{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T05:15:18Z","timestamp":1777871718280,"version":"3.51.4"},"reference-count":19,"publisher":"Public Library of Science (PLoS)","issue":"4","license":[{"start":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T00:00:00Z","timestamp":1777507200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"\n Background<\/jats:title>\n While tobacco smoking biologically elevates hemoglobin through chronic hypoxia, this study investigates an unexpected paradoxical reversal in conflict-affected Yemen, testing whether socioeconomic status may override biological pathways in extreme resource-limited settings.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n We conducted a multi-center cross-sectional study of 600 Yemeni university students (aged 18\u201325). Data on smoking, socioeconomic proxies, and hematological parameters were collected. We employed multivariate logistic regression, causal mediation analysis with bootstrapping, and E-value sensitivity analysis.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n Non-smokers had substantially higher odds of abnormal hemoglobin (adjusted Odds Ratio [aOR] = 11.25, 95% CI: 3.45--36.70, p\u2009<\u20090.001) and abnormal Mean Corpuscular Hemoglobin Concentration (aOR = 3.41, 95% CI: 1.58--7.35, p\u2009=\u20090.002) compared to smokers. Mediation analysis suggested that 38% of smoking\u2019s total effect on hemoglobin was mediated through nutritional pathways (indirect effect\u2009=\u20090.24, 95% CI: 0.08--0.45). The paradoxical association was significantly stronger among students from lower socioeconomic backgrounds (interaction p\u2009=\u20090.012) and females. E-value analysis (E\u2009=\u20094.32) indicated that substantial unmeasured confounding would be needed to explain away this association.<\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n These findings suggest a \u201chealthy smoker\u201d paradox in a humanitarian crisis context, where smoking status may serve as a proxy for higher SES and better nutritional access. This is consistent with the hypothesis that fundamental social causes can reverse established biological risk associations in contexts of extreme deprivation.<\/jats:p>\n <\/jats:sec>","DOI":"10.1371\/journal.pone.0348146","type":"journal-article","created":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T17:27:21Z","timestamp":1777570041000},"page":"e0348146","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Healthy Smoker Paradox: Socioeconomic status as a fundamental cause of reversed anemia risk among Yemeni youth"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-3341-7441","authenticated-orcid":true,"given":"Radfan Saleh","family":"Abdullah","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2266-1569","authenticated-orcid":true,"given":"Naif Taleb","family":"Ali","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mansour Abdelnabi","family":"H. 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