Primary hyperaldosteronism among Chinese hypertensive patients: how are we doing in a local district in Hong Kong.
OBJECTIVE
To estimate the point prevalence of primary hyperaldosteronism in a government out-patient setting and to compare associated patient characteristics with those having essential hypertension.


METHODS
Case series with external comparison.


METHODS
A single public hospital (Caritas Medical Centre) and all five associated general out-patient clinics in Sham Shui Po district in Hong Kong.


METHODS
All patients with confirmed primary hyperaldosteronism and randomly selected patients with essential hypertension from a medical specialist clinic and general out-patient clinics, retrieved from a computer database for the period January 2007 to December 2008.


METHODS
Estimated point prevalence of primary hyperaldosteronism among hypertensive patients treated in the public sector of Sham Shui Po district. Patient age when hypertension was diagnosed, number of antihypertensive drugs used for treatment, and the presence of target organ damage in the patients with primary hyperaldosteronism and those with essential hypertension were compared.


RESULTS
Among the 46 012 patients receiving antihypertensive treatment, 49 were confirmed to have primary hyperaldosteronism. The estimated point prevalence of primary hyperaldosteronism among these hypertensive patients was 0.106% only, which was far smaller than figures from other countries. When compared with the 147 patients with essential hypertension by multivariate analysis, those with primary hyperaldosteronism were: (1) associated with longer durations of hypertension (odds ratio=1.14; 95% confidence interval, 1.06-1.24) despite being younger at the time of study, (2) likely to be taking three or more antihypertensive drugs (odds ratio=2.51; 95% confidence interval, 1.59-3.95), and (3) more likely to have left ventricular hypertrophy (odds ratio=5.01; 95% confidence interval, 1.83-13.69). All primary hyperaldosteronism patients studied presented with hypokalaemia. The need for antihypertensive drugs was markedly reduced after adrenalectomy for adrenal adenoma.


CONCLUSIONS
Primary hyperaldosteronism, which is potentially a surgically curable cause of hypertension, appeared to be underdiagnosed in our locality. Screening by aldosterone-renin ratio of high-risk individuals may help improve patient outcomes.
Department of Family Medicine and Primary Health Care, Kowloon West Cluster, Hong Kong. winniesy@graduate.hku.hk
W M
WM
Sy
S N
SN
Fu
W
W
Luk
Carlos K H
CK
Wong
L M
LM
Fung
D000306:Adrenal Cortex Neoplasms / Q000150:complications* / Q000601:surgery; D000315:Adrenalectomy; D018246:Adrenocortical Adenoma / Q000150:complications* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D044466:Asian People; D005260:Female; D006723:Hong Kong; D006801:Humans; D006929:Hyperaldosteronism / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D006973:Hypertension / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D015995:Prevalence; D012189:Retrospective Studies
D000959:Antihypertensive Agents