Diurnal blood pressure variation in pheochromocytoma, primary aldosteronism and Cushing's syndrome

We examined circadian blood pressure (BP) variation (expressed as a relative night-time BP decline) in subjects with primary aldosteronism (78 patients), pheochromocytoma (n=45) and Cushing's syndrome (n=18). Subjects with aldosterone-producing adenoma (n=21) and pheochromocytoma (n=27) were also investigated after the tumour removal. In all, 65 patients with essential hypertension served as a control group. The night-time BP decline was significantly attenuated in all three forms of endocrine hypertension compared to the control group (primary aldosteronism P<0.0001, pheochromocytoma P<0.0001 for systolic and diastolic BP and Cushing's syndrome P<0.0001/<0.001 vs essential hypertension). In the case of pheochromocytoma, the absence of the night-time BP decrease was more prominent compared to the primary aldosteronism group (P=0.003/0.001) and for the diastolic BP also in comparison with the Cushing's syndrome group (P=0.03). Tumour removal led in both groups to the restoration of the previously altered circadian rhythm (aldosterone-producing adenoma: P=0.0005/0.0009; pheochromocytoma: P=0.001/0.0007). Our study demonstrates a blunted circadian BP variation in all forms of adrenal hypertension in comparison with essential hypertension. This reduction of the night-time BP decrease was more prominent in pheochromocytoma than in primary aldosteronism or Cushing's syndrome.     

Diurnal blood pressure pattern in patients with primary aldosteronism

BACKGROUND: The aim of the study was to evaluate diurnal blood pressure (BP) profiles in patients with primary aldosteronism and to compare them to those in subjects with essential hypertension. The effects of specific therapy on the circadian BP profiles have been studied. MATERIALS AND METHODS: Sixty-four patients with primary aldosteronism were included in the study. Thirty of them revealed an aldosterone-producing adenoma (APA) and 34 had idiopathic hyperaldosteronism (IHA) due to bilateral adrenal hyperplasia. RESULTS: We did not find any significant differences in ambulatory BP monitoring (ABPM) between patients with APA and IHA. However, the circadian BP variation in the patients with primary hyperaldosteronism due to APA was preserved, while the patients with IHA showed lower nocturnal decline in comparison with patients with essential hypertension. There was a significant decline in office and ambulatory BP levels after treatment in the patients with both APA and IHA. The awake-sleep BP difference in patients with APA remained unchanged after surgical treatment, while in patients with IHA the night-time systolic and diastolic BP decline was significantly higher after spironolactone treatment. CONCLUSIONS: Primary hyperaldosteronism due to APA was associated with normal circadian BP variability and the surgical treatment led to highly significant decline in all BP parameters but had no influence on the extent of nocturnal BP variation. Spironolactone therapy restored normal nocturnal BP decline in patients with IHA. Reduction of night-time BP decline in patients with IHA is more likely to be related to the duration of the disease rather than to the aldosterone levels.     

Risk factors associated with persistent postoperative hypertension in Cushing's syndrome

The aim of the present study was to assess the long-term results of adrenalectomy and to evaluate potential risk factors for the persistence or recurrence of hypertension. Forty-five patients with Cushing's syndrome caused by benign cortisol-producing adrenocortical adenomas were evaluated before and for a period of 1 year after surgical cure. When the patients were classified into two groups according to whether their preoperative BP was more (HBP group) or less (NBP group) than 140/90 mmHg, the BP level was found to be continuously higher in the HBP group than in the NBP group during the year after surgery. This finding suggests that the preoperative BP level in Cushing's syndrome may be a determinant factor for persistent hypertension after surgery (P<0.05). In addition, a correlation was found between postoperative BP level and duration of hypertension (P<0.05), but no relationships were found between postoperative BP levels and other factors, including age, BMI, tumor size, serum cortisol, aldosterone, potassium, total cholesterol, or glucose levels. The above findings indicate that intensive control of preoperative BP to maintain it below 140/90 mmHg with antihypertensive medication is a very important means of improving prognosis for postoperative BP. Immediate diagnosis and surgical treatment to reduce the duration of hypertension are also crucial for the long-term BP prognosis.     

老老年原发性高血压患者脑白质病变与夜间血压下降率的相关性

目的探讨在老老年（≥80岁）原发性高血压患者中,动态血压状况与脑白质病变（WML）的相关性。方法我们回顾性地选取了高血压患者共130例,均行头颅磁共振检查和动态血压监测,并同时收集患者的临床和实验室数据,并应用年龄相关的脑白质视觉评定法评分将患者分为三组：轻度WML,中度WML,重度WML。结果在三组患者之间,夜间平均收缩压、夜间平均舒张压及夜间血压下降率的差异有统计学意义;并且与轻度WML组相比,中度WML和重度WML组患者非杓型血压的发生率显著升高。进一步的多因素logistic回归分析示,夜间舒张压升高和夜间血压下降率减小是WML的独立的危险因素。结论在老老年原发性高血压患者中,夜间血压异常升高以及昼夜节律的异常在WML的进展中起重要作用。     

Black (or brown) adrenal cortical adenoma: its characteristic features on computed tomography and endocrine data

Seventeen patients with adrenal adenoma causing Cushing's syndrome, eight patients with Cushing's disease due to hypersecretion of ACTH, and five patients with primary aldosteronism due to an aldosteronoma were studied for their computed tomographic (CT) patterns, hormonal profiles, and macroscopic and microscopic findings of the adrenal gland. Black (or brown) adrenal adenomas were found in 71% of the patients with Cushing's syndrome, but not in patients with aldosteronoma. The adrenal tissue of patients with Cushing's disease was predominantly yellow. The number of compact cells was larger in black or brown adenomas than in yellow tumors or hyperplastic adrenal tissue. In patients with Cushing's syndrome, urinary excretion of 17-ketosteroids (17-KS) and serum aldosterone concentrations were lower in those with black or brown adenomas than in those with yellow adenomas (P less than 0.05). Patients with Cushing's disease had even higher 17-KS and serum aldosterone levels. No difference was found in serum cortisol concentrations and dexamethasone suppressibility in two types of adenomas causing Cushing's syndrome. Visual estimation of radiological density of the adrenal tissue relative to the kidney on CT scan and quantitative measurement of it by CT number revealed a difference between the two types of adrenal tumors causing Cushing's syndrome. Adrenal tumors with decreased density on CT scan were yellow adenomas with predominantly clear cells, and those with equal or increased density were black or brown adenomas with predominantly compact cells. All aldosteronomas had decreased density and consisted of clear cells. It is suggested that black or brown adenomas of the adrenal gland have higher radiological density and accompanying lower serum aldosterone and urinary 17-KS levels than ordinary yellow tumors. The abundance of compact cells may have some significance for the development of this particular type of adrenal tumor.     

Variant of pre-clinical Cushing's syndrome: hypertension and hypokalemia associated with normoreninemic normoaldosteronism.

The case of a 48-year-old woman with a left adrenocortical adenoma and showing hypokalemia, hypertension and normoreninemic normoaldosteronism is reported. Basal plasma adrenocorticotrophic hormone (ACTH) and cortisol levels were within the reference ranges. The patient's plasma cortisol level decreased insufficiently at night, and was insufficiently decreased by nighttime administration of dexamethasone. She showed no Cushingnoid stigmata. Iodocholesterol scintigraphy revealed tumor-sided uptake alone. The plasma dehydroepiandrosterone-sulfate level was low-to-normal for her age. Metabolic alkalosis and increased potassium clearance after sodium thiosulfate loading were revealed. The plasma aldosterone level was within the normal range, but it was statistically higher than the range for patients with pre-clinical Cushing's syndrome. However, peripheral plasma renin activity (PRA) increased normally after the patient resumed an upright posture following furosemide administration. After adenomectomy the hypokalemia and hypertension were resolved, and the plasma ACTH, cortisol, and PRA remained within the reference ranges. The plasma aldosterone level decreased slightly, but also remained within the reference range after adenomectomy. Paradoxical hyperplasia in the non-neoplastic adrenal glomerulosa zone, which indicates primary aldosteronism, and slight atrophy of the non-neoplastic adrenal cortex, which indicates pre-clinical Cushing's syndrome, were demonstrated. These findings satisfied the criteria of pre-clinical Cushing's syndrome, but did not completely satisfy those of primary aldosteronism. However, the level of CYP11 B2 mRNA in the tumor was in the lower-limit of the range for adenomas associated with primary aldosteronism and was higher than the ranges for adenomas associated with pre-clinical Cushing's syndrome and overt Cushing's syndrome. Based on these results, this case was suspected to constitute a variant of pre-clinical Cushing's syndrome with slight hypersecretion of aldosterone.     

The corticotropin-releasing hormone test in the postoperative evaluation of patients with cushing's syndrome

After surgical cure of Cushing's syndrome most patients develop transient secondary adrenal insufficiency that lasts for approximately 1 yr. Since ACTH-secreting pituitary adenomas generally respond to ovine CRH (oCRH), we tested the hypothesis that an early postoperative response to oCRH may indicate the presence of residual pituitary tumor and, therefore, predict recurrence. We also assessed the usefulness of oCRH for monitoring the recovery of the hypothalamic-pituitary-adrenal axis and for clarifying the pathophysiology of this condition. Thirty-four patients cured of Cushing's syndrome (29 with Cushing's disease, 3 with adrenal adenomas, and 2 with the ectopic ACTH syndrome) had an evening oCRH test 1-2 weeks after surgery. Nine patients (6 with Cushing's disease, 2 with adrenal adenomas, and 1 with the ectopic ACTH syndrome) participated in a longitudinal evaluation and had repeated oCRH and 1-h ACTH tests at 2-month intervals for a year after surgery. Patients were considered to be cured on the basis of at least 3 subnormal urinary [less than 20 micrograms/24 h (less than 55 nmol/day)] or morning plasma cortisol levels [0600-0900 h; less than 6 micrograms/dL (less than 170 nmol/L)] in the first 2 weeks after surgery. The plasma ACTH and cortisol responses to oCRH in the early postoperative period were subnormal in 23 and normal in 6 patients with Cushing's disease. Three patients developed recurrent Cushing's disease (3, 3, and 23 months after transphenoidal surgery). All 3 were among the 6 who had a normal early postoperative response to oCRH. All of the 23 patients who had a subnormal response to oCRH in the early postoperative period have remained in remission for an average follow-up period of 14 months (6-42 months). Thus, the recurrence rate was significantly greater in patients with normal oCRH tests in the early postoperative period (P less than 0.001, by chi 2 analysis). Surgically cured patients with adrenal adenomas or ectopic ACTH secretion also had subnormal plasma ACTH and cortisol responses to oCRH during the early postoperative period. During longitudinal evaluation for 12 months after surgery, the ACTH and cortisol responses to oCRH increased progressively (regardless of the cause of Cushing's syndrome). Cortisol responses to oCRH correlated significantly with the cortisol responses to exogenous ACTH (r = 0.89; P less than 0.00001). We conclude that most patients with Cushing's syndrome have suppressed responses to oCRH during the early postoperative period.(ABSTRACT TRUNCATED AT 400 WORDS)     

Vascular endothelial growth factor (VEGF), prostaglandin E2(PGE2) and active renin in hypertension of adrenal origin

There are limited data regarding the role of vascular endothelial growth factor (VEGF) in arterial hypertension. The aim of the present study was to determine some markers of vascular function, including VEGF, active renin and prostaglandin E2 (PGE2) in patients with endocrine hypertension. The study comprised: 30 patients with primary aldosteronism; 32 patients with active Cushing's syndrome; 19 patients with pheochromocytoma; 22 patients with essential hypertension and 24 healthy volunteers. VEGF was significantly elevated in all groups of patients as compared to the controls. VEGF levels in patients with Cushing's syndrome were significantly higher than those in patients with essential hypertension and primary aldosteronism. We did not find significant differences in VEGF levels between patients with Conn adenomas and idiopathic aldosteronism as well as between patients with Cushing's disease and Cushing's syndrome. PGE2 levels were not significantly different among the groups. Active renin was significantly the lowest in patients with primary aldosteronism and significantly the highest in those with pheochromocytoma compared to controls. The level of active renin in patients with primary aldosteronism was significantly lower than in patients with Cushing's syndrome and pheochromocytoma. In conclusion, VEGF levels were significantly elevated in patients with endocrine hypertension due to glucocorticoid, mineralocorticoid and/or catecholamine excess. The highest VEGF levels were detected in patients with Cushing's syndrome. The latter is associated with accelerated development of atherosclerosis and increased cardiovascular risk. VEGF might contribute to the cardiovascular risk in this disease. This effect was not likely to be PGE2 mediated.     

Cushing's syndrome due to bilateral adrenocortical adenomas with unique histological features

Cushing's syndrome due to bilateral cortisol-secreting adenomas rarely occurs. We present a case of Cushing's syndrome due to bilateral adenomas. Both adenomas had distinct cell compositions, and were compared with emphasis on immunohistochemical and enzyme histochemical analysis for cytochrome P450(11beta) and 3beta-hydroxysteroid dehydrogenase (3betaHSD). A 37 year-old female was diagnosed with ACTH-independent Cushing's syndrome based on physical findings and hormonal evaluation. High-resolution CT scan showed bilateral adrenocortical adenomas and atrophied glands. 131I-methylnorcholesterol incorporation into both glands suggested both adenomas were functional. Clinical diagnosis prior to surgery was ACTH-independent Cushing's syndrome due to functioning bilateral adenomas. The left adrenal gland was totally resected, while the right one was partially resected by laparoscopic approach. Both adenomas were black on cut sections, and were comparatively evaluated by immunohistochemical and enzyme histochemical analysis for P450(11beta) and 3betaSD. The left adenoma was 1.6 cm in diameter and had a complex cellular composition and enzyme expression similar to that of primary pigmented nodular adrenocortical disease (PPNAD), while the right adenoma was 1.8 cm in diameter with compact cells typical of a solitary cortisol-producing adenoma. Adjacent bilateral adrenal cortex showed marked atrophy, but contained several micronodules. Serum cortisol levels, both at basal and after a low dodexamethasone, normalized thirteen months after surgery. In conclusion, the present case of Cushing's syndrome with bilateral adrenal adenomas demonstrated for the first time the simultaneous occurrence of two distinct adenomas, an ordinary cortisol-producing adenoma and a PPNAD-like adenoma. Further case reports of multiple adrenal adenomas should be well-analyzed to clarify whether the results from this case represent a new subgroup of ACTH-independent Cushing's syndrome.     

The relationship between casual and ambulatory blood pressure in essential hypertension: the influence of work, duration of hypertension and antihypertensive treatment

Casual blood pressure (BP) and ambulatory BP (mean 24-h BP) were determined in 23 untreated patients with essential hypertension and in 11 normotensive healthy control subjects. Mean 24-h BP was significantly lower than casual BP in patients with essential hypertension, but not in control subjects. This was demonstrated in the patients who did not work during the ambulatory BP monitoring and in the patients with newly recognized hypertension, whereas no differences were revealed either in the patients who went to work or had a known duration of hypertension longer than 6 months. The size of the difference between casual BP and mean 24-h BP was unaffected by antihypertensive therapy with metoprolol and also individually reproducible. An accordance between casual and ambulatory BP measurements in evaluation of the efficacy of antihypertensive treatment was found in 75% of the patients. Casual BP and mean 24-h BP were weakly correlated both before and during antihypertensive treatment. It is concluded that the higher casual BP than ambulatory BP in essential hypertension may be a specific characteristic of the disease. Both work and known duration of hypertension longer than 6 months eliminate the difference between casual ambulatory BP in essential hypertension. Ambulatory BP monitoring seems to be superior to casual BP measurements in the evaluation of antihypertensive treatment.     

Forty-one cases of Cushing's syndrome: a comparison between Cushing's syndrome (adrenal adenoma) and Cushing's disease (adrenal hyperplasia)]

We experienced 41 cases of Cushing's syndrome (12 males and 29 females, 15 years old - 65 years old) during the last 20 years. These included 20 patients with unilateral adrenal adenoma (Cushing's syndrome), 19 patients with bilateral adrenal hyperplasia (Cushing's disease), one patient with adrenal carcinoma and one patient with primary adrenocortical nodular dysplasia (PAND). Moreover, these cases included some special ones, i.e. 5 cases with destructive thyroiditis after treatment, 2 cases with aggravation of arthritis after treatment, a case of Carney's complex with PAND, one case with paradoxical response to dexamethasone, and one case combined with empty sella syndrome. The most specific clinical signs were moon face (95% occurrence), hypertension (95%) and subcutaneous bruising (80%). Other significant signs were eye edema (66%), buffalo hump (68%), subcutaneous purpura (63%) and osteoporosis (49%). Skin striae was not a common sign in our cases (41%). Renal stone was observed in only 20% of our patients but was a significant sign in this syndrome. There was no difference in the occurrence of each clinical sign between Cushing's syndrome and Cushing's disease. The elevation of white blood cell count (WBC) and serum sodium, a decrease of serum potassium, and a decrease of reabsorption of phosphate (%TRP) were observed. Thyroid-stimulating hormone (TSH) and human growth hormone (HGH) were suppressed in patients with Cushing's syndrome and patients with Cushing's disease. These results were consistent with those of previous reports. However, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were high in those patients with Cushing's syndrome and those with Cushing's disease. Oral glucose tolerance test was carried out in 34 patients before and after treatment. Thirty-one percent of those had diabetes mellitus and 26% had impaired glucose tolerance (IGT). The response of IRI in this test was high in patients with Cushing's syndrome and patients with Cushing's disease, and decreased 4 weeks after treatment in those with Cushing's syndrome but remained high in those with Cushing's disease. Plasma ACTH level and urinary 17-OHCS excretion were significantly higher in Cushing's disease than in Cushing's syndrome. During an 8mg-high-dose dexamethasone suppression test, urinary 17-OHCS excretion in 13 of 14 patients with Cushing's disease (93%) was suppressed by more than 50% of baseline on the second day of testing. However, all of 18 patients with Cushing's syndrome, who had an 8mg-dexamethasone suppression test, failed to suppress urinary 17-OHCS by 50% of baseline.(ABSTRACT TRUNCATED AT 400 WORDS)     

CRF IN THE DIFFERENTIAL DIAGNOSIS OF CUSHING''S SYNDROME: A COMPARISON WITH THE DEXAMETHASONE SUPPRESSION TEST

Accurate differential diagnosis of the precise cause of Cushing's syndrome can be difficult, and conventional tests such as those based on the use of dexamethasone may be misleading. We have therefore studied the cortisol and ACTH responses to ovine corticotrophin-releasing factor (CRF-41) in 28 consecutive patients with Cushing's syndrome, and compared the diagnostic value of this test with that of the high-dose dexamethasone suppression test (8 mg/day for 48 h). Of 20 patients with confirmed Cushing's disease (pituitary-dependent Cushing's syndrome), only 16 (80%) showed the expected 50% or more suppression of serum cortisol following high-dose dexamethasone administration. Four patients each with adrenal adenomas and three patients with the ectopic ACTH syndrome failed to suppress, while a child with probable Cushing's disease showed a variable response depending on the dose used. Following CRF stimulation, 15 out of the 20 patients (75%) with Cushing's disease showed an excessive rise in serum cortisol, outside the normal range, while in five the response to CRF-41 was normal on at least one occasion. None of the patients with adrenal adenomas or the ectopic ACTH syndrome showed a cortisol response to CRF. Thus, either test on its own may be misleading in differentiating Cushing's disease from other causes of the syndrome. Every patient with Cushing's disease, however, showed either suppression in response to high-dose dexamethasone or an excessive cortisol response to CRF testing. It appears, therefore, that the combination of the high-dose dexamethasone and the CRF test, with measurement of serum cortisol, is superior to either test alone in the differential diagnosis of Cushing's syndrome.     

Markedly increased expression of cytochrome P-450 17 alpha-hydroxylase (P-450c17) mRNA in adrenocortical adenomas from patients with Cushing's syndrome.

We studied the contents of cortisol (F) and dehydroepiandrosterone (DHEA) and the expression of mRNA of cytochrome P-450 for side-chain cleavage (P-450scc), 17 alpha-hydroxylase (P-450c17), 21 alpha-hydroxylase (P-450c21) and 11 beta-hydroxylase (P-450c11) in adrenocortical adenomas from three patients with Cushing's syndrome. The F content was significantly higher in adrenocortical adenomas than in normal adrenal glands, while the DHEA level was similar to that in normal adrenal glands. The adrenal adenomas showed a markedly higher level of P-450c17 mRNA, and a slightly but not significantly increased level of P-450c21 mRNA, compared with normal adrenal glands. The expression of P-450scc and P-450c11 mRNA in the adenomas was similar to that in normal adrenal glands. These results suggest that the overproduction of cortisol in adrenocortical adenomas associated with Cushing's syndrome results from an increased expression of P-450c17 and P-450c21 mRNA.     

Primary adrenocortical nodular dysplasia, a distinct subtype of Cushing's syndrome. Case report and review of the literature

Non-iatrogenic Cushing's syndrome has been associated primarily with three entities: pituitary-dependent processes due to pituitary adenomas or microadenomas causing adrenal hyperplasia; pituitary-independent primary adrenal causes, predominantly unilateral adenomas, rarely multiple adenomas or adrenal carcinoma; ectopic sources of adrenocorticotropic hormone (ACTH) production. Although non-neoplastic bilateral adrenal disease generally has been ascribed to extra-adrenal stimulation, a rare cause of Cushing's syndrome that involves bilateral adrenal nodule formation independent of pituitary stimulation has been identified. Nodular adrenal diseases represent a confusion of terms in the literature, but one subgroup of Cushing's syndrome has most frequently--and, perhaps, most appropriately--been designated primary adrenocortical nodular dysplasia. A case of this unusual entity is presented, and previous case reports pertaining to this confusing area of adrenal hyperfunction are reviewed. The characteristic manifestations that separate this diagnosis from other types of nodular adrenal disease are also discussed. Recognition of this diagnosis, although rare, is important, as bilateral adrenalectomy in the treatment of choice.     

24-hour blood pressure in primary and secondary hypertension

The blood pressure is subject to physiological day-night fluctuations, which can be attenuated in secondary hypertension as well but not in essential hypertension. In this study, the blood pressure profile over 24 hours was determined in a large collective of patients with primary and secondary hypertension for comparison to assess the relevance of ambulatory blood pressure monitoring in secondary hypertension. There were 88 patients with essential hypertension (age 20 to 73 years) and 80 patients with secondary hypertension (age 19 to 70 years) with a mean blood pressure value from 8 a.m. to 8 p.m. greater than 135 mm Hg. Blood pressure and heart rate were monitored for 24 hours. In 58/80 patients with secondary hypertension renal parenchymal disease was present, 14 had renovascular disease, three had Cushing's syndrome, four had primary hyperaldosteronism and one had a pheochromocytoma. Of the 88 patients with essential hypertension 67, and of the 80 patients with secondary hypertension 69 were on antihypertensive treatment. The measurements were carried out with a portable automatic ambulatory monitor unit (SpaceLabs 90202) between 6 a.m. and midnight at intervals of 15 minutes and from midnight to 6 a.m. at intervals of 30 minutes. The duration of sleep was documented. In patients with secondary hypertension, as compared with patients with essential hypertension, there were higher blood pressure values during the night from 8 p.m. to 8 a.m., and during sleep (Table 1). The profile of the hourly mean values for systolic and diastolic blood pressure (Figure 1) shows that patients with secondary hypertension, as compared with patients with essential hypertension, have a clearly diminished blood pressure reduction during the night.(ABSTRACT TRUNCATED AT 250 WORDS)     

The improvement of insulin resistance in patients with adrenal incidentaloma by surgical resection

OBJECTIVE: Several recent studies have indicated that patients with adrenal incidentaloma often have disturbed glucose tolerance or/and hypertension. It is unclear whether these metabolic conditions could be caused by adrenal incidentaloma. We investigated the prevalence of disturbed glucose tolerance, hypertension and insulin resistance in the patients with non-functioning adrenal incidentaloma and evaluated the changes of the parameters such as glucose tolerance, blood pressure and insulin sensitivity after adrenalectomy. PATIENTS AND METHODS: Among 15 patients with incidentally discovered adrenal tumours in our department from 1996 to 1999, 4 patients were diagnosed as having pre-clinical Cushing's syndrome and the other 11 as having non-functioning tumours based on detailed endocrinological examinations including dexamethasone suppression testing. Four tumours with pre-clinical Cushing's syndrome and 8 tumours out of 11 patients with non-functioning tumours were diagnosed histopathologically as adrenocortical adenomas and the other 3 as of non-adrenal origin including a myelolipoma, an adrenal vascular cyst and an endothelioma. The prevalence of disturbed glucose tolerance was determined with an oral glucose tolerance test, and insulin sensitivity was evaluated by the method of steady state of plasma glucose (SSPG). RESULTS: All 12 patients with adrenocortical adenoma exhibited insulin resistance based on the SSPG (6.9-13.2 mmol/l). Before surgical removal of the tumours, the SSPG titre was relatively higher in the patients with pre-clinical Cushing's syndrome than in those with non-functioning with adrenocortical adenoma (mean value 11.65 vs. 8.99 mmol/l), whereas 2 of the 3 patients with non-adrenocortical tumours did not have insulin resistance. Among the 12 patients with adrenocortical adenoma, 7 (58%) and 9 (75%) patients exhibited hypertension and disturbed glucose tolerance, respectively. After removal of the tumours, SSPG of the patients with adrenocortical adenoma, but not that of the other 3 patients with non-cortical tumours, was significantly decreased compared to pre-adrenalectomy values. There are no significant differences in the changes of SSPG titres between in pre-clinical Cushing's syndrome and in non-functioning adrenocortical adenoma. Systolic blood pressure, but not diastolic blood pressure, was also significantly decreased in the patients with adrenocortical adenoma. CONCLUSION: High prevalences of disturbed glucose tolerance, insulin resistance and hypertension were found among the patients with non-functioning adrenocortical tumours. Adrenocortical adenoma may be one of the risk factors for insulin resistance that is believed to induce disturbed glucose tolerance and/or hypertension. Therefore, it is useful to evaluate insulin resistance for the patients with adrenal incidentalomas since results are likely to be helpful in deciding whether to remove the tumour by surgery.     

Aldosterone excess and resistance to 24-h blood pressure control

BACKGROUND: Aldosterone excess has been reported to be a common cause of resistant hypertension. To what degree this represents true treatment resistance is unknown. OBJECTIVE: The present study aimed to compare the 24-h ambulatory blood pressure monitoring (ABPM) levels in resistant hypertensive patients with or without hyperaldosteronism. METHODS: Two hundred and fifty-one patients with resistant hypertension were prospectively evaluated with an early-morning plasma renin activity (PRA), 24-h urinary aldosterone and sodium, and 24-h ABPM. Daytime, night-time, and 24-h blood pressure (BP) and nocturnal BP decline were determined. Hyperaldosteronism (H-Aldo) was defined as suppressed PRA (<1.0 ng/ml per h or <1.0 mug/l per h) and elevated 24-h urinary aldosterone excretion (>/= 12 mug/24-h or >/= 33.2 nmol/day) during ingestion of the patient's routine diet. RESULTS: In all patients, the mean office BP was 160.0 +/- 25.2/89.4 +/- 15.3 mmHg on an average of 4.2 medications. There was no difference in mean office BP between H-Aldo and normal aldosterone status (N-Aldo) patients. Daytime, night-time, and 24-h systolic and diastolic BP were significantly higher in H-Aldo compared to N-Aldo males. Daytime, night-time, and 24-h systolic BP were significantly higher in H-Aldo compared to N-Aldo females. Multivariate analysis indicated a significant interaction between age and aldosterone status such that the effects of aldosterone on ambulatory BP levels were more pronounced with increasing age. CONCLUSIONS: In spite of similar office BP, ABPM levels were higher in resistant hypertensive patients with H-Aldo. These results suggest that high aldosterone levels impart increased cardiovascular risk not reflected by office BP measurements.     

Subclinical Cushing's Syndrome

Clinically inapparent adrenal masses, or adrenal incidentalomas, are discovered inadvertently in the course of workup or treatment of unrelated disorders. Cortical adenoma is the most frequent type of adrenal incidentaloma accounting for approximately 50% of cases in surgical series and even greater shares in medical series. Incidentally discovered adrenal adenomas may secrete cortisol in an autonomous manner, that is not fully restrained by pituitary feed-back, in 5 to 20% of cases depending on study protocols and diagnostic criteria. A number of different alterations in the endocrine tests aimed to assess the function of the hypothalamic-pituitary-adrenal axis has been demonstrated in such patients. This heterogeneous condition has been termed as subclinical Cushing's syndrome, a definition that is more accurate than preclinical Cushing's syndrome since the evolution towards clinically overt hypercortisolism does occur rarely, if ever. The criteria for qualifying subclinical cortisol excess are controversial and we presently do not have sufficient evidence to define a gold standard for the diagnosis of subclinical Cushing's syndrome. An increased frequency of hypertension, central obesity, impaired glucose tolerance, diabetes and hyperlipoproteinemia has been described in patients with subclinical Cushing's syndrome; however, there is not evidence-based demonstration of its long-term complications and, consequently, the management of this condition is largely empirical. Either adrenalectomy or careful observation associated with treatment of metabolic syndrome has been suggested as treatment options because data are insufficient to indicate the superiority of a surgical or nonsurgical approach to manage patients with subclinical hyperfunctioning adrenal cortical adenomas. This work was partially supported by grants of the University of Turin (ex-60% funds).     

Imaging in Cushing's syndrome

Once the diagnosis of Cushing's syndrome (CS) has been established, the main step is to differentiate between ACTH dependent and independent disease. In adults, 80% of CS is due to ACTH-dependent causes and 20% due to adrenal causes. ACTH-secreting neoplasms cause ACTH-dependent CS. These are usually anterior pituitary microadenomas, which result in the classic Cushing's disease. Non-pituitary ectopic sources of ACTH, such as a small-cell lung carcinoma or carcinoid tumours, are the source of the remainder of ACTH-dependent disease. In the majority of patients presenting with clinical and biochemical evidence of CS, modern non-invasive imaging can accurately and efficiently provide the cause and the nature of the underlying pathology. Imaging is essential for determining the source of ACTH in ectopic ACTH production, locating the pituitary tumours and distinguishing adrenal adenomas, carcinomas and hyperplasias. In our chapter we review the adrenal appearances in ACTH-dependent and ACTH-independent CS. We also include a discussion on the use of MRI and CT for the detection and management of pituitary ACTH secreting adenomas. CT of the chest, abdomen and pelvis with intravenous injection of contrast medium is the most sensitive imaging modality for the identification of the ectopic ACTH source and detecting adrenal pathology. MRI is used for characterising adrenal adenomas, problem solving in difficult cases and for detecting ACTH-secreting pituitary adenomas.