Diabetes Care, Vol 19, Issue 5 435-440, Copyright © 1996 by American Diabetes Association
Raised serum sialic acid concentration precedes onset of microalbuminuria in IDDM. A 10-year follow-up study
H Yokoyama, JS Jensen, B Myrup, ER Mathiesen, B Ronn and T Deckert
Steno Diabetes Center, Gentofte, Denmark.
OBJECTIVE--Elevated concentrations of serum sialic acid, a potent
cardiovascular risk factor in the general population, have been found in
patients with IDDM and microalbuminuria. We investigated whether a
coincidence exists between the increase of sialic acid concentrations and
albuminuria in the transition from normoalbuminuria to microalbuminuria.
Furthermore, the predictability of increased sialic acid as well as von
Willebrand factor (vWF) and total and HDL cholesterol concentrations in
development of persistent microalbuminuria in IDDM was investigated.
RESEARCH DESIGN AND METHODS--This 10-year prospective study was carried out
in a cohort of 209 IDDM patients with normoalbuminuria at baseline.
RESULTS--Of the cohort, 198 patients completed the follow-up period and 27
developed persistent microalbuminuria (urinary albumin excretion rate
[UAER] > or = 30 mg/24 h). A coincident increase of UAER and serum
sialic acid concentration was seen before persistent microalbuminuria was
diagnosed. Elevation of serum sialic acid concentrations in those who later
developed microalbuminuria occurred 3 years before the diagnosis of
persistent microalbuminuria. Baseline serum sialic acid concentrations were
significantly higher in the group of patients who later developed
microalbuminuria than in the group who remained normoalbuminuric (2.02 +/-
0.41 vs. 1.85 +/- 0.31 mmol/l [means +/- SD], P < 0.05). Baseline serum
sialic acid concentration correlated significantly with HbA1c, UAER, blood
pressure, total cholesterol, HDL cholesterol, and vWF and was significantly
predictive for development of microalbuminuria (hazards ratio [95% CI], 3.1
[1.2-8.1]; P = 0.02) after adjustments for sex, duration of diabetes,
smoking, blood pressure, vWF, total cholesterol, and HDL cholesterol.
Adjustment for the effects of HbA1c and UAER, however, canceled out the
predictive effect of serum sialic acid. CONCLUSIONS: UAER and serum sialic
acid concentration increase coincidentally before the onset of persistent
microalbuminuria. An increased serum sialic acid concentration is
predictive for the onset of microalbuminuria independent of age, sex,
diabetes duration, smoking, blood pressure, vWF, and total HDL cholesterol.