Evaluating the Level of Lead, Chromium and Malondialdehyde in A Sample of Hypertensive Elderly Tobacco Smokers in Urban and Rural Populations and Impact of Physical Activity: A Cross-Sectional Comparative Study.

Background: Oxidative balance is known to be disrupted when individuals are exposed to heavy metals especially lead and chromium, which facilitate vascular dysfunction. Smoking adds to this load by producing free radicals which further augment the oxidative stress. A combination of these effects in elderly hypertensive patients can exacerbate cellular damage and degrade the vascular resilience. These outcomes can also be altered by differences in environmental exposure and physical activity of urban and rural populations. Objective: To determine serum levels of lead (Pb), chromium (Cr) and malondialdehyde (MDA) in urban and rural hypertensive elderly smokers, and to determine the effects of physical activity on oxidative stress. Methods: A cross-sectional comparative study was conducted on 80 hypertensive smokers aged 50-70 years (40 urban and 40 rural). Serum Pb and Cr concentrations were determined using atomic absorption spectrophotometry, while MDA was measured by the TBARS method. Demographic, lifestyle, and activity data were obtained through structured questionnaires. Statistical analysis included t-test, χ², and Pearson correlation using SPSS version 26. Results: Urban participants exhibited significantly higher mean serum lead and MDA levels compared with rural participants (p < 0.05), whereas chromium differences were nonsignificant. MDA correlated positively with Pb (r = 0.26, p = 0.020) and negatively with physical activity (r = -0.14, p = 0.227). The standardized beta coefficients disclosed that serum lead was the strongest positive predictor (β = 0.55, t = 5.01, p < 0.001) and serum chromium came in the second position (β = 0.21, t = 2.11, p = 0.038). The physical activity showed a strong negative correlation with oxidative stress (β = -0.36, t = -3.87, p < 0.001), which supports the protective effect of physical activity against lipid peroxidation caused by metals. Conclusion: Exposure to lead is a significant source of oxidative stress among hypertensive smokers as they grow old especially in urban settings. The exercise can contribute to reducing this oxidative load, thus the importance of maintaining an environment, as well as lifestyle change in the prevention of cardiovascular risks.