Montesanto Alberto, De Rango Francesco, Berardelli Maurizio, Mari Vincenzo, Lattanzio Fabrizia, Passarino Giuseppe, Corsonello Andrea
Department of Biology, Ecology and Earth Science, University of Calabria, 87036, Rende, Italy,
Age (Dordr). 2014 Jun;36(3):9641. doi: 10.1007/s11357-014-9641-4. Epub 2014 Mar 25.
The equations for estimating kidney function have become very popular in the last decade. However, the clinical and prognostic meaning of these measures may be very different in older populations. Two cohorts of people aged 65-89 years (older sample) and 90 or more (oldest old sample) were used to investigate the prognostic significance of estimated glomerular filtration rate (eGFR). Additionally, we also investigated whether combining frailty and eGFR may improve the accuracy of frailty in predicting mortality. We found that lower eGFR values were significantly more frequent among frail subjects in both groups. eGFR < 30 was associated with increased risk for all-cause mortality either in subjects aged 65-89 years (HR = 3.71, 95% CI = 1.23-11.2) or in those aged 90 or more (HR = 1.53, 95% CI = 1.05-2.23). In the latter group, a not significant trend for increasing mortality was also observed among people with eGFR > 60 (HR = 1.28, 95% CI = 0.72-2.26). In addition, the oldest old subjects with eGFR > 60 and eGFR < 30 had the lowest hand-grip strength and ADL values. Combining eGFR and frailty status significantly improved the accuracy of frailty in predicting mortality only in the older sample. In conclusion, a U-shaped relationship exists between eGFR and mortality in the oldest old, but not in older individuals. Our findings suggest that eGFR needs to be adjusted for muscle mass/physical performance when estimating kidney function in people aged 90 or more. Nevertheless, in subjects aged 65-89 years, eGFR may improve the accuracy of frailty status in predicting prognosis, thus suggesting that eGFR may represent an additional dimension of frailty syndrome.
在过去十年中，估算肾功能的公式变得非常流行。然而，这些指标在老年人群中的临床和预后意义可能有很大差异。我们使用了两组年龄分别为65 - 89岁（老年样本）和90岁及以上（高龄老年样本）的人群，来研究估算肾小球滤过率（eGFR）的预后意义。此外，我们还研究了将衰弱与eGFR相结合是否能提高衰弱对死亡率预测的准确性。我们发现，两组中衰弱受试者的eGFR值较低的情况明显更为常见。在65 - 89岁的受试者（HR = 3.71，95%CI = 1.23 - 11.2）或90岁及以上的受试者（HR = 1.53，95%CI = 1.05 - 2.23）中，eGFR < 30与全因死亡率风险增加相关。在后者中，eGFR > 60的人群中也观察到死亡率增加的不显著趋势（HR = 1.28，95%CI = 0.72 - 2.26）。此外，eGFR > 60和eGFR < 30的高龄老年受试者的握力和日常生活活动能力值最低。仅在老年样本中，将eGFR和衰弱状态相结合显著提高了衰弱对死亡率预测的准确性。总之，在高龄老年人中，eGFR与死亡率之间存在U型关系，但在老年人中不存在。我们的研究结果表明，在估算90岁及以上人群的肾功能时，eGFR需要根据肌肉量/身体表现进行调整。然而，在65 - 89岁的受试者中，eGFR可能会提高衰弱状态对预后预测的准确性，因此表明eGFR可能代表衰弱综合征的一个额外维度。
