Abstract Body (Do not enter title and authors here): Introduction: Consensus guidelines recommend a lower BMI threshold in Asians for diabetes screening and ASCVD primary prevention strategies, but limited data exist about the association between BMI level and ASCVD in contemporary Asian American, Native Hawaiian and Pacific Islander (AANHPI) adults.

Goal: To assess the relation of BMI level and incident ASCVD risk in individual AANHPI groups and non-Hispanic Whites (NHW) by sex.

Methods: We identified 2,040,654 members aged ≥30 years of Kaiser Permanente (KP) Northern California and KP Hawaii integrated healthcare systems from 2012-2022, with BMI 18.5-40 kg/m² and no prior CVD. Incident nonfatal and fatal ASCVD events (MI, stroke) were identified through 2023 using ICD-9/10 codes in hospitalization and vital status data. Age-adjusted cubic spline analysis for BMI and incident ASCVD was conducted, stratified by sex and AANHPI group.

Results: We identified 138,748 Chinese, 158,209 Filipino, 40,561 Native Hawaiian/other Pacific Islander (NH/PI), 35,067 Japanese, 16,130 Korean, 74,130 South Asian, 37,459 Vietnamese, 20,320 other Southeast Asian, and 1,520,029 NHW eligible adults. Mean (SD) age ranged from 41.8 (12.7) years in South Asian to 56.5 (16.7) years in Japanese, with 55.3% women and higher proportions of women in each Asian group vs. NHW and NH/PI. The age-adjusted association of BMI and incident ASCVD varied significantly by AANHPI ethnicity in men (Figure 1) and women (Figure 2) across BMI 18.5-40. At various BMI intervention thresholds (23, 25, 27.5, 30) proposed for overweight or obesity, compared with BMI 20, in men, the age-adjusted association became significantly higher for certain groups at BMI 23 (Chinese, Filipino, Korean, Vietnamese), BMI 25 (other Southeast Asian, NHW), and BMI 27.5 (South Asian), while there was no significantly higher risk for Korean or NH/PI between BMI 23-30 (Table). In contrast, in women, compared with BMI 20, the age-adjusted association became significantly higher for certain groups at BMI 23 (Chinese, NH/PI, Vietnamese, Other Southeast Asian), BMI 25 (Japanese, NHW), and BMI 27.5 (Filipino, Korean, South Asian).

Conclusion: Among AANHPI and NHW adults, the relation between BMI and incident ASCVD varied significantly in shape and strength of association by sex and AANHPI group. Our findings support better understanding the reasons for these differences and raise the question about the utility of BMI for primary prevention decision-making among different AANHPI groups.