title: Prevalence of vitamin D deficiency and association with metabolic syndrome in a Qatari population.
abstract: Despite long hours of sunlight in Qatar and other regions of the Middle East, vitamin D deficiency has been rising. In parallel, the prevalence of metabolic syndrome has also been increasing in Qatar. Vitamin D levels have been associated with metabolic syndrome but the data are inconsistent and no studies have addressed these inter-relationships in a Middle Eastern population where the prevalence of these conditions is high. The objective is to investigate the prevalence of vitamin D deficiency and its association with metabolic syndrome and its components in the Qatar Biobank population.
  
  
  
  A cross-sectional study of 1205 participants (702 women and 503 men) from the Qatar Biobank, comprising Qataris and non-Qataris between the ages of 18 and 80 years, was used to perform multivariate linear regression analyses to examine the association between metabolic syndrome and prevalence of vitamin D deficiency (defined as <20 ng ml-1serum vitamin D levels) adjusting for age, sex, ethnicity, season of blood collection, physical activity and education. Odds ratios and 95% confidence intervals were calculated for all analyses.
  
  
  
  Approximately 64% of participants were vitamin D deficient (<20 ng ml-1) with more men being deficient (68.6%) than women (61.3%). Serum vitamin D was 8% lower in individuals with metabolic syndrome (RR: 0.92, 95%CI: 0.87-0.98, P-value: 0.01) compared to individuals without metabolic syndrome. Waist circumference and HDL as well as high triglyceride levels were also significantly positively associated with vitamin D deficiency. No association was found between the other components of metabolic syndrome or diabetes and the presence of vitamin D deficiency.
  
  
  
  Vitamin D deficiency is prevalent in this Qatari population. Presence of metabolic syndrome was associated with presence of vitamin D deficiency. Future prospective studies need to be conducted to investigate the potential for causality.
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.
authors.forename: K
authors.initials: K
authors.lastname: Al-Dabhani
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.|Department of Hygiene and Epidemiology, University of Ioannina Medical School, Ioannina, Greece.
authors.forename: K K
authors.initials: KK
authors.lastname: Tsilidis
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.|Nutritional Epidemiology Group, International Agency for Research on Cancer.
authors.forename: N
authors.initials: N
authors.lastname: Murphy
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.
authors.forename: H A
authors.initials: HA
authors.lastname: Ward
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.|MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Elliott
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.
authors.forename: E
authors.initials: E
authors.lastname: Riboli
authors.affiliation: Nutritional Epidemiology Group, International Agency for Research on Cancer.
authors.forename: M
authors.initials: M
authors.lastname: Gunter
authors.affiliation: Department of Biostatistics and Epidemiology, School of Public Health, Imperial College London, London, UK.|Department of Hygiene and Epidemiology, University of Ioannina Medical School, Ioannina, Greece.|MRC-PHE Centre for Environment and Health, School of Public Health, Imperial College London, London, UK.
authors.forename: I
authors.initials: I
authors.lastname: Tzoulaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D008076:Cholesterol, HDL / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000209:etiology*; D008875:Middle Aged; D015995:Prevalence; D011780:Qatar; D012737:Sex Factors; D014280:Triglycerides / Q000097:blood*; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D055105:Waist Circumference; D055815:Young Adult
chemical_list: D008076:Cholesterol, HDL; D014280:Triglycerides; D014807:Vitamin D