title: Dietary pattern, serum magnesium, ferritin, C-reactive protein and anaemia among older people.
abstract: Epidemiological data of dietary patterns and anaemia among older Chinese remains extremely scarce. We examined the association between dietary patterns and anaemia in older Chinese, and to assess whether biomarkers of serum magnesium, C-reactive protein (CRP) and serum ferritin can mediate these associations.
  
  
  
  We analysed the 2009 China Health and Nutrition Survey data (2401 individuals aged ≥60 years for whom both dietary and biomarker data are available). Dietary data was obtained using 24 h-recall over three consecutive days. Fasting blood samples and anthropometry measurement were also collected. Factor analysis was used to identify dietary patterns. Factor scores representing dietary patterns were used in Poisson regression models to explore the association between each dietary pattern and anaemia.
  
  
  
  Of the 2401 participants, 18.9% had anaemia, 1.9% had anaemia related to inflammation (AI), and 1.3% had iron-deficiency anaemia (IDA). A traditional dietary pattern (high intake of rice, pork and vegetables) was positively associated with anaemia; a modern dietary pattern (high intake of fruit and fast food) was inversely associated with anaemia. Progressively lower magnesium and BMI levels were associated with increasing traditional dietary quartiles; while a progressively higher magnesium and BMI levels were associated with increasing modern dietary quartiles (p < 0.001). There were no significant differences (p > 0.05) in CRP and serum ferritin across quartiles for either dietary pattern. In the fully adjusted model, the prevalence ratio (PR) of anaemia, comparing the fourth quartile to the first quartile, was 1.75 (95% CI: 1.33; 2.29) for a traditional dietary pattern, and 0.89 (95% CI: 0.68; 1.16) for a modern dietary pattern. The association between dietary patterns and anaemia is mediated by serum magnesium.
  
  
  
  Traditional dietary pattern is associated with a higher prevalence of anaemia among older Chinese. Future studies need to examine whether correcting micronutrient deficiency (e.g. magnesium) by promoting overall healthy diet, rather than iron supplementation, is a suitable strategy for anaemia prevention in older Chinese people.
authors.affiliation: Priority Research Centre for Gender, Health and Ageing, School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia; Centre for Clinical Epidemiology and Biostatistics, School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia. Electronic address: xiaoyue.xu@uon.edu.au.
authors.forename: Xiaoyue
authors.initials: X
authors.lastname: Xu
authors.affiliation: Centre for Clinical Epidemiology and Biostatistics, School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Hall
authors.affiliation: Priority Research Centre for Gender, Health and Ageing, School of Medicine and Public Health, Hunter Medical Research Institute, University of Newcastle, Newcastle, Australia.
authors.forename: Julie
authors.initials: J
authors.lastname: Byles
authors.affiliation: Discipline of Medicine, School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia.
authors.forename: Zumin
authors.initials: Z
authors.lastname: Shi
mesh_terms: D000368:Aged; D018798:Anemia, Iron-Deficiency / Q000175:diagnosis / Q000453:epidemiology*; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001835:Body Weight; D002097:C-Reactive Protein / Q000378:metabolism*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004032:Diet; D019587:Dietary Supplements; D015444:Exercise; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology; D008274:Magnesium / Q000097:blood*; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015596:Nutrition Assessment; D009749:Nutrition Surveys; D015995:Prevalence; D012959:Socioeconomic Factors
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein; D005293:Ferritins; D008274:Magnesium
keywords: Anaemia; Anaemia of inflammation; Dietary pattern; Iron-deficiency anaemia; Serum magnesium