Vitamin D status and response to treatment in post-menopausal osteoporosis.
Treatment with anti-resorptive agents over 13 months was associated with for three to fivefold lower bone mineral density changes and 1.5-fold increased risk of incidence fracture in vitamin D insufficient as compared to vitamin D repleted postmenopausal osteoporotic women.


BACKGROUND
Several drugs were registered for the treatment of osteoporosis on the basis of clinical trials in which vitamin D repletion was a pre-requisite inclusion criteria and vitamin D supplements were used as adjunctive therapy. However, in routine clinical practice these supplements are not consistently recommended.


METHODS
We studied 1515 women with postmenopausal osteoporosis under treatment with anti-resorbing agents (alendronate, risedronate, raloxifene) for 13.1 months with an adherence > 75%. The patients were classified as vitamin D deficient (N = 514) or vitamin D repleted (N = 1001) according to risk factors (N = 1062) or the level of 25(OH) vitamin D [25(OH)D] above or below 50 nmol/l (N = 453).


RESULTS
Vitamin D deficient and vitamin D repleted subjects differed significantly for annualized spine and hip bone mineral density (BMD) changes adjusted for all available confounding factors (type of treatment, age, global calcium intake, baseline BMD values). One hundred fifty one patients suffered from a new incident clinical fracture. The adjusted odds ratio for incident fractures in vitamin D deficient as compared to vitamin D repleted women was 1.77 (1.20 - 2.59, 95% CI; p = 0.004).


CONCLUSIONS
Optimal vitamin D repletion seems to be necessary to maximize the response to anti-resorbers in terms of both BMD changes and anti-fracture efficacy.
Adami
S
S
Rheumatology Unit, Ospedale di Valeggio, Verona, Italy. silvano.adami@univr.it
Giannini
S
S
Bianchi
G
G
Sinigaglia
L
L
Di Munno
O
O
Fiore
C E
CE
Minisola
S
S
Rossini
M
M
D000203:Activities of Daily Living; D000368:Aged; D019386:Alendronate / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D001862:Bone Resorption; D002118:Calcium / Q000008:administration & dosage; D015986:Confounding Factors, Epidemiologic; D019587:Dietary Supplements; D012968:Etidronic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D005260:Female; D050723:Fractures, Bone / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D020849:Raloxifene Hydrochloride / Q000627:therapeutic use; D012189:Retrospective Studies; D000068296:Risedronic Acid; D012306:Risk; D016896:Treatment Outcome; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology
D015415:Biomarkers; D050071:Bone Density Conservation Agents; D014807:Vitamin D; D020849:Raloxifene Hydrochloride; C104450:25-hydroxyvitamin D; D000068296:Risedronic Acid; D012968:Etidronic Acid; D002118:Calcium; D019386:Alendronate