Association of Body Mass Index with Cardiopulmonary Parameters among Medical Students in a Tropical Academic Setting: A Cross-sectional Study

Background: Although body mass index (BMI) is a modifiable risk factor associated with respiratory and cardiovascular outcomes, little is known about its subclinical effects on Pacific medical students. Aim: To evaluate the association between BMI and cardiopulmonary metrics in young individuals in a tropical academic setting, particularly systolic blood pressure (SBP), forced expiratory volume in one second (FEV₁), and peak expiratory flow rate (PEFR). Methodology: A cross-sectional study was conducted among 59 medical students aged 18–25 years in a tropical academic setting. Participants were recruited by convenience sampling, with exclusion of individuals with known cardiovascular or chronic respiratory disease, recent respiratory infection, or use of medications affecting cardiopulmonary function. Height and weight were measured using standardized equipment to calculate BMI, which was classified according to World Health Organization criteria. Systolic blood pressure (SBP) was measured using a validated automated oscillometric device after a minimum of five minutes of seated rest, with two readings averaged for analysis. Pulmonary function was assessed using handheld spirometry, measuring FEV₁ and PEFR in accordance with standard guidelines; the highest values from at least three acceptable maneuvers were recorded. Associations between BMI and cardiopulmonary parameters were analysed using Pearson’s correlation coefficients, while differences in SBP across BMI categories were assessed using one-way analysis of variance (ANOVA), with statistical significance set at p < 0.05. Result: Fifty-nine medical students aged 18–25 years were included in the analysis. Systolic blood pressure differed significantly across BMI categories, with a progressive increase observed as BMI increased (one-way ANOVA: F3,55 = 6.91, p < 0.001). Pearson correlation analysis demonstrated a significant positive association between BMI and systolic blood pressure. In contrast, pulmonary function parameters showed inverse relationships with BMI. FEV₁ was negatively correlated with BMI (r = –0.28, p = 0.033), indicating lower expiratory volumes with increasing BMI. Similarly, PEFR demonstrated a stronger negative correlation with BMI (r = –0.35, p = 0.010). These findings suggest that higher BMI is associated with elevated systolic blood pressure and reduced pulmonary function even in young, apparently healthy individuals. Conclusion: Students with elevated BMI have lower pulmonary function and greater systolic blood pressure. Results support the use of early cardiopulmonary screening in student health initiatives.