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Cutoff value of 1 h, 50 g glucose challenge test for screening of gestational diabetes mellitus in a Japanese population
Diabetes Research and Clinical Practice 60 (2003) 63 /67 www.elsevier.com/locate/diabres
Cutoff value of 1 h, 50 g glucose challenge test for screening of gestational diabetes mellitus in a Japanese population Kei Miyakoshi *, Mamoru Tanaka, Kazunori Ueno, Katsuhiko Uehara, Hitoshi Ishimoto, Yasunori Yoshimura Department of Obstetrics and Gynecology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan Received 15 August 2002; received in revised form 31 October 2002; accepted 11 November 2002
Abstract A total of 2651 consecutive native Japanese women who underwent a glucose challenge test (GCT) were retrospectively investigated. GCT was performed between 24 and 27 weeks of gestation; each subject received a 50 g oral glucose load without regard to the fasting or fed state, followed by a determination of 1 h venous plasma glucose level. Women demonstrating GCT exceeding 130 mg/dl received a 75 g, 2 h oral glucose tolerance test to determine whether or not they had gestational diabetes mellitus (GDM). All women with GDM were treated with a strict diabetic protocol including insulin therapy. Forty-nine (1.8%) women were diagnosed to have GDM. The receiver /operator characteristic curve identified a GCT finding above 140 mg/dl as the cutoff value for detecting GDM, which showed a sensitivity and specificity of 96 and 76%, respectively. Our results suggest that the cutoff value of a 50 g GCT is 140 mg/dl to identify pregnancies with GDM in a Japanese population. # 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Gestational diabetes mellitus; Glucose challenge test; Cutoff value; A Japanese population
1. Introduction Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance that is first detected during pregnancy. The prevalence of GDM ranges between 2 and 10% of all pregnancies, depending on the population sampled and the diagnostic criteria [1 /8]. The identification of GDM is important for the prevention of such perinatal * Corresponding author. Tel.: /81-3-3353-1211; fax: /81-33226-1667 E-mail address: [email protected] (K. Miyakoshi).
complications as maternal hypertensive disorders and a large for gestational age neonate. The Fourth International Workshop-Conference on GDM proposed an assessment of the clinical characteristics of all pregnant women to determine the risk of GDM as well as serum glucose testing [9]. According to the screening strategy, universal screening using the 50 g, 1 h oral glucose challenge test (GCT) is recommended for East Asian women. GCT consists of a single plasma glucose concentration measurement 1 h after ingestion of 50 g glucose without regard to the fasting or fed state [9,10]. The effect of prior meal ingestion is
0168-8227/02/$ - see front matter # 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 1 6 8 - 8 2 2 7 ( 0 2 ) 0 0 2 7 4 - 7
64
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67
minimal and has been ignored as a matter of practice and convenience in GCT [10]. A plasma glucose value between 130 and 140 mg/dl is commonly used as a threshold for performing a diagnostic oral glucose tolerance test (OGTT). Several authors have shown that race-specific glucose screening test threshold should be used because of the racial differences in the incidence of GDM [11 /13]. In addition, environmental factors are demonstrated to be associated with the development of impaired glucose tolerance (IGT) [14]. To the best of our knowledge, few studies on the cutoff value for GCT have been reported among native Asian populations [5]. The purpose of the current study is to investigate the cutoff value of GCT for performing OGTT in a native Japanese population.
2. Materials and methods A total of 2651 consecutive native Japanese pregnant women who underwent universal screening for GDM at Keio University Hospital from June 1996 to December 2000 were retrospectively investigated. The gestational age had been confirmed in all cases by crown-rump length measurements done in the first trimester. Excluded from this study were multifetal pregnancy and women whose neonates exhibited congenital anomalies. In addition, we excluded women who either had a personal history of IGT or used medications known to affect glucose metabolism. Each subject underwent a standard 1 h 50 g oral GCT between 24 and 27 weeks of gestation; a venous blood sample was obtained 1 h after ingestion of 50 g oral glucose load, administered without regard for the fasting or fed state. Using the cutoff value of 130 mg/dl to define a positive GCT has been demonstrated to improve the sensitivity up to 100% [10]. Thus, we performed a diagnostic 75 g, 2 h OGTT within 2 weeks after GCT if the venous plasma glucose values exceeded 130 mg/dl. The diagnostic tests were performed between 25 and 29 weeks of gestation. Based on the criteria using the 75 g, 2 h OGTT proposed by the Japan Society of Obstetrics and Gynecology, GDM was diagnosed if two or more values
reached or exceeded the following threshold: fasting, 100 mg/dl; 1 h, 180 mg/dl; 2 h, 150 mg/dl [15]. All women found to have GDM were treated with a strict diabetic protocol to maintain their plasma glucose levels during fasting at less than 100 mg/dl and 2 h postprandial levels at less than 120 mg/dl. When diet treatment could not achieve this goal, then insulin therapy was initiated. A statistical analysis was performed by utilizing the JMP software (SAS Institute, Cary, NC). The receiver /operator characteristic (ROC) curve was calculated as sensitivity versus one minus specificity for determining the optimal cutoff value of GCT.
3. Results The characteristics of the patients in this study were as follows (expressed as the mean9/S.D.): the mean maternal age was 32.69/4.3 years, the gestational age at delivery 38.89/1.8 weeks, and the mean birth weight 29779/441 g. Eight hundred and eighty-four patients (33%) received a 75 g, 2 h OGTT. Of 884 patients, fortynine were found to have GDM. The overall incidence of GDM was found to be 1.8%. The probability of GDM in groups with different GCT results is shown in Fig. 1. One patient demonstrating the GCT value below 130 mg/dl was diagnosed to have GDM by the diagnostic OGTT because of the frequent glycosuria. The probability of GDM increased sharply at GCT results /190 mg/dl. Of 49 women with GDM, four needed insulin treatment. The GCT results of all patients requiring insulin treatment were over 200 mg/dl. Fig. 2 shows an ROC curve of various cutoff values of GCT. The curve identified the GCT result above 140 mg/dl as useful for detecting GDM. At this cutoff value, the sensitivity and specificity of GCT were 96 and 76%, respectively.
4. Discussion The occurrence of GDM in this study was 1.8%, indicating that the prevalence of GDM in native Japanese pregnant women is similar to that in
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67
65
Fig. 1. Probability of GDM in groups with different GCT results.
Caucasian pregnant women [1 /4]. Several authors have reported the incidence of GDM to range from 2.0 to 10% in Asian populations [1 /8]. Berkowitz et al. [2] demonstrated that Orientals are at a higher risk of the developing GDM. At the Fourth International Workshop-Conference on GDM, South or East Asian populations were
reported to belong to a high-risk group for GDM [9]. However, the reported prevalence of GDM in Korea and Thailand were around 2.0%, which were similar to our findings [5,6]. Fujimoto et al. [14,16] have shown that environmental factors may play an important role in the development of type 2 diabetes since the prevalence of
Fig. 2. The ROC curve of various cutoff points of the GCT to detect GDM.
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K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67
type 2 diabetes is about twofold higher in Japanese Americans than in native Japanese. Asian immigrants in the United Kingdom, the United States and Canada were investigated in previous studies on racial variations in the incidence of GDM [1 / 3]. As a result, environmental factors such as diet in Western countries may contribute to the high prevalence of GDM in Asian immigrants. The present study indicates that the optimal cutoff value for GCT in a native Japanese population is 140 mg/dl. A cutoff value between 130 and 140 mg/dl is commonly used for performing the diagnostic OGTT in the clinical settings. Then, using a value of 130 mg/dl to define a positive GCT, several authors evaluated the sensitivity and specificity to determine the cutoff value in different populations [5,12]. We also investigated the sensitivity and specificity of different GCT results exceeding 130 mg/dl. We used an ROC curve in which the best cutoff point is thought to be that where the curve ‘turns the corner’. The proportion of gravidas exceeding 140 mg/dl in our study was found to be 25% of all subjects, and 7.4% of women with a positive screening test were diagnosed to have GDM. A cutoff value of 140 mg/dl yielded a sensitivity of 96% and a specificity of 76% for GDM, which were consistent with those in previous reports [5,12,13]. There have been several screening tests for GDM such as glycosuria, random and fast plasma glucose [17 /19]. Although there are no comparative studies on the sensitivity and specificity of different screening methods, we recommend GCT as an internationally recommended method and which was evaluated by previous and present studies. Racial differences regarding the glucose screening test findings have been demonstrated. Nahum and Huffaker [11] suggested race-specific criteria for GCT because of the heterogeneity of glucose intolerance between ethnic groups. We propose that the place of residence as well as race need be taken into consideration to establish the cutoff level of GCT, since environmental factors may contribute to the occurrence of GDM. Our results suggest a 140 mg/dl as the cutoff value of GCT in a Japanese population.
References [1] A. Dornhorst, C.M. Paterson, J.S. Nicholls, et al., High prevalence of gestational diabetes in women from ethnic minority groups, Diabet. Med. 9 (1992) 820 /825. [2] G.S. Berkowitz, R.H. Lapinski, R. Wein, D. Lee, Race/ ethnicity and other risk factors for gestational diabetes, Am. J. Epidemiol. 135 (1992) 965 /973. [3] J.R. Green, I.G. Pawson, L.B. Schumacher, J. Perry, N. Kretchmer, Glucose tolerance in pregnancy: ethnic variation and influence of body habitus, Am. J. Obstet. Gynecol. 163 (1990) 86 /92. [4] S.L. Dooley, B.E. Metzger, N. Cho, K. Liu, The influence of demographic and phenotypic heterogeneity on the prevalence of gestational diabetes mellitus, Int. J. Gynaecol. Obstet. 35 (1991) 13 /18. [5] H.C. Jang, N.H. Cho, K.B. Jung, K.S. Oh, S.L. Dooley, B.E. Metzger, Screening for gestational diabetes mellitus in Korea, Int. J. Gynaecol. Obstet. 51 (1995) 115 /122. [6] S. Serirat, C. Deerochanawong, T. Sunthornthepvarakul, P. Jinayon, Gestational diabetes mellitus, J. Med. Assoc. Thai. 75 (1992) 315 /319. [7] I. Yasuhi, Evaluation of the diagnostic criteria of gestational diabetes mellitus in Japan: a study of women with mild glucose intolerance during late pregnancy, Acta Obstet. Gynaecol. Jpn. 43 (1991) 1501 /1507 (in Japanese). [8] T. Hamada, M. Tetsuou, K. Yoshimatsu, N. Amagase, T. Ooshima, N. Kubo, Studies on diagnostic criteria for gestational diabetes mellitus by 75 g glucose tolerance test, Asia Oceania J. Obstet. Gynaecol. 13 (1987) 187 /193. [9] B.E. Metzger, D.R. Coustan, Summary and recommendations of the Fourth International Workshop-Conference on Gestational Diabetes Mellitus. The Organizing Committee, Diabetes Care 21 (Suppl. 2) (1998) B161 /B167. [10] American College of Obstetricians and Gynecologists: Diabetes and Pregnancy, Technical Bulletin No. 200, December 1994. [11] G.G. Nahum, B.J. Huffaker, Racial differences in oral glucose screening test results: establishing race-specific criteria for abnormality in pregnancy, Obstet. Gynecol. 81 (1993) 517 /522. [12] H.R. Yalcin, C.G. Zorlu, Threshold value of glucose screening tests in pregnancy: could it be standardized for every population?, Am. J. Perinatol. 13 (1996) 317 /320. [13] N. Vitoratos, E. Salamalekis, P. Bettas, D. Kalabokis, A. Chrisikopoulos, Which is the threshold glucose value for further investigation in pregnancy?, Clin. Exp. Obstet. Gynecol. 24 (1997) 171 /173. [14] W.Y. Fujimoto, R.W. Bergstrom, E.J. Boyko, et al., Diabetes and diabetes risk factors in second- and thirdgeneration Japanese Americans in Seattle, Washington, Diabetes Res. Clin. Pract. 24 (1994) S43 /S52. [15] T. Sugawa, S. Takagi, Report of the Committee for Nutrition and Metabolism, the Japan Society of Gynecology and Obstetrics. A proposal of a guideline for the diagnosis of glucose intolerance particularly for gestational
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67 diabetes mellitus, Acta Obstet. Gynaecol. Jpn. 36 (1984) 2055 /2058 (in Japanese). [16] W.Y. Fujimoto, D.L. Leonetti, J.L. Kinyoun, et al., Prevalence of diabetes mellitus and impaired glucose tolerance among second-generation Japanese /American men, Diabetes 36 (1987) 721 /729. [17] N.I. Jowett, A.K. Samanta, A.C. Burden, Screening for diabetes in pregnancy: is a random blood glucose enough?, Diabet. Med. 4 (1987) 160 /163.
67
[18] A.J. Reichelt, E.R. Spichler, L. Branchtein, L.B. Nucci, L.J. Franco, M.I. Schmidt, Fasting plasma glucose in a useful test for the detection of gestational diabetes. Brazilian Study of Gestational Diabetes (EBDG) Working Group, Diabetes Care 21 (1998) 1246 /1249. [19] F.W.F. Hanna, J.R. Peters, Screening for gestational diabetes; past, present and future, Diabet. Med. 19 (2002) 351 /358.
Cutoff value of 1 h, 50 g glucose challenge test for screening of gestational diabetes mellitus in a Japanese population Kei Miyakoshi *, Mamoru Tanaka, Kazunori Ueno, Katsuhiko Uehara, Hitoshi Ishimoto, Yasunori Yoshimura Department of Obstetrics and Gynecology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan Received 15 August 2002; received in revised form 31 October 2002; accepted 11 November 2002
Abstract A total of 2651 consecutive native Japanese women who underwent a glucose challenge test (GCT) were retrospectively investigated. GCT was performed between 24 and 27 weeks of gestation; each subject received a 50 g oral glucose load without regard to the fasting or fed state, followed by a determination of 1 h venous plasma glucose level. Women demonstrating GCT exceeding 130 mg/dl received a 75 g, 2 h oral glucose tolerance test to determine whether or not they had gestational diabetes mellitus (GDM). All women with GDM were treated with a strict diabetic protocol including insulin therapy. Forty-nine (1.8%) women were diagnosed to have GDM. The receiver /operator characteristic curve identified a GCT finding above 140 mg/dl as the cutoff value for detecting GDM, which showed a sensitivity and specificity of 96 and 76%, respectively. Our results suggest that the cutoff value of a 50 g GCT is 140 mg/dl to identify pregnancies with GDM in a Japanese population. # 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Gestational diabetes mellitus; Glucose challenge test; Cutoff value; A Japanese population
1. Introduction Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance that is first detected during pregnancy. The prevalence of GDM ranges between 2 and 10% of all pregnancies, depending on the population sampled and the diagnostic criteria [1 /8]. The identification of GDM is important for the prevention of such perinatal * Corresponding author. Tel.: /81-3-3353-1211; fax: /81-33226-1667 E-mail address: [email protected] (K. Miyakoshi).
complications as maternal hypertensive disorders and a large for gestational age neonate. The Fourth International Workshop-Conference on GDM proposed an assessment of the clinical characteristics of all pregnant women to determine the risk of GDM as well as serum glucose testing [9]. According to the screening strategy, universal screening using the 50 g, 1 h oral glucose challenge test (GCT) is recommended for East Asian women. GCT consists of a single plasma glucose concentration measurement 1 h after ingestion of 50 g glucose without regard to the fasting or fed state [9,10]. The effect of prior meal ingestion is
0168-8227/02/$ - see front matter # 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 1 6 8 - 8 2 2 7 ( 0 2 ) 0 0 2 7 4 - 7
64
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67
minimal and has been ignored as a matter of practice and convenience in GCT [10]. A plasma glucose value between 130 and 140 mg/dl is commonly used as a threshold for performing a diagnostic oral glucose tolerance test (OGTT). Several authors have shown that race-specific glucose screening test threshold should be used because of the racial differences in the incidence of GDM [11 /13]. In addition, environmental factors are demonstrated to be associated with the development of impaired glucose tolerance (IGT) [14]. To the best of our knowledge, few studies on the cutoff value for GCT have been reported among native Asian populations [5]. The purpose of the current study is to investigate the cutoff value of GCT for performing OGTT in a native Japanese population.
2. Materials and methods A total of 2651 consecutive native Japanese pregnant women who underwent universal screening for GDM at Keio University Hospital from June 1996 to December 2000 were retrospectively investigated. The gestational age had been confirmed in all cases by crown-rump length measurements done in the first trimester. Excluded from this study were multifetal pregnancy and women whose neonates exhibited congenital anomalies. In addition, we excluded women who either had a personal history of IGT or used medications known to affect glucose metabolism. Each subject underwent a standard 1 h 50 g oral GCT between 24 and 27 weeks of gestation; a venous blood sample was obtained 1 h after ingestion of 50 g oral glucose load, administered without regard for the fasting or fed state. Using the cutoff value of 130 mg/dl to define a positive GCT has been demonstrated to improve the sensitivity up to 100% [10]. Thus, we performed a diagnostic 75 g, 2 h OGTT within 2 weeks after GCT if the venous plasma glucose values exceeded 130 mg/dl. The diagnostic tests were performed between 25 and 29 weeks of gestation. Based on the criteria using the 75 g, 2 h OGTT proposed by the Japan Society of Obstetrics and Gynecology, GDM was diagnosed if two or more values
reached or exceeded the following threshold: fasting, 100 mg/dl; 1 h, 180 mg/dl; 2 h, 150 mg/dl [15]. All women found to have GDM were treated with a strict diabetic protocol to maintain their plasma glucose levels during fasting at less than 100 mg/dl and 2 h postprandial levels at less than 120 mg/dl. When diet treatment could not achieve this goal, then insulin therapy was initiated. A statistical analysis was performed by utilizing the JMP software (SAS Institute, Cary, NC). The receiver /operator characteristic (ROC) curve was calculated as sensitivity versus one minus specificity for determining the optimal cutoff value of GCT.
3. Results The characteristics of the patients in this study were as follows (expressed as the mean9/S.D.): the mean maternal age was 32.69/4.3 years, the gestational age at delivery 38.89/1.8 weeks, and the mean birth weight 29779/441 g. Eight hundred and eighty-four patients (33%) received a 75 g, 2 h OGTT. Of 884 patients, fortynine were found to have GDM. The overall incidence of GDM was found to be 1.8%. The probability of GDM in groups with different GCT results is shown in Fig. 1. One patient demonstrating the GCT value below 130 mg/dl was diagnosed to have GDM by the diagnostic OGTT because of the frequent glycosuria. The probability of GDM increased sharply at GCT results /190 mg/dl. Of 49 women with GDM, four needed insulin treatment. The GCT results of all patients requiring insulin treatment were over 200 mg/dl. Fig. 2 shows an ROC curve of various cutoff values of GCT. The curve identified the GCT result above 140 mg/dl as useful for detecting GDM. At this cutoff value, the sensitivity and specificity of GCT were 96 and 76%, respectively.
4. Discussion The occurrence of GDM in this study was 1.8%, indicating that the prevalence of GDM in native Japanese pregnant women is similar to that in
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67
65
Fig. 1. Probability of GDM in groups with different GCT results.
Caucasian pregnant women [1 /4]. Several authors have reported the incidence of GDM to range from 2.0 to 10% in Asian populations [1 /8]. Berkowitz et al. [2] demonstrated that Orientals are at a higher risk of the developing GDM. At the Fourth International Workshop-Conference on GDM, South or East Asian populations were
reported to belong to a high-risk group for GDM [9]. However, the reported prevalence of GDM in Korea and Thailand were around 2.0%, which were similar to our findings [5,6]. Fujimoto et al. [14,16] have shown that environmental factors may play an important role in the development of type 2 diabetes since the prevalence of
Fig. 2. The ROC curve of various cutoff points of the GCT to detect GDM.
66
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67
type 2 diabetes is about twofold higher in Japanese Americans than in native Japanese. Asian immigrants in the United Kingdom, the United States and Canada were investigated in previous studies on racial variations in the incidence of GDM [1 / 3]. As a result, environmental factors such as diet in Western countries may contribute to the high prevalence of GDM in Asian immigrants. The present study indicates that the optimal cutoff value for GCT in a native Japanese population is 140 mg/dl. A cutoff value between 130 and 140 mg/dl is commonly used for performing the diagnostic OGTT in the clinical settings. Then, using a value of 130 mg/dl to define a positive GCT, several authors evaluated the sensitivity and specificity to determine the cutoff value in different populations [5,12]. We also investigated the sensitivity and specificity of different GCT results exceeding 130 mg/dl. We used an ROC curve in which the best cutoff point is thought to be that where the curve ‘turns the corner’. The proportion of gravidas exceeding 140 mg/dl in our study was found to be 25% of all subjects, and 7.4% of women with a positive screening test were diagnosed to have GDM. A cutoff value of 140 mg/dl yielded a sensitivity of 96% and a specificity of 76% for GDM, which were consistent with those in previous reports [5,12,13]. There have been several screening tests for GDM such as glycosuria, random and fast plasma glucose [17 /19]. Although there are no comparative studies on the sensitivity and specificity of different screening methods, we recommend GCT as an internationally recommended method and which was evaluated by previous and present studies. Racial differences regarding the glucose screening test findings have been demonstrated. Nahum and Huffaker [11] suggested race-specific criteria for GCT because of the heterogeneity of glucose intolerance between ethnic groups. We propose that the place of residence as well as race need be taken into consideration to establish the cutoff level of GCT, since environmental factors may contribute to the occurrence of GDM. Our results suggest a 140 mg/dl as the cutoff value of GCT in a Japanese population.
References [1] A. Dornhorst, C.M. Paterson, J.S. Nicholls, et al., High prevalence of gestational diabetes in women from ethnic minority groups, Diabet. Med. 9 (1992) 820 /825. [2] G.S. Berkowitz, R.H. Lapinski, R. Wein, D. Lee, Race/ ethnicity and other risk factors for gestational diabetes, Am. J. Epidemiol. 135 (1992) 965 /973. [3] J.R. Green, I.G. Pawson, L.B. Schumacher, J. Perry, N. Kretchmer, Glucose tolerance in pregnancy: ethnic variation and influence of body habitus, Am. J. Obstet. Gynecol. 163 (1990) 86 /92. [4] S.L. Dooley, B.E. Metzger, N. Cho, K. Liu, The influence of demographic and phenotypic heterogeneity on the prevalence of gestational diabetes mellitus, Int. J. Gynaecol. Obstet. 35 (1991) 13 /18. [5] H.C. Jang, N.H. Cho, K.B. Jung, K.S. Oh, S.L. Dooley, B.E. Metzger, Screening for gestational diabetes mellitus in Korea, Int. J. Gynaecol. Obstet. 51 (1995) 115 /122. [6] S. Serirat, C. Deerochanawong, T. Sunthornthepvarakul, P. Jinayon, Gestational diabetes mellitus, J. Med. Assoc. Thai. 75 (1992) 315 /319. [7] I. Yasuhi, Evaluation of the diagnostic criteria of gestational diabetes mellitus in Japan: a study of women with mild glucose intolerance during late pregnancy, Acta Obstet. Gynaecol. Jpn. 43 (1991) 1501 /1507 (in Japanese). [8] T. Hamada, M. Tetsuou, K. Yoshimatsu, N. Amagase, T. Ooshima, N. Kubo, Studies on diagnostic criteria for gestational diabetes mellitus by 75 g glucose tolerance test, Asia Oceania J. Obstet. Gynaecol. 13 (1987) 187 /193. [9] B.E. Metzger, D.R. Coustan, Summary and recommendations of the Fourth International Workshop-Conference on Gestational Diabetes Mellitus. The Organizing Committee, Diabetes Care 21 (Suppl. 2) (1998) B161 /B167. [10] American College of Obstetricians and Gynecologists: Diabetes and Pregnancy, Technical Bulletin No. 200, December 1994. [11] G.G. Nahum, B.J. Huffaker, Racial differences in oral glucose screening test results: establishing race-specific criteria for abnormality in pregnancy, Obstet. Gynecol. 81 (1993) 517 /522. [12] H.R. Yalcin, C.G. Zorlu, Threshold value of glucose screening tests in pregnancy: could it be standardized for every population?, Am. J. Perinatol. 13 (1996) 317 /320. [13] N. Vitoratos, E. Salamalekis, P. Bettas, D. Kalabokis, A. Chrisikopoulos, Which is the threshold glucose value for further investigation in pregnancy?, Clin. Exp. Obstet. Gynecol. 24 (1997) 171 /173. [14] W.Y. Fujimoto, R.W. Bergstrom, E.J. Boyko, et al., Diabetes and diabetes risk factors in second- and thirdgeneration Japanese Americans in Seattle, Washington, Diabetes Res. Clin. Pract. 24 (1994) S43 /S52. [15] T. Sugawa, S. Takagi, Report of the Committee for Nutrition and Metabolism, the Japan Society of Gynecology and Obstetrics. A proposal of a guideline for the diagnosis of glucose intolerance particularly for gestational
K. Miyakoshi et al. / Diabetes Research and Clinical Practice 60 (2003) 63 /67 diabetes mellitus, Acta Obstet. Gynaecol. Jpn. 36 (1984) 2055 /2058 (in Japanese). [16] W.Y. Fujimoto, D.L. Leonetti, J.L. Kinyoun, et al., Prevalence of diabetes mellitus and impaired glucose tolerance among second-generation Japanese /American men, Diabetes 36 (1987) 721 /729. [17] N.I. Jowett, A.K. Samanta, A.C. Burden, Screening for diabetes in pregnancy: is a random blood glucose enough?, Diabet. Med. 4 (1987) 160 /163.
67
[18] A.J. Reichelt, E.R. Spichler, L. Branchtein, L.B. Nucci, L.J. Franco, M.I. Schmidt, Fasting plasma glucose in a useful test for the detection of gestational diabetes. Brazilian Study of Gestational Diabetes (EBDG) Working Group, Diabetes Care 21 (1998) 1246 /1249. [19] F.W.F. Hanna, J.R. Peters, Screening for gestational diabetes; past, present and future, Diabet. Med. 19 (2002) 351 /358.