 ms per nmol/l testosterone, 95% CI -0.12 to 0.93) or heart rate (0.26 beats per minute per nmol/l testosterone, 95% CI -0.04 to 0.56), but was associated with longer QTb interval (0.66 ms per nmol/l testosterone, 95% CI 0.02 to 1.31). CONCLUSIONS: Our findings do not corroborate observed protective associations of testosterone with QT interval or heart rate among men, but potentially suggest effects in the other direction. Replication in a larger sample is required.

Alcohol consumption and electrocardiographic left ventricular hypertrophy and mediation by elevated blood pressure in older Chinese men: the Guangzhou Biobank Cohort Study.

BACKGROUND: Chinese people have a markedly lower alcohol consumption than people in the West. Whether alcohol consumption at such levels is associated with left ventricular hypertrophy, and the role of blood pressure (BP) in this relationship is unclear. We investigated the association between alcohol consumption and electrocardiographic left ventricular hypertrophy (ECG-LVH) and the mediating role of BP in Chinese men aged ≥50 years. METHODS AND RESULTS: A case-control analysis was conducted on baseline cross-sectional data from the community-based Guangzhou Biobank Cohort Study (2003-2008), using standard 12-lead resting electrocardiograms. By comparing 191 new ECG-LVH cases with 4311 controls, excessive drinking (>210 g/week) showed excess risks for ECG-LVH (odds ratio [OR] = 1.90, 95% confidence interval [CI] = 1.12-3.24), after adjusting for education, income, occupation, physical activity, smoking, body mass index, fasting glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, BP, and antihypertensive medication. Mediation analysis showed a significant mediating effect of BP on the association between excessive drinking and ECG-LVH: systolic (31%) and diastolic (16%). After multivariate adjustment, no significant association was found between occasional drinking (210 g/week in Chinese men is an independent risk factor for ECG-LVH. Low power prevented us from examining whether drinking at

Effectiveness of 3 surgical decompression strategies for treatment of multilevel cervical myelopathy in 3 spinal centers in China: a retrospective study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: To compare clinical outcomes and surgical-related adverse events in patients with multilevel cervical myelopathy (MCM) undergoing simple anterior, simple posterior, or 1-stage posterior-anterior surgical decompression strategies. SUMMARY OF BACKGROUND DATA: Simple anterior, simple posterior, and 1-stage posterior-anterior surgical decompression strategies have been advocated for MCM treatment in both Western and Chinese populations. However, there is limited evidence on whether 1-stage posterior-anterior strategy may offer equal or more advantages than the other 2 strategies for patients with MCM. METHODS: A retrospective review of medical records was conducted for 255 patients with MCM who had undergone surgical decompression in 3 Chinese spinal centers from 1999 to 2010. Neurological status, perioperative variables, and surgical complications were assessed. Multiple linear regression was used to evaluate factors associated with the outcomes of each strategy. RESULTS: Analyses were conducted on a total of 229 patients with MCM undergoing surgical decompression via 1-stage posterior-anterior (68 patients), simple anterior (102 patients), and simple posterior approaches (59 patients). One-stage posterior-anterior approach had the highest Japanese Orthopaedic Association recovery rate after adjusted for age and sex (adjusted mean ± SD: 50.0 ± 3.2, P < 0.001) and additionally adjusted for smoking, duration from onset of symptoms to surgery, comorbidities, preoperative Japanese Orthopaedic Association score, Ishihara's curvature index and Pavlov ratio, operative blood loss, operating time, anterior operated disc levels, and posterior operated levels (adjusted mean ± SD: 51.6 ± 11.6, P < 0.01). Anterior approach had the largest difference between the pre- and postoperative Ishihara's curvature indexes after adjusted for age and sex (adjusted mean ± SD: 5.3 ± 1.0, P < 0.01) and after multivariable adjustment (adjusted mean ± SD: 6.5 ± 2.8, P = 0.003). CONCLUSION: One-stage posterior-anterior strategy can be a reliable and effective treatment strategy for MCM in a subgroup of patients with anterior and posterior compression on spinal cord simultaneously.

MicroRNA-10a targets CHL1 and promotes cell growth, migration and invasion in human cervical cancer cells.

MicroRNAs (miRNAs) play an important role in cancer initiation, progression and metastasis by regulating their target genes. Here, we found microRNA-10a (miR-10a) is upregulated in human cervical cancer and promotes the colony formation activity, migration and invasion of HeLa and C33A cells. Subsequently, CHL1 is confirmed as a target of miR-10a and is negatively regulated by miR-10a at mRNA and protein levels. Furthermore, knockdown of CHL1 expression results in increased colony formation activity, migration and invasion. Finally, overexpression of CHL1 lacked the 3'UTR abolished the effects of miR-10a. Our results may provide a strategy for blocking tumor metastasis.

Atrial fibrillation and obesity among older Chinese: the Guangzhou Biobank Cohort Study.

BACKGROUND: Atrial fibrillation (AF) is the most common form of arrhythmia, and its prevalence is increasing. Few studies have examined its association with obesity as defined by different criteria, particularly in developing countries. We investigated the association between atrial fibrillation (AF) and obesity indices among older Chinese. METHODS: We conducted a community-based nested case control study using cross-sectional data of 5882 men and 14,548 women aged 50 or above from Phases I and II (September 2003 to May 2006) of the Guangzhou Biobank Cohort Study (GBCS). AF cases were identified by the 12-lead body surface electrocardiogram. RESULTS: 159 AF cases (65 men and 94 women) were identified from 19,964 participants with ECG records. 9249 participants with other abnormal ECG findings were excluded, resulting in a case control comparison on 159 AF cases and 10,369 controls. After multivariate adjustment, BMI (adjusted odds ratio (OR) 1.06 per kg/m(2), 95% confidence interval (CI)=1.01-1.11) and waist circumference (adjusted OR 1.02 per cm (1.00-1.04)) were significant risk factors. The adjusted OR per Z-score [(individual value-mean)/standard deviation] for BMI and waist circumference was 1.21 (1.03-1.41) and 1.18 (1.01-1.38) respectively. CONCLUSIONS: This is the first report showing that both general and central obesity are associated with increased risk of AF in an Eastern population with much lower level of obesity than in the West. As both AF and obesity are increasing in developing countries, the results should have important public health implications.