RESUMEN
AIMS: Increased glucose excursions and postprandial hyperglycaemia have been suggested as unique risk factors for cardiovascular disease (CVD) and mortality in patients with diabetes mellitus. Much of the evidence is based on a single 2 h glucose value after oral glucose tolerance testing in epidemiological studies. We examined the association between various indices of glycaemia measured during everyday activities and metabolic CVD risk factors in the A1C-Derived Average Glucose (ADAG) study. METHODS: Participants (268 with type 1 diabetes, 159 with type 2 diabetes) completed 16 weeks of intensive continuous glucose monitoring (CGM) and self-monitoring of blood glucose (SMBG). From these data, common indices of postprandial glycaemia, overall hyperglycaemia, glucose variability and HbA1(c) were derived. The associations between glycaemic indices and known CVD risk factors (lipids, high-sensitivity C-reactive protein and blood pressure) were explored in linear regression models. RESULTS: For both diabetes types, the overall strongest associations with CVD risk factors were seen for the measures of average glycaemia (mean blood glucose and HbA1(c)). Associations between self-monitored postprandial and fasting glucose and CVD risk factors were weaker, but significant. Measurements of blood glucose variability showed non-significant associations. Overall, calculations based on CGM were not more informative than those based on frequent SMBG. CONCLUSIONS/INTERPRETATION: Mean glycaemia and HbA1(c) show consistent and stronger associations with CVD risk factors than fasting glucose or postprandial glucose levels or measures of glucose variability in patients with diabetes.
Asunto(s)
Glucemia/metabolismo , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Hemoglobina Glucada/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/sangre , Humanos , Periodo Posprandial , Factores de RiesgoRESUMEN
AIMS/HYPOTHESIS: Real-life glycaemic profiles of healthy individuals are poorly studied. Our aim was to analyse to what extent individuals without diabetes exceed OGTT thresholds for impaired glucose tolerance (IGT) and diabetes. METHODS: In the A1C-Derived Average Glucose (ADAG) study, 80 participants without diabetes completed an intensive glucose monitoring period of 12 weeks. From these data, we calculated the average 24 h glucose exposure as time spent above different plasma glucose thresholds. We also derived indices of postprandial glucose levels, glucose variability and HbA(1c). RESULTS: We found that 93% of participants reached glucose concentrations above the IGT threshold of 7.8 mmol/l and spent a median of 26 min/day above this level during continuous glucose monitoring. Eight individuals (10%) spent more than 2 h in the IGT range. They had higher HbA(1c), fasting plasma glucose (FPG), age and BMI than those who did not. Seven participants (9%) reached glucose concentrations above 11.1 mmol/l during monitoring. CONCLUSIONS/INTERPRETATION: Even though the non-diabetic individuals monitored in the ADAG study were selected on the basis of a very low level of baseline FPG, 10% of these spent a considerable amount of time at glucose levels considered to be 'prediabetic' or indicating IGT. This highlights the fact that exposure to moderately elevated glucose levels remains under-appreciated when individuals are classified on the basis of isolated glucose measurements.
Asunto(s)
Glucemia/análisis , Hemoglobina Glucada/análisis , Adulto , Glucemia/metabolismo , Ayuno/sangre , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Ambulatorio , Valores de ReferenciaRESUMEN
BACKGROUND: for the diagnostic evaluation of microcytic or normocytic anaemia in a heterogeneous group of patients, the value of newer parameters, such as zinc protoporphyrin (ZPP), plasma transferrin receptor (PtrfR) and PtrfR/ferritin ratio is not clear. We have performed a prospective study to determine the predictive value of these parameters and ferritin, for diagnosing iron deficiency anaemia (IDA). METHODS: sixty-two patients with Hb<8.2 (men) or <7.0 (women) and mean cell volume (MCV)<96 fl were included. Exclusion criteria were: known haematological disease, pregnancy, bone marrow suppression or iron therapy within the previous 7 days. Bone marrow examination was used as a golden standard to discriminate between IDA and non-IDA. RESULTS: twenty-four patients had depleted iron stores. We found that the reticulocyte response on iron supplementation correlated well with the iron-status of the bone marrow. Univariate analysis showed that ferritin, PtrfR/ferritin ratio, ZPP and PtrfR have significant predictive values for differentiating IDA from non-IDA. Interestingly, multivariate analysis revealed that ferritin was the only significant, independent predictor of IDA, with a cut-off point of 32 microg/l (sensitivity 79.2%, specificity 96.9%). CONCLUSIONS: the low sensitivity and specificity of ZPP, PtrfR and PtrfR/ferritin ratio render them insufficient to be used as a single 'best' test for the identification IDA in a non-selected group of anaemic patients and do not even add to the prediction if the value of ferritin is known.