1] Sheffield Kidney Institute, Northern General Hospital, Sheffield, UK [2] School of Health and Related Research, University of Sheffield, Sheffield, UK.
Sheffield Kidney Institute, Northern General Hospital, Sheffield, UK.
Kidney Int. 2014 Dec;86(6):1221-8. doi: 10.1038/ki.2014.112. Epub 2014 Apr 9.
Obesity could affect associations between creatinine generation, estimated body surface area, and excretory burden, with effects on chronic kidney disease assessment. We therefore examined the impact of obesity on the performances of estimated glomerular filtration rate (eGFR), the urine albumin:creatinine ratio (ACR), and excretory burden in 3611 participants of the Chronic Renal Insufficiency Cohort. Urine creatinine excretion significantly increased with body mass index (BMI) (34 and 31% greater at 40 kg/m(2) or more versus the normal of 18.5-25 kg/m(2)) in men and women, respectively, such that patients with a normal BMI and an ACR of 30 mg/g had the same 24-h albuminuria as severely obese patients with ACR 23 mg/g. The bias of eGFR (referenced to body surface area-indexed iothalamate (i-)GFR) had a U-shaped relationship to obesity in men but progressively increased in women. Nevertheless, obesity-associated body surface area increases were accompanied by a greater absolute (non-indexed) iGFR for a given eGFR, particularly in men. Two men with eGFRs of 45 ml/min per 1.73 m(2), height 1.76 m, and BMI 22 or 45 kg/m(2) had absolute iGFRs of 46 and 62 ml/min, respectively. The excretory burden, assessed as urine urea nitrogen and estimated dietary phosphorus, sodium, and potassium intakes, also increased in obesity. However, obese men had lower odds of anemia, hyperkalemia, and hyperphosphatemia. Thus, for a given ACR and eGFR, obese individuals have greater albuminuria, absolute GFR, and excretory burden. This has implications for chronic kidney disease management, screening, and research.
肥胖可能会影响肌酐生成、估计的体表面积和排泄负担之间的关联，从而影响慢性肾脏病的评估。因此，我们在慢性肾功能不全队列的 3611 名参与者中检查了肥胖对估算肾小球滤过率（eGFR）、尿白蛋白/肌酐比值（ACR）和排泄负担的影响。男性和女性的尿肌酐排泄量分别随着体重指数（BMI）的增加而显著增加（BMI 为 40kg/m2 或更高时，比 18.5-25kg/m2 的正常值分别增加 34%和 31%），因此，具有正常 BMI 和 ACR 为 30mg/g 的患者与 ACR 为 23mg/g 的严重肥胖患者具有相同的 24 小时蛋白尿。eGFR（参照体表面积指数化碘海醇（i-）GFR）的偏差与男性的肥胖呈 U 型关系，但在女性中逐渐增加。然而，与肥胖相关的体表面积增加伴随着给定 eGFR 下更大的绝对（未指数化）iGFR，尤其是在男性中。两名 eGFR 为 45ml/min/1.73m2、身高 1.76m、BMI 为 22 或 45kg/m2 的男性，绝对 iGFR 分别为 46 和 62ml/min。作为尿尿素氮和估计的饮食磷、钠和钾摄入量评估的排泄负担也随着肥胖而增加。然而，肥胖男性患贫血、高钾血症和高磷血症的几率较低。因此，对于给定的 ACR 和 eGFR，肥胖个体具有更大的蛋白尿、绝对 GFR 和排泄负担。这对慢性肾脏病的管理、筛查和研究具有重要意义。
