OR13-02 Ethnic Variation In Non-vertebral Major Osteoporotic Fractures Among US Asian/Pacific Islander Men
Authors: Chu Clarence E , Chandra Malini , Gordon Nancy P , Zeltser David W , Lee Catherine , Darbinian Jeanne A , Lo Joan C 
Published: October 2023

Abstract
Disclosure: C.E. Chu: None. M. Chandra: None. N.P. Gordon: None. D.W. Zeltser: None. C. Lee: None. J.A. Darbinian: None. J.C. Lo: None.
Background: Our recent characterization of hip fracture incidence among Asian/Pacific Islander (PI) adults compared Chinese, Japanese, Filipino, and South Asian adults and found that South Asian men had a higher incidence of hip fracture compared to Chinese men, but Japanese and Filipino men did not. However, published data pertaining to major osteoporotic fracture (MOF) risk remain limited. We now further examine the incidence of non-vertebral MOF among Asian/PI men, including findings by Asian subgroup. METHODS: We used data from a previously reported retrospective cohort of 188,328 Asian/PI men in an integrated healthcare delivery system who were age ≥50y during 2000-2019. Asian/PI subgroups examined included 41,862 Chinese, 45,779 Filipino, 13,322 South Asian, and 7,838 Japanese men (the four largest Asian/PI subgroups among men and women), with the remaining 79,527 Asian/PI men comprising 8,293 Vietnamese, 3,500 other Southeast Asian, 6,629 Native Hawaiian/PI (NHPI), 3,132 Korean, 451 Central Asian, and 57,522 of multiple or unspecified Asian/PI ethnicity. Incident non-vertebral MOF was defined as the first hip, humerus, or wrist fracture identified by ICD diagnosis codes during follow up to 2021. Age adjusted fracture incidence [with 95% CI] was calculated using weights from the 2010 US Census. Log-Poisson regression was used to determine fracture incidence rate ratios (IRR) with Chinese adults as reference, adjusting for age and calendar year. RESULTS: Among 188,328 Asian/PI men (aged 55.3 ± 7.8 years at entry), 1501 experienced hip (43.3%), humerus (16.3%), or wrist (37.4%) fracture, or &gt;1 of these non-vertebral MOFs (3.0%) during follow-up, with mean age 71.0 ± 13.0 years at the time of incident fracture. The age-adjusted incidence of non-vertebral MOF for Asian/PI men was 1.18 [1.12-1.25] per 1000 person-years overall but varied among the major Asian/PI subgroups: 1.19 [1.08-1.29] for Chinese, 1.00 [0.88-1.12] for Filipino, 1.51 [1.28-1.77] for Japanese, and 2.01 [1.67-2.41] for South Asian men per 1000 person-years. Compared to Chinese men, the IRR for non-vertebral MOF were 0.83 [0.72-0.95] for Filipino, 1.21 [1.01-1.44] for Japanese, and 1.84 [1.54-2.20] for South Asian, and 0.89 [0.77-1.03] for all other Asian/PI men, including those with unspecified ethnicity. Conclusions: The majority of non-vertebral MOF occurred at the hip and wrist among men. When comparing fracture incidence across major Asian/PI subgroups, the largest difference in non-vertebral MOF incidence was seen among South Asian men compared to their Chinese counterparts, consistent with previous hip fracture findings. Japanese men also had somewhat higher incidence of MOF, while Filipino men had lower incidence. Future studies are needed to examine whether differences are evident in other Asian/PI subgroups and whether there are differences in clinical outcome after non-vertebral MOF fracture.
Presentation: Friday, June 16, 2023