Lower vitamin D level is associated with poor coronary collateral circulation

Vitamin D and bisphosphonates therapies for osteoporosis are associated with different risks of atrial fibrillation in women: A nationwide population-based analysis

Osteoporosis and atrial fibrillation (AF) are common in post-menopausal women. Vitamin D and bisphosphonates are widely used to treat osteoporosis, and these may have different effects on the risk of AF.The goal of this study was to evaluate whether different agents for treating osteoporosis modulate the risk of AF in a population-based database.We identified 20,788 female patients suffering from osteoporosis who were or were not treated with vitamin D or bisphosphonates using the Taiwan National Health Insurance nationwide database from 2000 to 2008 and followed them up for 5 consecutive years to determine if they had a new diagnosis of AF after the diagnosis of osteoporosis.There were 14 (2.67%) new AF diagnoses in osteoporosis patients treated with bisphosphonates, one (0.28%) new AF diagnosis in patients treated with vitamin D, and 279 (1.40%) new AF diagnoses in patients who were not treated with vitamin D or bisphosphonates (neither group). Osteoporosis patients who received bisphosphonates showed a higher incidence of AF occurrence than those that were not treated with bisphosphonates (P = .015). In contrast, 1 patient who received vitamin D had a new diagnosis of AF during the study period; thus, the incidence was significantly lower than that in the patients treated with bisphosphonates (P = .007). In addition, the patients who were treated with vitamin D had a lower incidence of AF than did those who were not treated with either vitamin D or bisphosphonates (P = .074). Kaplan-Meier analysis also showed a significant difference in AF occurrence in different groups during the 5-year follow-up (P = .010).Different treatment for osteoporosis may carry diverse risks of AF occurrence. Vitamin D may have potential beneficial effects of reducing AF occurrence in osteoporosis patients.

Seasonal variation in mortality secondary to acute myocardial infarction in England and Wales: a secondary data analysis

BACKGROUND

Acute myocardial infarction (AMI) is a leading cause of death globally. Increase in AMI mortality during winter has also been identified in existing literature. This has been associated with low outdoor and indoor temperatures and increasing age. The relationship between AMI and other factors such as gender and socioeconomic factors varies from study to study. Influenza epidemics have also been identified as a contributory factor.

OBJECTIVE

This paper aims to illustrate the seasonal trend in mortality due to AMI in England and Wales with emphasis on excess winter mortality (EWM).

METHODS

Monthly mortality rates per 10 000 population were calculated from data provided by the UK Office for National Statistics (ONS) for 1997-2005. To quantify the seasonal variation in winter, the EWM estimates (EWM, EWM ratio, Excess Winter Mortality Index) for each year were calculated. Negative binomial regression model was used to estimate the relationship between increasing age and EWM.

RESULTS

The decline in mortality rate for AMI was 6.8% yearly between August 1997 and July 2005. Significant trend for reduction in AMI-associated mortality was observed over the period (p<0.001). This decline was not seen with EWM (p<0.001). 17% excess deaths were observed during winter. This amounted to about 20 000 deaths over the 8-year period. Increasing winter mortality was seen with increasing age for AMI.

CONCLUSION

EWM secondary to AMI does occur in England and Wales. Excess winter deaths due to AMI have remained high despite decline in overall mortality. More research is needed to identify the relationship of sex, temperature, acclimatisation, vitamin D and excess winter deaths due to AMI.

Assessment of 25-Hydroxyvitamin D Levels in Patients with Resistant Hypertension

OBJECTIVE

To investigate the possible correlation between serum 25-hydroxyvitamin D levels and resistant hypertension (RH).

SUBJECTS AND METHODS

Patients who had undergone ambulatory blood pressure measurements (ABPM) during outpatient controls were enrolled. Fifty subjects with RH, 50 with controlled hypertension (CHT) and 50 normotensive subjects (NT) were included in the study. RH was defined as 'suboptimal blood pressure control despite using 3 antihypertensive agents including a diuretic or need for 4 or more drugs to control blood pressure'. The 25-hydroxyvitamin D and parathormone levels were compared between the groups. Pearson's correlation coefficient test was applied to assess the correlation between 25-hydroxyvitamin D levels and office blood pressure (BP) and ABPM. Logistic regression analysis was used to determine the independent correlates of RH.

RESULTS

The 25-hydroxyvitamin D level was significantly lower in the RH group (17.02 ± 5.4 ng/ml) compared to the CHT (24.9 ± 4.8 ng/ml) and NT groups (28.0 ± 5.7 ng/ml, p < 0.001). In univariate correlation analysis, 25-hydroxyvitamin D levels had a significant negative correlation with office systolic BP (r = -0.329, p < 0.001), office diastolic BP (r = -0.395, p < 0.001), systolic ambulatory BP (r = -0.844, p = 0.004), and diastolic ambulatory BP (r = -0.567, p = 0.005). ROC analysis revealed that 25-hydroxyvitamin D levels <21.50 ng/ml predicted the presence of RH with a sensitivity of 78% and a specificity of 79% (AUC = 0.89, 95% CI 0.83-0.94). In the multivariate logistic regression analysis, 25-hydroxyvitamin D level was independently correlated with the presence of RH (β 0.660, 95% CI 0.572-0.760, p < 0.001).

CONCLUSION

There was an independent correlation between lower 25-hydroxyvitamin D levels and presence of RH.

25-Hydroxy-vitamin D level may predict presence of coronary collaterals in patients with chronic coronary total occlusion

Introduction

Sufficient coronary collateral circulation (CCC) protects myocardial tissue against ischemia in patients with coronary chronic total occlusion (CTO). Vitamin D is a steroid hormone which has been related to increased prevalence of hypertension, left ventricular hypertrophy, heart failure, peripheral artery disease, coronary artery disease, myocardial infarction and cardiovascular mortality.

Aim

To investigate whether there is an association between serum 25-hydroxy-vitamin D levels and development of CCC in patients with coronary CTO.

Material and methods

A total of 188 patients with CTO at coronary angiography were included in this study. Vitamin D and parathyroid hormone (PTH) levels were measured on the day of coronary angiography. Development of collateral circulation was graded according to the Rentrop classification after coronary angiography. Then, patients were divided into two groups on the basis of CCC grades: group 1 included 68 (36%) patients with poorly developed CCC, and group 2 included 120 (64%) patients with well-developed CCC.

Results

Patients with poorly developed CCC had significantly lower serum 25-hydroxy-vitamin D levels compared to those with well-developed CCC (20 ±3 vs. 30 ±6 ng/ml, p<0.0001). Multivariate logistic regression analysis indicated serum 25-hydroxyvitamin D (25(OH)D) (OR = 1.794, 95% confidence interval (CI): 1.453–2.216; p<0.001) as an independent predictor of poor collateral flow in patients with CTO.

Conclusions

Low vitamin D level is an independent predictor of poor CCC in patients with CTO.

Coronary collateral development and arterial stiffness in patients with chronic coronary total occlusions

OBJECTIVE

Coronary collateral circulation (CCC) mainly develops through arteriogenesis in response to shear forces. Increased arterial stiffness (AS) causes decreased coronary perfusion, which may reduce shear stress, arteriogenesis, and thus collateral formation. The aim of this study was to assess the relationship between CCC and AS in patients with chronic coronary total occlusion (CTO).

DESIGN

We prospectively enrolled 163 patients with CTO. Patients were divided into two groups according to their Rentrop scores: (a) poorly developed (PD) CCC group (Rentrop 0-1) and (b) well-developed (WD) CCC group (Rentrop 2-3). AS measurements were carried out using a Mobil-O-Graph arteriography system.

RESULTS

Fasting glucose, creatinine, uric acid, neutrophil count, and neutrophil-to-lymphocyte ratio were found to be higher in patients with PD-CCC. Moreover, patients with PD-CCC had significantly higher augmentation index (AIx) and pulse wave velocity (PWV) compared with WD-CCC group (27.3 ± 8.9 vs. 18.7 ± 7.4, p < 0.001 and 11.7 ± 2.6 vs. 8.5 ± 1.4, p < 0.001, respectively). In multivariate logistic regression analysis, PWV, AIx, and serum uric acid were found to be independently associated with the development of CCC.

CONCLUSION

AS parameters, such as AIx and PWV, as well as serum uric acid are independently associated with the development of CCC in stable coronary artery disease with CTO.