Homocysteine, Cardiometabolic multimorbidity, Risk factors, Individual differences, Cross-sectional study, Nutritional diseases. Deficiency diseases, RC620-627

Abstract Background Elevated homocysteine (Hcy) levels have been linked to cardiovascular disease (CVD), but their association with cardiometabolic multimorbidity (CMM) remains uncertain. Methods Data from the baseline survey of the China Northwest Cohort-Ningxia Project (CNC-NX) were used to recruit 22,566 participants. Demographic characteristics, lifestyle factors, and laboratory exam results were collected. Logistic regression was used to evaluate the association between Hcy levels and CMM risk. Restricted cubic splines (RCS) explored potential non-linear relationships, and subgroup analyses assessed the consistency of the association across distinct groups. Sensitivity analysis accounted for cluster variability. Results The final analysis included 18,126 participants. Higher Hcy levels were significantly associated with an increased risk of CMM (adjusted OR = 1.005, P = 0.003), with a linear relationship confirmed by RCS analysis (P for non-linearity = 0.142). There was a stronger association between Hcy-CMM in high-risk people, including elderly, males, and those with high BMI (P