Prevalence of and risk factors for primary aldosteronism among patients with resistant hypertension in China

Department of Endocrinology and Metabolism, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital Affiliated to Shanghai Jiao-Tong University School of Medicine, Shanghai, China.
Journal of Hypertension (Impact Factor: 4.22). 07/2013; 31(7):1465-71; discussion 1471-2. DOI: 10.1097/HJH.0b013e328360ddf6
Source: PubMed

ABSTRACT It is estimated that there are more than 16 million adults with drug-resistant hypertension in China. Nevertheless, the prevalence of and risk factors for primary aldosteronism, a highly curable condition among adults with drug-resistant hypertension, has not been fully investigated.
Between January 2010 and October 2011, a multicenter epidemiologic study was conducted among 1656 patients with resistant hypertension in 11 provinces of China. Serum aldosterone and plasma renin activity were measured in every participant and aldosterone-to-renin ratio (ARR) was calculated. Patients with ARR more than 20 underwent an intravenous (i.v.) sodium infusion test, and diagnosis of primary aldosteronism was established by the presence of unsuppressed postinfusion aldosterone (>8 ng/dl). Patients with biochemically proved primary aldosteronism then underwent adrenal computed tomography (CT) scanning and adrenal vein sampling (AVS) for subtype classification.
Among the 1656 patients, 494 (29.8%) had ARR greater than 20 and underwent i.v. sodium infusion. Of these 494, 118 were diagnosed as primary aldosteronism, yielding a prevalence of 7.1% (95% confidential interval 5.9-8.3%). Seventy of the 118 patients were categorized into unilateral (39) and bilateral (31) by AVS. Generalized additive regression analysis revealed that among all the factors investigated (age of hypertension onset, BMI, family history of hypertension, cigarette smoking, alcohol consumption, diabetes, serum potassium, hyperlipidemia, and creatinine), only age of hypertension onset and serum potassium were independently associated with the presence of primary aldosteronism.
The prevalence of primary aldosteronism among Chinese patients with resistant hypertension is relatively lower than that reported previously for other ethnic populations. The screening for primary aldosteronism should be focused on those with early onset hypertension and/or hypokalemia.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives To develop algorithms of locating patients with primary aldosteronism (PA) using insurance reimbursement data and to validate the algorithms using medical charts. Study Design and Setting We extracted National Health Insurance (NHI) reimbursement data and medical charts in seven enrolled hospitals and analyzed diagnosis-related information for 1999–2010. The NHI codes PA as 255.1x, using the International Classification of Diseases, Ninth Revision, Clinical Modification. Confirmation of PA was based on suppression tests. Results We reviewed medical charts for 1,094 cases with at least one PA diagnosis. PA was confirmed for 563 cases. Compared with patients with essential hypertension, PA patients had higher systolic blood pressure, higher aldosterone, lower renin activity, and lower potassium level (all P-values <0.05). An algorithm based on PA diagnosis reported in at least one hospital stay or three outpatient visits had modest performance (sensitivity = 0.94 and specificity = 0.20). The best additional condition for the algorithm was use of mineralocorticoid receptor antagonist (MRA; sensitivity = 0.89 and specificity = 0.88). Conclusion Using information on PA diagnosis and MRA prescription reported in insurance claims data can precisely locate PA patients in high-risk groups. This algorithm can construct a reliable PA sample for conducting research in various fields, including epidemiology and clinical practice.
    Journal of Clinical Epidemiology 10/2014; 67(10). DOI:10.1016/j.jclinepi.2014.05.012 · 5.48 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Endocrine hypertension is an important secondary form of hypertension, identified in between 5% and 10% of general hypertensive population. Primary aldosteronism is the most common cause of endocrine hypertension, accounting for 1%-10% in uncomplicated hypertension and 7%-20% in resistant hypertension. Other less common causes of endocrine hypertension include Cushing syndrome, pheochromocytoma, thyroid disorders, and hyperparathyroidism. Diagnosis requires a high index of suspicion and the use of appropriate screening tests based on clinical presentation. Failure to make proper diagnosis may lead to catastrophic complications or irreversible hypertensive target organ damage. Accordingly, patients who are suspected to have endocrine hypertension should be referred to endocrinologists or hypertension specialists who are familiar with management of the specific endocrine disorders.
    Current Cardiology Reports 09/2014; 16(9):528. DOI:10.1007/s11886-014-0528-x
  • [Show abstract] [Hide abstract]
    ABSTRACT: Resistant hypertension-uncontrolled hypertension with 3 or more antihypertensive agents-is increasingly common in clinical practice. Clinicians should exclude pseudoresistant hypertension, which results from nonadherence to medications or from elevated blood pressure related to the white coat syndrome. In patients with truly resistant hypertension, thiazide diuretics, particularly chlorthalidone, should be considered as one of the initial agents. The other 2 agents should include calcium channel blockers and angiotensin-converting enzyme inhibitors for cardiovascular protection. An increasing body of evidence has suggested benefits of mineralocorticoid receptor antagonists, such as eplerenone and spironolactone, in improving blood pressure control in patients with resistant hypertension, regardless of circulating aldosterone levels. Thus, this class of drugs should be considered for patients whose blood pressure remains elevated after treatment with a 3-drug regimen to maximal or near maximal doses. Resistant hypertension may be associated with secondary causes of hypertension including obstructive sleep apnea or primary aldosteronism. Treating these disorders can significantly improve blood pressure beyond medical therapy alone. The role of device therapy for treating the typical patient with resistant hypertension remains unclear.
    JAMA The Journal of the American Medical Association 06/2014; 311(21):2216-2224. DOI:10.1001/jama.2014.5180 · 30.39 Impact Factor