Use of anti-osteoporosis therapy including anti-resorptives such as bisphosphonates or anabolic agents such as teriparatide or denosumab
Conditions in which bone loss is known to be present or expected to occur, such as lactation
Pregnant or planning to become pregnant
In the opinion of the CF care team or study investigators participant should not participate in the study
Inability to provide informed consent/assent
Feasibility Sub-Study:
All of above and
Contraindications to transdermal estradiol
Current use of systemic estrogen (such as estrogen-containing oral contraceptive pill)
Previous lung or liver transplant
Use of chronic systemic glucocorticoids
Severe vitamin D deficiency (serum 25(OH)D \< 6 ng/mL)
Conditions increasing risk of clot: history of previous deep vein thrombus or pulmonary embolism, current immobility, current peripherally inserted central catheter or mediport, known hypercoagulable condition
Baseline study visit falls between 1 and 8 weeks after initiation of CF transmembrane receptor (CFTR) modulator
Currently in pulmonary exacerbation
Recent antibiotic use within the past 4 weeks for an acute pulmonary exacerbation
Unwilling or unable to use a non-estrogen containing method of contraception such as barrier, abstinence, or progesterone-only method
