Activity restriction increases deoxypyridinoline excretion in hospitalized high-risk pregnant women.
OBJECTIVE
Activity restriction (AR), one of the most common interventions used in high-risk pregnancies, may exacerbate loss of bone mass. The purpose of this study was to determine changes over time in bone resorption in hospitalized AR women during late pregnancy.


METHODS
This was a short-term prospective study conducted in two tertiary-care obstetric hospitals. We measured urinary deoxypyridinoline (Dpd) excretion, a marker of bone resorption, once per week in a convenience sample of 14 hospitalized AR women in the third trimester and compared values at 28-31 and 34-36 weeks' gestation to those of 11 ambulatory control women. Both groups completed a bone-loading questionnaire, 3-day food intake record, and pedometer step counts at the same gestational age.


RESULTS
Urinary Dpd excretion increased from Days 1-7 (2.60 ± 0.32 nmol/mmol creatinine) to Days 22-28 (5.36 ± 0.83 nmol/mmol creatinine; p ≤ .05). Dpd excretion was higher in AR women (4.51 ± 0.31 nmol/mmol creatinine) than ambulatory women (2.72 ± 0.39 nmol/mmol creatinine) at 34-36 weeks' gestation (p ≤ .05). Energy intake between ambulatory and AR women was not different (p ≥ .05). All women met the daily requirements for calcium and vitamin D intake during pregnancy. Average daily pedometer steps for the AR women were significantly less compared to controls (1,329 ± 936 and 8,024 ± 1,890 steps/day, respectively; p ≤ .05).


CONCLUSIONS
AR leads to increased bone resorption in hospitalized pregnant women, which may impact future risk of developing osteopenia and osteoporosis.
1R. Samuel McLaughlin Foundation-Exercise and Pregnancy Lab, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada.
Dana
D
Vanderspank
Suzanne M
SM
Bernier
Maggie M
MM
Sopper
Patricia
P
Watson
Michelle F
MF
Mottola
D000328:Adult; D000596:Amino Acids / Q000652:urine*; D003404:Creatinine / Q000652:urine; D005260:Female; D006760:Hospitalization; D006801:Humans; D009043:Motor Activity; D011247:Pregnancy / Q000652:urine*; D018566:Pregnancy, High-Risk; D011795:Surveys and Questionnaires
D000596:Amino Acids; C036020:deoxypyridinoline; D003404:Creatinine