Abstract
BACKGROUND AND AIM: Low birth weight (birth weight of less than 2500 g) among Japanese women has a negative impact on physical form and physical strength evaluation in young adulthood, but there are very few research reports on birth weight and physical form and strength in young adulthood. In addition, there may be differences in the impact of birth weight on physical form and physical strength in young adulthood between men and women, as the extreme desire to be thin that is common among young adult women in Japan is not seen among young adult men. This study aimed to examine the impact of birth weight on the morphology, body composition, and muscle strength of Japanese adult men and women. METHOD: A total of 107 young adults (39 men and 68 women) participated in the study, and the Pearson product-moment correlation coefficients between birth weight and height, weight, BMI, skeletal muscle index (SMI), grip strength, knee extension strength, and chair stand test were examined. Multiple regression analysis was performed using the items that showed a significant relationship with birth weight as independent variables. RESULTS: The birth weight of women was significantly correlated with height, weight, skeletal muscle index (SMI), regional subcutaneous fat, regional skeletal muscle mass, grip strength, and knee extension strength. Multiple regression analysis revealed that only the skeletal muscle mass of the right leg was affected, and the coefficient of determination (R(2)) was 0.202 (p=0.01). However, no significant correlation was found between birth weight and any of the variables in men, so multiple regression analysis was not performed. CONCLUSION: Unlike in men, the birth weight of women has an impact on their body composition, muscle strength, and physical form in young adulthood. In particular, the results suggest that birth weight may have a strong impact on lower-limb muscle mass and that women's birth weight may be a factor to consider when determining the risk of becoming bedridden in the future and its impact on the next generation.