Physical Activity and Mortality in Type 2 Diabetes
Condition: Diabetes Mellitus, Type 2
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 2
Study type: Observational

Summary: 
      The primary aim of study is to study the association between leisure-time physical activity
      and all-cause mortality among individuals with type 2 diabetes in the UK Biobank cohort and
      the China Kadoorie Biobank cohort. Secondary outcomes are CVD-mortality (both cohorts) and
      risk of major adverse cardiovascular events (UK Biobank only). Secondary exposures are
      physical activity from transportation and occupation.
    

Detailed description: 
      AIM To determine dose-response patterns between leisure-time physical activity and all-cause
      mortality in individuals with type 2 diabetes in the United Kingdom and China. A secondary
      aim is to study the association between domain-specific physical activity and all-cause
      mortality and fatal and non-fatal CVD.

      Study design and setting The study is a nested cohort study based on the UK Biobank and China
      Kadoorie Biobank population-based prospective cohort studies. Both cohorts are designed to
      study the interrelations between environment, lifestyle, and genes, with the aims of
      improving the prevention, diagnosis, and treatment of chronic diseases. UK Biobank recruited
      a total of 502,682 participants (approximately 5.5% of 9.2 million invited) aged 37 to 82
      years via 22 assessment centers across England, Wales, and Scotland between 2006 and 2010. At
      the assessment centers participants completed a touch-screen questionnaire, an interview with
      a nurse, and a wide variety of physical measurements and biological sampling. A subsample has
      attended a repeat assessment of all data collected at the baseline examination. Data has been
      linked with several electronic registries for ongoing follow-up on health status. Ethical
      approval to establish the UK Biobank cohort was obtained by the North-West Research Ethics
      Committee and participants gave written informed consent before data collection. China
      Kadoorie Biobank recruited 515,420 participants aged 30 to 79 years between 2004 and 2008
      from 10 regions of mainland China. At the assessment centers participants completed an
      interviewer-administered questionnaire, physical measurements and provided blood spot tests
      and non-fasting blood samples. Data has been linked with several electronic registries for
      ongoing follow-up on health status. China Kadoorie Biobank was approved by the Ethics
      Committees at Oxford University, the China National Center for Disease Control and from
      institutional research boards at the local Centers for Disease Control in the 10 included
      regions.

      Study population The Investigators identified individuals with prevalent type 2 diabetes in
      the UK Biobank from the baseline assessment (2006-2010) and the 1st repeat assessment
      (2012-2013), and in China Kadoorie Biobank from the baseline assessment (2004-2008).

      UK Biobank: Prevalent type 2 diabetes is determined by the algorithm by Eastwood (PMID:
      27631769) or from measured Hba1c ≥48 mmol/mol. The algorithm is based on combining
      information on self-reported diabetes, insulin use, age of diabetes onset, and ethnicity
      obtained from a questionnaire in addition to self-reported diabetes, self-reported use of
      medications (see SAP), and age at diabetes diagnosis obtained from an interview with a
      trained nurse. Both 'probable' and 'possible' type 2 diabetes from the algorithm are included
      as type 2 diabetes cases. Type I diabetes is removed from the sample by combining information
      on insulin use, time from diagnosis to initiation of insulin use, and age of diagnosis. These
      criteria identify 29,236 individuals with type 2 diabetes.

      China Kadoorie Biobank: prevalent type 2 diabetes is based on self-reported current diabetes
      with a diagnosis age above 30 years, a random plasma blood glucose ≥11.1 mmol/L, or fasting
      plasma blood glucose ≥7.0 mmol/L. These criteria identify 30,300 individuals with type 2
      diabetes.

      For further detail, please see attached predefined statistical analysis plan (SAP).
    

Intervention name(s): Leisure-time physical activity
Intervention type(s): Behavioral
Intervention description(s): Self-reported leisure-time physical activity, categorized as; zero (reference), >0-7.49 MET-hrs/week, 7.5-14.9 MET-hrs/week, or ≥15 MET-hrs/week.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        See statistical analysis plan