ArticlePloS one2011
Vitamin D status and bone and connective tissue turnover in brown bears (Ursus arctos) during hibernation and the active state.
Article in PloS one, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
18 citing papers in PubMed, 35 citations in OpenAlex.
- Differential bone remodeling mechanism in hindlimb unloaded and hibernating Daurian ground squirrels: a comparison between artificial and natural disuse within the same species.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2023Article
- Hypothyroidism in hibernating brown bears.Thyroid research · 2023Article
- Differential bone remodeling mechanism in hindlimb unloaded rats and hibernating Daurian ground squirrels: a comparison between artificial and natural disuse.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2021Article
- Body Protein Sparing in Hibernators: A Source for Biomedical Innovation.Frontiers in physiology · 2021Review
- Expression of Paracrine Effectors in Human Adipose-Derived Mesenchymal Stem Cells Treated With Plasma From Brown Bears (Ursus arctos).Clinical and translational science · 2021Article
- Denning in brown bears.Ecology and evolution · 2020Review
- Calcium homeostasis during hibernation and in mechanical environments disrupting calcium homeostasis.Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2020Review
- Development and validation of protein biomarkers of health in grizzly bears.Conservation physiology · 2020Article
- Krogh's principle for musculoskeletal physiology and pathology.Journal of musculoskeletal & neuronal interactions · 2018Article
- A dramatic blood plasticity in hibernating and 14-day hindlimb unloading Daurian ground squirrels (Spermophilus dauricus).Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology · 2017Article
- Biochemical Foundations of Health and Energy Conservation in Hibernating Free-ranging Subadult Brown Bear Ursus arctos.The Journal of biological chemistry · 2016Article
- Insights from the Den: How Hibernating Bears May Help Us Understand and Treat Human Disease.Clinical and translational science · 2015Review
- Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears (Ursus arctos) - an observational study.Cardiovascular ultrasound · 2014Observational
- Endocrine regulation of bone and energy metabolism in hibernating mammals.Integrative and comparative biology · 2014Review
- Renal adaptation during hibernation.American journal of physiology. Renal physiology · 2013Review
- Effect of non-pharmacologic vitamin D status correction on circulating bone markers in healthy overweight and obese Saudis.Molecules (Basel, Switzerland) · 2013Article
- Metabolic changes in summer active and anuric hibernating free-ranging brown bears (Ursus arctos).PloS one · 2013Article
- Capture, anesthesia, and disturbance of free-ranging brown bears (Ursus arctos) during hibernation.PloS one · 2012Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 3 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundExtended physical inactivity causes disuse osteoporosis in humans. In contrast, brown bears (Ursus arctos) are highly immobilised for half of the year during hibernation without signs of bone loss and therefore may serve as a model for prevention of osteoporosis.
aimTo study 25-hydroxy-vitamin D (25OHD) levels and bone turnover markers in brown bears during the hibernating state in winter and during the active state in summer. We measured vitamin D subtypes (D₂ and D₃), calcitropic hormones (parathyroid hormone [PTH], 1,25-dihydroxy-vitamin D [1,25(OH)₂D]) and bone turnover parameters (osteocalcin, ICTP, CTX-I), PTH, serum calcium and PIIINP. MATERIAL AND
methodsWe drew blood from seven immobilised wild brown bears during hibernation in February and in the same bears while active in June.
resultsSerum 25-hydroxy-cholecalciferol (25OHD₃) was significantly higher in the summer than in the winter (22.8±4.6 vs. 8.8±2.1 nmol/l, two tailed p-2p = 0.02), whereas 25-hydroxy-ergocalciferol (25OHD₂) was higher in winter (54.2±8.3 vs. 18.7±1.7 nmol/l, 2p<0.01). Total serum calcium and PTH levels did not differ between winter and summer. Activated 1,25(OH)₂D demonstrated a statistically insignificant trend towards higher summer levels. Osteocalcin levels were higher in summer than winter, whereas other markers of bone turnover (ICTP and CTX-I) were unchanged. Serum PIIINP, which is a marker of connective tissue and to some degree muscle turnover, was significantly higher during summer than during winter.
conclusionsDramatic changes were documented in the vitamin D₃/D₂ ratio and in markers of bone and connective tissue turnover in brown bears between hibernation and the active state. Because hibernating brown bears do not develop disuse osteoporosis, despite extensive physical inactivity we suggest that they may serve as a model for the prevention of this disease.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.