Evaluate whether treatment with a widely used beta blocker, atenolol, will prevent bone loss at the lower back and hip in postmenopausal women.

Inclusion Criteria:

• Able and willing to provide informed consent
• Postmenopausal women (FSH ≥ 16 IU/L) (no menses for at least one year)
• Aged 50-75 years

Exclusion Criteria:

• Clinical diagnosis of diabetes mellitus requiring insulin

• Clinically significant abnormality in any of the additional screening laboratory studies

• A1c- ≥8

• Calcium - > upper limit lab value per site

• AST- 2x upper normal limit

• FSH- < 16IU/L

• eGFR- < 45 mL/min/1.73m2 based on creatinine

• CBC- Per PI interpretation of each patient

• Presence of (documented clinical diagnosis of any of the following):

  • Significant liver or renal disease
  • Malignancy (current diagnosis including myeloma or melanoma)
  • Radiation (the site PI will determine eligibility on a case-by-case basis)
  • Malabsorption (current clinical diagnosis or actively receiving treatment)
  • Hypoparathyroidism (current clinical diagnosis or actively receiving treatment)
  • Hyperparathyroidism (current clinical diagnosis or actively receiving treatment)
  • Acromegaly
  • Cushing syndrome
  • Hypopituitarism
  • Severe chronic obstructive pulmonary disease
  • Pheochromocytoma (current clinical diagnosis or actively receiving treatment)
  • History of cardiac failure
  • Ejection Fraction <35% (based on most recent EF within the last 12 months, if available)
  • PR interval > 200 msec on screening ECG or known heart block
  • History of bronchospastic disease with treatment (asthma, bronchitis)
  • Gastric Bypass
  • Parkinson's
  • Rheumatoid Arthritis
  • Psoriatic Arthritis
  • Connective Tissue disease

• Undergoing treatment with any medications that affect bone turnover, including the following:

  • adrenocorticosteroids (oral for > 3 months within the past year or year-round use of inhaled corticosteroid use)
  • anticonvulsant therapy for seizures (carbamazepine, phenobarbital, or phenytoin within the previous year) pharmacological doses of: thyroid hormone (causing decline of thyroid stimulating hormone below normal, i.e. < 0.3 miU/L) bisphosphonates (within the past 3 yrs; if taken orally >1 month in past 3 years) denosumab, romosozumab, estrogen therapy (does not include creams or suppositories) or treatment with a selective estrogen receptor modulator, or teriparatide/abaloparatide (> 1 month within the past year); aromatase inhibitors (>1 month within the past year)
  • Current use of digitalis glycosides
  • Thiazides (< 6 months of use prior to screening)
  • Current or within the past 3 months use of beta blockers

• Any recent fracture within the past 6 months prior to screening (other than fingers, toes and facial fractures, which are all acceptable)

• Bilateral hip replacements or metal in both hips

• Patients with serum 25-hydroxyvitamin D levels of < 20 ng/ml, in order to ensure vitamin D sufficiency

• Resting systolic blood pressure < 115 mm Hg, heart rate < 55 bpm (average of 3 readings after a 5-minute rest and one minute between readings with an automatic cuff)