Obesity and Overweight in Relation to Mortality in Men With and Without Type 2 Diabetes/Impaired Glucose Tolerance
The original Whitehall Study
- G. David Batty, PHD1,
- Mika Kivimaki, PHD2,
- George Davey Smith, MD3,
- Michael G. Marmot, FRCP2 and
- Martin J. Shipley, MSC2
- 1Social and Public Health Sciences Unit, Medical Research Council, University of Glasgow, Glasgow, U.K
- 2Department of Epidemiology and Public Health, University College London, London, U.K
- 3Department of Social Medicine, University of Bristol, Bristol, U.K
- Address correspondence and reprint requests to G. David Batty, Medical Research Council, Social and Public Health Sciences, 4 Lilybank Gardens, Glasgow, U.K., G12 8RZ. E-mail: david-b{at}msoc.mrc.gla.ac.uk
In studies of apparently healthy individuals, overweight and obesity, typically assessed using BMI, have been consistently associated with an increased risk of all-cause mortality, cardiovascular disease (CVD), and select cancers (1–4). However, extrapolating these results to individuals with type 2 diabetes is complex and perhaps inappropriate. Studies of the influence of obesity and overweight on mortality risk in individuals with type 2 diabetes reveal highly inconsistent findings. With all-cause mortality, obesity shows inverse (5,6), positive (7–10), null (11–16), and “J-” or “U-” shaped (17–19) associations; similarly discrepant results are apparent with coronary heart disease (CHD) (10,12,20,21). This discordance may be at least partially explained by methodological limitations in some studies, such as a modest sample size, a differential categorization of weight across studies, a tendency not to separate diabetes into its two main subtypes, and a failure to adjust for potentially important mediating and confounding variables. Using an extended follow-up of a U.K. prospective cohort study, we addressed this paucity of evidence and methodological shortcomings.
RESEARCH DESIGN AND METHODS—
In the Whitehall Study, data were collected on 19,019 male government employees aged 40–69 years when examined between 1967 and 1970, representing a 74% response (22). Height and weight were measured using standard protocols, and BMI was computed (weight [kg]/height2 [m2]) and categorized according to current guidelines (23): normal weight …
