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[Metabolic disorders in survivors of myocardial infarct]
M Ahumada Ayala1, D Lozano, O Lozano
1Clínica de Diabetes Instituto Nacional de la Nutrición, Salvador Zubiran, México, D.F.
Insights
Lipoprotein disorders are common in myocardial infarction survivors under 60, with nearly half at risk for atherosclerosis. Early cholesterol levels are misleading due to acute stress, highlighting the need for later assessment in hyperlipidemia patients.
Area of Science:
- Cardiology
- Metabolic Disorders
- Epidemiology
Background:
- Lipoproteins are established risk factors for atherosclerosis.
- Hyperlipidemia affects approximately one-third of myocardial infarction survivors under 60.
- Acute myocardial infarction triggers metabolic changes, including altered lipid profiles and blood glucose levels.
Purpose of the Study:
- To determine the prevalence and severity of lipoprotein disorders in myocardial infarction survivors in Mexico City.
- To assess coronary risk factors in patients post-myocardial infarction.
- To compare lipid profiles during the acute phase versus the chronic phase after myocardial infarction.
Main Methods:
- Prospective study of 106 myocardial infarction survivors under 60 admitted to the National Institute of Cardiology.
- Blood samples and coronary risk factor profiles collected within 72 hours of symptom onset (acute sample).
- Follow-up sampling of 81 patients after three months (chronic sample) for lipid analysis and diagnosis of diabetes.
Main Results:
- Total cholesterol and low-density lipoprotein levels were significantly higher in the chronic sample compared to the acute sample.
- Prevalence of hyperlipoproteinemia was 35.8%, with an additional 12.3% having hypo-HDL phenotype, totaling 48.1% at risk.
- Other prevalent risk factors included tobacco smoking (70.3%), hypertension (35.8%), obesity (33.4%), and diabetes mellitus (30.8%).
- Eight new cases of diabetes mellitus were diagnosed in the chronic phase.
Conclusions:
- Lipoprotein disorders are highly prevalent in myocardial infarction survivors under 60 in Mexico City.
- Acute phase lipid measurements underestimate the true lipid profile and atherosclerosis risk.
- Comprehensive assessment of lipoproteins and other risk factors is crucial for managing patients post-myocardial infarction.
Abstract:
Several lines of evidence have clearly established the role of lipoproteins as risk factors for the development of atherosclerosis. Epidemiologic studies from different countries have found that about one third of myocardial infarction survivors under 60 years of age are hyperlipidemic. The acute stress reaction occurring in the first hours following an acute myocardial infarction causes distinct changes in the patient's metabolic profile, these changes include a significant reduction of total cholesterol and cholesterol associated with low density lipoproteins and a usually mild elevation of blood glucose. With the purpose of establishing the prevalence and severity of lipoprotein disorders found in myocardial infarction survivors living in Mexico city we conducted a prospective study of 106 consecutive admissions to the coronary care unit at the National Institute of Cardiology with the fully proven diagnosis of acute myocardial infarction, we included only patients younger than 60 years of age that could be sampled within the first 72 hours of the appearance of typical symptoms, at this time the coronary risk factor profile was assessed and blood samples were drawn (acute sample). After three months of the diagnosis we sampled 81 of the original 106 patients (chronic sample). The comparison of these 81 patients showed remarkable differences in the lipid values obtained on each sample. The mean value for total cholesterol in the acute sample was 225 mg/dl whereas the corresponding value for the chronic sample was 240.5 mg/dl (p less than 0.005). This difference was also highly significant for the low density fraction. On the basis of the chronic sample analysis we estimated a prevalence of hyperlipoproteinemia of 35.8%. (II: 18.5%, III: 2.5%, IV: 14.8%), an additional subgroup of 10 patients (12.3%) had the hypo-HDL phenotype raising the number of subjects at risk for atherosclerosis to as high as 48.1% considering only the lipoproteins. The prevalence figures for the rest of the risk factors were as follows: 70.3% for tobacco smoking, 35.8% for Systemic Arterial Hypertension, 33.4% for Obesity and 30.8% for Diabetes Mellitus. Among the group of 81 patients, 17 were known diabetics, eight additional cases of Diabetes Mellitus were diagnosed at the chronic phase (two with fasting hyperglycemia and six with diagnostic oral glucose tolerance tests). The "acute plase" glycemia for these eight subjects was significantly higher (mean: 98.4 mg/dl) than the corresponding value for the non diabetic patients (mean: 83.4 mg/dl p less than 0.002), the seventeen known diabetics had a mean glycemia of 150.6 mg/dl in the acute sample.(ABSTRACT TRUNCATED AT 400 WORDS)