Definição de valores de referência para os índices HOMA-IR e HOMA-BETA e sua importância clínica em amostra populacional do Distrito Federal

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Background: The assessment of insulin sensitivity is an important tool for epidemiological studies and for understanding the pathophysiology and development of type 2 diabetes, metabolic syndrome, polycystic ovary syndrome, obesity, hypertension, dyslipidemia, and atherosclerotic disease. Insulin resistance, despite recent studies, still lacks a method to laboratory research that meets all the criteria for the use of a universal parameter. The determination of benchmarks should be established for each population and corrected for the method used for the determination of insulin and glucose. Objectives: This study aimed to validate and determine reference values for a sample population of Brasilia, using mathematical models such as HOMA-β and HOMA-IR, whereas the chemiluminescence method for determination of plasma levels of insulin. In addition, examined the influence of blood glucose, age, gender, BMI and triglyceride levels on the index HOMA-IR and HOMA-β. Patients and Methods: We retrospectively evaluated 1101 patients, recruited through the system of the Laboratory of Clinical Analysis Sabin, who were referred by various medical prescribers, with the purpose of dose levels of plasma glucose and fasting insulin, glycated hemoglobin and lipidogram, the months between July 2007 and December 2008. The anthropometric data such as weight, height, body mass index, medications in use, were obtained through registration in the database at the time of admission. Were excluded from the analysis all patients who were using anti-hyperglycemic, hypoglycemic or derivatives of statins medications. Were determined HOMA-IR, HOMA-β, established correlations for other variables and compared with other models. Results and Discussion: In subjects examined the distribution was 811 females and 290 males, aged between 18 and 86 years (mean age 40.59 14.14 years). Patients were categorized by blood glucose and triglycerides levels, age, gender, BMI and values of HOMA-IR index. The group presented normoglycemic fasting plasma glucose average of 87.33 6.82 mg/dl and insulin average of 9.63 6.62 μU/ml, with a median of 8.4 μU/ml. The mean HOMA-IR was 2.10 1.52, with a median of 1.80 and 75th percentile of 2.7, and HOMA-β, 152.31 105.81, with a median of 126.94. Hyperglycemic patients had higher values of glucose, insulin, BMI and HOMA-IR and lower values of HOMA-β when compared with normoglycemic patients, with statistically significant differences (p <0.05). The fasting plasma glucose in the hyperglycemic group ranged from 100 to 205 mg/dl, and insulin average was 14.74 8.35 μU/ml, with a median of 12.70 μU/ml. The average value of HOMA-IR index was 4.01 2.47, with a median of 3.35 and HOMA-β, 118.16 67.52, with a median of 107.00. Individuals with normal parameters of BMI, total cholesterol, HDL cholesterol, triglycerides and glucose showed mean values of HOMA-IR index of 1.47 1.44, median 1.18, 75th percentile of 1.68 and 90th percentile of 2.19. The average values for the index HOMA-β were 115.02 89.11, with a median of 93.24, 75th percentile of 155.29 and 90th percentile of 188.25. Conclusion: Age has a strong effect on the function of pancreatic β-cells, with reduction in HOMA-β index over the age categories, but does not exert itself to influence insulin resistance. The adiposity demonstrated strong influence on the increased levels of triglycerides and lower levels of HDL cholesterol. There were no significant differences between the values of total cholesterol and LDL cholesterol in the comparison between categories of BMI in both the analysis of the total as in the analysis of each gender. The hypertriglyceridemia is associated with increased insulin resistance and the function of pancreatic β-cells.

ASSUNTO(S)

homa-ir homa-β homa-ir ciencias da saude chemiluminescence quimioluminescência homa-β

ACESSO AO ARTIGO

Documentos Relacionados