uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Left-Shifted Relation between Calcium and Parathyroid Hormone in Obesity
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Endocrine Surgery.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Endocrine Surgery.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Upper Abdominal Surgery.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Endocrine Surgery.
2010 (English)In: Journal of Clinical Endocrinology and Metabolism, ISSN 0021-972X, E-ISSN 1945-7197, Vol. 95, no 8, 3973-3981 p.Article in journal (Refereed) Published
Abstract [en]

Background: A condition resembling secondary hyperparathyroidism (HPT), including raised levels of PTH and normal levels of serum calcium, has been reported in obesity. A plausible reason may be vitamin D deficiency, but conflicting data have been reported. Objective: Our objective was to investigate calcium homeostasis in obese individuals with emphasis on the function of the parathyroid glands. Design and Intervention: Morbidly obese patients (mean body mass index = 46.6 +/- 6) were examined for their status of calcium homeostasis. A subset was thoroughly investigated with calcium-citrate (CiCa) clamping. Patients: Of 108 morbidly obese patients, 11 underwent CiCa clamping as well as 21 healthy volunteers of normal weight and 15 with primary HPT (pHPT). Large patient cohorts of normal individuals and pHPT patients were also used as comparisons. Outcome Measures and Results: All obese individuals had normal serum calcium and creatinine levels. Mean levels of 25-OH-vitamin D-3 in serum were low, 53 nmol/liter (reference range 75-250 nmol/liter). Mean intact plasma PTH was 5.1 pmol/liter (reference range 1.1-6.9 pmol/liter). There was a significant positive correlation between PTH and duration of obesity. CiCa clamping in obese subjects revealed a remarkably high sensitivity for calcium and a left-shifted relation between plasma calcium and PTH (set point) compared with the normal population. CiCa clamping in pHPT patients demonstrated a right-shifted PTH-Ca curve. Conclusion: Although vitamin D levels in the obese individuals were low, few displayed overt signs of secondary HPT. The CiCa clamping implied a disturbance in the calcium homeostasis comparable to early renal insufficiency, with a left-shifted Ca-PTH curve and a lower set point compared with the normal population.

Place, publisher, year, edition, pages
2010. Vol. 95, no 8, 3973-3981 p.
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:uu:diva-135604DOI: 10.1210/jc.2009-2822ISI: 000280652400057PubMedID: 20519351OAI: oai:DiVA.org:uu-135604DiVA: diva2:375265
Available from: 2010-12-07 Created: 2010-12-07 Last updated: 2017-12-11Bibliographically approved
In thesis
1. Calciumhomeostasis and Vitamin D in Obesity and Preeclampsia
Open this publication in new window or tab >>Calciumhomeostasis and Vitamin D in Obesity and Preeclampsia
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Normal physiological functioning is highly dependent of calcium and the concentration range is very narrow. Normal calcium levels are so crucial to survival that the body will de-mineralize bone if the levels are insufficient. A prerequisite for normal calcium uptake is a normal Vitamin D level. Insufficient levels of Vitamin D are associated to several diseases.

The aims of this thesis were to study the relationship between pregnancies and hyperparathyroidism (pHPT) (I), between pHPT and pregnancy with preeclampsia (II) and also to determine if disturbances in calcium homeostasis with vitamin D deficiency are apparent in preeclamptic women (III).  The aim was also to study calciumhomeostasis in obese patients before and after bariatric surgery (IV and V) with emphasis on vitamin D status, parathyroid secretion and bone mineral density (BMD).

A correlation was found between a history of pHPT and pregnancy with preeclampsia, with an odds ratio of 6,89 ( 95% CI 2.30, 20.58).  Parathyroid hormone was significantly raised in preeclamptic pregnancies but vitamin D deficiency was present both in preeclamptic and healthy pregnancies. A certain polymorphism of the Vitamin D receptor (baT haplotype), overrepresented in pHPT, was not over expressed in preeclampsia. Hypovitaminosis D was present in more than 70% of bariatric patients preoperatively, which did not change after surgery, despite great weight loss and start of Vitamin D supplementation. BMD was significantly lower in bariatric patients with a negative correlation to the time elapsed since surgery. A small increase in BMD could be noted 10-13 years after bariatric surgery, possibly due to gradual weight gain. CiCa-clamping in obese patients demonstrated a disturbed calcium homeostasis with a left-shifted calcium-PTH relationship and a lower set-point of calcium. This disturbance persisted one year postoperatively.

In conclusion, derangements in calcium homeostasis with decreased levels of Vitamin D are present in preeclampsia and obesity. A history of pHPT should be viewed as a risk factor for preeclampsia. Life long follow-up is necessary after bariatric surgery, and an individually adjusted high dose Vitamin D substitute is probably needed to avoid a development of osteoporosis.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2011. 68 p.
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 650
Keyword
Calcium homeostasis, vitamin D, preeclampsia, obesity, parathyroid hormone
National Category
Surgery
Research subject
Surgery
Identifiers
urn:nbn:se:uu:diva-145209 (URN)978-91-554-8017-2 (ISBN)
Public defence
2011-04-08, Grönwallssalen, ing 70, Akademiska sjukhuset, Uppsala, 09:15 (Swedish)
Opponent
Supervisors
Available from: 2011-03-18 Created: 2011-02-07 Last updated: 2011-05-04

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Authority records BETA

Hultin, HellaEdfeldt, KatarinaSundbom, MagnusHellman, Per

Search in DiVA

By author/editor
Hultin, HellaEdfeldt, KatarinaSundbom, MagnusHellman, Per
By organisation
Endocrine SurgeryUpper Abdominal Surgery
In the same journal
Journal of Clinical Endocrinology and Metabolism
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 424 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf