Bone mineral density as a mediator in the association of abdominal aortic calcification with mortality among the general population aged over 50.

BACKGROUND AND AIMS: The prevalence of vascular calcification and osteoporosis is increasing in the general population. We aimed to investigate the combined impact of abdominal aortic calcification (AAC) and bone mineral density (BMD) on mortality risk.

METHODS AND

RESULTS

Data were from the 2013-2014 National Health and Nutrition Examination Survey (NHANES). AAC was assessed using the AAC-24 scoring system (range 0-24) and categorized as none (0), mild (1-4), or severe (≥5). Bone mineral density (BMD) was classified according to WHO criteria as normal (T-score ≥ -1.0), osteopenia (T-score between -1.0 and -2.5), or osteoporosis (T-score ≤ -2.5). Among 2099 participants (median age 61.0 years; 51.2 % female), 231 (8.9 %) died over a median follow-up of 6 years, including 53 (1.9 %) from cardiovascular disease. Among those with osteoporosis, severe AAC was linked to the highest all-cause mortality risk versus no AAC (HR 2.59; 95 % CI, 1.22-5.49; P = 0.013). In contrast, among those with normal BMD, mild and severe AAC showed no significant increase in mortality. Compared with individuals with severe AAC and normal BMD, those with osteoporosis and severe AAC had higher all-cause mortality (HR 2.8; 95 % CI, 1.41-5.58; P = 0.003). The combination of osteoporosis and severe AAC was also associated with an increased cardiovascular mortality risk. Mediation analysis revealed BMD accounted for 11.64 % of the association between AAC and all-cause mortality in the fully adjusted model.

CONCLUSION

Severe AAC and low BMD jointly contributed to increased all-cause and cardiovascular mortality in adults over 50, and BMD partially mediated the effect of AAC on adverse outcomes.