Effect of once-yearly zoledronic acid five milligrams on fracture risk and change in femoral neck bone mineral density.
BACKGROUND
In the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly - Pivotal Fracture Trial (HORIZON-PFT), zoledronic acid (ZOL) 5 mg significantly reduced fracture risk.


OBJECTIVE
The aim of the study was to identify factors associated with greater efficacy during ZOL 5 mg treatment.


METHODS
We conducted a subgroup analysis (preplanned and post hoc) of a multicenter, double-blind, placebo-controlled, 36-month trial in 7765 women with postmenopausal osteoporosis.


METHODS
A single infusion of ZOL 5 mg or placebo was administered at baseline, 12, and 24 months.


METHODS
Primary endpoints were new vertebral fracture and hip fracture. Secondary endpoints were nonvertebral fracture and change in femoral neck bone mineral density (BMD). Baseline risk factor subgroups were age, BMD T-score and vertebral fracture status, total hip BMD, race, weight, geographical region, smoking, height loss, history of falls, physical activity, prior bisphosphonates, creatinine clearance, body mass index, and concomitant osteoporosis medications.


RESULTS
Greater ZOL induced effects on vertebral fracture risk were seen with younger age (treatment-by-subgroup interaction, P = 0.05), normal creatinine clearance (P = 0.04), and body mass index >or= 25 kg/m(2) (P = 0.02). There were no significant treatment-factor interactions for hip or nonvertebral fracture or for change in BMD.


CONCLUSIONS
ZOL appeared more effective in preventing vertebral fracture in younger women, overweight/obese women, and women with normal renal function. ZOL had similar effects irrespective of fracture risk factors or femoral neck BMD.
Eastell
Richard
R
Academic Unit of Bone Metabolism, Metabolic Bone Centre, Sorby Wing, Northern General Hospital, Herries Road, Sheffield, South Yorkshire S5 7AU, United Kingdom. r.eastell@sheffield.ac.uk
Black
Dennis M
DM
Boonen
Steven
S
Adami
Silvano
S
Felsenberg
Dieter
D
Lippuner
Kurt
K
Cummings
Steven R
SR
Delmas
Pierre D
PD
Palermo
Lisa
L
Mesenbrink
Peter
P
Cauley
Jane A
JA
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D004164:Diphosphonates / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005272:Femur Neck / Q000187:drug effects* / Q000378:metabolism; D006620:Hip Fractures / Q000517:prevention & control*; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use*; D016103:Spinal Fractures / Q000517:prevention & control*; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid