Predicting of trend of hemoglobin a1c in type 2 diabetes: a longitudinal linear mixed model.
BACKGROUND
There are some evidences that control the blood sugar decreasing the risk of diabetes complications, and even fatal. There are so many studies, but they are mostly cross-sectional and ignore the trend and hence it is necessary to implement a longitudinal study. The aim of this prospective study is to find the trend of glycosylated hemoglobin (HbA1c) over time and the associative factors on it.


METHODS
Participants of this longitudinal study were 3440 eligible diabetes patients referred to Isfahan Endocrine and Metabolism Research Center during 2000-2012 who are measured 2-40 times. A linear mixed model was applied to determine the association between HbA1c and variables, including lipids, systolic, diastolic blood pressure and complications such as nephropathy, and retinopathy. Furthermore, the effect of mentioned variables on trend of HbA1c was determined.


RESULTS
The fitted model showed total cholesterol, retinopathy, and the method of therapy including oral antidiabetic drugs (OADs) plus insulin and insulin therapy decreased the trend of HbA1c and high-density lipoprotein, weight, hyperlipidemia and the method of therapy including diet, and OADs increased the trend of HbA1c.


CONCLUSIONS
The present study shows that regular visits of diabetic patients as well as controlling blood pressure, lipid profile, and weight loss can improve the trend of HbA1c levels during the time.
Department of Biostatistics and Epidemiology, Research Center for Modeling in Health, Faculty of Health, Kerman University of Medical Sciences, Iran.
Elahe
E
Kazemi
Department of Biostatistics and Epidemiology, Faculty of Health, Skin Diseases and Stem Cell Research Centre, Isfahan University of Medical Science, Isfahan, Iran.
Seyed Mohsen
SM
Hosseini
Department of Biostatistics and Epidemiology, Research Center for Modeling in Health, Faculty of Health, Kerman University of Medical Sciences, Iran.
Abbass
A
Bahrampour
Endocrinologist, Endocrinology and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan.
Elham
E
Faghihimani
Endocrinologist, Endocrinology and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan.
Masood
M
Amini
Hemoglobin A1c; linear mixed models; longitudinal study; trend; type 2 diabetes