Low body weight and involuntary weight loss are associated with Raynaud's phenomenon in both men and women.

: Low body weight is an easily assessable cause of Raynaud's phenomenon (RP), and is frequently overlooked by clinicians. We aim to investigate the association of low body weight (body mass index < 18.5 kg/m), involuntary weight loss, and nutritional restrictions with the presence of RP.: Participants from the Lifelines Cohort completed a validated self-administered connective tissue disease questionnaire. Subjects who reported cold-sensitive fingers and biphasic or triphasic colour changes were considered to suffer from RP. Patient characteristics, anthropometric measurements, and nutritional habits were collected. Statistical analyses was stratified for gender.: Altogether, 93 935 participants completed the questionnaire. The prevalence of RP was 4.2% [95% confidence interval (CI) 4.1-4.4%], and was three-fold higher in women than in men (5.7% vs 2.1%, p < 0.001). Subjects with RP had a significantly lower daily caloric intake than those without RP. Multivariate analysis, correcting for creatinine level, daily caloric intake, and other known aetiological factors associated with RP, revealed that low body weight [men: odds ratio (OR) 5.55 (95% CI 2.82-10.93); women: 3.14 (2.40-4.10)] and involuntary weight loss [men: OR 1.32 (1.17-1.48); women: 1.31 (1.20-1.44)] were significantly associated with the presence of RP. Low-fat diet was also associated with RP in women [OR 1.27 (1.15-1.44)].: Low body weight and prior involuntary weight loss are associated with an increased risk of RP in both men and women. This study emphasizes that low body weight and weight loss are easily overlooked risk factors for RP, and should be assessed and monitored in subjects with RP.