Exercise and cardiovascular diseases

The association between physical activity and neck circumference with cardiovascular disease risk in older wheelchair users

OBJECTIVE

To examine the association between physical activity, neck circumference, and cardiovascular disease risk in older wheelchair users.

DESIGN

A cross-sectional study.

SUBJECTS/PATIENTS

Sixty-one Korean wheelchair users aged 50 years and older.

METHODS

Physical activity was assessed using a self-administered questionnaire. Neck circumference was measured with a tape ruler. Cardiovascular disease risk was evaluated by calculating the Framingham risk score (FRS) for estimating 10-year cardiovascular disease risk, which was classified as low-moderate (19% or less) or high risk (20% or more).

RESULTS

The FRS for 10-year cardiovascular disease risk was inversely related to physical activity (beta [SE] = -0.213 (0.103), p = 0.043) and positively related to neck circumference (beta [SE] = 1.331 ± 0.419, p = 0.003). Binary logistic regression showed that those with low physical activity (odds ratio [95% confidence interval] = 4.256 (1.188~15.243), p = 0.026) or a large neck circumference (odds ratio [95% confidence interval] = 3.645 (1.172~11.338), p = 0.025) had a higher risk for high cardiovascular disease risk compared with those with high physical activity or normal neck circumference.

CONCLUSION

The current study findings suggest that an intervention targeting physical inactivity and upper-body obesity should be implemented to reduce cardiovascular disease risk in older wheelchair users.

Abnormal Mitochondria-Endoplasmic Reticulum Communication Promotes Myocardial Infarction

Myocardial infarction is characterized by cardiomyocyte death, and can be exacerbated by mitochondrial damage and endoplasmic reticulum injury. In the present study, we investigated whether communication between mitochondria and the endoplasmic reticulum contributes to cardiomyocyte death after myocardial infarction. Our data demonstrated that hypoxia treatment (mimicking myocardial infarction) promoted cardiomyocyte death by inducing the c-Jun N-terminal kinase (JNK) pathway. The activation of JNK under hypoxic conditions was dependent on overproduction of mitochondrial reactive oxygen species (mtROS) in cardiomyocytes, and mitochondrial division was identified as the upstream inducer of mtROS overproduction. Silencing mitochondrial division activators, such as B cell receptor associated protein 31 (BAP31) and mitochondrial fission 1 (Fis1), repressed mitochondrial division, thereby inhibiting mtROS overproduction and preventing JNK-induced cardiomyocyte death under hypoxic conditions. These data revealed that a novel death-inducing mechanism involving the BAP31/Fis1/mtROS/JNK axis promotes hypoxia-induced cardiomyocyte damage. Considering that BAP31 is localized within the endoplasmic reticulum and Fis1 is localized in mitochondria, abnormal mitochondria-endoplasmic reticulum communication may be a useful therapeutic target after myocardial infarction.

Association of exercise participation levels with cardiometabolic health and quality of life in individuals with hepatitis C

Objective

Hepatitis C virus (HCV) infection is associated with an increased risk of cardiovascular disease (CVD) and reduced health-related quality of life (HRQoL). Although physical activity (PA)/exercise has been shown to reduce CVD risk and improve HRQoL in patients with liver disease, there is limited data in HCV. We aimed to explore the association between PA/exercise levels, CVD risk and HRQoL in patients with HCV and assess individuals’ attitudes to PA/exercise.

Design

Cross-sectional observational study recruiting consecutive patients with HCV from viral hepatitis clinics. Data were collected on CVD risk factors, anthropometry, HRQoL and the Exercise Benefits and Barriers Scale (EBBS).

Results

86 patients were recruited (71% men, 94% white, age 52±13 years); 49% of the cohort self-reported to be currently active. Although HRQoL was reduced across the cohort, patients that were regularly ‘active’ reported significantly higher HRQoL scores across Short-Form 36v2 domains compared with their inactive counterparts (p<0.05). Metabolic and cardiovascular characteristics were no different between groups stratified by PA/exercise status (p>0.05). EBBS scores were similar in the ‘active’ versus ‘inactive’ groups, however, patients categorised as ‘active’ scored significantly higher on the psychological outlook and social interaction subscales (p<0.05) than those that were ‘inactive’. There were significant associations between EBBS scores and HRQoL (p<0.05).

Conclusions

PA/exercise is associated with increased HRQoL in patients with HCV irrespective of clinical parameters. Addressing specific motivators/barriers to exercise for patients will be key to designing effective PA/exercise interventions in this patient population to ensure maximum uptake and adherence.