This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Loh, K.-C. Articles by Young, W. F. Search for Related Content PubMed PubMed Citation Articles by Loh, K.-C. Articles by Young, W. F., Jr.

Prevalence of Primary Aldosteronism among Asian Hypertensive Patients in Singapore¹

Endocrine Unit, Department of Medicine, Tan Tock Seng Hospital (K.-C.L.); Department of Pathology, National University of Singapore (E.S.K., M.-C.K.); and Family Health Service, Ministry of Health (S.C.E.), Republic of Singapore; and Department of Medicine, Mayo Clinic (W.F.Y.), Rochester, Minnesota 55905

Address all correspondence and requests for reprints to: Dr. Keh-Chuan Loh, Endocrine Unit, Department of Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Republic of Singapore. E-mail: keh_chuan_loh{at}notes.ttsh.gov.sg

Recent studies using the ratio of plasma aldosterone concentration (PAC) to PRA as the screening test for primary aldosteronism in hypertensive populations suggested that the prevalence may be as high as 5–15%, with well over half of the subjects having normal serum potassium concentrations. Despite an increasing clinical awareness of this entity, many clinicians are reluctant to consider routine screening for primary aldosteronism in essential hypertensive patients because there are few community-based prevalence studies of primary aldosteronism in different populations. Furthermore, genetic and environmental differences may affect the prevalence and presentation of primary aldosteronism in distinct populations.

This study was designed to determine the prevalence of primary aldosteronism in the predominantly Chinese population in Singapore. Three hundred and fifty unselected adult hypertensive patients attending two primary care clinics had random ambulatory measurements for PAC (nanograms per dL) and PRA (nanograms per mL/h). Serum urea, creatinine, and electrolyte measurements were obtained simultaneously. Subjects with renal insufficiency (serum creatinine, >140 µmol/L) and those treated with glucocorticoids or spironolactone were excluded. Screening was considered positive if the PAC:PRA ratio was more than 20 and the PAC was more than 15 ng/dL (>416 pmol/L). Primary aldosteronism was confirmed with the determination of PAC after 2 L saline administered iv over 4 h. Adrenal computed tomographic (CT) scans were performed in biochemically confirmed cases of primary aldosteronism. Further localization with adrenal vein sampling was carried out in selected patients with equivocal findings on adrenal CT scan.

Sixty-three (18%) of the 350 hypertensive patients (215 women and 135 men; age range, 23–75 yr) were screened positive for primary aldosteronism. Only 13 of these 63 subjects (21%) were hypokalemic (serum potassium, <3.5 mmol/L). Confirmatory studies were carried out in 56 (89%) of the subjects with a positive PAC:PRA ratio. Using a PAC above 10 ng/dL (>277 pmol/L) after saline infusion as the diagnostic cut-off, 16 of the 56 patients had biochemically confirmed primary aldosteronism. Hypokalemia was found in 6 of the 16 patients (37.5%) with primary aldosteronism. Subtype evaluation with adrenal CT scan and adrenal vein sampling indicated that half of the patients with primary aldosteronism may have had potentially curable unilateral adrenal adenoma.

Our data suggest that primary aldosteronism occurs in at least 5% of the adult Asian hypertensive population, and approximately half of these individuals may have potentially curable, unilateral, aldosterone-producing adrenal adenoma. Our findings also confirm the poor predictive value of hypokalemia in both the diagnosis and the exclusion of primary aldosteronism.

This article has been cited by other articles:

				E. Born-Frontsberg, M. Reincke, L. C. Rump, S. Hahner, S. Diederich, R. Lorenz, B. Allolio, J. Seufert, C. Schirpenbach, F. Beuschlein, et al. Cardiovascular and Cerebrovascular Comorbidities of Hypokalemic and Normokalemic Primary Aldosteronism: Results of the German Conn's Registry J. Clin. Endocrinol. Metab., April 1, 2009; 94(4): 1125 - 1130. [Abstract] [Full Text] [PDF]

				J. W. Funder, R. M. Carey, C. Fardella, C. E. Gomez-Sanchez, F. Mantero, M. Stowasser, W. F. Young Jr., and V. M. Montori Case Detection, Diagnosis, and Treatment of Patients with Primary Aldosteronism: An Endocrine Society Clinical Practice Guideline J. Clin. Endocrinol. Metab., September 1, 2008; 93(9): 3266 - 3281. [Abstract] [Full Text] [PDF]

				E. Pimenta, K. K. Gaddam, M. N. Pratt-Ubunama, M. K. Nishizaka, I. Aban, S. Oparil, and D. A. Calhoun Relation of Dietary Salt and Aldosterone to Urinary Protein Excretion in Subjects With Resistant Hypertension Hypertension, February 1, 2008; 51(2): 339 - 344. [Abstract] [Full Text] [PDF]

				V.C. Wu, S.C. Chueh, H.W. Chang, W.C. Lin, K.L. Liu, H.Y. Li, Y.H. Lin, K.D. Wu, and B.S. Hsieh Bilateral aldosterone-producing adenomas: differentiation from bilateral adrenal hyperplasia QJM, January 1, 2008; 101(1): 13 - 22. [Abstract] [Full Text] [PDF]

				N. M. Kaplan and D. A. Calhoun Is There an Unrecognized Epidemic of Primary Aldosteronism? (Con) Hypertension, September 1, 2007; 50(3): 454 - 458. [Full Text] [PDF]

				G. E. Umpierrez, P. Cantey, D. Smiley, A. Palacio, D. Temponi, K. Luster, and A. Chapman Primary Aldosteronism in Diabetic Subjects With Resistant Hypertension Diabetes Care, July 1, 2007; 30(7): 1699 - 1703. [Abstract] [Full Text] [PDF]

				M. Stowasser and R. D. Gordon Aldosterone Excess, Hypertension, and Chromosome 7p22: Evidence Continues to Mount Hypertension, April 1, 2007; 49(4): 761 - 762. [Full Text] [PDF]

				M. Barr, S. M. MacKenzie, E. C. Friel, C. D. Holloway, D. M. Wilkinson, N. J.R. Brain, M. C. Ingram, R. Fraser, M. Brown, N. J. Samani, et al. Polymorphic Variation in the 11{beta}-Hydroxylase Gene Associates With Reduced 11-Hydroxylase Efficiency Hypertension, January 1, 2007; 49(1): 113 - 119. [Abstract] [Full Text] [PDF]

				G. P. Rossi, G. Bernini, C. Caliumi, G. Desideri, B. Fabris, C. Ferri, C. Ganzaroli, G. Giacchetti, C. Letizia, M. Maccario, et al. A Prospective Study of the Prevalence of Primary Aldosteronism in 1,125 Hypertensive Patients J. Am. Coll. Cardiol., December 5, 2006; 48(11): 2293 - 2300. [Abstract] [Full Text] [PDF]

				M. Stowasser and R. D. Gordon Aldosterone Assays: An Urgent Need for Improvement Clin. Chem., September 1, 2006; 52(9): 1640 - 1642. [Full Text] [PDF]

				D. A. Calhoun Aldosteronism and Hypertension Clin. J. Am. Soc. Nephrol., September 1, 2006; 1(5): 1039 - 1045. [Abstract] [Full Text] [PDF]

				P. Mulatero, A. Milan, F. Fallo, G. Regolisti, F. Pizzolo, C. Fardella, L. Mosso, L. Marafetti, F. Veglio, and M. Maccario Comparison of Confirmatory Tests for the Diagnosis of Primary Aldosteronism J. Clin. Endocrinol. Metab., July 1, 2006; 91(7): 2618 - 2623. [Abstract] [Full Text] [PDF]

				F. E. Nwariaku, B. S. Miller, R. Auchus, S. Holt, L. Watumull, B. Dolmatch, S. Nesbitt, W. Vongpatanasin, R. Victor, F. Wians, et al. Primary Hyperaldosteronism: Effect of Adrenal Vein Sampling on Surgical Outcome Arch Surg, May 1, 2006; 141(5): 497 - 503. [Abstract] [Full Text] [PDF]

				A. Karagiannis, K. Tziomalos, K. Dona, A. Pyrpasopoulou, N. Kartali, V. Athyros, and C. Zamboulis Bilateral renal artery stenosis and primary aldosteronism in a diabetic patient QJM, December 1, 2005; 98(12): 913 - 915. [Full Text] [PDF]

				N. Daunt Adrenal Vein Sampling: How to Make It Quick, Easy, and Successful RadioGraphics, October 1, 2005; 25(suppl_1): S143 - S158. [Abstract] [Full Text] [PDF]

				M. Stowasser, J. Sharman, R. Leano, R. D. Gordon, G. Ward, D. Cowley, and T. H. Marwick Evidence for Abnormal Left Ventricular Structure and Function in Normotensive Individuals with Familial Hyperaldosteronism Type I J. Clin. Endocrinol. Metab., September 1, 2005; 90(9): 5070 - 5076. [Abstract] [Full Text] [PDF]

				G. L. Schwartz and S. T. Turner Screening for Primary Aldosteronism in Essential Hypertension: Diagnostic Accuracy of the Ratio of Plasma Aldosterone Concentration to Plasma Renin Activity Clin. Chem., February 1, 2005; 51(2): 386 - 394. [Abstract] [Full Text] [PDF]

				S.-C. Tiu, C.-H. Choi, C.-C. Shek, Y.-W. Ng, F. K. W. Chan, C.-M. Ng, and A. P. S. Kong The Use of Aldosterone-Renin Ratio as a Diagnostic Test for Primary Hyperaldosteronism and Its Test Characteristics under Different Conditions of Blood Sampling J. Clin. Endocrinol. Metab., January 1, 2005; 90(1): 72 - 78. [Abstract] [Full Text] [PDF]

				O. Olivieri, A. Ciacciarelli, D. Signorelli, F. Pizzolo, P. Guarini, C. Pavan, A. Corgnati, S. Falcone, R. Corrocher, A. Micchi, et al. Aldosterone to Renin Ratio in a Primary Care Setting: The Bussolengo Study J. Clin. Endocrinol. Metab., September 1, 2004; 89(9): 4221 - 4226. [Abstract] [Full Text] [PDF]

				F. H. Perschel, R. Schemer, L. Seiler, M. Reincke, J. Deinum, C. Maser-Gluth, D. Mechelhoff, R. Tauber, and S. Diederich Rapid Screening Test for Primary Hyperaldosteronism: Ratio of Plasma Aldosterone to Renin Concentration Determined by Fully Automated Chemiluminescence Immunoassays Clin. Chem., September 1, 2004; 50(9): 1650 - 1655. [Abstract] [Full Text] [PDF]

				E. M. Freel and J. M.C. Connell Mechanisms of Hypertension: The Expanding Role of Aldosterone J. Am. Soc. Nephrol., August 1, 2004; 15(8): 1993 - 2001. [Abstract] [Full Text] [PDF]

				P.-F. Plouin, L. Amar, and G. Chatellier Trends in the prevalence of primary aldosteronism, aldosterone-producing adenomas, and surgically correctable aldosterone-dependent hypertension Nephrol. Dial. Transplant., April 1, 2004; 19(4): 774 - 777. [Full Text] [PDF]

				P. Mulatero, M. Stowasser, K.-C. Loh, C. E. Fardella, R. D. Gordon, L. Mosso, C. E. Gomez-Sanchez, F. Veglio, and W. F. Young Jr. Increased Diagnosis of Primary Aldosteronism, Including Surgically Correctable Forms, in Centers from Five Continents J. Clin. Endocrinol. Metab., March 1, 2004; 89(3): 1045 - 1050. [Abstract] [Full Text] [PDF]

				L. Mosso, C. Carvajal, A. Gonzalez, A. Barraza, F. Avila, J. Montero, A. Huete, A. Gederlini, and C. E. Fardella Primary Aldosteronism and Hypertensive Disease Hypertension, August 1, 2003; 42(2): 161 - 165. [Abstract] [Full Text] [PDF]

				W. F. Young Jr. Minireview: Primary Aldosteronism--Changing Concepts in Diagnosis and Treatment Endocrinology, June 1, 2003; 144(6): 2208 - 2213. [Abstract] [Full Text] [PDF]

				D. A. Calhoun, M. K. Nishizaka, M. A. Zaman, R. B. Thakkar, and P. Weissmann Hyperaldosteronism Among Black and White Subjects With Resistant Hypertension Hypertension, December 1, 2002; 40(6): 892 - 896. [Abstract] [Full Text] [PDF]

				P. Mulatero, F. Rabbia, A. Milan, C. Paglieri, F. Morello, L. Chiandussi, and F. Veglio Drug Effects on Aldosterone/Plasma Renin Activity Ratio in Primary Aldosteronism Hypertension, December 1, 2002; 40(6): 897 - 902. [Abstract] [Full Text] [PDF]

				M. Stowasser, R. D Gordon, J. C Rutherford, N. Z Nikwan, N. Daunt, and G. J Slater Review: Diagnosis and management of primary aldosteronism Journal of Renin-Angiotensin-Aldosterone System, September 1, 2001; 2(3): 156 - 169. [PDF]

				A. M. Sawka, W. F. Young Jr., G. B. Thompson, C. S. Grant, D. R. Farley, C. Leibson, and J. A. van Heerden Primary Aldosteronism: Factors Associated with Normalization of Blood Pressure after Surgery Ann Intern Med, August 21, 2001; 135(4): 258 - 261. [Abstract] [Full Text] [PDF]

				C. E. Fardella and L. Mosso Authors' Response: Prevalence of Primary Aldosteronism in Unselected Hypertensive Populations--Screening and Definitive Diagnosis J. Clin. Endocrinol. Metab., August 1, 2001; 86(8): 4003 - 4004. [Full Text] [PDF]