Serum fructosamine as a screening test for diabetes in the elderly: a pilot study.
OBJECTIVE
To determine the value of serum glycated protein, measured as serum fructosamine, as a screening test for diabetes in the elderly.


METHODS
Cross-sectional pilot study.


METHODS
Ambulatory research clinic in university setting.


METHODS
One hundred fifty-seven consecutive community-dwelling participants in the Cardiovascular Health Study, average age 71.8 + 5 (mean +/- SD, range 65-88 years).


METHODS
Serum fructosamine levels (first and second generation assay) were obtained. All subjects who did not have a diagnosis of diabetes were given a 75-g glucose tolerance test (GTT).


RESULTS
Twenty-six subjects (17%) (10 previously diagnosed, 16 undiagnosed and asymptomatic) had diabetes mellitus, and 38 subjects (24%) had impaired glucose tolerance by history or by the GTT (WHO criteria). Only the 16 asymptomatic diabetics were included in the analysis for the pilot study. There was a significant difference in the fasting fructosamine level between non-diabetics and asymptomatic diabetics for the first generation (2.06 +/- .21 vs 2.53 +/- .49 mMol/L, P < 0.0015) and second generation assay (221 +/- 27 vs 269 +/- 48 mMol/L, P < 0.0012). Receiver operator curves were constructed to evaluate the test characteristics of serum fructosamine. Using a point of > or = 2.3 mMol/L for the first-generation assay, the sensitivity to detect asymptomatic diabetes was 75%, specificity 83%, and positive predictive value 35%. To detect both diabetes and impaired glucose tolerance using a cutpoint of > or = 2.3 mMol/L, the sensitivity was 24%, specificity 95%, and positive predictive value 68%. Employing a cut point of 250 muMol/L for the second generation assay, the sensitivity to detect diabetes was 81%, specificity 87%, and positive predictive value 43%. However, to detect diabetes and glucose intolerance using the second generation assay, the sensitivity was 39% and specificity was 86%.


CONCLUSIONS
This study demonstrated that a single measurement of either first or second generation fructosamine showed promise as a screening test for diabetes, but not impaired glucose tolerance, in older people.
Cefalu
W T
WT
Department of Internal Medicine, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157-1047.
Ettinger
W H
WH
Bell-Farrow
A D
AD
Rushing
J T
JT
D000368:Aged; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis*; D005260:Female; D019270:Fructosamine; D005951:Glucose Tolerance Test; D006595:Hexosamines / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D006595:Hexosamines; D007328:Insulin; D019270:Fructosamine