Association of different lipid measures with incident bone fractures: Tehran lipid and glucose study

ABSTRACT

Objective

To investigate the association between different lipid measures and long-term hospitalization-required incident fracture among Iranian men and women.

Methods

A total of 3309 individuals aged ≥50 years (men = 1598) were included in the study. Multivariate Cox proportional hazard analyses were performed to assess the risk of incident fracture across quintiles, considering first quintile as reference, as well as for 1-standard deviation (SD) increase in each lipid measure, i.e. total cholesterol (TC), triglycerides (TG), low- and high-density lipoprotein cholesterol (LDL-C and HDL-C, respectively), non-HDL-C, and related indices (TG/HDL-C and TC/HDL-C). Covariates included age, body mass index, current smoking, type 2 diabetes mellitus, hypertension, lipid lowering-drugs, and steroid medications (for women).

Results

During a median follow-up of 18 years, incident fracture was observed in 201 cases (men = 87). In both gender, no linear association was found between different lipid measures and incident fracture. Among men, only the fourth quartile of TG was associated with lower risk of fracture in the age-adjusted analysis with the hazard ratio (HR) and 95% confidence interval (CI) of [0.45 (0.21–0.95)]. Among women, the age-adjusted HRs and 95% CIs for the second, third, fourth, and fifth quintiles of non-HDL-C were [0.46 (0.25–0.87)], [0.73 (0.42–1.25)], [0.90 (0.54–1.51)], and [0.52 (0.29–0.95)], respectively; the corresponding values in the multivariate model were [0.48 (0.26–0.90)], [0.76 (0.4–1.32)], [0.94 (0.56–1.58)], and [0.52 (0.28–0.95)], respectively. The second quintile of LDL-C was also associated with lower risk for incident fracture in the multivariate analysis [0.53 (0.29–0.98)].

Conclusions

Among Iranian women, a nonlinear association between non-HDL-C and LDL-C and incident fracture was found as the second and fifth quintile of the former and the second quintile of the latter were associated with about 50% lower risk of fracture. Generally, our findings did not support harmful impact of these lipid measures on incident fracture.

KEYWORDS:

• Lipid measures
• fracture
• Tehran lipid glucose study

Acknowledgments

The authors would like to thank the participants and executive team of the TLGS for their passionate cooperation. We would also like to acknowledge Dr Fatemeh Eskandari for her careful documentation of fracture events.

Declaration of financial/other relationships

The authors have no financial involvement with any organization or any financial interest in or financial conflict with the subject or materials discussed in the manuscript. This manuscript has no relevant financial or other relationships to disclose. Peer reviewers of this manuscript have no relevant financial or other relationships to disclose.

Availability of data and materials

The data sets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This study was supported by the Shahid Beheshti University of Medical Sciences [grant number 27488] and by the National Research Council of the Islamic Republic of Iran [grant number 121].