Longitudinal study of urinary albumin excretion in young diabetic patients- Wessex Diabetic Nephropathy Project

Aims This study was established to follow changes in albumin/creatinine rat io (ACR) and to determine the prevalence and degree of progression of micro albuminuria (MA) or of clinical proteinuria (CP) in children with Type 1 di abetes. The study has investigated subjects for up to 12 years in establish ing the correlation between MA and gender, age, duration of diabetes and gl ycated haemoglobin (HbA(1c)). The study has defined clinical cut-offs for M A in daytime clinic urine samples in young diabetic subjects. Methods Three hundred and sixty-one patients were involved in the study, wi th 221 (61.2%) having over six sets of data. Urine samples were collected a t routine annual clinic visits and analysed without prior freezing for ACR. Blood samples were taken for HbA(1c) measurement. Data including sex, age and duration of diabetes were recorded. Results A random clinic ACR of < 4.5 mg/mmol (males) and 5.2 mg/mmol (femal es) creatinine was used as the 'clinical cut-off' to define the presence of MA. The presence of MA was independent of HbA(1c) and duration of diabetes but appeared be associated with the adolescent years (> 10 years). There w as little evidence of progression from normoalbuminuria to MA, or from MA t o CP. Of patients aged 10-18 years, 30.9% of males and 40.4% of females had one or more episodes of MA. Conclusions Persistent MA and random episodes of MA or CP may be associated with the adolescent years but not with duration of diabetes. Further study will reveal if the substantial increases in ACR sometimes seen during adol escence are predictive of diabetic nephropathy. Clinical cut-offs of < 4.5 and < 5.2 mg/mmol creatinine for males and females, respectively, are sugge sted for the interpretation of changes in ACR in random urine samples in yo ung people with Type 1 diabetes.