title: Incidence rate of type 2 diabetes is >50% lower in GrassrootsHealth cohort with median serum 25-hydroxyvitamin D of 41 ng/ml than in NHANES cohort with median of 22 ng/ml.
abstract: Higher serum 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with lower risk of type 2 diabetes. This study compared incidence rates of type 2 diabetes among participants aged ≥20 years in two U.S. cohorts with markedly different median 25(OH)D concentrations. The median 25(OH)D concentration in the GrassrootsHealth (GRH) cohort was 41 ng/ml (N=4933) while in the 2005-6 National Health and Nutrition Examination Survey (NHANES) it was 22 ng/ml (N=4078) (P<0.0001). The adjusted annual incidence rate of type 2 diabetes was 3.7 per 1000 population (95% confidence interval=1.9, 6.6) in the GRH cohort, compared to 9.3 per 1000 population (95% confidence interval=6.7, 12.6) in NHANES. In the NHANES cohort, the lowest 25(OH)D tertiles (<17, 17-24 ng/ml) had higher odds of developing diabetes than the highest tertile (OR: 4.9, P=0.02 and 4.8, P=0.01 respectively), adjusting for covariates. Differences in demographics and methods may have limited comparability. Raising serum 25(OH)D may be a useful tool for reducing risk of diabetes in the population.
authors.affiliation: GrassrootsHealth, Encinitas, CA, USA. Electronic address: sharon@grassrootshealth.org.
authors.forename: S L
authors.initials: SL
authors.lastname: McDonnell
authors.affiliation: GrassrootsHealth, Encinitas, CA, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Baggerly
authors.affiliation: GrassrootsHealth, Encinitas, CA, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: French
authors.affiliation: Creighton University, Omaha, NE, USA.
authors.forename: R P
authors.initials: RP
authors.lastname: Heaney
authors.affiliation: Department of Family and Preventive Medicine, University of California San Diego, La Jolla, CA, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Gorham
authors.affiliation: Department of Medicine, Boston University Medical Center, Boston, MA, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Holick
authors.affiliation: School of Population Health, University of Auckland, Auckland, New Zealand.
authors.forename: R
authors.initials: R
authors.lastname: Scragg
authors.affiliation: Department of Family and Preventive Medicine, University of California San Diego, La Jolla, CA, USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Garland
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys / Q000706:statistics & numerical data; D012306:Risk; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Serum 25–hydroxyvitamin D; Type 2 diabetes; Vitamin D