A mistaken diagnosis of type 2 diabetes due to hemoglobin N-Baltimore.
ABSTRACT Glycohemoglobin (HbA1c) estimation is the gold standard for assessing long-term glycemic control in diabetic patients. Some hemoglobin variants interfere with HbA1c assay, thus, limiting its utility. Over 150,000 diabetic patients are estimated to have hemoglobin variants in the United States; but this number may be up to 30% in some parts of the world. Although, most of the hemoglobinopathies are clinically silent, some of them cause biochemical aberrations, which could interfere with HbA1c assay. However, hemoglobin N-Baltimore has not been reported to give false HbA1c estimation. We present a woman with mistaken diagnosis of diabetes due to hemoglobin N-Baltimore that produced a spuriously elevated HbA1c level.
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ABSTRACT: Increasing evidence suggests a continuous relationship between blood glucose concentrations and cardiovascular risk, even below diagnostic threshold levels for diabetes. To examine the relationship between hemoglobin A1c, cardiovascular disease, and total mortality. Prospective population study. Norfolk, United Kingdom. 4662 men and 5570 women who were 45 to 79 years of age and were residents of Norfolk. Hemoglobin A1c and cardiovascular disease risk factors were assessed from 1995 to 1997, and cardiovascular disease events and mortality were assessed during the follow-up period to 2003. In men and women, the relationship between hemoglobin A1c and cardiovascular disease (806 events) and between hemoglobin A1c and all-cause mortality (521 deaths) was continuous and significant throughout the whole distribution. The relationship was apparent in persons without known diabetes. Persons with hemoglobin A1c concentrations less than 5% had the lowest rates of cardiovascular disease and mortality. An increase in hemoglobin A1c of 1 percentage point was associated with a relative risk for death from any cause of 1.24 (95% CI, 1.14 to 1.34; P < 0.001) in men and with a relative risk of 1.28 (CI, 1.06 to 1.32; P < 0.001) in women. These relative risks were independent of age, body mass index, waist-to-hip ratio, systolic blood pressure, serum cholesterol concentration, cigarette smoking, and history of cardiovascular disease. When persons with known diabetes, hemoglobin A(1c) concentrations of 7% or greater, or a history of cardiovascular disease were excluded, the result was similar (adjusted relative risk, 1.26 [CI, 1.04 to 1.52]; P = 0.02). Fifteen percent (68 of 521) of the deaths in the sample occurred in persons with diabetes (4% of the sample), but 72% (375 of 521) occurred in persons with HbA1c concentrations between 5% and 6.9%. Whether HbA1c concentrations and cardiovascular disease are causally related cannot be concluded from an observational study; intervention studies are needed to determine whether decreasing HbA1c concentrations would reduce cardiovascular disease. The risk for cardiovascular disease and total mortality associated with hemoglobin A1c concentrations increased continuously through the sample distribution. Most of the events in the sample occurred in persons with moderately elevated HbA1c concentrations. These findings support the need for randomized trials of interventions to reduce hemoglobin A1c concentrations in persons without diabetes.Annals of internal medicine 10/2004; 141(6):413-20. · 13.98 Impact Factor
- Nature 05/1967; 214(5084):189-90. · 38.60 Impact Factor
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ABSTRACT: Cardiovascular disease causes severe morbidity and mortality in type 1 diabetes, although the specific risk factors and whether chronic hyperglycemia has a role are unknown. We examined the progression of carotid intima-media thickness, a measure of atherosclerosis, in a population with type 1 diabetes. As part of the Epidemiology of Diabetes Interventions and Complications (EDIC) study, the long-term follow-up of the Diabetes Control and Complications Trial (DCCT), 1229 patients with type 1 diabetes underwent B-mode ultrasonography of the internal and common carotid arteries in 1994-1996 and again in 1998-2000. We assessed the intima-media thickness in 611 subjects who had been randomly assigned to receive conventional diabetes treatment during the DCCT and in 618 who had been assigned to receive intensive diabetes treatment. At year 1 of the EDIC study, the carotid intima-media thickness was similar to that in an age- and sex-matched nondiabetic population. After six years, the intima-media thickness was significantly greater in the diabetic patients than in the controls. The mean progression of the intima-media thickness was significantly less in the group that had received intensive therapy during the DCCT than in the group that had received conventional therapy (progression of the intima-media thickness of the common carotid artery, 0.032 vs. 0.046 mm; P=0.01; and progression of the combined intima-media thickness of the common and internal carotid arteries, -0.155 vs. 0.007; P=0.02) after adjustment for other risk factors. Progression of carotid intima-media thickness was associated with age, and the EDIC base-line systolic blood pressure, smoking, the ratio of low-density lipoprotein to high-density lipoprotein cholesterol, and urinary albumin excretion rate and with the mean glycosylated hemoglobin value during the mean duration (6.5 years) of the DCCT. Intensive therapy during the DCCT resulted in decreased progression of intima-media thickness six years after the end of the trial.New England Journal of Medicine 07/2003; 348(23):2294-303. · 51.66 Impact Factor