Osteoporosis and apolipoprotein E genotype in older adults: the Rancho Bernardo study.

Recent studies reported an association between apolipoprotein E (ApoE) 4 and osteoporosis. We examined the association of ApoE 4 genotype with bone mineral density (BMD), bone loss and fracture risk in 596 men and 332 community-dwelling women aged 45-95 years. Women were postmenopausal and not using estrogen. At the baseline visit, BMD was measured at the ultradistal and midshaft radius using single photon densitometry, and at the hip and lumbar spine using dual-energy X-ray absorptiometry. Hip and lumbar spine BMD levels were remeasured 4 years later. Self-reported fractures were confirmed by radiology reports in 95% of cases. ApoE allele distribution did not vary by age; 25% of men and 20% of women had one ApoE 4 allele. There were no differences in BMD at the lumbar spine, total hip, ultradistal or midshaft radius in men or women with the ApoE 4 allele compared with men or women without the ApoE 4 allele. After an average 4 year interval, there were also no differences in the annualized percent change in BMD at the hip or lumbar spine in men or women with or without an ApoE 4 allele. One or more clinical fractures were reported by 55 men and 109 women. Fewer, not more, clinical fractures were reported in men and women with an ApoE 4 allele; these differences were not statistically significant (p = 0.21 and p = 0.62, respectively). These data do not support the hypotheses that there is an association between ApoE genotype and BMD, bone loss or osteoporotic fractures in older community-dwelling men or women.