Ouyang Fengxiu, Necheles Jonathan, Wang Binyan, Ma Wei, Li Zhiping, Liu Xue, Tang Genfu, Xing Houxun, Xu Xiping, Venners Scott A, Brickman Wendy J, Christoffel Katherine Kaufer, Zimmerman Donald, Wang Xiaobin
Mary Ann and J. Milburn Smith Child Health Research Program, Department of Pediatrics, Northwestern University Feinberg School of Medicine and Children's Memorial Hospital and Children's Memorial Research Center, 2300 Children's Plaza, Chicago, IL 60614, USA.
Eur J Nutr. 2009 Sep;48(6):323-32. doi: 10.1007/s00394-009-0016-z. Epub 2009 Apr 1.
Most studies linking obesity and metabolic syndrome (MS) have used body mass index (BMI) and waist circumference (WC) to measure obesity. While BMI is correlated with direct measures of total and central adiposity, it is influenced by lean body and bone mass. We hypothesize that direct measures of adiposity may help develop further insight into the link between obesity and MS, thus more accurately identifying individuals at high risk for MS.
We examined how surrogate and direct measures of adiposity were associated with MS risk and if direct adiposity measures enhanced BMI and WC identification of MS risk.
3,734 Chinese female twins aged 20-39 years were studied. Percent body fat (%BF) and proportion of trunk fat to total BF (%TF) were assessed by DEXA. Graphic plots and generalized estimating equations were used to examine the associations of adiposity measures with MS and its components. Concordance of adiposity measures and MS abnormalities between monozygotic (MZ) and dizygotic (DZ) twin pairs were compared.
The prevalence of MS increased for high BMI (>or=23 kg/m(2)), %BF (>or=32), WC (>or=80 cm), and (to a lesser degree) %TF (>or=50). Below those thresholds, the prevalence of MS was low (0-5.3%). %TF was independently associated with higher risk of MS and its components even after adjusting for BMI and WC. As a result, among women with normal BMI and WC, high %TF was associated with 1.3-2.0-fold elevated risk of MS components. In contrast, women with high BMI but normal WC and %TF neither have significantly increased risk of MS, nor for any component other than high BP. MZ twins showed higher concordance for MS and its components than DZ twins.
In this lean Chinese rural female sample, BMI >or= 23 and WC >or= 80 were associated with a markedly increased risk of MS, which was further enhanced by elevated %TF. Even in women with a normal BMI and WC, %TF was independently associated with MS and its components. Twin analysis findings suggest that adiposity measurements and MS risk are influenced by genetics.
大多数将肥胖与代谢综合征（MS）联系起来的研究都使用体重指数（BMI）和腰围（WC）来衡量肥胖。虽然BMI与总体脂和中心性肥胖的直接测量指标相关，但它会受到瘦体重和骨量的影响。我们假设，肥胖的直接测量指标可能有助于更深入地了解肥胖与MS之间的联系，从而更准确地识别MS高危个体。
我们研究了肥胖的替代指标和直接测量指标与MS风险之间的关联，以及直接肥胖测量指标是否能增强BMI和WC对MS风险的识别能力。
对3734名年龄在20 - 39岁的中国女性双胞胎进行了研究。通过双能X线吸收法（DEXA）评估体脂百分比（%BF）和躯干脂肪占总脂肪的比例（%TF）。使用图形图和广义估计方程来研究肥胖测量指标与MS及其组分之间的关联。比较了同卵（MZ）和异卵（DZ）双胞胎对之间肥胖测量指标与MS异常的一致性。
对于高BMI（≥23 kg/m²）、%BF（≥32）、WC（≥80 cm）以及（程度较轻的）%TF（≥50），MS的患病率增加。低于这些阈值时，MS的患病率较低（0 - 5.3%）。即使在调整了BMI和WC之后，%TF仍与MS及其组分的较高风险独立相关。因此，在BMI和WC正常的女性中，高%TF与MS组分风险升高1.3 - 2.0倍相关。相比之下，BMI高但WC和%TF正常的女性，MS风险以及除高血压外的任何组分风险均未显著增加。MZ双胞胎在MS及其组分方面的一致性高于DZ双胞胎。
在这个瘦型中国农村女性样本中，BMI≥23和WC≥80与MS风险显著增加相关，%TF升高会进一步增强这种相关性。即使在BMI和WC正常的女性中，%TF也与MS及其组分独立相关。双胞胎分析结果表明，肥胖测量指标和MS风险受遗传因素影响。
