Table 3.

Non-HIV-specific factors affecting bone health

Factor	Description
Preterm birth	Negative effect increases as gestational age decreases. Short-term fracture risk mainly for very preterm infants.
Abnormal weight (BMI)	Low BMI (general malnutrition and adolescents with eating disorders) associated with low BMD; high BMI (obesity) associated with increased fracture risk.
Specific nutritional deficiency	Inadequate vitamin D and calcium most important. Role of protein and other micronutrients less clear.
Genetic factors	Genetic disorders (osteogenesis imperfecta); family history of osteoporosis; blacks at low risk of osteoporosis relative to other racial/ethnic groups.
Exercise	Weight-bearing activity improves bone mass accrual and BMD; sedentary lifestyle and impaired mobility (as in cerebral palsy) compromise bone health.
Hormones	Normal pubertal increases in endogenous androgens, estrogens and growth hormone promote bone mass accrual. Lower PBM with delayed puberty. Pregnancy and lactation associated with transient BMD decline. Substantial BMD loss and fracture risk with menopause.
Lifestyle factors	Cigarette smoking, alcohol consumption and sedentary lifestyle all impair bone health.
Endocrinopathies	Hypogonadism, hypercortisolism (e.g., Cushing syndrome), hyperthyroidism and growth hormone deficiency associated with poor bone health.
Medications	Well-established negative effect on BMD: corticosteroids, anticonvulsants, medroxyprogesterone. Full list at http://www.nof.org/articles/6.
Inflammation	Juvenile arthritis, inflammatory bowel disease and other inflammatory disorders and conditions; risk related to proinflammatory cytokines and treatment (corticosteroids).
Other medical conditions	Malignancy, renal failure.

BMI=body mass index; BMD=bone mineral density; PBM=peak bone mass.