Higher circulating hsCRP levels are associated with lower bone mineral density in healthy pre- and postmenopausal women: evidence for a link between systemic inflammation and osteoporosis

Factors involved in inflammation are linked with those critical for bone remodeling. We examined the association between serum high sensitivity C-reactive protein (hsCRP) levels and bone mineral density (BMD) in healthy women. Serum concentrations of hsCRP and total alkaline phosphatase (ALP) were measured in premenopausal (n =3,662) and postmenopausal (n =1,031) women aged 30 years or older. BMD was measured at the femoral neck and lumbar spine using dual energy X-ray absorptiometry. According to the WHO definition, osteopenia was diagnosed at -2.5 < T -score <-1.0 SD, and osteoporosis was diagnosed at T -score <= 2.5 SD at any sites. Compared with normal subjects, log-transformed serum hsCRP levels were higher in osteopenic and osteoporotic subjects (all, P < 0.001) with linearity (P for trend < 0.001), after adjustment for age, BMI and menopausal status. Menopausal status did not have a significant interaction on the association (P =0.457). In both premenopausal and postmenopausal women, serum total ALP levels were higher in the subjects with higher hsCRP quintiles than those with the lowest quintile (all, P for trend < 0.001). Multivariate-adjusted odds ratio (OR) for osteoporosis and osteopenia were 1.35 (95% CI, 1.08 to 1.68) in the highest hsCRP quintile of premenopausal women, and OR for osteoporosis was 1.54 (95% CI, 1.10 to 2.53) in the highest hsCRP quintile of postmenopausal women. These findings suggest that subclinical systemic inflammation may be associated with bone turnover rate and bone mass in healthy women.