title: Are active sun exposure habits related to lowering risk of type 2 diabetes mellitus in women, a prospective cohort study?
abstract: OBJECTIVE
  An inverse relationship exists between vitamin D levels and diabetes mellitus. However, little is known about the correlation of sun exposure habits and type 2 diabetes mellitus (DM).
  
  
  METHODS
  A South Swedish cohort study comprising 1000 women from each age group between 25 and 64 (n=40,000) drawn from the Southern Swedish population registry 1990-1992. At the inception of the study 74% answered the inquiry (n=29,518) and provided detailed information on their sun exposure habits and other variables. A follow-up inquiry was sent 2000-2002 which 24,098 women answered. The mean follow-up time was 11 years. Logistic regression analysis was used and the main outcome was the relationship between type 2 DM and sun exposure habits.
  
  
  RESULTS
  Our findings indicated that women with active sun exposure habits were at a 30% lower risk of having DM, as compared to those with non-active habits. There was an inverse relation between this risk reduction and BMI.
  
  
  CONCLUSIONS
  Our investigation gives possible epidemiological explanation to ethnic and seasonal differences in type 2 DM and metabolic control. The study supports that sunlight is involved in the glucose metabolism.
authors.affiliation: Department of Obstetrics and Gynecology, Clintec, Karolinska University Hospital, Huddinge, Kvinnokliniken K 57, Stockholm, Sweden. Pelle.lindqvist@ki.se
authors.forename: Pelle G
authors.initials: PG
authors.lastname: Lindqvist
authors.forename: Håkan
authors.initials: H
authors.lastname: Olsson
authors.forename: Mona
authors.initials: M
authors.lastname: Landin-Olsson
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000517:prevention & control*; D015444:Exercise; D005260:Female; D006184:Habits; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008875:Middle Aged; D009043:Motor Activity; D012306:Risk; D012621:Seasons; D055108:Sunbathing / Q000706:statistics & numerical data*; D013472:Sunlight; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000517:prevention & control