Figure 1.

The ORs and 95% CIs of insomnia according to four anemia groups. (1) Normal was defined as the level of hemoglobin ≥13.0 (if man, g/dL)/12.0 (if woman, g/dL); mild anemia was defined as the level of hemoglobin ≥12.0 and <13.0 (if man, g/dL)/≥11.0 and <12.0 (if woman, g/dL); moderate anemia was defined as the level of hemoglobin ≥9 and <12 (if man, g/dL)/≥8 and <11 (if woman, g/dL); and severe anemia was defined as the level of hemoglobin <9 (if man, g/dL)/8 (if woman, g/dL). (2) Adjusted for age, sex, education level (primary, middle, and college), income level (<600, 600–1000, and >1000 RMB/month), occupation (white-collar, blue-collar, and coalminer), physical activity (never, <4, and 4+ times/week), smoking status (never, past smoker, and current smoker), alcohol status (never, past drinker, and current drinker), myocardial infarction history (no and yes), stroke history (no and yes), cancer history (no and yes), hypertension (no, prehypertension, and hypertension), diabetes (no, prediabetes, and diabetes), C-reactive protein (mg/L), body mass index (<24 kg/m², 24–27.9 kg/m², ≥28 kg/m²), triglyceride (<0.82 mmol/L, 0.82–1.21 mmol/L, 1.22–1.86 mmol/L, ≥1.87 mmol/L), low density lipoprotein (<1.76 mmol/L, 1.76–2.11 mmol/L, 2.12–2.64 mmol/L, ≥2.65 mmol/L), and high-density lipoprotein (<1.31 mmol/L, 1.31–1.53 mmol/L, 1.54–1.78 mmol/L, ≥1.79 mmol/L). CI: Confidence interval; OR: Odds ratio.