Background: The cardiorespiratory fitness in prediabetic population at pre- and post-interventional stage after 8 weeks of moderate intensity exercise was determined. This study is part of PhD project and carried out in Physiology department, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan. Methods: It was an experimental study design. Adult prediabetics (n=50), 22 females and 28 males of 18 to 35y age group were included in the study. Diagnosis of prediabetes was made with HbA1c falling in the range of 5.7â€“ 6.4%, and fasting blood glucose (100-125mg/dL). Cardiorespiratory fitness parameters (Ventilation, oxygen consumed during exercise VO2, carbon dioxide exhaled VCO2, metabolic equivalents (ME), heart rate (HR), heart rate reserve (HRR), rate of carbohydrate oxidation (RCHO), fat oxidation (RFO) and energy expenditure (EE)) were determined at pre- and post-exercise intervention using breath-by-breath analyzer. The participants performed moderate exercise protocol of 30 min with HRmax% of 70 Â± 5% for 5 days a week for 8 weeks during their leisure time, monitored with pedometers. Results: The results showed a significant improvement in cardiorespiratory fitness parameters at post exercise analysis.Â  Similar changes were observed for fasting blood glucose (P value &lt; 0.001)Â  and HbA1c (P value &lt; 0.001).Conclusion: Moderate physical activity for 8 weeks showed significant Improvement in cardiorespiratory fitness parameters and glycemic status of patients with prediabetes

Fayyaz, F

Malik, O

Shah, I

Shah, Z

English

Sarhad University of Science & Information Technology (SUIT), Peshawar: E-Journals

71    THE PHYSIOLOGICAL RESPONSE OF CARDIORESPIRATORY FITNESS PARAMETERS TO EXERCISE IN PREDIABETIC POPULATION: AN EXPERIMENTAL PRE- POST DESIGN Z. Shah1, I. Shah*2, O. Malik3, F. Fayyaz4  ABSTRACT Background: The cardiorespiratory fitness in prediabetic population at pre- and post-interventional stage after 8 weeks of moderate intensity exercise was determined. This study is part of PhD project and carried out in Physiology department, Institute of Basic Medical Sciences, Khyber Medical University, Peshawar, Pakistan. Methods: It was an experimental study design. Adult prediabetics (n=50), 22 females and 28 males of 18 to 35y age group were included in the study. Diagnosis of prediabetes was made with HbA1c falling in the range of 5.7– 6.4%, and fasting blood glucose (100-125mg/dL). Cardiorespiratory fitness parameters (Ventilation, oxygen consumed during exercise VO2, carbon dioxide exhaled VCO2, metabolic equivalents (ME), heart rate (HR), heart rate reserve (HRR), rate of carbohydrate oxidation (RCHO), fat oxidation (RFO) and energy expenditure (EE)) were determined at pre- and post-exercise intervention using breath-by-breath analyzer. The participants performed moderate exercise protocol of 30 min with HRmax% of 70 ± 5% for 5 days a week for 8 weeks during their leisure time, monitored with pedometers. Results: The results showed a significant improvement in cardiorespiratory fitness parameters at post exercise analysis.  Similar changes were observed for fasting blood glucose (P value < 0.001)  and HbA1c (P value < 0.001).Conclusion: Moderate physical activity for 8 weeks showed significant Improvement in cardiorespiratory fitness parameters and glycemic status of patients with prediabetes.  Key Words: Exercise,  Prediabetes,  glycemic  status,  cardiorespiratory fitness.  INTRODUCTION Prediabetes is a preclinical stage with a higher risk of developing diabetes mellitus type 2 (T2DM) (Shimodaira et al., 2013). It has been reported by WHO (World Health Organization) that ‘’12.9 million people in Pakistan are diabetic with an estimated 38 million suffering from prediabetes (Wang et al., 2010). The second National Diabetes Survey of Pakistan conducted from  1-3 Khyber Medical University, Peshawar-Pakistan. 4 Kabir Medical College, Peshawar-Pakistan. * Corresponding Author: Dr Inayat Shah, Director KMU, Peshawar. drinayatshah@kmu.edu.pkReceived 25 March, 2021 Accepted 23 June, 2021 72      February 2016 to August 2017, showed a prevalence of 26.3% for diabetes and 14.4% for prediabetes. The estimated count of prediabetics in the world is 314 million and is expected to rise by 2025 to 418 million (Akhtar et al., 2016). The role of exercise as a treatment tool for DM and its complications is very well established (Powers et al., 2010) and as outlined by ‘landmark Diabetes Prevention Program’ that exercise is a standard therapeutic intervention for prevention of diabetes and prediabetes (Knowler et al., 2002). The assessment of functional capacity of the cardiorespiratory system is important in exercise physiology and sports medicine. The parameters used for cardiorespiratory fitness includes many parameters such as basal heart rate (BHR), heart rate reserve, oxygen uptake, carbon dioxide exhaled, VO2/ VCO2, VO2/kg/min, Metabolic equivalents (METS) and energy expenditure (Akalan et al., 2008; Bruce et al., 1973). The prevalence of physical inactivity is on the rise and is being associated with modernization and use of gadgets. Approximately, 14% of adolescents and 30% of adults have been reported to be physically inactive (Hales et al., 2018). In addition, the prevalence of physical inactivity rises with age; 25% for young adults between 18–44 years, 33%, for 45–64 years age group, 36% for 65–74 years age group and 53% for elderly ≥ 75 years age (Kasiakogias & Sharma, 2020). There are detrimental effects of inadequate physical activity on health. Increasing sitting time by one hour a day in type 2 diabetes mellitus increases the mortality risk by 13%. Furthermore, inactive lifestyle can lead to poor circulation, arthritis, osteoporosis, less social interactions, and overall poor quality of life (Liu et al., 2018; Mondal & Mishra, 2017). Regular exercise ensures good health; however, intense, irregular, or unplanned physical activity can have detrimental effects on health (Yavari et al., 2015). Sub-maximal exercise testing has become very popular, because it reduces the risk of adverse events and is safer than maximal exercise testing. There is no structured protocol till date in literature that can guide exercise physiologists, medical personnel, sport scientists towards an appropriate ‘sub-maximal protocol selection’ (Akalan et al., 2008). The modalities mostly used are stepping, walking, cycling, and running. Treadmill exercise is ideal for gym and clinical testing because the speed is well defined and can be monitored. Walk, run, or step count can be used as a modality for exercise but step count is ideal in different settings and can be given to a wider population, monitored with pedometers (Gibbons et al., 2001). In addition, little is known about the effect of planned exercise activity for prolonged duration on the cardiorespiratory fitness in prediabetics population. Due to non-availability of any pharmaceutical management for prediabetes, regular physical activity can be considered as one of the best alternatives. As it 73      is evident from the literature that development of diabetes is a multi-factorial complex process and can lead to deranged cardiorespiratory fitness parameters. The current study is therefore designed to find out the effect of regular exercise of moderate intensity for 8 weeks on the cardiorespiratory fitness of prediabetics.  METHODS Experimental design It was an experimental study design with convenience sampling. All experimental work was carried out from February 2019 – January 2020 in the Physiology Department, Institute of Basic Medical Sciences (IBMS) Khyber Medical University (KMU) Peshawar, Pakistan. Ethical approval for the study was granted by Ethical review board of Khyber Medical University under letter No: DIR/KMU-EB/BP/000580 dated 09/04/2019 and all the procedures were carried in accordance with declaration of Helsinki 1964. The Prediabetic volunteers 18 to 35y, n=50; with sedentary lifestyle were included in the study with no history of chronic or active health problem. The inclusion criteria for prediabetes were fasting blood glucose (FBG) level 100 -125 mg/dL and HbA1c between 5.7 - 6.4% according to American Diabetes Association, 2014 (Herman, 2017). After explaining the procedure to each participant, consent (informed) was taken. Those with diabetes mellitus, hypertension, renal  disease, or any other chronic or active disease were excluded from the study. The International Physical Activity Questionnaire (IPAQ) short form was filled (Cerqueira et al., 2020). Dietary history was taken through 24-hour dietary recall questionnaire (Uhm et al., 2017).  Exercise Test The exercise tests were done in skill lab of IBMS, KMU. The volunteers were made to walk on motorized treadmill (Revo RT, Taiwan) for 45min (including 5 minutes warm up and 10 minutes cool down) at 70 ± 5 % of maximal heart rate (Thirupathi & Pinho, 2018) and step counts during this activity were counted with pedometers (Mi band 2, China). The step counts were standardized for each participant, and they completed the study by performing the same protocol for 5 days a week for 8 weeks monitoring the step count with the provided pedometers. Cardiorespiratory fitness parameters including basal heart rate (BHR), heart rate reserve, oxygen uptake, carbon dioxide exhaled, VO2/ VCO2, VO2/kg/min, Metabolic equivalents (METS) and energy expenditure (EE) of the participants were determined through breath-by-breath analyzer (Cosmed, Italy). 74      Statistical Analysis SPSS version 20 was used for analysis. Normality was checked for all variables by Kolmogorov Smirnov and Shapiro Wilk normality tests and histograms. The glycemic status and cardiorespiratory fitness parameters were expressed as mean ± Standard deviation. Pre and post intervention values of study variables were compared by paired sample t test. P ≤ 0.05 was considered statistically significant.  RESULTS Of the 50 participants, females were 22 (44%) with mean age 27.64 ± 6.1 years and males were 28 (56%) with mean age 30.18 ± 3.86 years. A significant improvement in cardiorespiratory fitness parameters was observed at post- intervention analysis. In addition, statistically significant decrease was observed at post-intervention for FBG from 110 ± 7 mg/dl to 93.24 ± 10 mg/dl (P < 0.001) and HbA1c from 6.02 ± 0.24 % to 5.66 ± 0.29 % (P < 0.001). The mean values of breath-by-breath analysis data are shown in table 1. The statistically significant results are highlighted. Ventilation (VE), oxygen consumed (VO2), carbon dioxide exhaled (VCO2), VO2/kg, metabolic equivalents (METS), heart rate (HR), rate of carbohydrate oxidation (RCHO) and energy expenditure (EE) values were higher at pre- intervention while heart rate reserve (HRR) and rate of fat oxidation (RFO) were lower at pre- intervention. However, after 8 weeks of exercise intervention, they showed improved cardiorespiratory fitness and were able to do the same physical activity at lower VO2, VCO2, VO2/kg, METS, and EE while fat oxidation and heart rate improved also reflect improved fitness as shown in table 1.    Table 1:  Comparison of Mean Values of Cardiorespiratory Fitness    # Cardiorespiratory Fitness Mean ± SD   n = 50  P value  1  VE (L/min) Pre-Intervention Post-Intervention 35.3 ± 9.16 32.17 ± 6.4  0.012 2 VO2 (ml/min) 1091 ± 287 1023 ± 210 0.113 3 VCO2 (ml/min) 979 ± 283 874 ± 186 0.014 4 RQ 0.89 ± 0.05 0.86 ± 0.03 < 0.001 5 VO2/Kg (ml/min/kg) 14.96 ± 2.64 13.91 ± 1.53 0.003 75      6 METS 4.27 ± 0.75 3.98 ± 0.44 0.003 7 HR (bpm) 123.08 ± 7.71 118.12 ± 8.56 0.001 8 HRR (bpm) 67.37 ± 8.33 72.97 ± 10.18 < 0.001 9 RFAT (kcal/30min) 56.65 ± 25 72.35 ± 20.42 < 0.001 10 RCHO (kcal/30min) 103.73 ± 46.3 76.3 ± 24.7 < 0.001 11 EE (kcal/30min) 167 ± 39.67 140 ± 29.5 < 0.001  VE = ventilation, VO2 = oxygen consumed, VCO2 = carbon dioxide exhaled, RQ = Respiratory Quotient, METS = metabolic equivalents, HR = heart rate, HRR = heart rate reserve, RFO = fat oxidation, RCHO = carbohydrates oxidation, EE = energy expenditure. P ≤ 0.05 is considered statistically significant.  DISCUSSION The prime objective of the study was to determine the cardiorespiratory fitness of all the participants at pre-and post- interventional stage through breath-by- breath analyzer. The different parameters including respiratory quotient (RQ), oxygen consumed (VO2), carbon dioxide exhaled (VCO2), oxygen consumed per kg (VO2/kg), metabolic equivalents (METS), energy expenditure (EE), heart rate (HR), heart rate reserve (HRR), carbohydrate and fat oxidation were taken into consideration. The cardiorespiratory fitness of the participants improved significantly as determined by decrease in RQ (P < 0.001), VO2 (P = 0.113), EE (P < 0.001), METS (P = 0.003), carbohydrate oxidation (P < 0.001). and HR (P = 0.001) at post- intervention, while heart rate reserve (P < 0.001) and fat oxidation (P < 0.001) increased at post- intervention. Our results are supported by Gaitán et al., 2019 who reported an increase in fat oxidation (P < 0.001) whereas CHO oxidation declined at post- interventional stage (Naves et al., 2018). Similarly, the decrease in heart rate and improved heart rate reserve is consistent with the findings of Plaza et al., 2019 (Plaza-Florido et al., 2019). The most likely mechanism involved in improving cardiorespiratory fitness is enhanced activity of lipoprotein lipase in skeletal muscle that can lead  to greater clearance rate of TGs, transport of lipids to the liver and improved HDL level (Goodrich et al., 2012). Current research literature supports the fact that enhanced physical activity leads to optimal function of the physiological systems of the human body. It can improve myocardial function, by lowering oxygen demand and increasing myocardial strength consistent with our findings. In addition, decreasing blood pressure and energy expenditure are signs of improved cardiorespiratory 76      fitness. All these adaptations result in improved overall health without the side effects of medicines. Therefore, the intervention adopted in this study can be used as a tool in prevention and treatment of prediabetes, diabetes, and other chronic diseases (Anderson & Durstine, 2019; Lavie et al., 2015). CONCLUSIONS Enhanced physical activity had a significant effect on improving the glycaemic status and cardiorespiratory fitness at post intervention. Future studies must focus on the best preventive methodologies, incorporating physical fitness programs for prediabetes and diabetes prevention and management  with limited financial resources especially in developing countries  like  Pakistan and in other diverse settings.  ACKNOWLEDGMENTS We are thankful to the volunteers for their participation in the study. 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THE PHYSIOLOGICAL RESPONSE OF CARDIORESPIRATORY FITNESS PARAMETERS TO EXERCISE IN PREDIABETIC POPULATION: AN EXPERIMENTAL PRE- POST DESIGN

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THE PHYSIOLOGICAL RESPONSE OF CARDIORESPIRATORY FITNESS PARAMETERS TO EXERCISE IN PREDIABETIC POPULATION: AN EXPERIMENTAL PRE- POST DESIGN

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