Involvement of pro- and anti-inflammatory adipokines in the pathogenesis of postmenopausal osteoporosis: data from a pilot study

摘要

Context: A wealth of evidence suggests that increase in body fat may exert beneficial effects on bone health and prevent the onset of osteoporosis in postmenopausal women. However, the mechanism underlying the interplay between these two tissues is still unclear. Objective: To evaluate if adipokines act as biological mediators of the protective role of fat on bone tissue.\udPatients: Total sample (119 postmenopausal women, median age= 56 years, median BMI= 35.1kg/m2) subdivided into 30 women with normal bone mass density (BMD), 45 osteopenic and 44 osteopenic.Methods: Serum levels of adipokines including interleukin (IL)-6, IL-8, IL-1b, adipsin, lipocalin-2, tumor necrosis factor alpha, resistin, leptin and adiponectin were assessed in all study subjects.\udMain outcomes: Waist circumference and BMI were positively correlated (p50.01 for all correlations) with BMD at all sites (spine, femoral neck, total hip trochanter). Concerning adipokines: leptin was positively associated with BMD at spine (r = 0.24, p50.05), femoral neck (r = 0.22, p50.05), and total hip (r = 0.28, p50.01), while adiponectin was inversely correlated with BMD at trochanter (r = 0.23, p50.05). Of note, the observed association were all influenced by systemic level of IL-6. Indeed, at high level of this pro- inflammatory cytokines they all disappeared, while they persisted (with strength comparable to that observed in whole sample) at low IL-6 levels.\udConclusions: Our data suggest that adiponectin and leptin might be biological determinants of bone health in postmenopausal women, with an effect that is likely abolished when frank inflammatory responses take place.