Clinical Features and Associated Factors of Asymptomatic Nephrolithiasis/Nephrocalcinosis in Primary Aldosteronism

Abstract

Background Urinary calculi in primary aldosteronism (PA) have been studied almost only in case reports, and most of which have been reported to be associated with nephrolithiasis. Literature review demonstrates that there are few reports on the prevalence, clinical characteristics and possible causative factors of asymptomatic nephrolithiasis/nephrocalcinosis in PA. Objective To investigate clinical features and possible causative factors of asymptomatic nephrolithiasis/nephrocalcinosis in primary aldosteronism patients in Sichuan. Methods In this retrospective study, we enrolled 147 PA patients from Department of Endocrinology, Sichuan Provincial People's Hospital from January 2017 to April 2021, including 34 also with asymptomatic nephrolithiasis/nephrocalcinosis and 113 patients with PA alone. Clinical data were collected, including sex, age, duration of hypertension, duration of hypokalemia, the lowest serum potassium level in medical history, abnormal glucose metabolism, smoking history, drinking history, systolic blood pressure at admission, diastolic blood pressure at admission, body mass index, waist circumference, estimated glomerular filtration rate (eGFR) , fasting blood glucose, serum uric acid, total protein, albumin, potassium, sodium, calcium, magnesium, phosphorus, carbon dioxide, pH value, bicarbonate (HCO3) , total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, and glycated hemoglobin, plasma aldosterone concentration, direct renin concentration, and aldosterone-renin ratio in upright posture, serum 25 hydroxyvitamin D, and parathyroid hormone (PTH) , 24-hour urinary electrolyte excretion (K, Na, Ca, Mg, P) , urine microalbumin to creatinine ratio, and urinary pH value. Binary Logistic regression analysis was used to explore the independent risk factors of asymptomatic nephrolithiasis/nephrocalcinosis in PA. Results Compared with patients with PA alone, those also with asymptomatic nephrolithiasis/nephrocalcinosis had higher proportion of males, previous or current smokers, and previous or current drinkers, higher mean levels of serum pH value, HCO3 and PTH, longer mean duration of hypertension, as well as lower eGFR (P<0.05) . Binary Logistic regression analysis showed that serum PTH level〔OR=1.009, 95%CI (1.001, 1.017) , P=0.034〕 was associated with asymptomatic nephrolithiasis/nephrocalcinosis in PA. Conclusion Clinical features manifested by PA patients with asymptomatic nephrolithiasis/nephrocalcinosis are as follows: male predominate, longer duration of hypertension, higher rates of smoking and alcohol consumption, and higher serum pH, HCO3 and PTH levels. Elevated serum PTH level or secondary hyperparathyroidism may be associated with increased risk of asymptomatic nephrolithiasis/nephrocalcinosis in PA.

Keywords

• hyperaldosteronism|kidney calculi|nephrocalcinosis|disease attributes|root cause analysis