zulkarnain jaafar

The comparison of the exercise stress test tolerance using Bruce and Balke-Ware protocols in Malaysians. Gazzetta Medica Italiana Archivio per le Scienze Mediche

Jaafar Z., Mokhtar A.H., Abdul Hamid M.S., Mohamed Ali M.R.
Background: The issue of premature termination of exercise stress test in Asian people due to intolerance to rapid exercise workload increment in Bruce protocol has been pointed out. In this study, we want to compare the exercise stress test tolerance using Bruce and Balke-Ware protocols. Methods: This was a cross-over experimental study involving 30 male subjects aged 40-65 year-old performing exercise stress test using Bruce and Balke-Ware protocols. Hemodynamic responses, electrocardiographic pattern and exercise duration were monitored during the test and the reason for termination was recorded. Results: Bruce protocol achieved equivalent hemodynamic responses, completion rate and test findings to Balke-Ware (P>0.001). C50% of the subjects were able to complete the stress test using both protocols. 46.7% (n=14) of subjects terminate the test prematurely for Bruce and 50% (n=15) for Balke-Ware protocol. Fatigue was the commonest cause with (57.2% n=8, 60% n=9), followed by achieved target heart rate (35.5% n=5, 33.3% n=5) and shortness of breath (7.1% n=1, 6.7% n=1) for Bruce and Balke-Ware respectively. The exercise capacity (Metabolic Equivalent) attained during exercise was similar in both protocol (p>0.001), and exercise duration in Balke-Ware was significantly longer than the Bruce protocol (p<0.001). Conclusions: We found that protocol selection does not affect the completion rate and outcome of the exercise stress test and their tolerance was similar regardless of the protocols used. For Asian peoples who were unable to complete the exercise stress test due to any reasons, their cardiac status is best evaluated using other methods. Keyword: Exercise test, Workload, Exercise tolerance, Coronary Artery Disease, Electrocardiography

VALIDATION OF SMARTPHONE FREE HEART RATE MONITORING APPLICATION DURING TREADMILL EXERCISE

Zulkarnain Jaafar Aravind Kumar Murugan
Objective: The number of people participating in leisure sports activities and amateur competitions has been rising sharply. Free smartphone heart rate monitoring applications are readily available for use; however, information on their accuracy during exercise is still limited. Therefore, the purpose of our study was to validate a smartphone free heart rate monitoring application during treadmill exercise in healthy individuals. Methods: This was a prospective experimental study testing the free heart rate app 'INSTANT HEART RATE: AZUMIO.' Twenty-seven healthy participants were requested to perform the treadmill task with four different workloads: walking at 2.0 mph, walking at 3.5 mph, jogging at 4.5 mph and running at 6.0 mph. Participants had to perform the exercises for 3 minutes for each workload, and heart rates were recorded using the smartphone app and ECG at rest, during the exercise and recovery periods at each 60-second interval. Results: Heart rates measured using the free smartphone app at rest, walking at 2.0 mph, brisk walking at 3.5 mph, slow jogging at 4.5 mph and recovery stage were accurate with correlation coefficient value ≥0.95 and standard error of estimate <1 bpm. However, the correlation values during running at 6 mph were inconsistent with a standard error of estimate >5 bpm. Conclusion: The free smartphone app that we tested accurately estimates heart rate at rest, during low to moderate intensity exercise and the recovery period, but becomes less consistent during high-intensity exercise, making this app suitable for use during indoor activities of low to moderate intensity. Level of evidence II; Diagnostic Studies - Investigating a diagnostic test.

Correlation between body composition and cardiorespiratory fitness in female adults of different Body Mass Index

Zulkarnain JAAFAR, Mun Y. OOI, Nurhanani RAZALI
BACKGROUND: Obesity has become a major public concern as it leads to significant health risk and economic burden especially to the developing countries. The prevalence of obesity is also significantly higher among the female adults. It is also known that low fitness level is a powerful and independent risk factor for premature mortality. However, the understanding of the relationship between overall body composition indices and cardiorespiratory fitness in adults remains limited. This study aimed to investigate the correlation between body composition with cardiorespiratory fitness among normal weight, overweight and obese in female adults. METHODS: Eighty-one female participants aged between 18 to 59 years who cleared the inclusion and exclusion criteria were divided into three groups; normal weight (N.=23), overweight (N.=29) and obese (N.=29). They went through bio-electrical impedance analysis measurement and cardiopulmonary fitness testing using ramp protocol in Sport Medicine human performance lab. RESULTS: It was noted that there was an inverse strong strength significant correlation between VO 2 max and Body Mass Index (r=-0.588, P<0.001, Waist Hip Ratio (r=-0.596, P<0.001), Percentage Body Fat (r=-0.684, P<0.001) and Body Fat Mass (r=-0.667, P<0.001). However, skeletal muscle mass showed no significant correlation with VO 2 max. There was also a high significant difference among the three groups in term of VO 2 max (F=7.683, P=0.001) after alleviating the age factor. CONCLUSIONS: In conclusion, our study showed significant correlation between VO 2 and body composition particularly percentage of body fat (%) and body fat mass (kg). It will be more convenience and cost-effective especially in developing countries, if body composition can be used as an independent entity to predict cardiorespiratory fitness among individual. Furthermore, cardiorespiratory exercise testing showed significant differences of VO 2 max among 3 groups. This will be beneficial if the VO 2 max is used as a tool to predict cardiovascular risk. Therefore, we would suggest in-depth studies to be done in the future to provide more knowledge regarding this important topic on a bigger scale subjects.

The Association Between Physical Activity and Work Schedule among Hospital Nurses: A Cross-Sectional Study

Zhuang Li Lim, Mahmoud Danaee, Zulkarnain Jaafar
Physically sedentary and overweight nurses appear to be less credible in inculcating healthy behaviour among patients. Shift-work has been shown to promote physical inactivity, whilst sedentarism strongly correlates with a high body mass index (BMI). We aim to determine the level of physical activity among hospital nurses of different work schedules, i.e. shift-work and day-work; and explore any associations between nurses’ demographic backgrounds, BMI, and work schedules with their physical activity level. This cross-sectional study design was employed. The self-administered Malaysian International Physical Activity Questionnaire – Long form (IPAQ-L) and a demographic survey sheet were provided to the eligible nurses. Bivariate and subsequent regression analyses were performed to determine their associations. A total of 1988 nurses from the University Malaya Medical Centre, Kuala Lumpur were invited to participate in this study. There were 1504 (76%) returned responses, with 77% of responding nurses working shift. Based on the IPAQ-L, 87% of the nurses were deemed highly active, while another 11% were moderately active. Upon stratifying into shift-work and day-work, statistically significant differences were observed between the groups in the domains of ‘work’ (p = 0.016), ‘domestic chores’ (p = 0.038), and in intensity-specific ‘walking’ (p = 0.046) and ‘vigorous’ activities (p = 0.034). There were no differences among groups within categories of physical activities (p = 0.355). Regression analysis showed significant difference for ‘duration of daily vehicle travel’, with the day-workers reporting a longer adjusted travel time (76.50 minutes/day, p < 0.001). Working shift does not seem to harm an individual nurse’s overall measured physical activity, as evidenced by equivalent high values of physical activity engagement between both work schedules. Any differences within domains and intensities of physical activities may be attributed to the respective cohort characteristics.

Anthropometrical and fitness level changes following a 12-week walking football program for obese primary school children aged 8-11

Zulkarnain Jaafar, Jeffrey Kee, Haireen Abdul Hadi, Nur Amani NATASHA Ahmad Tajuddin
BACKGROUND: Many children are currently adopting a sedentary lifestyle at a very young age, making the obesity in children increase at an alarming rate. Walking is the most accessible type of physical activity as it is safe and its benefits are similar to exercise. The researchers introduced a walking football game to obese primary school children with the aim of gathering pilot data on the changes in the anthropometrical and fitness level throughout the 12-week program. METHODS: This was a cohort repeated-measures study involving 32 healthy male school children aged 8-11-year-old with the BMI of more than 21 kg/m² (>95th centile) from 8 primary schools around Petaling Jaya. The subjects were instructed to train in a multiple short 6-a-side semi-structured moderate-intensity walking football training sessions for 75 minutes each week. Anthropometry, body composition, and 6-minute walk test were measured at the baseline and after the program ended. RESULTS: There was a significant increase in the mean weight, BMI, muscle mass and 6-minute walk test distance post-intervention, P<0.001. Even though there was a reduction in the body fat percentage, it was not statistically significant P>0.05. It was also noted that there was an inverse moderate strength correlation between age and fat mass (r -0.458, P<0.01), body fat percentage (r -0.448, P<0.05), and a moderately positive correlation between age and muscle mass (r 0.395, P<0.05). CONCLUSIONS: This study demonstrates positive outcomes on the anthropometrical and fitness changes among the obese school children participating in a 12-week walking football program, a low impact moderate-intensity exercise. The cost-effectiveness of walking football suggests its feasibility to be implemented nationwide to combat the rising problems of inactivity and childhood obesity.

Plasma antioxidants and oxidative stress status in obese women: correlation with cardiopulmonary response

Dyg Mastura Adenan, Zulkarnain Jaafar, Jaime Jacqueline Jayapalan, Azlina Abdul Aziz
Introduction A high body fat coupled with low cardiopulmonary fitness and an increase in oxidative stress has been connoted as contributing factors in developing cardiovascular comorbidities. This study aimed to investigate the correlation between antioxidants and oxidative stress status with cardiopulmonary responses in women of different body mass index (BMI). Subjects and Methods Eighty female adults were recruited and divided into three groups; normal weight ( n = 23), overweight ( n = 28) and obese ( n = 29), according to their BMI. Blood samples were obtained prior to cardiopulmonary exercise testing. Plasma samples were separated by centrifugation and analysed for enzymatic antioxidant activity including catalase, glutathione peroxidase and superoxide dismutase. Non-enzymatic antioxidant activities were assessed using 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging and ferric reducing ability of plasma (FRAP) assays. To evaluate the oxidative stress status of subjects, levels of reactive oxygen species and malondialdehyde, the by-product of lipid peroxidation, were measured. Cardiopulmonary responses were analysed using cardiopulmonary exercise testing (CPET) which involved 15 various parameters such as peak oxygen consumption, metabolic equivalents and respiratory exchange ratio. Results The obese group had significantly lower ABTS radical scavenging and FRAP activities than the normal weight group. A higher catalase activity was observed in the obese group than the normal weight group. Spearman’s correlation showed an inverse relationship between catalase and peak oxygen consumption, while partial correlation analysis showed inverse correlations between superoxide dismutase and respiratory frequency, ABTS activity and oxygen pulse, and between ABTS activity and cardiac output. Conclusion Our results demonstrate a lower cardiovascular fitness and antioxidant capacity in obese women; the higher catalase activity may be a compensatory mechanism. The negative correlations found between these two parameters may indicate the potential effect of antioxidants on the cardiopulmonary system and deserve further analysis in a larger population. Nevertheless, this study provides the basis for future studies to further explore the relationships between redox status and cardiopulmonary responses. This can potentially be used to predict future risk of developing diseases associated with oxidative stress, especially pulmonary and cardiovascular diseases.