High Prevalence of Diabetes in Patients With Primary Aldosteronism

Prevalence of diabetes is higher in patients with primary aldosteronism and was found to be related to suspected subclinical hypercortisolism, according to study results published in Diabetes Care.

Researchers evaluated the prevalence of glucose intolerance and its association with aldosterone concentration, hypokalemia, and subclinical hypercortisolism in patients with primary aldosteronism. Patients with diagnosed primary aldosteronism had clinical evaluations and biochemical sampling analyzed retrospectively. Diabetes was defined as having hemoglobin A1c ≥6.5%, subclinical hypercortisolism was defined as having serum cortisol ≥1.8 µg/dL after a 1-mg dexamethasone suppression test, and primary aldosteronism subtypes were defined using a lateralized aldosterone-to-cortisol ratio. The prevalence and characteristics of glucose metabolism disturbances were compared with the general population and within subclassifications of primary aldosteronism.

Of 2210 patients included in this study, 1134 were women, the average body mass index (BMI) was 24.9 kg/m², the average age was 53.5 years, 21.6% met the criteria for diabetes, and 28.4% met the criteria for prediabetes. The overall prevalence of diabetes in the general Japanese population is 12.1%.

After logistic regression analysis, subclinical hypercortisolism, age, and BMI were significantly associated with the prevalence of diabetes (P <.001). When comparing patients based on subclassifications of primary aldosteronism, patients with unilateral characteristics (n = 505) had higher plasma aldosterone concentration and aldosterone-to-renin ratios and lower plasma renin activity and serum potassium concentrations (P <.001 for all). Patients with bilateral characteristics (n = 881) had higher hemoglobin A1c values (P <.001) and BMI (P =.018) compared with patients who had unilateral primary aldosteronism. In addition, patients with bilateral primary aldosteronism had a higher prevalence of prediabetes than patients with unilateral primary aldosteronism (41.3% vs 30.5%; P <.001).

Limitations to this study included the small population sizes in the subgroup analysis, use of data collected only before treatment began for primary aldosteronism, and potential variation in overnight 1-mg dexamethasone suppression test protocol, which could have led to false-positive data.

Researchers concluded “that individuals with [primary aldosteronism] are prone to developing diabetes independent of age and sex, but dependent on BMI or [subclinical hypercortisolism].”

Reference

Akehi Y, Yanase T, Motonaga R, et al. High prevalence of diabetes in patients with primary aldosteronism (PA) associated with subclinical hypercortisolism and prediabetes more prevalent in bilateral than unilateral PA: a large, multicenter cohort study in Japan. Diabetes Care. 2019;42(5):938-945.