Biomedical subjects
Peter C Elwood
Publications and source records attributed to Peter C Elwood.
Glucoregulation has greater impact on cognitive performance than macro-vascular disease in men with type 2 diabetes: data from the Caerphilly study.
OBJECTIVE: To compare vascular and glucose related mechanisms of type 2 diabetes on cognitive performance. RESEARCH DESIGN AND METHODS: A cross-sectional observational study of type 2 diabetes defined by non insulin dependant self-report diabetes or fasting blood glucose < or = 7.0 mmol/l of 2205 men eligible for the third phase of the Caerphilly Collaborative Heart Disease Study. Men were aged 55-69 years at time of testing. Tests of cognitive function included NART (crystallised IQ), AH4 (fluid IQ), verbal fluency (executive function) Cambridge Cognitive Examination (CAMCOG) and Mini Mental State Examination (MMSE) (global function), four choice serial reaction time (psychomotor function) and memory. Men with prior stroke were omitted from the analysis. RESULTS: Men with diabetes showed cognitive deficits for verbal fluency, National Adult Reacting Test (NART) and AH4. Adjusting for vascular risk factors had minimal effect. Including blood glucose removed the deficit for verbal fluency and NART but the effect on AH4 score (-2.58; 95% CI: -5.0, -0.1, p = 0.039) was retained. More detailed analyses of AH4 score on men with diabetes showed a curvilinear relationship indicating that men with both low and high glucose levels had worse performance (AH4 = -66 + 80 log(e) glucose - 18 log(e )glucose(2); 95% CI: -29, -6; p=0.002). CONCLUSIONS: These data identify a direct effect of glucose regulation on cognitive performance associated with diabetes in a population sample. These data suggest that an effect of glucose regulation on cognitive performance in diabetes is distinct from any effect of macro-vascular disease.
Vascular disease and cognitive function in older men in the Caerphilly cohort.
OBJECTIVES: Stroke can impair cognitive function, but the associations between other manifestations of vascular disease and cognitive function have not been adequately studied in representative population samples of subjects. We report the associations between cardiac and peripheral vascular disease and cognitive function for a large representative sample of men in Caerphilly, South Wales, UK. DESIGN: The Caerphilly cohort is the basis of on-going studies of vascular disease, of cognitive function and of predictors of these. We have made intensive attempts to identify all cases of vascular disease: myocardial infarction, angina, ECG ischaemia, peripheral vascular disease (intermittent claudication) and stroke. Here we present data on associations between vascular disease and cognitive function. SETTING: The study is based upon a representative population sample of over 1,500 men in South Wales, aged 55-69 years when cognitive function was measured. The men, and hospital and GP notes relating to them, had been repeatedly examined for evidence of vascular disease during the previous ten years. MAIN OUTCOME MEASURES: Standard tests of cognitive function: the AH4, CAMCOG, MMSE and choice reaction time. RESULTS: After the omission of men who had had a stroke, we detected significant associations between cognitive function and the presence of angina, ECG ischaemia, past myocardial infarction and intermittent claudication. The strength of the associations between cognitive function and the various manifestations of vascular disease were similar, and the various cognitive function tests showed effects of similar size. Overall, cardiac and peripheral vascular disease is associated with a significant reduction in cognitive function equivalent to about one sixth of the standard deviation of a number of tests of cognitive function. The size of this effect is roughly equivalent to the decline in cognitive performance over five years of ageing. CONCLUSIONS: Subjects with evidence of cardiac or peripheral vascular disease have on average a significant reduction in cognitive function equivalent to about four or five years of additional age. The effect of long-term, low-dose aspirin on cognitive decline should now be tested.
Fibrinogen, viscosity and white blood cell count predict myocardial, but not cerebral infarction: evidence from the Caerphilly and Speedwell cohort.
Fibrinogen, plasma viscocity, and the white blood cell count predict ischaemic heart disease, but there is less certainty for their predictive power for ischaemic stroke. Studying stroke and ischaemic heart disease in the same cohort prospectively allows comparison of predictive strengths. The Caerphilly and Speedwell cohorts consist of a population sample of 4,860 men aged 45-59 years at recruitment who had baseline measurements of fibrinogen, plasma viscosity, and white blood cell counts. After 15-19 years of follow-up, men in the two cohorts experienced 312 ischaemic strokes and 557 ischaemic heart disease events. Mean fibrinogen, plasma viscosity and white blood cell counts differed significantly after adjustment for confounding factors between men with and without ischaemic heart disease, 0.25 g/l (95% CIs 0.1 8-0.32); 0.036 cp (95% CIs 0.027-0.044); 0.67 x 10(9)/l (95% CIs 0.50-0.84) respectively. The same measurements showed no significant differences after adjustment for the same confounding factors for men with and without ischaemic stroke, 0.05 g/l (95% CIs -0.04-0.14); 0.008 cp (95% CIs -0.003-0.019); 0.16 x 10(9)/l (95% CIs -0.06-0.38) respectively.
Is type A behavior really a trigger for coronary heart disease events?
OBJECTIVE: The purpose of this study was to compare chronic with acute mechanisms by which Type A might predict incident coronary heart disease (CHD). METHOD: The study included 2394 men aged 50 to 64 years who were assessed for CHD, Type A behavior, and CHD risk factors. Type A was assessed using the Jenkins Activity Survey (JAS), the Bortner scale, and the Framingham scale. Further examinations were completed at 5 and 9 years for incident CHD. RESULTS: After 9 years, there was no increased risk of CHD associated with any Type A score. Nevertheless, high Bortner scores were associated with increased risk of incident CHD at 5 years and high JAS and Bortner scores were associated with a decreased risk between 5 and 9 years. Further analysis of Type A scores on time to first coronary event found strong inverse associations for all type A scores (JAS = 205 -0.49 months to first event, 95% CI = -0.20, -0.78, p =.001) (Bortner = 176 -0.27 months; 95% CI = -0.10, -0.44; p =.002) (Framingham = 0.44 -0.0011 months; 95% CI = -0.0002, -0.0019; p =.01). CONCLUSIONS: The data show Type A is a strong predictor of when incident coronary heart disease (or coronary event) will occur rather than if it will occur. These findings suggest that Type A increases exposure to potential triggers, rather than materially affecting the process of atherosclerosis.