Natural History and Risk Factors for Microalbuminuria in Adolescents With Type 1 Diabetes
A longitudinal study
- Monique L. Stone, MBBS, FRACP12,
- Maria E. Craig, MBBS, PHD, FRACP234,
- Albert K. Chan, MAPPSTAT3,
- Jenny W. Lee, BAPPSC3,
- Charles F. Verge, MBBS, PHD, FRACP12 and
- Kim C. Donaghue, MBBS, PHD, FRACP34
- 1Department of Endocrinology, Sydney Children’s Hospital, Randwick, Sydney, Australia
- 2School of Women’s and Children’s Health, The University of New South Wales, Sydney, Australia
- 3Institute of Endocrinology and Diabetes, The Children’s Hospital at Westmead, Westmead, Sydney, Australia
- 4Department of Paediatrics and Child Health, The University of Sydney, Sydney, Australia
- Address correspondence and reprint requests to Dr. Kim Donaghue, Paediatric Endocrinologist, Institute of Endocrinology and Diabetes, The Children’s Hospital at Westmead, Hawkesbury Road, Westmead, Sydney, Australia. E-mail:kimd{at}chw.edu.au
Abstract
OBJECTIVE— To describe the natural history and risk factors for persistent microalbuminuria in children and adolescents with type 1 diabetes followed for up to 15 years.
RESEARCH DESIGN AND METHODS— This study contained a longitudinal cohort of 972 patients; analysis of baseline risk factors was performed using logistic regression and predictors over time using survival analysis. Albumin excretion rate was measured on three consecutive timed overnight urine collections on at least two occasions. Normoalbuminuria was defined as a median albumin excretion rate <7.5 μg/min, borderline microalbuminuria as 7.5–20 μg/min, and microalbuminuria as 20–200 μg/min. Microalbuminuria was further classified as persistent if its duration was >12 months. Median age was 12.7 years (interquartile range 11.5–14.4) and diabetes duration 6.5 years (4.1–9.3) at first assessment, and median follow-up was 6.2 years (range 1–15.3).
RESULTS— The incidence of persistent microalbuminuria was 4.6 (95% CI 3.3–6.1) per 1,000 patient-years. Predictors of persistent microalbuminuria from the first assessment using multiple logistic regression were high cholesterol (odds ratio 2.2 [95% CI 1.2–4.0]) and borderline microalbuminuria (2.5 [1.2–5.2]). Predictors using Cox regression were HbA1c (hazard ratio 1.4 [95% CI 1.1–1.7]), age at diagnosis (1.2 [1.1–1.3]), obesity (3.6 [0.8–15.5]), and insulin dose (2.7 [1.0–7.5]).
CONCLUSIONS— Children and adolescents with type 1 diabetes who have borderline microalbuminuria are more than twice as likely to develop persistent microalbuminuria. In addition to poor glycemic control, clinical markers of insulin resistance were associated with an increased risk of microalbuminuria.
- AER, albumin excretion rate
- DHEAS, dehydroepiandrosterone sulfate
- SHBG, sex hormone–binding globulin
Footnotes
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A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Accepted May 28, 2006.
- Received January 30, 2006.
- DIABETES CARE
