Association of physical activity and sedentary behaviour with bone mineral density and micronutrient status among middle-aged adults of Punjab

Abstract

Sedentary work, reduced outdoor activity and micronutrient insufficiency may jointly affect bone metabolism and hematological health in midlife. Punjab is a relevant setting because urbanising lifestyles coexist with diet diversity, anemia concerns and heterogeneous physical activity patterns. Objective: To compare bone-health indicators and micronutrient profile between sedentary and physically active middle-aged adults of Punjab and identify predictors of BMD. Methods: A comparative cross-sectional manuscript was developed using the uploaded rough paper as the methodological scaffold. Because that file did not contain bone, or micronutrient observations, a reconstructed academic dataset of 200 adults aged 35-60 years was generated for demonstration, comprising 100 sedentary and 100 active participants. Variables included demographics, anthropometry, activity score, lumbar BMD, T-score, vitamin D, calcium, iron profile, B12, folate, magnesium and zinc. t-tests, chi-square tests, correlations and regression models were applied. Results: Active adults had higher activity scores (2589.66 ± 703.50 vs. 532.62 ± 177.87 MET-min/week; p < 0.001), higher BMD (0.94 ± 0.09 vs. 0.84 ± 0.10 g/cm²; p < 0.001), higher vitamin D and better hemoglobin/ferritin profile. Osteopenia/osteoporosis was more common in sedentary adults (68.0%) than active adults (30.0%). Physical activity correlated positively with BMD (r = 0.512, p < 0.001). Regression explained 32.6% of adjusted BMD variance. Conclusion: The reconstructed findings support an integrated preventive model linking activity, micronutrient adequacy and bone health. These results are demonstration-only and must be replaced with audited field and laboratory data before journal submission.