Objective: Our study is to evaluate the association between body mass index (BMI), Body composition and pulmonary function tests among undergraduate medical students of Mahavir institute of medical sciences Methods: A cross-sectional study conducted among 80 MBBS students of Mahavir institute of medical sciences Basic information, body composition and pulmonary function tests such as FVC, FEV1, FEV1/FVC, PEFR were measured. We divided the subjects into two groups according to their BMI.18.5– 24.9 kg/m2 as normal weight, (n=40) and 25.0–29.9 kg/m2 is considered as overweight(n=40). Results: There was a significant difference in BMI between the groups (P < 0.0001). Mean visceral fat % of the Normal weight individuals was 3.95 and mean of visceral fat% in Overweight individuals was 11.03 Showed significantly higher level (p<0.0001) The pulmonary function test parameter Mean of FEV1/FVC of the Normal weight individuals was 87.49 and Mean of FEV1/FVC of the overweight individuals was 66.86 Showed significantly higher level (p<0.0001) Conclusion: According to our research, those who are overweight likely have a considerable deterioration of their lung functioning
Over the past few decades, the prevalence of overweight and obesity has reached alarming levels worldwide, transcending the boundaries of economic development and affecting both developed and developing nations1. A chronic medical condition called obesity is defined by an excessive build-up of fat on the body, which results in a generalised rise in body mass. Body mass index (BMI), which is a function of height and weight, is used to measure it. The world Health Organization (WHO) classified obesity using BMI cut-off values of 25 and 30 kg/m2. Body mass index (BMI) of 18 to 24.9 kg/m2 is considered normal weight, a BMI of 25.0-29.9 kg/m2 is considered overweight and a BMI of 30 kg/m2 or higher is considered obesity2. Obesity, a growing global epidemic, has been linked to a myriad of adverse health outcomes, significantly impacting individuals' overall well-being and quality of life3.The respiratory system is impacted by obesity as well. The results of pulmonary function tests (PFT) are typically used by researchers to examine how obesity affects the respiratory system4,5.
Pulmonary function is a crucial aspect of human physiology that is influenced by various factors, including gender, age, body composition, and geographical location 6-9. When considering the importance of pulmonary function tests, it is essential to recognize their role as both a tool for clinical assessment and a method for physiological study. PFTs are utilized in a variety of contexts, including routine respiratory, occupational, and sports medicine health examinations. These tests provide valuable insights into an individual's respiratory status, allowing for the identification of potential issues and the monitoring of lung function over time. Additionally, PFTs can be instrumental in informing treatment decisions and assessing the effectiveness of interventions aimed at improving respiratory health10Reports on pulmonary function in overweight and obesity are conflicting. Some studies have found abnormal spirometry only in massively obese subjects. Others revealed altered spirometry in obese but not in overweight subjects. Decreased static lung volume parameter has also been found in overweight group in one study.11-14
However, evidence is limited with regard to whether BMI, Body composition is associated with pulmonary function test among undergraduate medical students
This study was carried out among undergraduate medical students including male and female subjects to study the effect between Body mass index, Body composition on Pulmonary function tests. and provide theoretical reference for under graduate medical students' physical health.
This was a cross-sectional study conducted at the Department of Physiology, Mahavir institute of medical sciences among 80 MBBS students between the ages of 18 to 20 years without any chronic diseases and no smoking were included anthropometric measurements which includes Height was measured by using a stadiometer, inform consent was taken from all the participants.
Assessment of Body weight,BMI Total body fat % (TBF %), Visceral Fat (VF%) was done by Omron HBF 375, a body fat analyzer working under principle of bio impedance analysis (BIA) method 15,16
Lung function tests FEV1 (Forced Expiratory Volume in 1 second), PEFR (Peak Expiratory Flow Rate) and FVC (Forced Vital Capacity) was performed using a Spiro meter (RMS-HELIOS 702) by following standard protocols.
Measuring FEV1, FVC, and Flow–Volume Curves: Attach a clean, disposable, one-way mouthpiece to the spirometer.
Instruct the patient to breathe in fully until the lungs feel full. The patient should hold their breath long enough to seal their lips tightly around the mouthpiece.
Blast the air out as forcibly and fast as possible until there was no more air left to expel.
Repeat the procedure at least twice until three acceptable and repeatable blows were obtained.
There should be three readings, of which the best two were within 150 mL or 5% of each other and best.
The numbers appear as a table of actual and predicted figures together with volume–time and flow–volume traces.
Spirometers with real-time traces and printouts were preferred as they provide helpful information about the quality and acceptability of the blows
Statistical analysis: Data were expressed as mean±S.E.M (n=80)
Table 1: Effects of BMI, Visceral fat, total body fat on PFTs
PARAMETERS |
NORMAL WEIGHT (n =40) |
OVERWEIGHT (n = 40) |
P-VALUE |
BMI |
20.67±1.58
|
27.95±1.30 |
P < 0.0001 |
VISCERAL FAT% |
3.95 ± 1.82 |
11.03±4.42 |
P < 0.0001 |
TOTAL BODY FAT % |
28.63± 6.84 |
32.50±6.58 |
P = 0.0118 |
FEV1 (L)
|
2.41 ± 0.62 |
2.13±0.44 |
P = 0.02 |
FVC (L)
|
2.68 ± 0.70 |
2.74±0.65 |
P = 0.6923 |
FEV1/FVC (%)
|
87.49 ± 10.41 |
66.86±19.83 |
P < 0.0001 |
PEFR
|
5.90 ± 1.05 |
5.07±1.13 |
P = 0.0011 |
Table 2: FEV1/FVC parameter and its association with visceral fat in over weight subjects.
PARAMETER |
Visceral fat % (Over weight) |
r value p-value
|
|
FEV1/FVC (%) |
= 0.2685 .016034(p <.05)
|
Mean BMI of the Normal weight individuals was 20.67and mean of BMI in overweight individuals was 27.95 showed significantly higher level (p<0.0001)
Mean visceral fat % of the Normal weight individuals was 3.95 and mean of visceral fat% in Overweight individuals was 11.03 Showed significantly higher level (p<0.0001)
Mean Total body fat % of the Normal weight individuals was 28.63 and mean of Total body fat % in Overweight individuals was 32.50 Showed no significant difference (p=0.0118)
Mean of FEV1 of the Normal weight individuals was 2.41 and Mean of FEV1 of the overweight individuals was 2.13 Showed no significant difference (p=0.02)
Mean of FVC of the Normal weight individuals was 2.68 and Mean of FVC of the overweight individuals was 2.74 Showed no significant difference (p=0.6923)
Mean of FEV1/FVC of the Normal weight individuals was 87.49 and Mean of FEV1/FVC of the overweight individuals was 66.86 Showed significantly higher level (p<0.0001)
Mean of PEFR of the Normal weight individuals was 5.90 and Mean of PEFR of the overweight individuals was 5.07 Showed no significant difference (p=0.0011)
According to the WHO, obesity is a more recent chronic non-communicable disease and one of the most ignored public health issues of our time.17, Although it is commonly known that obesity can lead to complications including diabetes, cardiovascular disease, and osteoarthritis, the impact of obesity on the respiratory system has historically received less attention18,19
There were 80 individuals in this study, 40 of them were overweight and 40 of normal weight. Each of the 18–20-year-old individuals appears to be in good health. According to BMI categorized into two groups, i.e., BMI.18.5– 24.9 kg/m2 as normal weight and 25.0–29.9 kg/m2 is considered as overweight.
BMI of overweight individuals showed significantly higher level than Normal weight individuals (p<0.0001) Respiratory parameters such as FEV1 and PEFR are found to be lower in over weight participants in comparison to normal weight participants as shown in Table1.However FEV1/FVC of the overweight individuals was Showed significantly lower level (p<0.0001) than Normal weight individuals. Our resuts are similar to Tanu Aggarwal et al observed a positive correlation among all the lung function parameters with BMI when BMI of participants is within the normal range for their age and sex but there was negative correlation with increasing BMI. The buildup of excess fat may impede the mobility of the chest wall and the lowering of the diaphragm, which is the proposed mechanism explaining the link between obesity and decreased PFTs19. It was found that there is reduction in pulmonary function was correlated with visceral fat. FEV1/FVC r =0.2685 .016034(p <.05) Similar to our results Sudhir Modala et al observed There was a correlation between visceral fat and this decline in lung function15. Yang Yang Pi et al noted FVC and FEV1 showed a positive correlation with body composition measures.20Comparable to our outcome Shengyu Wang et al found that FVC, not FEV1, FEV1/FVC, PEF, or FEF25–75, significantly decreased in obese individuals. Additionally, they found an intriguing finding that normal participants had higher FEV1, FVC, and PEF than underweight subjects21. According to BMI classification, Sağlıklı et al. demonstrated that there was no individual variation in forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), or FEV1/FVC values.22
The design of the current study was one of its limitations. In a small group setting, this cross-sectional study was conducted. It is necessary to conduct a longer-term, multicentric investigation on a larger population.
Our research indicates that there is a notable decline in lung function among overweight people, and that this population is more likely to develop small airway illnesses. Future, larger-scale epidemiological research could contribute to a better understanding of these connections in order to develop public health policies and initiatives.