Improvement of hypercortisolism by ß-blocker therapy in subclinical Cushing's syndrome associated with ACTH-independent macronodular adrenocortical hyperplasia.

A 61-year-old man with hypertension and diabetes was referred for the evaluation of multiple bilateral adrenal tumors. While Cushingoid features were not apparent, an elevated cortisol level in response to a low-dose dexamethasone suppression test (187.7 nmol/l), an elevated urinary cortisol level (170.9 nmol/day), and a weak response to a cosyntropin-releasing hormone (CRH) provocation test were observed. Furthermore, the serum cortisol level increased in response to a posture test or isoproterenol infusion. Accordingly, the patient was diagnosed as having ACTH-independent macronodular adrenal hyperplasia (AIMAH) with subclinical Cushing's syndrome associated with the aberrant expression of ß-adrenergic receptors. After 2 months of propranolol therapy, the serum cortisol responses to a posture test and isoproterenol infusion, the cortisol level in response to a low-dose dexamethasone suppression test (102.1 nmol/l), and the urinary cortisol level (165.9 nmol/day) all normalized. While the suppression of cortisol secretion was sustained for 24 months, glucose metabolism and adrenal size were unaffected. To our knowledge, this is the first report of AIMAH accompanied by subclinical Cushing's syndrome associated with the aberrant expression of ß-adrenergic receptors. Furthermore, propranolol inhibited cortisol hypersecretion in the present case. Additional cases or controlled studies are needed to determine the potential effect of propranolol on metabolic disorders and adrenal size in patients with AIMAH.

Prevalence of metabolic syndrome compared between native Japanese and Japanese-Americans.

Metabolic syndrome is a condition characterized by the accumulation of multiple risk factors for atherosclerosis. Japanese-Americans in the U.S. have a more rapid and intense progression of atherosclerosis than native Japanese in Japan due to a westernization of their lifestyle. We investigated the prevalence of metabolic syndrome between 416 native Japanese (194 men and 222 women) in Hiroshima and 574 Japanese-Americans (217 men and 357 women) in Los Angeles, aged 30-89 years. According to the criteria proposed by the Japanese Society of Internal Medicine, the prevalence was 13.9 and 2.7% for native Japanese men and women, and 32.7 and 3.4% for Japanese-American men and women, respectively. According to the IDF or AHA/NHLBI criteria, the prevalence was 20.1 and 6.3%, and 38.7 and 4.5%, or 13.4 and 14.4%, and 30.9 and 27.7%, respectively. Thus, the prevalence of metabolic syndrome in men was significantly higher in Japanese-American than in native Japanese by all the three criteria. However, the prevalence in women was similar between native Japanese and Japanese-American by the Japanese and IDF criteria, whereas it was significantly higher in Japanese-American than in native Japanese by the AHA/NHLBI criteria. This report demonstrates that a westernization of lifestyle can increase the prevalence of metabolic syndrome among Japanese-Americans as compared to native Japanese.

Association of Chlamydia pneumoniae infection and carotid intima-media wall thickness in Japanese Americans.

BACKGROUND: Chlamydia pneumoniae (Cp) infection has been proposed as a risk factor for coronary artery disease (CAD), but it remains unclear whether Cp plays a role in the progression of early stage carotid atherosclerosis. METHODS AND RESULTS: The associations among Cp IgG/IgA antibodies, inflammation markers such as C-reactive protein (CRP) and interleukin (IL)-6, and the maximal progression of carotid intima-media wall thickness (max IMT) were evaluated using ultrasonography in 259 Japanese Americans. The presence of Cp IgG or IgA antibodies itself did not show significant correlation with max IMT after adjustment for age and sex. However, in the Cp IgG seropositive group, the subjects with high IL-6 levels showed more pronounced max IMT progression than those with low IL-6 levels after adjustment of the other CAD risk factors. Moreover, in the Cp IgA seropositive group, the subjects with high CRP or IL-6 levels had significantly higher levels of max IMT compared with those with low CRP or IL-6. CONCLUSIONS: The results support the hypothesis that a chronic latent Cp infection with inflammation might accelerate the development of early stage atherosclerotic lesions.