Association of plasma homocysteine with cardiometabolic multimorbidity: a cross-sectional study in northwest China.

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 < 0.05). No significant association was observed between Hcy levels and more severe types of CMM.

Conclusions: Elevated Hcy levels are correlated with an increased risk of CMM, warranting further investigation into the underlying mechanisms and potential interventions. Given the individual differences in the Hcy-CMM relationship, targeted comprehensive interventions for high-risk groups are necessary to reduce the risk of CMM.