BMI可能是兒童與青少年高膽固醇血症一個不好的標記


  August 6, 2009 — 根據一項發表於8月號小兒與青少年醫學誌的斷面研究結果分析,身體質量指數(BMI)是兒童與青少年高膽固醇血症一個不好的標記。
  
  安那堡密西根大學Joyce M. Lee醫師與其同事們寫到,美國小兒科醫學會改寫了其膽固醇篩檢指引,呼籲兒童照護者對所有具心血管疾病危險因子兒童進行空腹血脂篩檢。這些具風險的兒童包括有家族遺傳高膽固醇血症、或是早發性心血管疾病(男性≦55歲,女性≦65歲);有高血壓、糖尿病、或是吸菸病史兒童;以及體重過重兒童(年齡與性別BMI≧85百分位數且<95百分位數),或是肥胖(年齡或是性別BMI≧95百分位數)。
  
  這項研究的目的在於確定特定BMI百分位數界線在找出高膽固醇血症兒童與青少年上的表現。使用國家健康與營養檢查普查1999年到2004年的數據,研究者找出年齡介於3至18歲的兒童,這些兒童都有非空腹總膽固醇(TC)與高密度脂蛋白(HDL)膽固醇濃度,以及12至18歲的青少年,他們都接受空腹低密度脂蛋白(LDL)膽固醇與三酸甘油酯(TG)濃度檢驗。
  
  高膽固醇血症以TC高於200 mg/dl定義,HDL低於35 mg/dl、以及LDL高於130 mg/dl、或是TG高於150 mg/dl定義。計算特定BMI百分位數的敏感度、專一性與可能性比值,以及接受者操作特性曲線來計算曲線下面積。
  
  以BMI百分位數預測異常TC與LDL的接受者操作特性曲線曲線下面積分別為0.60與0.63,稍低於鑑別可接受的標準(定義為0.7-0.8)。在確認異常HDL與TG濃度兒童方面,BMI百分位數提供較好的鑑別力,曲線下面積分別為0.69與0.72。然而,沒有特定指引提到如何處理有這些異常的兒童。
  
  這項研究的限制包括,缺乏小、高密度LDL膽固醇的數據、或是特定其他危險因子、斷面性分析、以及無法針對種族或是青春期分期的差異進行分析。
  
  研究作者寫到,根據指引,異常LDL膽固醇濃度被用來決定哪些兒童需要營養與藥物治療。因為BMI百分位數無法充分地找出哪些兒童與青少年的TC與LDL膽固醇濃度異常,針對肥胖兒童與青少年篩檢的新建議可能需要更進一步的考量。
  
  Robert Wood Johnson基金會贊助這項研究。作者們表示沒有相關資金上的往來。Lee醫師接受國家糖尿病與消化及腎臟疾病機構、以及密西根大學臨床科學學者計劃經費贊助。
  
  

BMI May Be a Poor Marker for Hypercholesterolemia in Children, Adolescents

By Laurie Barclay, MD
Medscape Medical News

August 6, 2009 — Body mass index (BMI) may be a poor marker for hypercholesterolemia in children and adolescents, according to the results of a cross-sectional analysis reported in the August issue of the Archives of Pediatric and Adolescent Medicine.

"The American Academy of Pediatrics...revised its cholesterol screening guidelines to advocate that pediatric providers perform a fasting lipid profile in all children with cardiovascular risk factors," write Joyce M. Lee, MD, MPH, from the University of Michigan, Ann Arbor, and colleagues. "This group includes children with a family history of hypercholesterolemia or early cardiovascular disease (?55 years for men and ?65 years for women); children with hypertension, diabetes mellitus, or a smoking history; and children who are overweight" (BMI ? 85th percentile and <95th percentile for age and sex) or obese (BMI ? 95th percentile for age and sex).

The goal of this study was to determine the test performance of specific BMI percentile cutoffs for identifying children and adolescents with hypercholesterolemia. Using data from the National Health and Nutrition Examination Survey from 1999 to 2004, the investigators identified children (aged 3 – 18 years) who had their nonfasting total cholesterol (TC) and high-density lipoprotein (HDL) cholesterol levels tested and adolescents (aged 12 – 18 years) who had their fasting low-density lipoprotein (LDL) cholesterol and triglyceride (TG) levels tested.

Hypercholesterolemia was defined as TC higher than 200 mg/dL, HDL lower than 35 mg/dL, LDL higher than 130 mg/dL, or TG higher than 150 mg/dL. Sensitivity, specificity, and likelihood ratios were calculated for specific BMI percentiles, and receiver operating characteristic curves were constructed to calculate area under the curve.

Receiver operating characteristic curves using BMI percentiles to predict abnormal TC and LDL had area-under-the-curve values of 0.60 and 0.63, respectively, which were less than the threshold of acceptable discrimination (defined as 0.7 – 0.8). For identifying children with abnormal HDL cholesterol and TG levels, BMI percentiles offered better discrimination, with area-under-the-curve values of 0.69 and 0.72, respectively. However, management of children with these abnormalities is not addressed by specific guidelines.

Limitations of this study include lack of data on small, dense LDL cholesterol or on certain other risk factors, cross-sectional analysis, and inability to look at differences by race or pubertal stage.

"According to the...guidelines, abnormal levels of LDL cholesterol are used to determine which children require nutritional and pharmacologic therapy," the study authors write. "Because BMI percentiles did not adequately identify children and adolescents with abnormal TC and LDL cholesterol levels, the new recommendations for targeted screening of obese children and adolescents may require further consideration."

The Robert Wood Johnson Foundation supported this study. The authors have disclosed no relevant financial relationships. Dr. Lee was supported by the National Institute of Diabetes and Digestive and Kidney Diseases and the Clinical Sciences Scholars Program at the University of Michigan.

Arch Pediatr Adolesc Med. 2009;163:716–722.

    
相關報導
兒科醫師提供的肥胖介入方法難以減少BMI
2016/9/26 下午 03:57:35
即便BMI低 久坐仍與脂肪肝疾病有關
2015/10/2 上午 10:37:49
腸道微生物與高密度脂蛋白、三酸甘油脂及身體質量指數有關
2015/9/25 上午 10:23:47

上一頁
   1   2   3   4   5   6   7   8   9   10  
回上一頁