CKD is more prevalent in women, but more men receive kidney replacement therapy for kidney failure. This apparent contradiction is not well understood.

We investigated sex differences in the loss of kidney function and whether any sex disparities could be explained by comorbidity or CKD risk factors. In the Renal Iohexol Clearance Survey (RENIS) in northern Europe, we recruited 1837 persons (53% women, aged 50–62 years) representative of the general population and without self-reported diabetes, CKD, or cardiovascular disease. Participants’ GFR was measured by plasma iohexol clearance in 2007–2009 (n=1627), 2013–2015 (n=1324), and 2018–2020 (n=1384). At each study visit, healthy persons were defined as having no major chronic diseases or risk factors for CKD. We used generalized additive mixed models to assess age- and sex-specific GFR decline rates.

Women had a lower GFR than men at baseline (mean [SD], 90.0 [14.0] versus 98.0 [13.7] ml/min per 1.73 m²; P<0.001). The mean GFR change rate was –0.96 (95% confidence interval [CI], –0.88 to –1.04) ml/min per 1.73 m² per year in women and –1.20 (95% confidence interval [CI], –1.12 to –1.28) in men. Although the relationship between age and GFR was very close to linear in women, it was curvilinear in men, with steeper GFR slopes at older ages (nonlinear effect; P<0.001). Healthy persons had a slower GFR decline, but health status did not explain the sex difference in the GFR decline.

Among middle-aged and elderly individuals in the general population, decline in the mean GFR in women was slower than in men, independent of health status.

慢性肾病在女性中更为常见，但更多男性因肾衰竭而接受肾脏替代治疗。这种明显的矛盾并没有得到很好的理解。

我们调查了肾功能丧失的性别差异，以及是否存在任何性别差异可以通过合并症或 CKD 危险因素来解释。在北欧的肾脏碘海醇清除率调查 (RENIS) 中，我们招募了 1837 名代表一般人群（53% 为女性，年龄 50-62 岁）的受试者，他们没有自我报告的糖尿病、慢性肾病或心血管疾病。通过 2007-2009 年 ( n = 1627)、2013-2015 年 ( n = 1324) 和 2018-2020 年 ( n = 1384) 的血浆碘海醇清除率测量参与者的 GFR 。在每次研究访问中，健康人被定义为没有重大慢性疾病或 CKD 危险因素。我们使用广义加性混合模型来评估特定年龄和性别的 GFR 下降率。

基线时，女性的 GFR 低于男性（平均 [SD]，每 1.73 m 2 90.0 [14.0] vs 98.0 [13.7] ml/min ^； P < 0.001）。女性的平均 GFR 变化率为每年每 1.73 m ² –0.96（95% 置信区间 [CI]，–0.88 至 –1.04）ml/min，以及 –1.20（95% 置信区间 [CI]，–1.12 至 – 1.28) 男性。虽然年龄和 GFR 之间的关系在女性中非常接近线性，但在男性中却呈曲线关系，年龄较大时 GFR 斜率更陡（非线性效应；P <0.001）。健康人的 GFR 下降较慢，但健康状况并不能解释 GFR 下降的性别差异。

在一般人群的中老年人中，女性平均 GFR 的下降速度慢于男性，与健康状况无关。