scholarly journals Low peak bone mass and attenuated anabolic response to parathyroid hormone in mice with an osteoblast-specific deletion of connexin43

2006 ◽  
Vol 119 (20) ◽  
pp. 4187-4198 ◽  
Author(s):  
D. J. Chung ◽  
C. H. M. Castro ◽  
M. Watkins ◽  
J. P. Stains ◽  
M. Y. Chung ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Peak Bone Mass ◽  
Anabolic Response ◽  
Specific Deletion

scholarly journals Mammary-specific deletion of parathyroid hormone-related protein preserves bone mass during lactation

2004 ◽  
Vol 113 (3) ◽  
pp. 492-492
Author(s):  
Joshua N. VanHouten ◽  
Pamela Dann ◽  
Andrew F. Stewart ◽  
Christine J. Watson ◽  
Michael Pollak ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Specific Deletion

scholarly journals Variable number of tandem repeats polymorphism in parathyroid hormone-related protein as predictor of peak bone mass in young healthy Finnish males

2008 ◽  
Vol 158 (5) ◽  
pp. 755-764 ◽  
Author(s):  
Ajay Gupta ◽  
Ville-Valtteri Välimäki ◽  
Matti J Välimäki ◽  
Eliisa Löyttyniemi ◽  
Marilyn Richard ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Lumbar Spine ◽  
Bone Mass ◽  
Peak Bone Mass ◽  
Tandem Repeats ◽  
Broadband Ultrasound Attenuation ◽  
Variable Number ◽  
Related Protein ◽  
Mineral Density ◽  
Parathyroid Hormone Related Protein

ObjectiveMice with osteoblast-specific deletion of parathyroid hormone-related protein (PTHrP) exhibit impaired recruitment and increased apoptosis of osteogenic cells resulting in decreased bone formation and premature osteoporosis. The PTHrP levels within the bone microenvironment are therefore critical in influencing bone mass acquisition. Whether this is applicable in humans has not been established. Here, we studied the association of a variable number of tandem repeats (VNTR) polymorphism in PTHrP with peak bone mass.MethodsEnrolled in the study were 234 young Finnish males, with median age of 19.6 years (range 18.3–20.6 years). Lifestyle factors, serum bone markers, osteodensitometric measurements (lumbar spine and hip) and calcaneal quantitative ultrasound readings were obtained. The PTHrP VNTR length was determined by the PCR amplification of genomic DNA extracted from peripheral blood and correlated to bone parameters by the multiple regression models.ResultsThe presence of at least one 252 bp allele was associated with increased lumbar spine bone mineral density (BMD; P<0.0034), broadband ultrasound attenuation (BUA; P<0.0012) and speed-of-sound (SOS; P<0.0023) measurements. The correlation with increased lumbar spine BMD (P=0.0008), BUA (P=0.005) and SOS (P=0.001) was further strengthened by the pairing of the 252 bp allele with a 460 bp allele in comparison with those without any 252 bp allele. Electrophoretic mobility shift assays were used to illustrate the potential transcriptional functionality of the VNTR sequence.ConclusionThe results indicate that the PTHrP VNTR sequence likely modulates local PTHrP expression within the skeletal microenvironment and could serve as a diagnostic predictor of peak bone mass acquisition.

scholarly journals Mammary-specific deletion of parathyroid hormone–related protein preserves bone mass during lactation

2003 ◽  
Vol 112 (9) ◽  
pp. 1429-1436 ◽  
Author(s):  
Joshua N. VanHouten ◽  
Pamela Dann ◽  
Andrew F. Stewart ◽  
Christine J. Watson ◽  
Michael Pollak ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Mass ◽  
Related Protein ◽  
Parathyroid Hormone Related Protein ◽  
Specific Deletion

scholarly journals Vitamin D status and its relationship with parathyroid hormone and bone mineral status in older adolescents

2005 ◽  
Vol 64 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Alexis M. Willett
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Bone Mass ◽  
Bone Health ◽  
Peak Bone Mass ◽  
Early Adulthood ◽  
Later Life ◽  
Vitamin D Status ◽  
Bone Mineral Status ◽  
25Ohd Concentration

Osteoporosis is an important contributor to the global burden of disease, and in the UK alone results in one in three women and one in twelve men aged >50 years experiencing a fragility fracture. Optimising peak bone mass in early adulthood is thought to reduce osteoporosis risk by offsetting bone losses in later life. Ensuring sufficient vitamin D status (measured as 25-hydroxyvitamin D (25OHD) in plasma), among other factors, is believed to facilitate the achievement of optimum peak bone mass. Lower 25OHD is associated with a higher plasma concentration of parathyroid hormone (PTH). As PTH is associated with increased bone turnover and bone loss, maintenance of sufficient 25OHD is thought to have a protective effect on bone health. However, there is a lack of consensus internationally on what constitutes an optimum 25OHD concentration, and values between 30 and 80 nmol/l have been suggested. These values have been based on findings from various studies in adults in which PTH has been observed to plateau at a 25OHD concentration of >30 nmol/l; however, not all studies have found such a plateau. Although studies in younger adolescents (14–16 years) have shown an inverse relationship between PTH and 25OHD, the concentration of 25OHD required for achievement of optimum peak bone mass is unknown. The present review examines the evidence defining vitamin D insufficiency thresholds, and the relevance of such thresholds to adolescent bone health.

scholarly journals Biochemical and Dietary Indicators of Bone Health in Rural Adolescent Girls from Konkan Region of Maharashtra, India (DERVAN-5)

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Patil SN ◽  
◽  
Patil N ◽  
Bhat P ◽  
Jadhav D ◽  
...  
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Parathyroid Hormone ◽  
Bone Mass ◽  
Adolescent Girls ◽  
Bone Health ◽  
Calcium Intake ◽  
Peak Bone Mass ◽  
Dietary Calcium Intake ◽  
Rural Adolescent

Adolescent period is marked by bone modeling and remodeling and leads to accrual of peak bone mass. Ideal peak bone mass depends on diet, hormones, genetic influence and environment and has consequences on bone health in adulthood. We measured biochemical indicators of bone health in rural adolescent girls. Methods: Five hundred fifty adolescent girls from longitudinal DERVAN cohort study from Indian state of Maharashtra underwent anthropometry. Biochemical parameters (intact parathyroid hormone, vitamin D, calcium, phosphorus and alkaline phosphatase) were measured. Results: Prevalence of underweight & stunting was 28.8%, 30.7% respectively. More than 56% were thin & only 5% were obese. Median body fat% & bone mass measured by bio-impedance were 23.3 and 1.6 Kg respectively. More than 80% were vitamin D deficient and 12.0% were calcium deficient. Median dietary calcium intake was 158.5mg/day which was far below recommended 850 mg/day. Median parathyroid hormone concentration was 8.49pmol/L and 66.7% had elevated concentrations (> 6.89pmol/L). Elevated phosphorus and alkaline phosphatase were observed in 23.3% and 23.0%. Parathyroid hormone was inversely associated with age (p<0.001) and vitamin D (p<0.001) and directly with phosphorus and alkaline phosphatase (p<0.05) for both. On multivariate analysis elevated parathyroid hormone was associated with low vitamin D (p<0.001). Conclusion: The adolescent girls of KONKAN are undernourished and vitamin D deficient. Despite poor dietary calcium intake the serum calcium levels were maintained at the cost of elevated parathyroid hormone. Thus parathyroid hormone may be used as a marker of bone health. This could be useful in planning early interventions to improve bone health.

Kontrazeption zu Beginn und Ende der fertilen Lebensphase

2009 ◽  
Vol 66 (2) ◽  
pp. 109-115 ◽  
Author(s):  
Joseph Neulen ◽  
Christian Thaler ◽  
Martin Birkhäuser ◽  
Wilhelm Braendle ◽  
Paul J. Keller ◽  
...  
Keyword(s):  
Bone Mass ◽  
Peak Bone Mass ◽  
Arterielle Hypertonie

Die Nutzen-/Risiko-Bilanz einer hormonalen Kontrazeption (OH) ist sowohl bei Jugendlichen als auch bei der Frau über 40 Jahren günstig, sofern bestimmte Regeln beachtet werden. Bei Jugendlichen betrifft dies insbesondere den Ermöglichung des Erwerbs einer normalen Peak-Bone-Mass durch die Wahl eines korrekt dosierten OH, bei älteren Frauen den aktiven Ausschluss von Kontraindikationen wie arterielle Hypertonie, Adipositas, Rauchen und Dyslipidämie. In beiden Altersgruppen ist in jedem Falle das Risiko einer korrekt indizierten OH geringer als dasjenige einer unerwünschten Schwangerschaft.

Mehr Muskulatur – gesündere Knochen?

2013 ◽  
Vol 22 (02) ◽  
pp. 87-92 ◽  
Author(s):  
O. Semler ◽  
E. Schoenau ◽  
H. Hoyer-Kuhn
Keyword(s):  
Bone Mass ◽  
Peak Bone Mass

ZusammenfassungAufgrund einer steigenden Anzahl von Osteo porose-Erkrankungen gilt es, präventive Ansätze zu finden, um das Risiko spontaner Frakturen im höheren Lebensalter zu reduzieren. Lange wurde postuliert, dass Frakturen aufgrund einer reduzierten Knochenmasse entstehen. Das Konzept der “Peak Bone Mass” beruht auf der Hypothese, dass eine Anhäufung von Knochenmasse in der Adoleszenz die Frakturrate im Alter senken könne. Die Knochenmasse beschreibt jedoch nur, wie viel Knochenmasse absolut ein Individuum besitzt, nicht jedoch, ob die Knochen die erforderliche Festigkeit aufweisen. Die Knochenmasse ist vielmehr eine Funktion aus Körperlänge und muskulärer Beanspruchung, weniger jedoch des Alters. Die Knochenfestigkeit wird dabei durch verschiedene Einflussfaktoren geregelt, wie das Osteozytennetzwerk “Mechanostat”, das die aktuelle Beanspruchung misst und Adaptationsvorgänge einleitet, aber auch durch Hormone, Ernährung und Medikamente. Von der Beschreibung der reinen Knochenmasse aus ist, basierend auf diesen regulierenden Faktoren und Erkenntnissen über die Interaktion der aufgeführten Faktoren, das Konzept der funktionellen Muskel-Knochen-Einheit entstanden, welches beschreibt, dass die Entwicklung und der Erhalt der knöchernen Stabilität mit ihrer Festigkeit von der Muskulatur abhängig ist. In der Schlussfolgerung muss bei auftretenden Frakturen sowohl in der adulten Medizin als auch in der Pädiatrie zur Beurteilung des Skelettsystems die Muskulatur mit einbezogen werden, um eine Aussage darüber treffen zu können, ob es sich um eine primäre oder sekundäre Knochenerkrankung handelt.

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