<prompt> All are causes of osteoporosis except -Old ageChronic heparin therapyHypothyroidismThyrotoxicosis  <response>: Osteoporosis Osteoporosis is a disease characterized by increased porosity of the skeleton resulting from reduced mineral mass.Important causes of osteoporosisPrimaryPostmenopausalSenileIdiopathicSecondaryEndocrine disordersHyperparathyroidismThyrotoxicosisHypogonadismCushing syndromeDM type 1Addison diseasesNeoplasiaMultiple myelomaCarcinomatosisGastrointestinalMalnutrition and malabsorptionVit. C, D deficienciesImportant drugsHeparinGlucocorticoidsLithiumCyclosporinGn RH agonistsAnticonvulsantsAlcoholOthersOsteogenesis imperfectaImmobilizationHomocystinuriaRheumatological disease 