Physical activity and the incidence of type 2 diabetes in the Shanghai women's health study

Int J Epidemiol. 2006 Dec;35(6):1553-62. doi: 10.1093/ije/dyl209. Epub 2006 Sep 19.

Abstract

Background: Leisure-time physical activity (LPA) has been associated with a reduced risk of type 2 diabetes. However, the potential effect of other types of physical activity on type 2 diabetes is still uncertain. The aim of this study was to examine the effect of occupational, commuting, daily living, and LPA on the incidence of type 2 diabetes in a cohort of middle-aged women.

Methods: We prospectively followed 70,658 women who had no prior history of diabetes at study recruitment for 4.6 years. Participants completed in-person interviews at baseline that collected information on diabetes risk factors including physical activity habits. Anthropometric measurements were taken by trained interviewers. Multivariate-adjusted hazard ratios were estimated by levels of occupational, commuting, daily living, and LPA.

Results: We documented 1973 incident cases of diabetes during 326,625 person-years of follow-up. LPA and daily living physical activity (DPA) were associated with a moderately reduced risk of type 2 diabetes. The relative risk for type 2 diabetes associated with LPA and DPA categories were 1.00, 0.89, 1.05, and 0.83, (P trend = 0.12) and 1.00, 0.98, 0.95, and 0.88, (P trend = 0.06) respectively. LPA was associated with lower risk of type 2 diabetes in employed participants (P trend = 0.09) while DPA was mainly associated with a reduction in risk in non-employed participants (P trend <0.01). While occupational physical activity was not associated with type 2 diabetes risk in this population, commuting to work was associated with a reduction in risk. A combination of DPA and LPA was associated with a reduced risk of type 2 diabetes.

Conclusions: This study suggests that physical activity, either from leisure-time exercise or daily activity reduces the risk of type 2 diabetes in women, supporting the current health promotion efforts encouraging both exercise and non-exercise activity levels.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Activities of Daily Living
  • Adult
  • Aged
  • Body Mass Index
  • China / epidemiology
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Diabetes Mellitus, Type 2 / physiopathology
  • Diet
  • Employment
  • Exercise* / physiology
  • Female
  • Humans
  • Incidence
  • Leisure Activities
  • Middle Aged
  • Physical Exertion / physiology*
  • Prospective Studies
  • Risk Factors
  • Waist-Hip Ratio