Progression to microalbuminuria in type 1 diabetes: development and validation of a prediction rule

AIMS/HYPOTHESIS

Microalbuminuria is common in type 1 diabetes and is associated with an increased risk of renal and cardiovascular disease. We aimed to develop and validate a clinical prediction rule that estimates the absolute risk of microalbuminuria.

METHODS

Data from the European Diabetes Prospective Complications Study (n = 1115) were used to develop the prediction rule (development set). Multivariable logistic regression analysis was used to assess the association between potential predictors and progression to microalbuminuria within 7 years. The performance of the prediction rule was assessed with calibration and discrimination (concordance statistic [c-statistic]) measures. The rule was validated in three other diabetes studies (Pittsburgh Epidemiology of Diabetes Complications [EDC] study, Finnish Diabetic Nephropathy [FinnDiane] study and Coronary Artery Calcification in Type 1 Diabetes [CACTI] study).

RESULTS

Of patients in the development set, 13% were microalbuminuric after 7 years. Glycosylated haemoglobin, AER, WHR, BMI and ever smoking were found to be the most important predictors. A high-risk group (n = 87 [8%]) was identified with a risk of progression to microalbuminuria of 32%. Predictions showed reasonable discriminative ability, with c-statistic of 0.71. The rule showed good calibration and discrimination in EDC, FinnDiane and CACTI (c-statistic 0.71, 0.79 and 0.79, respectively).

CONCLUSIONS/INTERPRETATION

We developed and validated a clinical prediction rule that uses relatively easily obtainable patient characteristics to predict microalbuminuria in patients with type 1 diabetes. This rule can help clinicians to decide on more frequent check-ups for patients at high risk of microalbuminuria in order to prevent long-term chronic complications.

Targets and reality: a comparison of health care indicators in the U.S. (Pittsburgh Epidemiology of Diabetes Complications Study) and Hungary (DiabCare Hungary)

OBJECTIVE

In the U.S., both primary care and specialist physicians share in the care of type 1 diabetic patients, often in an informal collaboration. In Hungary, however, type 1 diabetic patients are generally managed in special centralized diabetes units. These different treatment settings may lead to different health care practices and outcomes. To determine if this is true, diabetes care indicators and complications were compared across representative study populations from the 2 countries.

RESEARCH DESIGN AND METHODS

The Pittsburgh Epidemiology of Diabetes Complications Study (EDC) is a prospective cohort of childhood-onset type 1 diabetic patients. DiabCare Hungary, a multicenter cross-sectional study, was developed for quality control purposes and provides a nationwide data set of diabetic patients. We identified 2 comparable populations (EDC, n = 416; DiabCare, n = 405) in terms of age (> or =14 years) and age at onset (<17 years).

RESULTS

EDC patients were less likely to receive diabetes education (P<0.0001), see an ophthalmologist (P<0.0001), be treated by diabetologists (P<0.0001), or perform self-monitoring of blood glucose (P<0.0001). They were more likely to use conservative insulin regimens (i.e., 1-2 injections/day, P<0.0001) and have a higher glycated hemoglobin (P< 0.0001). DiabCare patients more often experienced severe hypoglycemia (P<0.01) and had a lower prevalence of proliferative retinopathy (P<0.0001), legal blindness (P<0.05), and albuminuria (> or =30 mg/day P<0.01). No significant differences in macrovascular complications were seen, although rates were generally low

CONCLUSIONS

These data suggest that the 2 populations differ by their diabetes care practices, degree of glycemic control, and microvascular complication status.