THU0489 The impact of calcium intake and physical exercise on peak bone mineral density

Background Regular exercise and adequate nutrition are frequently prescribed as strategies to optimise peak bone mass and maintain bone and muscle health throughout life. Objectives The aim of our work was to determine the relationship of clinically assessed milk intake and physical exercise with bone mineral density (BMD) in young adults. Methods This cross-sectional study included members of the general population aged between 20 and 30 years from the Portuguese cohort SAOL (individuals aged 18+years randomly selected from a local county of Coimbra, Portugal). No exclusion criteria were applied. Individuals were asked to describe their milk intake (up to 2 glass/day and 2+glass/day, corresponding to up to and more than 480 mg/day), regular physical activity (categorised as none-to-moderate and at least intense physical activity) and strenuous sports practice (up to 2 hour/week and 2+hour/week) from the age of 10 to 25. They underwent a Dual-energy x-ray absorptiometry (DEXA) of the lumbar spine (LS) and proximal femur (PF). Categorical data is presented as proportions/percentages and continuous variable as median ±standard deviation. Differences between groups were assessed by Mann–Whitney U test. Potential predictors of a higher BMD of PF and LS were identified using multiple linear regression analysis. P-values Results We included 259 individuals (mean age of 24.7±2.7 years, 60.6% being female). The majority (82.6%), described having a moderate regular physical activity (equivalent to working as a mailman), practicing strenuous sports at least 2 hours per week (81.1%) and ingesting at least two glasses of milk per day (83.4%). The current BMD of the PF and LS were 0.8±0.13 and 0.99±0.11, respectively. On univariate analysis, the only significant association related the PF BMD and milk intake (p=0.008). Multiple linear regression analysis showed that while physical activity and sports practice did not predict BMD values, milk intake persisted as a predictor of a higher BMD of PF (p=0.022), even after including other explanatory variables. No statistically significant predictors were found for BMD of the LS. Conclusions Our study showed that clinically assessed milk intake between the ages of 10 and 25 years, but not physical exercise, is a significant predictor of higher bone mineral density assessed by DEXA at the PF. These results do not exclude a positive impact of exercise upon peak bone mass, but suggest that its retrospective evaluation in a clinical setting should not be taken as reassurance that a good peak bone mass was achieved in early adulthood. Disclosure of Interest None declared