A simple index for detection of gestational diabetes mellitus.
The conventional screening test for gestational diabetes mellitus is measurement of plasma glucose 1 hour after 50 g glucose by mouth. The sensitivity and specificity of this test are lower than desirable; we therefore developed an index including other plasma constituents. In a preliminary study, 138 pregnant women had the standard oral glucose load screening test, and plasma fructosamine and total proteins were measured, in addition to glucose, in the 1-hour samples. An index value (I) was calculated as [fructosamine (micro mol/L) divided by total proteins (g/L)]x[glucose (mmol/L) divided by 100]. Cut-off values for I were then assessed in a second prospective study, of 642 pregnant women. Definitive diagnosis of gestational diabetes was by oral glucose tolerance test (OGTT). The index was also assessed in terms of fetal macrosomia (birthweight>or=4000 g). With a cut-off value of I=27.2, sensitivity was 98%, specificity 89%, diagnostic efficiency 90%, positive likelihood ratio 8.76. Application of the index would have avoided 42% of the OGTTs demanded by the standard screening test, reducing false positives from about 24% to 10%. Predictive efficacy for macrosomia was 10.3% versus 7.9%. Our index offers an efficient screening test for gestational diabetes, and with more stringent cut-off points may be applicable as a single-step diagnostic procedure.
Department of Clinical Biochemistry, Hospital General de Riotinto, Huelva, Spain. rperea@hrt.sas.junta_andalucia.es
Rafael
R
Perea-Carrasco
Rocio
R
Pérez-Coronel
Rogelio
R
Albusac-Aguilar
Manuel
M
Lombardo-Grifol
Elena
E
Bassas-Baena de León
Carlos
C
Romero-Diaz
D001786:Blood Glucose / Q000032:analysis; D016640:Diabetes, Gestational / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods* / Q000592:standards; D011446:Prospective Studies; D012680:Sensitivity and Specificity
D001786:Blood Glucose