Aldosteronism increases risk for metabolic syndrome, adverse events

Aldosterone excess appears more damaging than essential hypertension.

Issue: January 2006

Francesco Fallo, MD [photo]
Francesco Fallo

Aldosterone excess was found to have a negative effect on glucose metabolism, and increases the risk of metabolic syndrome and subsequent adverse cardiovascular events.

Research has shown that metabolic syndrome and its component characteristics are more prominent in hypertensive than in normotensive individuals. Aldosterone has also been shown to be a cardiovascular risk factor; researchers wrote in the Journal of Clinical Endocrinology and Metabolism that “aldosterone excess may lead to cardiovascular damage involving mechanisms independent of its effect on blood pressure.”

Francesco Fallo, MD, of the University of Padova in Italy, led a study assessing the prevalence and characteristics of metabolic syndrome in patients with hypertension due to aldosteronism and others with essential hypertension.

Study cohort

Researchers enrolled a total of 466 hypertensive patients divided into two groups: 85 patients had primary aldosteronism and 381 patients had essential hypertension. There were no significant differences between the two groups with regard to age and gender.

Patients in the aldosteronism group had higher mean blood glucose (P<.05) and systolic blood pressure levels (P<.01) than patients in the essential hypertension group; duration of hypertension was also longer in the aldosteronism group (P<.05).

Left ventricular hypertrophy was more frequent in primary aldosteronism than in essential hypertension (P<.05). In both univariate and multivariate analyses, only systolic blood pressure and duration of hypertension were associated with left ventricular hypertrophy.

Thirty-five patients with primary aldosteronism had metabolic syndrome as well (41.1%); a lower percentage of patients with essential hypertension had metabolic syndrome (29.6%; P<.05).

The presence of hyperglycemia was higher among patients in the aldosteronism group (27.0% vs. 15.2%; P<.05), as was the presence of diabetes mellitus (8.2% vs. 3.4%; P<.05).

In patients with primary aldosteronism, high waist circumference occurred more frequently than the other individual components of metabolic syndrome, followed by hypertriglyceridemia, high fasting plasma glucose and low HDL cholesterol. This was similar in the essential hypertension group with the exception of high fasting glucose, which occurred less frequently than low HDL cholesterol.

Prevalence of metabolic syndrome

“Analyzing the order of prevalence of each component of the metabolic syndrome, high waist circumference was the most frequent in both essential hypertension and primary aldosteronism,” the investigators wrote.

“Therefore, in our patients the higher prevalence of the metabolic syndrome in primary aldosteronism than in essential hypertension was mainly due to the association of hypertension, hyperglycemia and high waist circumference.”

The researchers suggested that aldosterone overproduction could induce an elevation in blood glucose, which would increase the probability of metabolic syndrome.

Left ventricular hypertrophy was more prominent in primary aldosteronism than in essential hypertension, but there was no difference in left ventricular hypertrophy between patients with and without metabolic syndrome.

“Systolic hypertension as the component of the metabolic syndrome most strongly associated with left ventricular hypertrophy in primary aldosteronism does not exclude that aldosterone may act as a cardiovascular risk factor through mechanisms independent from cardiac cell hypertrophy and hyperplasia.

“Our findings confirm a negative effect of aldosterone excess on glucose metabolism and suggest that the recently reported higher rates of cardiovascular events in primary aldosteronism than in essential hypertension might be due to increased prevalence of the metabolic syndrome in the former condition,” investigators wrote. – by Dave Levitan

For more information:

Fallo F, Veglio F, Bertello C, et al. Prevalence and characteristics of the metabolic syndrome in primary aldosteronism. J Clin Endocrinol Metab. 2006;91:454-459.