Abstract Body (Do not enter title and authors here): BACKGROUND: Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death worldwide. Even after optimal lowering of low-density lipoprotein (LDL) cholesterol, ASCVD risk persists. Remnant cholesterol (RC), calculated as total cholesterol minus high-density lipoprotein and LDL cholesterol, may be a contributor to this risk. Although RC has been associated with ASCVD, few studies have examined this in South Asian populations, who experience higher rates of ASCVD compared to other racial/ethnic groups.

AIMS: Using data from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) Study, a community-based prospective cohort of South Asian men and women in the San Francisco Bay Area and greater Chicago area without ASCVD at baseline, we examined the association between RC and change in coronary artery calcium (CAC).

METHODS: Baseline fasting plasma specimens and questionnaires were obtained between 2010-2013. CAC was assessed by computed tomography at baseline and again after 5-year follow-up in 698 participants. We used multivariable linear and logistic regression to examine relationships between RC quartile and CAC incidence, progression, and change. Incident CAC was defined as CAC>0 at follow-up in individuals with CAC=0 at baseline. CAC progression was defined as an increase in CAC score in those with CAC>0 at baseline. CAC change was the difference in CAC score between baseline and follow-up.

RESULTS: In 892 participants at baseline, mean RC was 25.8±11.8 mg/dL. Increasing RC quartile was associated with male gender, greater body mass index, greater CT adiposity measures, higher levels of HOMA-IR, HOMA-B, and higher prevalence of smoking and diabetes (p<0.05). Mean CAC incidence was 25.8±43.8% and increased by quartile of baseline RC (p=0.002, Figure 1). After adjusting for age, gender, smoking status, hypertension, diabetes, and cholesterol-lowering medication use, individuals with RC levels in the third (OR: 2.24, 95% CI: 1.01–4.98) and fourth quartiles (OR: 2.57, 95% CI: 1.20–5.51) had significantly higher odds of incident CAC at 5 years than those in the lowest RC quartile. This association persisted after sequential adjustment for behaviors, adiposity, and measures of insulin sensitivity, and did not vary by gender. However, RC quartiles were not associated with CAC progression or CAC change.

CONCLUSION: Higher RC levels were associated with increased odds of incident CAC independent of risk factors for ASCVD.