Between 2003 and 2005, the authors recruited 821 middle-aged normoalbuminuric individuals with type 2 diabetes and followed them through to the end of 2010. The average follow-up time was 6.2 years. The authors defined microalbuminuria as a urine albumin to creatinine ratio of 30 mg/g (3.4 mg/mmol) or higher.
HbA1c variability was calculated by the SD of serially measured HbA1c. The Cox proportional hazards model was used to evaluate the association between HbA1c SD quartile and development of microalbuminuria.
The results showed that,the incidence of microalbuminuria for the overall population was 58.4, 58.6, 60.8 and 91.9 per 1,000 person-years for Q1- to Q4-adjusted HbA1c SD, respectively (p for trend = 0.042).
Compared with patients in Q1, those in Q4 were about 37% more likely to develop microalbuminuria.
The HR derived from a series of 2-year HbA1c measurements was similar to that from data collection for longer than 4 years.
Diabetologia, Sept, 2012