ABSTRACT
The purpose of this study was to examine the relationships between peak bone mass and genetic and environmental factors. We measured whole-body bone mineral density (BMD), lumbar spine BMD, and radius BMD with dual-energy X-ray absorptiometry (DXA) and analyzed eight genetic factors: vitamin D receptor (VDR)-3', VDR-5', estrogen receptor (ER), calcitonin receptor (CTR), parathyroid hormone (PTH), osteocalcin (OC), apolipoprotein E (ApoE), and fatty acid binding protein 2 (FABP2) allelic polymorphisms using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs). We also surveyed menstrual history, food intake, and history of physical activity using questionnaires. After adjusting for age, body mass index (BMI), current smoking status, current Ca intake, alcohol intake, menoxenia, and physical activity, the mean BMD in subjects with the HH/Hh genotype was significantly higher than that of subjects with the hh genotype for whole-body BMD (mean±SD, 1.20±0.10 vs. 1.18 ±0.09 g/cm2; HH/Hh vs. hh, p=0.04) and at lumbar spine BMD (mean±SD, 1.18±0.14 vs. 1.14±0.12 g/cm2; HH/Hh vs. hh, p=0.02) in OC allelic polymorphism. Furthermore, the results of multiple regression analyses taking the 8 genetic factors plus the 7 environmental factors listed above into account showed that the strongest factor contributing to BMD was BMI at any site (whole-body and lumbar BMD p<0.0001, radius BMD p=0.0029). In addition, OC polymorphism (p=0.0099), physical activity (p=0.0245), menoxenia (p=0.0384), and PTH polymorphism (p=0.0425) were independent determinants for whole-body BMD, and OC polymorphism (p=0.0137) and physical activity (p=0.0421) were independent determinants for lumbar BMD and radius BMD, respectively.
Subject(s)
ExerciseABSTRACT
Objectives: The goal of the present study was to investigate the relationship between occlusal function and body composition in 108 premenopausal healthy Japanese women aged 20−45 years. Methods: Pressure-sensitive sheets were used to measure occlusal function. Whole fat mass and lean mass, fat-free mass, and whole-bone mineral content were measured by dual-energy X-ray absorptiometry (DXA). Results: After being adjusted for age and the square of height, the whole lean mass and grip strength of the large occlusal contact-area group were found to be significantly higher than those of the small occlusal area groups (p<0.05, respectively). In the 1-year follow-up study, changes in weight in the small-occlusal contact-area group and the low-occlusal force group were significantly larger than other occlusal-contact area or occlusal-force groups. The mean occlusal-contact area and occlusal force were both significantly smaller in subjects with partial dentures than in those without (p<0.05). Conclusion: Large occlusal contact-area, high occlusal force, and no dentures may be associated with some good health conditions in premenopausal Japanese women.