title: Effects of age, grip strength and smoking on forearm volumetric bone mineral density and bone geometry by peripheral quantitative computed tomography: comparisons between female and male.
abstract: Peripheral quantitative computed tomography (pQCT) is useful to measure volumetric bone mineral density (vBMD) distinguishing trabecular from cortical bones as well as quantity of bone geometry. In the present study, we examined the effects of age, grip strength and smoking on vBMD, bone geometry and bone strength index (polar strength strain index (SSIp)), and then compared with the differences between female and male by employing pQCT in Japanese 252 female and 230 male subjects. Age was negatively correlated with vBMD, cortical area (Ct.Ar) and cortical thickness (Ct.Th) as well as SSIp in both sexes, and the correlation coefficients were higher in female, compared with those in male. Although age was correlated with endocortical circumferences (En.Le) in both sexes, periosteal circumferences (Ex.Le) were correlated with age only in male. Volumetric BMD, Ct.Ar, Ct.Th and SSIp were significantly lower in the group with vertebral fractures, although En.Le and Ex.Le were similar between subjects with and without vertebral fractures. Grip strength was positively correlated with vBMD, Ct.Ar, Ct.Th as well as SSIp. The extent of correlation was much higher in female, compared with that in male. Ct.vBMD, Ct.Ar, Ct.Th and SSIp, but not trabecular vBMD, were significantly lower in the group with high Brinkman index (number of cigarettes smoked per day) x (duration of smoking (years)) in female. These parameters were not significantly different between groups with high and low Brinkman index in male. In conclusion, the present study demonstrated that age, grip strength and smoking affected forearm vBMD, bone geometry and bone strength index by pQCT. These effects were greater in female, compared with those in male.
authors.affiliation: Division of Endocrinology/Metabolism, Neurology and Hematology/Oncology, Department of Clinical Molecular Medicine, Kobe University Graduate School of Medicine, Kobe.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaji
authors.forename: Rieko
authors.initials: R
authors.lastname: Kosaka
authors.forename: Mika
authors.initials: M
authors.lastname: Yamauchi
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kuno
authors.forename: Kazuo
authors.initials: K
authors.lastname: Chihara
authors.forename: Toshitsugu
authors.initials: T
authors.lastname: Sugimoto
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015519:Bone Density; D005260:Female; D005542:Forearm; D018737:Hand Strength; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011884:Radius / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012727:Sex Characteristics; D012907:Smoking; D016103:Spinal Fractures; D014057:Tomography, X-Ray Computed; D014457:Ulna / Q000033:anatomy & histology* / Q000000981:diagnostic imaging