Atenolol for the Prevention of Osteoporosis (APO)

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 Bypas…