title: Immobility as a major cause of bone remodeling in residents of a long-stay geriatric ward.
abstract: Residents of a long-stay geriatric ward at the University Hospital Basel were included in a study to investigate the effects of hypovitaminosis D and immobility. All 91 women (mean age 82.5 years) and 92 men (mean age 78.7 years) were enrolled in the study. Measurements included bone resorption, as measured by urinary deoxypyridinoline (dpd), serum 25-hydroxyvitamin D (25OHD), serum intact parathyroid hormone (iPTH), and their correlations with a four grade mobility score. Mobility score reflected the degree of weight bearing, ranging from walking independently to primarily bed bound. In 86% of all residents, serum 25OHD levels were below the normal limit of 12 ng/ml. Secondary hyperparathyroidism (HPT) was detected in 24% of all patients, using 55 pg/ml as the upper limit for serum iPTH. No significant correlation was found between urinary dpd and serum 25OHD or serum iPTH. Mobility index and both urinary dpd (f: P = 0.001, r = 0.37; m: P < 0.0001, r = 0.47) and serum calcium (female: P = 0.007, r = 0.28; male: P = 0.02, r = 0.24) were positively related. In institutionalized elderly people with a high prevalence of vitamin D deficiency serum intact PTH levels did not correlate with bone resorption as measured by urinary deoxypyridinolin. However, more immobile subjects had significantly higher excretion rates for urinary dpd and higher serum calcium levels. Our results suggest that in elderly people immobility may contribute to bone loss that might preempt the development of secondary HPT through elevation of serum calcium.
authors.affiliation: Department of Geriatrics, University Hospital Basel, Kantonsspital, Hebelstrasse 10, 4031 Basel, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Bischoff
authors.forename: H B
authors.initials: HB
authors.lastname: Stähelin
authors.forename: P
authors.initials: P
authors.lastname: Vogt
authors.forename: P
authors.initials: P
authors.lastname: Friderich
authors.forename: R
authors.initials: R
authors.lastname: Vonthein
authors.forename: A
authors.initials: A
authors.lastname: Tyndall
authors.forename: R
authors.initials: R
authors.lastname: Theiler
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000652:urine; D016723:Bone Remodeling; D001862:Bone Resorption / Q000209:etiology* / Q000378:metabolism / Q000503:physiopathology; D002118:Calcium / Q000097:blood; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006299:Health Services for the Aged; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D007103:Immobilization / Q000009:adverse effects* / Q000502:physiology; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D018434:Sickness Impact Profile; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D000596:Amino Acids; D010281:Parathyroid Hormone; D014807:Vitamin D; C036020:deoxypyridinoline; C104450:25-hydroxyvitamin D; D002118:Calcium