Low body mass index is related to post-lumbar puncture headache in Chinese adults: A cross-sectional study

ObjectivePost-lumbar puncture headache is a common complication following lumbar puncture. Although several risk factors have been established, the role of low body mass index remains controversial. This study aimed to evaluate the association between body mass index and post-lumbar puncture headache in Chinese adults undergoing lumbar puncture.MethodsIn total, 499 patients who underwent lumbar puncture at the Department of Neurology between January 2022 and March 2024 were enrolled. Data on demographic characteristics, blood pressure, lumbar puncture history, and cerebrospinal fluid parameters were collected. Univariate and multivariate logistic regression models were employed to assess the relationship between body mass index and post-lumbar puncture headache. Subgroup analyses were conducted to evaluate the consistency of this association across sex, age, blood pressure, cerebrospinal fluid volume, and cerebrospinal fluid protein levels.ResultsPost-lumbar puncture headache occurred in 13% (65/499) of patients; among these, 63.1% were female. Compared with those without post-lumbar puncture headache, those with a headache were younger (p < 0.001), had lower body mass index (p = 0.003), lower systolic and diastolic blood pressures (p = 0.001 and p = 0.001), lower cerebrospinal fluid protein level (p < 0.001), and greater cerebrospinal fluid collection volume (p < 0.001). No significant association was found between primary disease classification and post-lumbar puncture headache (p = 0.164). In univariate logistic regression analysis, the risk of post-lumbar puncture headache significantly decreased with increasing body mass index values (odds ratio = 0.9, 95% confidence interval: 0.84-0.97, p = 0.003). After multivariable adjustment for sex, age, blood pressure, cerebrospinal fluid protein level, and cerebrospinal fluid volume, the association remained significant (odds ratio = 0.92, 95% confidence interval: 0.85-0.99, p = 0.033). Further analysis, in which patients were grouped by body mass index levels and assessed using two multivariate regression models, revealed that individuals with a low body mass index had a significantly higher risk of post-lumbar puncture headache. In Model I, adjusted for sex and age, the odds ratio was 3.2 (95% confidence interval: 1.41-7.23, p = 0.005); in Model II, further adjusted for systolic pressure, diastolic pressure, cerebrospinal fluid protein level, and cerebrospinal fluid collection volume, the odds ratio was 3.14 (95% confidence interval: 1.36-7.25, p = 0.007). The findings were robust across both models. The findings were consistent in the subgroup analyses.ConclusionLower body mass index is significantly associated with an increased risk of post-lumbar puncture headache. These findings underscore the importance of considering body mass index in preoperative risk assessment and postoperative management for patients undergoing lumbar puncture. However, due to the cross-sectional study design, causal inference cannot be established.