The aim of this thesis was to investigate the role of dietary fat in the aetiology of type 2 diabetes. The associations of dietary fat and fish consumption with two intermediates in the development of diabetes, insulin resistance and glycaemia, and with the risk of developing diabetes, were examined. The analyses were based on data collected by the Ely and EPIC-Norfolk cohort studies. The cross-sectional associations of dietary fat and fish consumption with fasting insulin, a measure of insulin resistance, were investigated in 815 men and women aged 30-64 years. The dietary polyunsaturated:saturated fat ratio (P:S ratio) was independently related to (log<SUB>e</SUB>) fasting insulin (b = -0.231, p = 0.004). There was no evidence that total fat, saturated, monounsaturated and polyunsaturated fats, and fish consumption were associated with fasting insulin. Body mass index (BMI), waist:hip ratio (WHR), and physical activity were associated with fasting insulin. The cross-sectional associations of dietary fat and fish consumption with glycosylated haemoglobin (HbA<SUB>1c</SUB>), a measure of average blood glucose, were examined in 6414 men and women aged 40-79 years. Total fat, the P:S ratio and saturated fat were independently associated with HbA<SUB>1c</SUB> (b = 0.00726, p < 0.001; b = -0.0919, p = 0.013; and b = 0.0143, p < 0.001 respectively). Oily fish consumption was related to HbA<SUB>1c</SUB> in women (b = -0.0504, p = 0.016). There was no evidence that monounsaturated and polyunsaturated fats were related to HbA<SUB>1c</SUB>. BMI and WHR were related to HbAlc. The evidence for an effect of physical activity was weak. Incident cases of type 2 diabetes were identified for a case-control study nested within EPIC-Norfolk. Capture-recapture analysis suggested that 98-99% of cases were identified. The risk of developing diabetes was analysed in a study of .417 cases and matched controls. There were no statistically significant associations with any dietary factors. BMI, WHR and physical activity were associated with the risk of diabetes. The findings confirm the importance of obesity and physical activity as risk factors for diabetes and suggest that, despite attenuation by measurement error, the quantity and composition of dietary fat have a role in the aetiology of diabetes.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:603696 |
| Date | January 2001 |
| Creators | Harding, A. H. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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