Miyahara Hiroyuki, Shigeyasu Yoshie, Fujii Chikako, Tanaka Chie, Hanzawa Mana, Sugihara Akiko, Okada Ayumi, Tsukahara Hirokazu
Department of Clinical Pediatrics, Okayama University Academic Field of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-Cho, Kita-Ku, Okayama, 700-8558, Japan.
Department of Pediatrics, Okayama University Hospital, 2-5-1 Shikata-Cho, Kita-Ku, Okayama, 700-8558, Japan.
Biopsychosoc Med. 2024 Sep 29;18(1):19. doi: 10.1186/s13030-024-00316-6.
A decreased glomerular filtration rate (GFR), estimated using creatinine (Cr- eGFR), is often found at the initial presentation of anorexia nervosa (AN). Its pathophysiology has been explained mainly by dehydration, and chronic hypokalemia is also thought to be a cause. However, because we have often experienced cases of AN with decreased Cr-eGFR without these conditions, we must consider different etiologies. The focus of this paper is on low free triiodothyronine (FT3) syndrome. We also discuss the utility of eGFR, estimated using cystatin-C (CysC-eGFR), for these patients.
The data of 39 patients diagnosed with AN between January 2005 and December 2023 was available for study. The characteristics of patients at the lowest and highest body mass index standard deviation score (BMI-SDS) were examined. Data on the parameters Cr-eGFR, CysC-eGFR, dehydration markers, potassium (K), and hormonal data and BMI-SDS were assessed during the treatment course to evaluate the correlations in these parameters. Blood hematocrit, uric acid (UA), blood urine nitrogen (BUN) level, and urine specific gravity were adopted as dehydration markers; FT3, free thyroxine, thyroid stimulating hormone, and insulin-like growth factor were adopted as hormonal data. Cr-eGFR and simultaneously evaluated dehydration markers, K, or hormonal data were extracted and correlations associated with the changes in BMI-SDS were examined. Furthermore, Cr-eGFR and simultaneously assessed CysC-eGFR were compared.
When the BMI-SDS was at the lowest value, low-FT3 syndrome was shown. Severe hypokalemia was not found in our study. A linear relation was not found between Cr-eGFR and BMI-SDS. A statistically significant correlation was found between Cr-eGFR and FT3 (p = 0.0025). Among the dehydration markers, statistically significant correlations were found between Cr-eGFR and BUN or UA. The difference between Cr-eGFR and CysC-eGFR was prominent, and CysC-eGFR showed much higher values.
Our data indicates that low-FT3 syndrome and dehydration were related to the renal function of our patients with AN. Furthermore, our data suggest that caution is needed in the interpretation of kidney function evaluation when using CysC-eGFR in cases of AN.
在神经性厌食症（AN）初诊时，常发现使用肌酐估算的肾小球滤过率（Cr - eGFR）下降。其病理生理学主要由脱水解释，慢性低钾血症也被认为是一个原因。然而，由于我们经常遇到没有这些情况但Cr - eGFR下降的AN病例，我们必须考虑不同的病因。本文重点关注低游离三碘甲状腺原氨酸（FT3）综合征。我们还讨论了使用胱抑素C估算的eGFR（CysC - eGFR）对这些患者的实用性。
研究纳入了2005年1月至2023年12月期间诊断为AN的39例患者的数据。检查了最低和最高体重指数标准差评分（BMI - SDS）时患者的特征。在治疗过程中评估Cr - eGFR、CysC - eGFR、脱水标志物、钾（K）、激素数据和BMI - SDS等参数的数据，以评估这些参数之间的相关性。采用血细胞比容、尿酸（UA）、血尿素氮（BUN）水平和尿比重作为脱水标志物；采用FT3、游离甲状腺素、促甲状腺激素和胰岛素样生长因子作为激素数据。提取Cr - eGFR以及同时评估的脱水标志物、K或激素数据，并检查与BMI - SDS变化相关的相关性。此外，比较Cr - eGFR和同时评估的CysC - eGFR。
当BMI - SDS处于最低值时，出现低FT3综合征。在我们的研究中未发现严重低钾血症。未发现Cr - eGFR与BMI - SDS之间存在线性关系。发现Cr - eGFR与FT3之间存在统计学显著相关性（p = 0.0025）。在脱水标志物中，发现Cr - eGFR与BUN或UA之间存在统计学显著相关性。Cr - eGFR与CysC - eGFR之间的差异显著，CysC - eGFR显示出更高的值。
我们的数据表明，低FT3综合征和脱水与我们的AN患者的肾功能有关。此外，我们的数据表明，在AN病例中使用CysC - eGFR评估肾功能时，在解释结果时需要谨慎。
