Good glycemic control remains crucial in prevention of late diabetic complications--the Linköping Diabetes Complications Study.
BACKGROUND
Several intervention studies have convincingly demonstrated the importance of good glycemic control to avoid long-term diabetic complications, but the importance of other risk factors remains controversial. We previously reported a markedly reduced incidence of severe retinopathy and nephropathy during the past decades in an unselected population of type 1 diabetes mellitus diagnosed in childhood. The aim of the present study was to analyze possible risk factors, which could explain the improved prognosis.


METHODS
In this longitudinal population-based cohort study, we followed all 269 patients in whom type 1 diabetes mellitus was diagnosed in childhood 1961-1985 in a well-defined geographical area in Sweden. The patients were followed until the end of 1990 s. Multivariable regression models were used to analyze the importance of hemoglobin A1c (HbA(1c)), diabetes duration, blood pressure, cardiovascular risk factors and persisting C-peptide secretion for the development of diabetic retinopathy and nephropathy.


RESULTS
Beside longer duration and higher HbA(1c), blood pressure and lipid values were higher and cardiovascular disease and smoking were more common in patients with severe complications. However, multivariable analysis abolished these associations. Diabetes duration and long-term HbA(1c) were the only significant independent risk factors for both retinopathy and nephropathy. The risk of overt nephropathy increased substantially when HbA(1c) was above 9.6% [Diabetes Control and Complications Trial (DCCT) corrected value], while the risk of severe retinopathy increased already when HbA(1c) exceeded 8.6%.


CONCLUSIONS
In this unselected population, glycemic control was the only significant risk factor for the development of long-term complications.
Nordwall
Maria
M
Division of Pediatrics and Diabetes Research Centre, Department of Clinical and Experimental Medicine, Faculty of Health Science, Linköping University, Linköping, Sweden. maria.nordvall@lio.se
Arnqvist
Hans J
HJ
Bojestig
Mats
M
Ludvigsson
Johnny
J
D017668:Age of Onset; D000419:Albuminuria / Q000453:epidemiology / Q000517:prevention & control; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D002318:Cardiovascular Diseases / Q000453:epidemiology; D002648:Child; D002784:Cholesterol / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000150:complications*; D003925:Diabetic Angiopathies / Q000453:epidemiology / Q000517:prevention & control*; D003928:Diabetic Nephropathies / Q000453:epidemiology / Q000517:prevention & control*; D003930:Diabetic Retinopathy / Q000453:epidemiology / Q000517:prevention & control*; D006442:Glycated Hemoglobin / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D002096:C-Peptide; D002784:Cholesterol; D006442:Glycated Hemoglobin; D014280:Triglycerides