Ljung T, Andersson B, Bengtsson B A, Björntorp P, Mårin P
Department of Heart and Lung Diseases, Sahlgren's Hospital, University of Göteborg, Sweden.
Obes Res. 1996 May;4(3):277-82. doi: 10.1002/j.1550-8528.1996.tb00546.x.
There is now evidence of a hypersensitive hypothalamo-pituitary-adrenal (HPA) axis in subjects with an elevated waist/hip circumference ratio (WHR), an indicator of the centralization of body fat stores. The activity of the HPA axis is regulated by central glucocorticoid receptors, whose activity can be tested by the administration of exogenous glucocorticoids, which normally inhibit cortisol secretion. In this study, dexamethasone (dex) was administered in random order in doses of 0.05, 0.125, 0.25 and 0.5 mg at 10 p.m. with measurements of serum cortisol in the morning (8 a.m.) of this and the following day. The test was performed on 22 apparently healthy men, 40 to 60 years of age, recruited from laboratory personnel, outpatient clinics or advertisements in a newspaper. Eight had a body mass index (BMI) (kg/m2) of < 25 and 14 of > 25. Twelve men had a waist hip ratio (WHR) of < 1.0 and 10 men had a WHR of > 1.0. Cortisol values at baseline were correlated inversely with WHR and were usually lower in men with a high (> 1.0) rather than a low than low (< 1.0) WHR after dex inhibition. There was apparently no inhibition by dex at 0.05 and 0.125 mg on average in men with a WHR of > 1.0. In addition, the inhibition at 0.5 mg dex correlated negatively with the WHR and was significantly lower (p < 0.05) in men with a WHR of > 1.0 than in men with a WHR of < 1.0. None of these differences or relationships was found to be dependent on BMI. It is concluded that men with an elevated WHR experience a decrease in the inhibition of cortisol secretion by dex. It is suggested that this could explain or contribute to the elevated sensitivity of their HPA axis. Furthermore, lower morning cortisol concentrations suggest a change in diurnal secretion patterns.
现在有证据表明，腰臀围比（WHR）升高的受试者存在下丘脑-垂体-肾上腺（HPA）轴过敏，WHR是身体脂肪储存集中化的一个指标。HPA轴的活性受中枢糖皮质激素受体调节，其活性可通过给予外源性糖皮质激素来测试，外源性糖皮质激素通常会抑制皮质醇分泌。在本研究中，地塞米松（dex）于晚上10点以0.05、0.125、0.25和0.5毫克的剂量随机给药，并在给药当天及次日上午8点测量血清皮质醇。该测试对22名年龄在40至60岁之间、表面健康的男性进行，这些男性是从实验室工作人员、门诊患者或报纸广告中招募的。其中8人体重指数（BMI）（kg/m²）<25，14人体重指数>25。12名男性腰臀比（WHR）<1.0，10名男性腰臀比>1.0。基线时的皮质醇值与WHR呈负相关，在接受dex抑制后，WHR高（>1.0）的男性的皮质醇值通常低于WHR低（<1.0）的男性。WHR>1.0的男性平均给予0.05和0.125毫克dex时，显然没有抑制作用。此外，0.5毫克dex的抑制作用与WHR呈负相关，WHR>1.0的男性的抑制作用明显低于（p<0.05）WHR<1.0的男性。未发现这些差异或关系依赖于BMI。结论是，WHR升高的男性dex对皮质醇分泌的抑制作用降低。有人认为，这可以解释或导致他们HPA轴敏感性升高。此外，较低的早晨皮质醇浓度表明昼夜分泌模式发生了变化。
