Adiponectin and insulin sensitivity in primary aldosteronism.
BACKGROUND
A high prevalence of metabolic syndrome has been reported in primary aldosteronism. Low levels of adiponectin, an adipokine with insulin-sensitizing properties, are considered a hallmark of the metabolic syndrome. We evaluated the relationship between adiponectin and insulin sensitivity in primary aldosteronism, with and without metabolic syndrome, compared with essential hypertension.


METHODS
Forty patients with primary aldosteronism and 40 matched patients with low-renin essential hypertension (LREH) were studied. Patients with type 2 diabetes were excluded. Each group was divided into two subsets: one including patients with metabolic syndrome and one including patients without metabolic syndrome (ie, hypertension alone or associated with another component of the syndrome).


RESULTS
Insulin resistance, defined by increased homeostasis model assessment (HOMA index), was higher in patients with primary aldosteronism than in those with LREH only in the absence of metabolic syndrome (P<.01), whereas in the subsets bearing the syndrome it was similar. Adiponectin levels were lower in primary aldosteronism than in patients with LREH (P<.01). Like HOMA index, the difference was maintained (P<.01) only in the subsets without metabolic syndrome. Adiponectin levels were inversely correlated with HOMA index and positively correlated with potassium levels both in primary aldosteronism (P<.001) or in LREH (P<.05) groups.


CONCLUSIONS
Lower adiponectin as well as lower insulin sensitivity in primary aldosteronism compared with LREH seem to result from both direct (aldosterone excess) and indirect (hypokalemia) mechanisms. Therapeutic interventions aimed at correcting both potassium and adiponectin levels by specific antihypertensive agents might improve insulin sensitivity, providing better cardiovascular protection in primary aldosteronism.
Department of Medical and Surgical Sciences, University of Padova, Padova, Italy. francesco.fallo@unipd.it
Francesco
F
Fallo
Paolo
P
Della Mea
Nicoletta
N
Sonino
Chiara
C
Bertello
Mario
M
Ermani
Roberto
R
Vettor
Franco
F
Veglio
Paolo
P
Mulatero
D052242:Adiponectin / Q000097:blood*; D000450:Aldosterone / Q000097:blood; D015415:Biomarkers / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood* / Q000150:complications; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D008163:Luminescent Measurements; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D011863:Radioimmunoassay; D012044:Regression Analysis; D012307:Risk Factors
D052242:Adiponectin; D015415:Biomarkers; D007328:Insulin; D000450:Aldosterone; D011188:Potassium