Association of adipokines and estradiol with bone and carotid calcifications in postmenopausal women

Abstract

Objectives Carotid artery calcifications (CAC) and high carotid artery intima-media thickness (cIMT) are associated with low bone mineral density (BMD) by unknown mechanisms in postmenopausal women. Leptin, adiponectin and estradiol may mediate these associations. Our aim was to study the relationships of the aforementioned factors to bone health (BMD) and carotid atherosclerosis (CAC and cIMT).

Method Participants (n = 290, mean age 73.6 years) for this cross-sectional OSTPRE-BBA study (Kuopio Osteoporosis Risk Factor and Prevention – Bone, Brain and Atherosclerosis) were randomly selected from the OSTPRE cohort in 2009. Femoral neck and total body BMDs, trunk and total body fat mass were measured with dual-energy X-ray absorptiometry, and cIMT (mm) and CAC (no/yes) were measured with B-type ultrasound. Free estradiol, adiponectin and leptin were measured from serum samples.

Results Circulating estradiol levels were associated with leptin (β = 0.131, p < 0.001), but not with adiponectin (p > 0.05), when adjusted for total body fat mass. There were no associations between estradiol tertiles and BMDs, or with cIMT or CAC. Adiponectin levels were inversely associated with femoral neck BMD (p = 0.019, β = −0.138) and total body BMD (p = 0.009, β = −0.142), adjusted for total body fat mass, age, current smoking and estradiol, but showed no relationship with CAC or cIMT. Leptin levels were not associated with BMDs or cIMT; but the odds ratio was 1.5 between the CAC and leptin quartiles (p = 0.014), adjusted for total body fat mass, age, statin use and calcium intake.

Conclusion The adipokines are associated with vascular calcification and low BMD. Moreover, estradiol was not independently associated with BMD or CAC.

KEYWORDS:

• Adiponectin
• leptin
• estradiol
• carotid calcification
• bone mineral density
• women

Acknowledgements

We thank Jarmo Tiikkainen for performing IMT measurements and Kimmo Ronkainen for help with the statistical analyses.

Conflict of interest

All authors state that they have no conflicts of interests. The authors alone are responsible for the content and writing of this paper.

Source of funding

The study was supported by Kuopio University Hospital EVO-grants (Tuppurainen M, grant number 5302460), Finnish Academy (Kröger H, grant number 250707), The Ministry of Education and Culture of Finland (grant numbers 116/626/2012, 46/627/2011 and 93/627/2010), Kuopio University Hospital Funding (V.T.R. grant number 5203024), and Strategic Funding of the University of Eastern Finland (grant number 931053).