Predicting Masked Renal Insufficiency in Aldosteronism
Predicting Masked Renal Insufficiency in Aldosteronism
Forty-five patients with unilateral PA who were treated with unilateral adrenalectomy from 2006 to 2013 and followed for at least 1 month after surgery at the Kyoto Medical Center, Fukushima Medical University Hospital, St. Marianna University School of Medicine, Kyusyu Medical Center, Okazaki City Hospital or Matsuyama Red Cross Hospital were enrolled. Thirty-four of 45 patients were followed for 6 months and 25 of 45 were followed for up to 12 months after surgery. The diagnosis of PA was confirmed using the captopril challenge test (judged to be positive with a PAC/PRA ratio >20 after captopril administration), furosemide upright test (judged to be positive with PRA<2·0 ng/ml/h after furosemide loading) or saline infusion test (judged to be positive with postloading PAC >6·0 ng/dl), as recommended by the guidelines from the Japanese Society of Hypertension and the Japan Endocrine Society. Subtype testing and lateralization of aldosterone excess was determined by adrenal venous sampling in 40 of the patients (88·9%) and by adrenal scintigraphy in 5 (11·1%) if adrenal venous sampling was not applicable. All the tumours identified in this study were consistent with the diagnosis of adrenocortical adenoma. Thirty-one patients with various non-PA adrenal diseases who underwent unilateral adrenalectomy (5 nonfunctioning adenomas, 1 myelolipoma, 1 ganglioneuroma, 5 metastatic tumours, 5 subclinical Cushing syndrome, 8 Cushing syndrome and 6 pheochromocytoma) and followed for at least 1 month after surgery were also studied as control.
The eGFR values were obtained using the following equation: eGFR (ml/min/1·73 m) = 194 × (serum creatinine) × (age) × 0·739 (if female). Patients with a pre-operative eGFR < 60 ml/min/1·73 m were excluded from both groups. Both PAC and PRA were measured by RIA. Although the outsourcing laboratories were different, the reference values for PAC and PRA were practically the same (PAC under supine position: 3·0–15·9 ng/dl; PRA under supine position: 0·2–2·7 in one centre and 0·3–2·9 ng/ml/h in the other centre).
The variables studied included age, gender, body mass index (BMI), estimated duration of hypertension, the presence of diabetes mellitus, blood pressure, number of antihypertensive agents, antihypertensive treatment score (the summed percentages of the maximum recommended daily doses for the antihypertensive agents), eGFR, serum potassium, plasma aldosterone concentration (PAC), plasma renin activity (PRA) and aldosterone-to-renin ratio (ARR). The study was approved by the respective institutional ethics review committees of the participating hospitals.
Continuous variables are expressed as the mean ± standard deviation, if not stated otherwise. Significance of differences between independent groups was determined by the Mann–Whitney U test and Fisher's exact test. Logistic regression analysis was used for univariate and multivariate analyses. A P value < 0·05 was considered to indicate statistical significance. Receiver operating characteristic (ROC) curves were used for setting and evaluating the cut-offs. All statistical analyses were performed using jmp version 5.1 (SAS Institute Inc., Cary, NC, USA), except the comparison of ROC curves, which was conducted with stata (Lightstone Corp., College Station, TX, USA).
Patients and Methods
Forty-five patients with unilateral PA who were treated with unilateral adrenalectomy from 2006 to 2013 and followed for at least 1 month after surgery at the Kyoto Medical Center, Fukushima Medical University Hospital, St. Marianna University School of Medicine, Kyusyu Medical Center, Okazaki City Hospital or Matsuyama Red Cross Hospital were enrolled. Thirty-four of 45 patients were followed for 6 months and 25 of 45 were followed for up to 12 months after surgery. The diagnosis of PA was confirmed using the captopril challenge test (judged to be positive with a PAC/PRA ratio >20 after captopril administration), furosemide upright test (judged to be positive with PRA<2·0 ng/ml/h after furosemide loading) or saline infusion test (judged to be positive with postloading PAC >6·0 ng/dl), as recommended by the guidelines from the Japanese Society of Hypertension and the Japan Endocrine Society. Subtype testing and lateralization of aldosterone excess was determined by adrenal venous sampling in 40 of the patients (88·9%) and by adrenal scintigraphy in 5 (11·1%) if adrenal venous sampling was not applicable. All the tumours identified in this study were consistent with the diagnosis of adrenocortical adenoma. Thirty-one patients with various non-PA adrenal diseases who underwent unilateral adrenalectomy (5 nonfunctioning adenomas, 1 myelolipoma, 1 ganglioneuroma, 5 metastatic tumours, 5 subclinical Cushing syndrome, 8 Cushing syndrome and 6 pheochromocytoma) and followed for at least 1 month after surgery were also studied as control.
The eGFR values were obtained using the following equation: eGFR (ml/min/1·73 m) = 194 × (serum creatinine) × (age) × 0·739 (if female). Patients with a pre-operative eGFR < 60 ml/min/1·73 m were excluded from both groups. Both PAC and PRA were measured by RIA. Although the outsourcing laboratories were different, the reference values for PAC and PRA were practically the same (PAC under supine position: 3·0–15·9 ng/dl; PRA under supine position: 0·2–2·7 in one centre and 0·3–2·9 ng/ml/h in the other centre).
The variables studied included age, gender, body mass index (BMI), estimated duration of hypertension, the presence of diabetes mellitus, blood pressure, number of antihypertensive agents, antihypertensive treatment score (the summed percentages of the maximum recommended daily doses for the antihypertensive agents), eGFR, serum potassium, plasma aldosterone concentration (PAC), plasma renin activity (PRA) and aldosterone-to-renin ratio (ARR). The study was approved by the respective institutional ethics review committees of the participating hospitals.
Statistics
Continuous variables are expressed as the mean ± standard deviation, if not stated otherwise. Significance of differences between independent groups was determined by the Mann–Whitney U test and Fisher's exact test. Logistic regression analysis was used for univariate and multivariate analyses. A P value < 0·05 was considered to indicate statistical significance. Receiver operating characteristic (ROC) curves were used for setting and evaluating the cut-offs. All statistical analyses were performed using jmp version 5.1 (SAS Institute Inc., Cary, NC, USA), except the comparison of ROC curves, which was conducted with stata (Lightstone Corp., College Station, TX, USA).