One-hour plasma glucose (1-h
PG) during the oral glucose tolerance test (OGTT) is an accurate predictor of type
2 diabetes. We performed a meta-analysis to determine the optimum cut-off of
1-h PG to detect type 2 diabetes using 2-h PG as the gold standard.
Design and Methods We included 15 studies with 35,551 participants
from multiple ethnic groups (53.8% Caucasian) and 2705 newly detected cases of diabetes based on 2-h PG during OGTT. We
excluded cases identified only by elevated fasting plasma glucose and/or HbA1c.
We determined the optimal 1-h PG threshold and its accuracy at this cut-off to
detect diabetes (2-h PG ≥ 11.1
mmol/L) using a mixed linear effects regression model with different weights to
sensitivity/specificity (2/3, 1/2, and 1/3).
Results Three cut-offs of 1-h PG at 10.6 mmol/L, 11.6 mmol/L,
and 12.5 mmol/L had sensitivities of 0.95, 0.92, and 0.87 and specificities of 0.86,
0.91, and 0.94 at weights 2/3, 1/2, and 1/3, respectively. The cut-off of 11.6 mmol/L
(95% CI 10.6, 12.6) had a sensitivity 0.92 (0.87, 0.95), specificity of 0.91
(0.88, 0.93), AUC 0.939 (95% confidence region for sensitivity at a given specificity:
0.904, 0.946), and a positive predictive value of 45%.
Conclusions The 1-h PG of ≥ 11.6 mmol/L during OGTT has a good sensitivity and specificity for detecting type 2 diabetes. Prescreening with a
diabetes-specific risk calculator to identify high-risk individuals is
suggested to decrease the proportion of false-positive cases. Studies
including other ethnic groups and assessing complication risk are warranted.
VA was funded through a grant from the Academy of Finland (grant no 312072). The Botnia studies (LG, TT) have been financially supported by grants from Folkhälsan Research Foundation, the Sigrid Juselius Foundation, The Academy of Finland (grants no. 263401, 267882, 312063 to LG, 312072 to TT), University of Helsinki, Nordic Center of Excellence in Disease Genetics, EU (EXGENESIS, MOSAIC FP7-600914), Ollqvist Foundation, Swedish Cultural Foundation in Finland, Finnish Diabetes Research Foundation, Foundation for Life and Health in Finland, Signe and Ane Gyllenberg Foundation, Finnish Medical Society, Paavo Nurmi Foundation, State Research Funding via the Helsinki University Hospital, Perklén Foundation, Närpes Health Care Foundation and Ahokas Foundation. The study has also been supported by the Ministry of Education in Finland, Municipal Heath Care Center and Hospital in Jakobstad and Health Care Centers in Vasa, Närpes and Korsholm. The Botnia Study has received research funding from Pfizer Inc. and Regeneron Pharmaceuticals. The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement no 269045. TVF was supported by the European Foundation for the Study of Diabetes. DIAPASON study was supported by the Fondazione Romeo ad Enrica Invernizzi – Milano, EFSD/Sanofi programme (to LLS), and Italian Ministry of Health-Ricerca Corrente. The GENFIEV study has been supported by FoRiSID, Rome, Italy and with an unconditional grant from Eli Lilly, Italy. The GOH study was funded by The DCURE Foundation. Oulu45 and Oulu45P studies were funded by the Finnish Cultural Foundation - Central fund. The PIBS study was funded by the Division of Intramural Research of NIDDK, NIH. The PSW and PSWP study were funded by the Japan Health Promotion Foundation and Grant-in-Aid from Toyama Medical Association.