Migraine is a common clinical neurological disorder that adversely affects humans and society. The relationship between copper intake and migraine has been less studied and controversial. The purpose of this study was to determine the relationship between copper intake and migraine and to guide dietary interventions. The data for this study were obtained from the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2004, involving a total of 12,724 participants. The relationship between copper intake and migraine was examined using weighted multivariate logistic regression models, and smooth-fit curves were plotted to explore the relationship. After non-linear relationships were found, recursive algorithms and two-stage linear regression models were used to calculate inflection points. Stratified analyses were also performed to explore population differences. In the model corrected for all covariates, the OR (95% CI) of copper intake with migraine was 1.19 (0.97, 1.46), which was not statistically significant. However, the results of the linear trend test suggested that their relationship might be non-linear. Smooth-fit curves confirmed the non-linear relationship between copper intake and migraine, and an inflection point (0.98 mg/day) was identified. There was no statistical significance before the inflection point, but after the inflection point, copper intake was positively associated with migraine attacks. Stratified analyses showed that this non-linear relationship persisted in females, people under 45 years old, and people with BMI less than 30. In this large cross-sectional study, we found a non-linear correlation between copper intake and migraine.

偏头痛是一种常见的临床神经系统疾病，对人类和社会产生不利影响。铜摄入量与偏头痛之间的关系研究较少，也存在争议。本研究的目的是确定铜摄入量与偏头痛之间的关系并指导饮食干预。这项研究的数据来自1999年至2004年的国家健康和营养检查调查（NHANES）数据库，总共涉及12,724名参与者。使用加权多元逻辑回归模型检查铜摄入量与偏头痛之间的关系，并绘制平滑拟合曲线来探索这种关系。找到非线性关系后，使用递归算法和两阶段线性回归模型来计算拐点。还进行了分层分析以探索人群差异。在校正所有协变量的模型中，铜摄入量与偏头痛的 OR (95% CI) 为 1.19 (0.97, 1.46)，不具有统计学意义。然而，线性趋势检验的结果表明它们的关系可能是非线性的。平滑拟合曲线证实了铜摄入量与偏头痛之间的非线性关系，并确定了拐点（0.98 毫克/天）。拐点之前没有统计学意义，但拐点之后，铜摄入量与偏头痛发作呈正相关。分层分析表明，这种非线性关系在女性、45 岁以下人群和 BMI 小于 30 的人群中持续存在。在这项大型横断面研究中，我们发现铜摄入量与偏头痛之间存在非线性相关性。