huotcz

作者：Laurie Barclay, MD  
出處：WebMD醫學新聞

　　March 1, 2010 — 國際糖尿病協會與懷孕研究小組(IADPSG)發布懷孕時高血糖的診斷與分類指引，新版的妊娠糖尿病(gestational diabetes mellitus，GDM)指引登載於3月的糖尿病照護(Diabetes Care)期刊。
　　
　　雖然孕婦的明顯糖尿病可以預測不佳的母嬰結果，但較不嚴重的高血糖症對於結果之不良影響的瞭解有限。
　　
　　IADPSG共識小組寫道，如目前的定義，GDM包括比較嚴重的高血糖症(類似原本就有的糖尿病)，在懷孕和產後追蹤時有特定的照護考量。
　　
　　這些GDM病患，因為較年輕者的肥胖、第2型糖尿病與其他代謝異常的發生率增加而引起更多關注，HAPO [Hyperglycemia and Adverse Pregnancy Outcome]這項研究，目標在區分血糖耐受不佳程度低於明顯糖尿病者懷孕時之相關不良結果風險的類別。
　　
　　在HAPO研究中，對於初級結果，隨著母親的高血糖程度增加，持續增加的關係包括出生體重大於第90百分位、剖腹產、新生兒低血糖、脊索C-胜肽大於第90百分位。
　　
　　【懷孕時高血糖症的建議】
　　懷孕時確認與診斷高血糖異常的特定建議包括：
　　* 初次產前檢查時，根據人口與當地環境之異常葡萄糖代謝頻率資料，所有孕婦或者只有高風險孕婦檢查空腹血糖(FPG)、血色素A1c或者隨機血漿血糖。
　　* 懷孕時明顯糖尿病的診斷臨界值為FPG至少7.0 mmol/L (126 mg/dL)；血色素A1c值至少6.5% (根據糖尿病控制與併發症試驗/英國前瞻糖尿病研究標準化)；或者隨機血漿血糖值至少11.1 mmol/L (200 mg/dL)加上確認。
　　* 如果檢測結果顯示為明顯糖尿病，治療與追蹤需視同原本即有糖尿病者。如果檢測結果非明顯糖尿病且FPG至少5.1 mmol/L (92 mg/dL)但是低於7.0 mmol/L (126 mg/dL)，診斷為GDM。
　　* 如果FPG低於5.1 mmol/L (92 mg/dL)，病患應在妊娠第24-28週時使用75克口服葡萄糖耐受測試(OGTT)檢測GDM。
　　* 為了診斷妊娠第24-28週時的GDM，所有在當次懷孕時未曾診斷有明顯糖尿病或GDM的婦女，應在整夜空腹之後進行兩小時的75克OGTT測試。
　　* 如果空腹血漿血糖至少7.0 mmol/L (126 mg/dL)，診斷為明顯糖尿病。如果FPG值5.1 mmol/L (92 mg/dL)、一小時血漿血糖值10.0 mmol/L (180 mg/dL)和/或兩小時血漿血糖值8.5 mmol/L (153 mg/dL)等數值有一項或一項以上等於或超過，診斷為GDM。正常檢測定義為OGTT的這些檢測結果都需小於前述臨界值。
　　* 該小組結論表示，沒有進行充分研究來確認於24-28週之前進行綜合檢查對於診斷和治療GDM是否有助益。
　　* 所有在懷孕期間診斷有GDM或明顯糖尿病的婦女，都應接受產後葡萄糖檢查。
　　
　　共識小組指出，在某些區域和/或國家中，這些建議顯然改變自長久建立的實務，多數區域中，使用這種偵測策略會明顯增加懷孕期高血糖異常的頻率，不過，該小組指出，孕婦的既有明顯糖尿病和GDM盛行率增加，與一般年輕成人之肥胖和葡萄糖代謝異常盛行率一致。
　　
　　【需要後續研究】
　　研究作者結論表示，HAPO研究是一個基礎流行病學研究，首次毫無爭論地確認葡萄糖值低於糖尿病診斷之孕婦和嚴重生產前後結果之間的明顯連續關聯。
　　
　　它並不是一個臨床試驗，但是，報告指出，已經有兩篇葡萄糖值位於臨界值病患之輕微GDM治療隨機控制試驗成功地進行。不過，另外需要有設計良好的隨機控制試驗與其他臨床研究來確認：1)使用IADPSG共識小組建議之規範診斷GDM治療策略的成本效益；2)適當的血糖治療目標；3)母親的適當追蹤，以確認後來發生糖尿病、其他代謝異常、或心血管疾病(CVD [cardiovascular disease])風險因素的風險；以及4)追蹤小孩，以評估母親高血糖的潛在關聯和長期肥胖、葡萄糖代謝改變、CVD風險因素等的關聯。
　　
　　【對GDM領域有大貢獻的建議】
　　澳洲新南威爾斯臥龍岡、東南雪梨和伊拉瓦拉地區(South Eastern Sydney and Illawarra Area)健康服務的Robert G. Moses醫師在編輯評論中指出，新的IADPSG建議對於我們對GDM的知識與暸解有顯著貢獻，但是對這個迫切性問題的解決方式在未來仍然有些問題。
　　
　　Moses醫師寫道，確認更多婦女有不佳懷孕結果這件事情本身是否會引起傷害？新版指引明確指出GDM的診斷分類，而不考慮達到血糖控制，在某些例證中，這可能導致增加介入、早產、增加剖腹產率、較多新生兒住進特殊照護病房，這些實際風險是否會抵消了潛在的助益？
　　
　　國家兒童健康與人類發展研究中心；國家糖尿病、消化道與腎臟疾病研究中心；美國糖尿病協會資助HAPO研究；回顧作者之一接受參與非侵犯式偵察裝置試驗的研究支持，且接受來自Veralight的研究支持。
　　
　　Moses醫師宣告沒有相關財務關係。


Guidelines Issued for Diagnosis and Classification of Hyperglycemia in Pregnancy

By Laurie Barclay, MD
Medscape Medical News

March 1, 2010 — The International Association of Diabetes and Pregnancy Study Groups (IADPSG) has issued recommendations on the diagnosis and classification of hyperglycemia in pregnancy. The new guidelines for gestational diabetes mellitus (GDM) are published in the March issue of Diabetes Care.

Although overt diabetes in pregnant women predicts adverse maternal and fetal outcomes, the effect of less severe degrees of hyperglycemia on adverse outcomes is poorly understood.

"As currently defined, GDM includes a subgroup with more severe hyperglycemia (similar to that seen in preexisting diabetes) that presents special issues concerning management during pregnancy and postpartum follow-up," the IADPSG Consensus Panel writes.

"The issues raised by inclusion of this subgroup with those with GDM are of greater concern because of the rising prevalence of obesity, type 2 diabetes, and other metabolic disturbances among younger age groups. The HAPO [Hyperglycemia and Adverse Pregnancy Outcome] study was designed to clarify risks of adverse outcome associated with degrees of maternal glucose intolerance less severe than those with overt diabetes during pregnancy."

In the HAPO study, there were continuous graded relationships with increasing maternal hyperglycemia for primary outcomes of birth weight greater than the 90th percentile, cesarean delivery, neonatal hypoglycemia, and cord C-peptide greater than the 90th percentile.

Recommendations for Hyperglycemia in Pregnancy

Specific recommendations for identifying and diagnosing hyperglycemic disorders in pregnancy include the following:

At the first prenatal visit, all or only high-risk women should undergo testing of fasting plasma glucose (FPG), hemoglobin A1c, or random plasma glucose, based on the background frequency of abnormal glucose metabolism in the population and on local circumstances.
Thresholds for diagnosis of overt diabetes during pregnancy are FPG of at least 7.0 mmol/L (126 mg/dL); hemoglobin A1c level of at least 6.5% (Diabetes Control and Complications Trial/UK Prospective Diabetes Study standardized); or random plasma glucose at least 11.1 mmol/L (200 mg/dL), plus confirmation.
If this testing result indicates overt diabetes, treatment and follow-up should be the same as for preexisting diabetes. If testing is not diagnostic of overt diabetes and FPG is at least 5.1 mmol/L (92 mg/dL) but less than 7.0 mmol/L (126 mg/dL), GDM should be diagnosed.
If FPG is less than 5.1 mmol/L (92 mg/dL), the patient should be tested for GDM from 24 to 28 weeks of gestation with a 75-g oral glucose tolerance test (OGTT).
To diagnose GDM at 24 to 28 weeks of gestation, a 2-hour, 75-g OGTT should be performed after overnight fast on all women not previously found to have overt diabetes or GDM during testing earlier in this pregnancy.
Overt diabetes is diagnosed if fasting plasma glucose level is at least 7.0?mmol/L (126 mg/dL). GDM is diagnosed if 1 or more values equals or exceeds thresholds of FPG of 5.1 mmol/L (92 mg/dL), 1-hour plasma glucose level of 10.0 mmol/L (180 mg/dL), and/or a 2-hour plasma glucose level of 8.5?mmol/L (153 mg/dL). Normal test results are defined as all values on OGTT less than these thresholds.
The panel concluded that insufficient studies have been done to determine whether there is a benefit of generalized testing to diagnose and treat GDM before the usual window of 24 to 28 weeks of gestation.
All women diagnosed with GDM or overt diabetes during pregnancy should undergo postpartum glucose testing.
The consensus panel notes that in some regions and/or countries, the recommendations may be a significant departure from long-established practices. In most areas, use of this detection strategy will substantially increase the frequency of hyperglycemic disorders in pregnancy. However, the panel notes that this is consistent with the high prevalence of obesity and disorders of glucose metabolism in the general population of young adults and with the increasing prevalence of GDM and preexisting overt diabetes in pregnant women.

Further Trials Needed

"The HAPO study was a basic epidemiological investigation that for the first time conclusively identified strong continuous associations of maternal glucose levels below those diagnostic of diabetes with several perinatal outcomes," the study authors conclude.

"It was not a clinical trial, but two randomized controlled trials of treatment of mild GDM have been carried out successfully in participants with glucose values that overlap with the thresholds recommended in this report. However, it is likely that additional well-designed randomized controlled trials and other clinical studies will be needed to determine 1) cost-effective therapeutic strategies for treatment of GDM diagnosed by the IADPSG Consensus Panel–recommended criteria; 2) optimal glycemic treatment targets; 3) appropriate follow-up of mothers to determine risks for later development of diabetes, other metabolic disorders, or CVD [cardiovascular disease] risk factors; and 4) follow-up of children to assess potential associations of maternal glycemia with long-term risks of obesity, altered glucose metabolism, and CVD risk factors."

Recommendations Great Contribution to GDM Field

In an accompanying editorial, Robert G. Moses, MD, from the South Eastern Sydney and Illawarra Area Health Service in Wollongong, New South Wales, Australia, notes that the new IADPSG recommendations are "a significant contribution to our knowledge and understanding of GDM" but that "solutions of an immediate problem raise questions for the future."

"Could the identification of a greater number of women at risk of an adverse pregnancy outcome itself cause harm?" Dr. Moses writes. "It is well documented that a diagnostic category of GDM, irrespective of the glucose control achieved, in some instances is likely to result in increased interventions, earlier delivery, an increased caesarean section rate, and a higher number of babies being admitted to special care nurseries. Could these real hazards offset some of the potential advantages?"

The HAPO study was funded by National Institute of Child Health and Human Development; the National Institute of Diabetes, Digestive and Kidney Diseases; and the American Diabetes Association. One of the review authors received research support to participate in a trial of the noninvasive Scout device and has received research support from Veralight.

Dr. Moses has disclosed no relevant financial relationships.

Diabetes Care. March 2010;33:676-682.