Body composition and metabolic features in women with adrenal incidentaloma or Cushing's syndrome

Are comorbidities of patients with adrenal incidentaloma tied to sex?

Background

A recent cross-sectional study showed that both comorbidities and mortality in patients with adrenal incidentaloma (AI) are tied to sex. However, few longitudinal studies evaluated the development of arterial hypertension, hyperglycemia, dyslipidemia and bone impairment in patients with AI. The aim of this study is to analyze the impact of sex in the development of these comorbidities during long-term follow-up.

Methods

We retrospectively evaluated 189 patients (120 females, 69 males) with AI, from four referral centers in Italy and Croatia. Clinical characteristics, comorbidities and cortisol after 1-mg dexamethasone suppression test (1-mg DST) were assessed at baseline and at last follow-up visit (LFUV). Median follow-up was 52 (Interquartile Range 25-86) months.

Results

The rates of arterial hypertension and hyperglycemia increased over time both in females (65.8% at baseline versus 77.8% at LFUV, p=0.002; 23.7% at baseline versus 39.6% at LFUV, p<0.001; respectively) and males (58.0% at baseline versus 69.1% at LFUV, p=0.035; 33.8% at baseline versus 54.0% at LFUV, p<0.001; respectively). Patients were stratified in two groups using 1.8 µg/dl as cut-off of cortisol following 1-mg DST: non-functional adrenal tumors (NFAT) and tumors with mild autonomous cortisol secretion (MACS). In the NFAT group (99 patients, females 62.6%), at baseline, we did not observe any difference in clinical characteristics and comorbidities between males and females. At LFUV, males showed a higher frequency of hyperglycemia than females (57.6% versus 33.9%, p=0.03). In the MACS group (89 patients, females 64.0%), at baseline, the prevalence of hypertension, hyperglycemia and dyslipidemia was similar between sexes, despite females were younger (60, IQR 55-69 versus 67.5, IQR 61-73, years; p=0.01). Moreover, females presented higher rates of bone impairment (89.3% versus 54.5%, p=0.02) than males. At LFUV, a similar sex-related pattern was observed.

Conclusion

Patients with AI frequently develop arterial hypertension and hyperglycemia and should be periodically checked for these comorbidities, regardless of sex. In patients with MACS, the lack of difference between sexes in the frequency of cardiometabolic comorbidities despite that females are younger, and the higher frequency of bone impairment in females, suggest a sex-specific effect of cortisol.

Frequently asked questions and answers (if any) in patients with adrenal incidentaloma

PURPOSE

Adrenal incidentalomas (AIs) are incidentally discovered adrenal masses, during an imaging study undertaken for other reasons than the suspicion of adrenal disease. Their management is not a minor concern for patients and health-care related costs, since their increasing prevalence in the aging population. The exclusion of malignancy is the first question to attempt, then a careful evaluation of adrenal hormones is suggested. Surgery should be considered in case of overt secretion (primary aldosteronism, adrenal Cushing's Syndrome or pheochromocytoma), however the management of subclinical secretion is still a matter of debate.

METHODS

The aim of the present narrative review is to offer a practical guidance regarding the management of AI, by providing evidence-based answers to frequently asked questions.

CONCLUSION

The clinical experience is of utmost importance: a personalized diagnostic-therapeutic approach, based upon multidisciplinary discussion, is suggested.

New DXA Diagnostic Indexes of Abdominal Obesity

Aim: Cushing's syndrome (CS) is associated with weight gain and extreme central, visceral, abdominal obesity which is confirmed with dual-energy X-rays absorptiometric (DXA) diagnostic cut-off point (CP) values of central obesity indexes (COI), determined as an android to gynoid tissue and fat mass ratios. These best differentiate CS from non-CS obese women matched with CS according to their age and BMI. The aim of this study was to determine the CP values of new DXA indexes of central, abdominal obesity as a ratio of android and trunk to legs as well as trunk and legs to total tissue and fat mass that best differentiate CS and matched non-CS obese women in order to confirm central abdominal obesity, and to determine their normal CP values that best differentiate healthy non-obese women from CS and non-CS obese women, and to exclude abdominal obesity completely. Material and Methods: DXA indexes of abdominal obesity, calculated as а ratio of regional body fat and tissue mass compartments android to legs (A/L), trunk to legs (Tr/L), trunk to total (Tr/To) and legs to total (L/To) values were determined among 4 groups. Each group consisted of 18 women: 1^st group of CS, 2^nd group of obese women (O₁) not different according to their age and BMI from CS, 3^rd group of obese women (O₂) with higher BMI of 35 ± 1.2 kg and a 4^th group of non-obese, healthy women (C) with a normal BMI. Diagnostic accuracy (DG) of CP values of DXA indexes of abdominal obesity and indexes of normal body fat distribution (BFD) were determined. Results: A/L, Tr/L, Tr/To, and L/To DXA indexes were significantly different between CS and O₁ as well as between non-CS women O₂ compared to O₁ and C. These indexes had a highly significant correlation among each other and also in relation to their BMI (p < 0.0001). A/L-Tm CP value of 0.3 best differentiated the CS from group O₁, with the highest DG of 100 % and an A/L-Fm CP value of 0.26 differentiated them with a DG of 94.44% and sensitivity of 100 %. An A/L-Tn CP value of 0.23 and an A/L-Fn CP value of 0.25 best differentiated CS and C as well as O₂ and C for the highest DG of 100 %. Conclusions: DXA indexes A/L, Tr/L, Tr/To and L/To values were significantly different among the four groups. These values correlated significantly among them and with their BMI in non-CS groups, thus confirming a BMI increase association with a more pronounced abdominal BFD. An A/L-Tm CP value of 0.3 and an A/L-Fm CP value of 0.26 were discovered as the best DXA diagnostic indexes of extreme abdominal obesity in CS and these could also be used in discovering abdominal BFD in non-CS obese women with metabolic syndrome (MS). An A/L-Tn CP value of 0.23 and an A/L-Fn CP value of 0.25 were discovered as the best DXA diagnostic indexes of normal BFD which completely excluded abdominal obesity.

Effects of Long-Term Endogenous Corticosteroid Exposure on Brain Volume and Glial Cells in the AdKO Mouse

Chronic exposure to high circulating levels of glucocorticoids has detrimental effects on health, including metabolic abnormalities, as exemplified in Cushing’s syndrome (CS). Magnetic resonance imaging (MRI) studies have found volumetric changes in gray and white matter of the brain in CS patients during the course of active disease, but also in remission. In order to explore this further, we performed MRI-based brain volumetric analyses in the AdKO mouse model for CS, which presents its key traits. AdKO mice had reduced relative volumes in several brain regions, including the corpus callosum and cortical areas. The medial amygdala, bed nucleus of the stria terminalis, and hypothalamus were increased in relative volume. Furthermore, we found a lower immunoreactivity of myelin basic protein (MBP, an oligodendrocyte marker) in several brain regions but a paradoxically increased MBP signal in the male cingulate cortex. We also observed a decrease in the expression of glial fibrillary acidic protein (GFAP, a marker for reactive astrocytes) and ionized calcium-binding adapter molecule 1 (IBA1, a marker for activated microglia) in the cingulate regions of the anterior corpus callosum and the hippocampus. We conclude that long-term hypercorticosteronemia induced brain region-specific changes that might include aberrant myelination and a degree of white matter damage, as both repair (GFAP) and immune (IBA1) responses are decreased. These findings suggest a cause for the changes observed in the brains of human patients and serve as a background for further exploration of their subcellular and molecular mechanisms.

Diagnostic Central Obesity Indexes Cut - Off Point Values Determined with Dual-Energy X-Ray Absorptiometry in Cushing's and Obese Women

AIM

The aim of this study was to develop quantiative criteria for defining visceral obesity and to establish dual-energy X-ray absorptiometric (DXA) diagnostic cut-off points (CP) for normal and abnormal values of the central obesity indexes (COI) that best differentiate extreme visceral obesity in Cushing's syndrome (CS) from non CS obese and non obese women.

MATERIAL AND METHODS

COI1-4 values calculated as a ratio of android to gynoid tissue mass, fat mass and their % were determined in 4 groups, each consisting of 18 women: 1st group of CS, 2nd group of obese women (O1) not different according to their age and BMI from CS, 3rd group of obese women (O2) with BMI of 35 ± 1.2 kg and 4th group of non obese healthy women (C) with normal BMI. Diagnostic accuracy (DG) of CP values of COI1m-4m indexes of abdominal obesity and CP values of COI1n-4n indexes of normal body fat distribution (BFD) was determined.

RESULTS

COI1-4 indexes values were highly significantly different among the 4 examined groups and were significantly highest in CS patients and lowest in group C (p < 0.0001). COI1m-4m CP values differentiated extreme visceral, abdominal obesity in CS with highest DG as well as COI1n-4n CP values differentiated normal BFD in group C. COI1m CP of 0.55 best differentiated CS from O1 for DG of 100%. COI2n of 0.38 best differentiated C from CS and O2 for highest DG of 100% compared to O1 because of the significantly higher BMI and COI1n-4n values in O2 that were associated with more pronounced abdominal obesity and highly significantly positive correlation with BMI.

CONCLUSIONS

DXA cut-off point values of indexes COI1m-4m and COI1n-4n were established as diagnostic indexes and criteria useful in discovering extreme abdominal and normal BFD. COI1m CP value of 0.55 was discovered as a diagnostic criterion of extreme abdominal obesity and COI2n of 0.38 as a diagnostic criterion of normal BFD that excluded abdominal obesity. The other indexes COI1m-4m and COI1n-4n CP values had also high DG in discovering abdominal and normal body fat distribution.

Evaluation of body composition using dual-energy X-ray absorptiometry in patients with non-functioning adrenal incidentalomas and an intermediate phenotype: Is there an association with metabolic syndrome?

PURPOSE

Metabolic syndrome (MS) and sarcopenia are associated with increased cardiovascular risk. No studies using dual-energy x-ray absorptiometry (DXA) have evaluated association between body composition (BC) changes and MS in adrenal incidentaloma (AI). Our aim was to analyse BC in non-functioning AI (NFAI) and intermediate phenotype (IP) relative to controls and to correlate with cortisol levels.

METHODS

Cross-sectional study with 44 NFAI (serum cortisol ≤ 50 nmol/L after the overnight 1 mg dexamethasone suppression test), 27 IP (cortisol 51-138 nmol/L), and 41 controls (normal adrenal on imaging examination) using DXA. Autonomic cortisol secretion (cortisol > 138 nmol/L) was excluded from the study. BC data were compared using criteria for MS (World Health Organization, National Cholesterol Education Program-Adult Treatment Panel-III, American Association of Clinical Endocrinologists (AACE), and International Diabetes Federation).

RESULTS

There was no significant difference in clinical data and body mass index (BMI) among the three groups. Waist circumference (WC) was larger in AI vs. controls (p < 0.01). Waist-to-hip ratio was higher in NFAI vs. controls and waist-to-height ratio was higher in IP vs. controls (p = 0.03 and p = 0.02, respectively). The frequency of MS was higher in AI vs. controls. BC was not different among the groups. Patients with AI there was a significant association of MS with both an increase in total fat and body fat index (all criteria), and a significant difference between MS and smaller BMI-adjusted lean mass (AACE, p = 0.036). No correlation of cortisol after 1 mg dexamethasone test with BC or MS. AI and WC were independently associated with MS.

CONCLUSIONS

AI presented high frequency of MS and was independently associated with MS. Possible deleterious effects of cortisol secretion seem to initially affect the muscular system.

Diagnosis and treatment of lipodystrophy: a step-by-step approach

AIM

Lipodystrophy syndromes are rare heterogeneous disorders characterized by deficiency of adipose tissue, usually a decrease in leptin levels and, frequently, severe metabolic abnormalities including diabetes mellitus and dyslipidemia.

PURPOSE

To describe the clinical presentation of known types of lipodystrophy, and suggest specific steps to recognize, diagnose and treat lipodystrophy in the clinical setting.

METHODS

Based on literature and in our own experience, we propose a stepwise approach for diagnosis of the different subtypes of rare lipodystrophy syndromes, describing its more frequent co-morbidities and establishing the therapeutical approach.

RESULTS

Lipodystrophy is classified as genetic or acquired and by the distribution of fat loss, which can be generalized or partial. Genes associated with many congenital forms of lipodystrophy have been identified that may assist in diagnosis. Because of its rarity and heterogeneity, lipodystrophy may frequently be unrecognized or misdiagnosed, which is concerning because it is progressive and its complications are potentially life threatening. A basic diagnostic algorithm is proposed. Effective management of lipodystrophy includes lifestyle changes and aggressive, evidence-based treatment of comorbidities. Leptin replacement therapy (metreleptin) has been found to improve metabolic parameters in many patients with lipodystrophy. Metreleptin is approved in the United States as replacement therapy to treat the complications of leptin deficiency in patients with congenital or acquired generalized lipodystrophy and has been submitted for approval in Europe.

CONCLUSIONS

Here, we describe the clinical presentation of known types of lipodystrophy, present an algorithm for differential diagnosis of lipodystrophy, and suggest specific steps to recognize and diagnose lipodystrophy in the clinical setting.

The Occurrence of Subclinical Hypercortisolism and Osteoporosis in Patients with Incidentally Discovered Unilateral and Bilateral Adrenal Tumors

BACKGROUND

Adrenal incidentalomas (AI) are clinically silent adrenal masses that are detected incidentally during imaging procedures performed for unrelated diseases. The aim of this study was to investigate the prevalence of sub-clinical hypercortisolism (SH) and associated co-morbidities in patients with unilateral AI (UAI) and bilateral AI (BAI).

METHODS

We evaluated 152 patients, 105 (69.1%) with UAI and 47 (30.9%) with BAI. SH was diagnosed in the presence of serum cortisol levels after 1 mg dexamethasone suppression test (DST) or after 2-day low-dose DST (LDDST) > 50 nmol/L with at least one of the following parameters: midnight serum cortisol > 208 nmol/L, 24-h urinary free cortisol > 245 nmol/24 h, or ACTH < 10 ng/L. Bone mineral density (BMD) was measured at lumbar spine (LS) and femoral neck (FN).

RESULTS

Age, BMI, and waist circumference were comparable, and diabetes, hypertension and dyslipidemia occurred with similar frequency in both groups. The overall prevalence of SH was 20.5% based on post-1 mg DST, and 20.0% based on post-LDDST cortisol levels, and it was more prevalent in BAI than UAI patients (31.1% vs 15.2%, respectively, p=0.026). LS BMD was lower in BAI than in UAI patients (0.96±0.14 vs 0.87±0.15, p=0.002). There were no differences in FN BMD. The prevalence of osteoporosis was higher in BAI compared to UAI patients (37.1% vs 15.9%, respectively, p=0.011).

CONCLUSIONS

Patients with BAI had higher prevalence of SH and osteoporosis than those with UAI. Frequency of other co-morbidities was similar. This may be due to the higher degree of autonomous cortisol secretion or different tissue-specific sensitivity to glucocorticoids.

A prospective study of appetite and food craving in 30 patients with Cushing's disease

CONTEXT

Glucocorticoid (GC) exposure increases food intake, but the mechanisms in humans are not known. Investigation of appetite and food craving has not been done in patients with chronic GC exposure due to Cushing's disease (CD), either before or after treatment, and could provide insight into mechanisms of food intake and obesity in these patients.

PURPOSE

To examine whether surgical remission of CD changes appetite (prospective consumption, hunger, satisfaction, and fullness) and food cravings (sweet, salty, fatty, and savory); and to identify predictors of appetite and craving in CD remission.

METHODS

30 CD patients, mean age 40.0 years (range 17-70), mean BMI 32.3 ± 6.4, were prospectively studied before and at a mean of 17.4 mo. after remission. At each visit fasting and post-test meal (50% carbohydrate, 35% protein, 15% fat) appetite and craving scores were assessed.

RESULTS

Remission decreased prospective consumption, sweet and savory craving (p < 0.05), but did not change hunger, satisfaction, fullness, or fat craving, despite decreases in BMI and fat mass. In CD remission, serum cortisol predicted lower satisfaction and fullness, and masses of abdominal fat depots predicted higher hunger and consumption (p < 0.05).

CONCLUSIONS

Chronic GC exposure in CD patients may stimulate the drive to eat by enhancing craving, rather than regulating the sensation of hunger. Continued alterations in appetite regulation due to abdominal fat mass and circulating cortisol could play a role in the cardiovascular and metabolic risk that has been reported in CD patients despite remission.

Clinical Characteristics and Metabolic Features of Patients with Adrenal Incidentalomas with or without Subclinical Cushing's Syndrome

BACKGROUND

The aim of this study was to examine the clinical characteristics of adrenal incidentalomas discovered by computed tomography (CT) and to investigate metabolic features of subclinical Cushing's syndrome (SCS) in patients with adrenal incidentalomas in a tertiary hospital in Korea.

METHODS

This retrospective study examined the clinical aspects of 268 patients with adrenal incidentalomas discovered by CT at Soonchunhyang University Bucheon Hospital. Clinical data and endocrine function of the patients as well as histological findings were obtained from medical records, while anatomic characteristics were analyzed by reviewing imaging studies. Hormonal tests for pheochromocytoma, Cushing's syndrome, and aldosterone-secreting adenoma were performed.

RESULTS

Most (n=218, 81.3%) cases were nonfunctioning tumors. Of the 50 patients with functioning tumors (18.7%), 19 (7.1%) were diagnosed with SCS, nine (3.4%) with overt Cushing's syndrome, 12 (4.5%) with primary aldosteronism, and 10 (3.7%) with pheochromocytoma. Malignant tumors (both primary and metastatic) were rare (n=2, 0.7%). Body mass index, fasting glucose, hemoglobin A1c, and total cholesterol were significantly higher in patients with SCS in comparison with those with nonfunctioning tumors. The prevalence of type 2 diabetes mellitus and hypertension were significantly higher in patients with SCS compared with those with nonfunctioning tumors.

CONCLUSION

Functioning tumors, especially those with subclinical cortisol excess, are commonly found in patients with adrenal incidentalomas, although malignancy is rare. In addition, patients with SCS in adrenal incidentalomas have adverse metabolic and cardiovascular profiles.

Non-functioning adrenal incidentalomas are associated with higher hypertension prevalence and higher risk of atherosclerosis

INTRODUCTION

Adrenal incidentalomas (AIs) have been associated with an increased incidence of several cardiovascular risk factors. The aim of this study was to investigate plasma adiponectin, leptin, resistin, homocysteine, high sensitive C-reactive protein levels, and carotid intima media thickness (CIMT) in patients with non-functioning AI (NFAI).

MATERIALS AND METHODS

This study included data from 28 patients with NFAI (Group 1) and 41 controls (Group 2). Of the patients, 50 were female and 19 were male, and the mean age was 46.7 (range 37-65) years.

RESULTS

There were no significant differences between Group 1 and 2 in terms of age, sex, or BMI. Hypertension prevalence was significantly higher in the NFAI group than in the control group (p = 0.01). Both groups had similar lipid, blood glucose, homocysteine, uric acid, high-sensitivity CRP levels. Adiponectin, leptin, and resistin levels were similar in both groups. CIMTs were significantly higher in the NFAI group.

CONCLUSION

There is increasing evidence that several cardiometabolic risk factors occur with higher prevalence in non-functioning adrenal incidentaloma patients compared to age-matched healthy subjects. In our study, hypertension prevalence and CIMT were higher in the NFAI group. Serum adipokine levels were similar for both groups.

Mechanisms of glucocorticoid-induced insulin resistance: focus on adipose tissue function and lipid metabolism

Glucocorticoids (GCs) are critical in the regulation of the stress response, inflammation and energy homeostasis. Excessive GC exposure results in whole-body insulin resistance, obesity, cardiovascular disease, and ultimately decreased survival, despite their potent anti-inflammatory effects. This apparent paradox may be explained by the complex actions of GCs on adipose tissue functionality. The wide prevalence of oral GC therapy makes their adverse systemic effects an important yet incompletely understood clinical problem. This article reviews the mechanisms by which supraphysiologic GC exposure promotes insulin resistance, focusing in particular on the effects on adipose tissue function and lipid metabolism.

Adequately adapted insulin secretion and decreased hepatic insulin extraction cause elevated insulin concentrations in insulin resistant non-diabetic adrenal incidentaloma patients

Background

Insulin-resistance is commonly found in adrenal incidentaloma (AI) patients. However, little is known about beta-cell secretion in AI, because comparisons are difficult, since beta–cell-function varies with altered insulin-sensitivity.

Objectives

To retrospectively analyze beta–cell function in non-diabetic AI, compared to healthy controls (CON).

Methods

AI (n=217, 34%males, 57±1years, body-mass-index:27.7±0.3kg/m²) and CON [n=25, 32%males, 56±1years, 26.7±0.8kg/m²] with comparable anthropometry (p≥0.31) underwent oral-glucose-tolerance-tests (OGTTs) with glucose, insulin, and C–peptide measurements. 1mg-dexamethasone-suppression-tests were performed in AI. AI were divided according to post–dexamethasone-suppression–test cortisol-thresholds of 1.8 and 5µg/dL into 3subgroups: pDexa<1.8µg/dL, pDexa1.8-5µg/dL and pDexa>5µg/dL. Using mathematical modeling, whole-body insulin-sensitivity [Clamp-like-Index (CLIX)], insulinogenic Index, Disposition Index, Adaptation Index, and hepatic insulin extraction were calculated.

Results

CLIX was lower in AI combined (4.9±0.2mg·kg^-1·min^-1), pDexa<1.8µg/dL (4.9±0.3) and pDexa1.8-5µg/dL (4.7±0.3, p<0.04 vs.CON:6.7±0.4). Insulinogenic and Disposition Indexes were 35%–97% higher in AI and each subgroup (p<0.008 vs.CON), whereas C–peptide–derived Adaptation Index, compensating for insulin-resistance, was comparable between AI, subgroups, and CON. Mathematical estimation of insulin–derived (insulinogenic and Disposition) Indexes from associations to insulin-sensitivity in CON revealed that AI-subgroups had ~19%-32% higher insulin-secretion than expectable. These insulin-secretion-index differences negatively (r=-0.45, p<0.001) correlated with hepatic insulin extraction, which was 13-16% lower in AI and subgroups (p<0.003 vs.CON).

Conclusions

AI-patients show insulin-resistance, but adequately adapted insulin secretion with higher insulin concentrations during an OGTT, because of decreased hepatic insulin extraction; this finding affects all AI-patients, regardless of dexamethasone-suppression-test outcome.

Body composition and cardiovascular risk markers after remission of Cushing's disease: a prospective study using whole-body MRI

CONTEXT

Cushing's Disease (CD) alters fat distribution, muscle mass, adipokine profile, and cardiovascular risk factors. It is not known whether remission entirely reverses these changes.

OBJECTIVES

Our objective was to determine whether the adverse body composition and cardiovascular risk profile in CD change after remission.

DESIGN, SETTING, AND PATIENTS

Fourteen CD patients were studied prospectively: before surgery (active disease) and again postoperatively 6 months after discontinuing oral glucocorticoids (remission). Whole-body magnetic resonance imaging was used to examine lean and fat tissue distributions.

OUTCOME MEASURES

Body composition (skeletal muscle and fat in the visceral, bone marrow, sc, and inter-muscular compartments) and cardiovascular risk factors (serum insulin, glucose, leptin, high-molecular-weight adiponectin, C-reactive protein, and lipid profile) were measured in active CD and remission (mean 20 months after surgery).

RESULTS

Remission decreased visceral, pelvic bone marrow, sc (including trunk and limb sc), and total fat; waist circumference; and weight (P < 0.05). Remission altered fat distribution, resulting in decreased visceral/total fat (P = 0.04) and visceral fat/skeletal muscle ratios (P = 0.006). Remission decreased the absolute muscle mass (P = 0.015). Cardiovascular risk factors changed: insulin resistance, leptin, and total cholesterol decreased (P < 0.05), but adiponectin, C-reactive protein, and other lipid measures did not change.

CONCLUSIONS

CD remission reduced nearly all fat depots and reverted fat to a distribution more consistent with favorable cardiovascular risk but decreased skeletal muscle. Remission improved some but not all cardiovascular risk markers. Remission from CD dramatically improves body composition abnormalities but may still be associated with persistent cardiovascular risk.

Anthropometric measures and fasting insulin levels in children before and after cure of Cushing syndrome

BACKGROUND & AIMS

Children with Cushing syndrome present with growth delay and excess adiposity that tends to be generalized rather than centripetal. There are no prospective studies of this phenotype as it evolves before and after treatment in children. The aims of this study were to evaluate children prior to and one-year after surgical cure compared to controls and to determine fasting insulin levels and their possible association with waist circumference and waist-height ratio, pre- and post-cure of Cushing syndrome.

METHODS

30 children with Cushing syndrome were evaluated prior to and one-year post-treatment and compared to 14 age and body mass index-matched controls.

RESULTS

Only triceps skin fold z- score showed a significant difference between patients with active Cushing syndrome and controls. A positive correlation between fasting insulin levels and waist circumference z- score was found for children with Cushing syndrome; this association persisted one-year following cure.

CONCLUSIONS

Unlike adults affected with Cushing syndrome, upper arm muscle area of children with Cushing syndrome did not differ from obese children without Cushing syndrome. The persistence of a positive correlation between waist circumference and fasting insulin despite remission of Cushing syndrome suggests that children with a history of Cushing syndrome may have an increased risk for adverse long-term effects of increased abdominal fat mass.

MRI assessment of lean and adipose tissue distribution in female patients with Cushing's disease

OBJECTIVE

Chronic hypercortisolemia due to Cushing's disease (CD) results in abnormal adipose tissue (AT) distribution. Whole-body magnetic resonance imaging (MRI) was used to examine lean and AT distribution in female patients with CD to further understand the role of glucocorticoid excess in the development of abnormal AT distribution and obesity.

DESIGN

Cross-sectional and case-control study.

PATIENTS

Fifteen women with CD and 12 healthy controls.

MEASUREMENTS

Mass of skeletal muscle (SM) and AT in the visceral (VAT), subcutaneous (SAT), and intermuscular (IMAT) compartments from whole-body MRI and serum levels of insulin, glucose, and leptin were measured.

RESULTS

CD patients had leptin values that correlated to total AT (TAT) and SAT (P < 0.05) but not to VAT. CD patients had higher VAT/TAT ratios (P < 0.01) and lower SAT/TAT ratios (P < 0.05) compared to controls. TAT, VAT, and trunk SAT (TrSAT) were greater in CD patients (P < 0.01). SM was less in CD (P < 0.001) but IMAT was not different.

CONCLUSIONS

TAT, VAT, trSAT, and the proportion of AT in the visceral depot were greater in CD although the proportion in the subcutaneous depot was less. SM was less but IMAT was not different. These findings have implications for understanding the role of cortisol in the abnormal AT distribution and metabolic risk seen in patients exposed to chronic excess glucocorticoids.

Approach to the patient with an adrenal incidentaloma

Unsuspected adrenal masses, or incidentalomas, are increasingly found with the widespread use of thoracic and abdominal imaging. These masses may be hormonally active or nonfunctional and malignant or benign. Clinicians must determine the nature of the mass to decide what treatment, if any, is needed. Measurement of precontrast Hounsfield units (HU) and contrast washout on computed tomography scan provide useful diagnostic information. All patients should undergo biochemical testing for pheochromocytoma, either with plasma or urinary catecholamine measurements. This is particularly important before surgical resection, which is routinely recommended for masses larger than 4 cm in diameter without a clear-cut diagnosis and for others with hormonal secretion or ominous imaging characteristics. Hypertensive patients should undergo biochemical testing for hyperaldosteronism. Patients with features consistent with Cushing's syndrome, such as glucose intolerance, weight gain, and unexplained osteopenia, should be evaluated for cortisol excess. Here, the dexamethasone suppression test and late-night salivary cortisol may be preferred over measurement of urine cortisol. The ability of surgical resection to reverse features of mild hypercortisolism is not well established. For masses that appear to be benign (<10 HU; washout, >50%), small (<3 cm), and completely nonfunctioning, imaging and biochemical reevaluation (pheochromocytoma and hypercortisolism only) at 1-2 yr (or more) is appropriate. For more indeterminate lesions, repeat evaluation for growth after 3-12 months is useful, with subsequent testing intervals based on the rate of growth.

Screening for Cushing's syndrome in obese patients

OBJECTIVES

The aim of this study was to examine the frequency of Cushing's syndrome (CS) in obese patients devoid of specific clinical symptoms of Cushing's syndrome.

METHODS

A total of 150 obese patients (129 female, 21 male; mean age 44.41 +/- 13.34 yr; mean BMI 35.76 +/- 7.13) were included in the study. As a first screening step, we measured 24-h urinary free cortisol (UFC). An overnight 1-mg dexamethasone suppression test was also performed on all patients. Urinary free cortisol levels above 100 microg/24 h were considered to be abnormal. Suppression of serum cortisol <1.8 microg/dL after administration of 1 mg dexamethasone was the cut-off point for normal suppression. The suppression of the serum cortisol levels failed in all of the patients.

RESULTS

MEASURED LABORATORY VALUES WERE AS FOLLOWS: ACTH, median level 28 pg/ml, interquartile range (IQR) 14-59 pg/ml; fasting glucose, 100 (91-113) mg/dL; insulin, 15.7 (7.57-24.45) mU/ml; fT(4), 1.17 (1.05-1.4) ng/dL; TSH, 1.70 (0.91-2.90) mIU/L; total cholesterol, 209 (170.5-250) mg/dL; LDL-c, 136 (97.7-163) mg/dL; HDL-c, 44 (37.25-50.75) mg/dL; VLDL-c, 24 (17-36) mg/dL; triglycerides, 120.5 (86-165) mg/dL. The median UFC level of the patients was 30 microg/24 h (IQR 16-103). High levels of UFC (>100 microg/24 h) were recorded in 37 patients (24%). Cushing's syndrome was diagnosed in 14 of the 150 patients (9.33%). Etiologic reasons for Cushing's syndrome were pituitary microadenoma (9 patients), adrenocortical adenoma (3 patients), and adrenocortical carcinoma (1 patient).

CONCLUSION

A significant proportion (9.33%) of patients with simple obesity were found to have Cushing's syndrome. These findings argue that obese patients should be routinely screened for Cushing's syndrome.

The pituitary-adrenal axis and body composition

The activity of the pituitary-adrenal axis can profoundly impact on body composition. This is dramatically seen in Cushing's syndrome (CS) but changes in body composition are also implicated in depression and alcoholic pseudocushing's. The pathophysiological mechanisms underlying these changes remain poorly understood. Changes to body composition in CS include increased fat mass, decreased bone mass, thinning of the skin and reduced lean mass. Why these tissues are affected so dramatically is unclear. Additionally, the change in body composition between individuals varies considerably for reasons which are only now becoming evident. This paper reviews the phenotypic changes with altered pituitary-adrenal axis activity and discusses the mechanisms involved. The primary focus is on adipose, bone, muscle and skin since the most dramatic changes are seen in these tissues.

Percentage extremity fat, but not percentage trunk fat, is lower in adolescent boys with anorexia nervosa than in healthy adolescents

BACKGROUND

Anorexia nervosa (AN) is a condition of severe undernutrition associated with altered regional fat distribution in females. Although primarily a disease of females, AN is increasingly being recognized in males and is associated with hypogonadism. Testosterone is a major regulator of body composition in males, and testosterone administration in adults decreases visceral fat. However, the effect of low testosterone and other hormonal alterations on body composition in boys with AN is not known.

OBJECTIVE

We hypothesized that testosterone deficiency in boys with AN is associated with higher trunk fat, as opposed to extremity fat, compared with control subjects.

DESIGN

We assessed body composition using dual-energy X-ray absorptiometry and measured fasting testosterone, estradiol, insulin- like growth factor-1, leptin, and active ghrelin concentrations in 15 boys with AN and in 15 control subjects of comparable maturity aged 12-19 y.

RESULTS

Fat and lean mass in AN boys was 69% and 86% of that in control subjects. Percentage extremity fat and extremity lean mass were lower in boys with AN (P = 0.003 and 0.0008); however, percentage trunk fat and the trunk to extremity fat ratio were higher after weight was adjusted for (P = 0.005 and 0.003). Testosterone concentrations were lower in boys with AN, and, on regression modeling, positively predicted percentage extremity lean mass and inversely predicted percentage trunk fat and trunk to extremity fat ratio. Other independent predictors of regional body composition were bone age and weight.

CONCLUSIONS

In adolescent boys with AN, higher percentage trunk fat, higher trunk to extremity fat ratio, lower percentage extremity fat, and lower extremity lean mass (adjusted for weight) are related to the hypogonadal state.

Lower growth hormone and higher cortisol are associated with greater visceral adiposity, intramyocellular lipids, and insulin resistance in overweight girls

Although body composition, insulin sensitivity, and lipids are markedly altered in overweight adolescents, hormonal associations with these parameters have not been well characterized. Growth hormone (GH) deficiency and hypercortisolemia predispose to abdominal adiposity and insulin resistance, and GH secretion is decreased in obese adults. We hypothesized that low-peak GH on the GH-releasing hormone (GHRH)-arginine stimulation test and high cortisol in overweight adolescents would be associated with higher regional fat, insulin resistance, and lipids. We examined the following parameters in 15 overweight and 15 bone age-matched control 12- to 18-yr-old girls: 1) body composition using dual-energy X-ray absorptiometry and MR [visceral and subcutaneous adipose tissue at L(4)-L(5) and soleus intramyocellular lipid ((1)H-MR spectroscopy)], 2) peak GH on the GHRH-arginine stimulation test, 3) mean overnight GH and cortisol, 4) 24-h urinary free cortisol (UFC), 5) fasting lipids, and 6) an oral glucose tolerance test. Stepwise regression was the major tool employed to determine relationships between measured parameters. Log peak GH on the GHRH-arginine test was lower (P = 0.03) and log UFC was higher (P = 0.02) in overweight girls. Log mean cortisol (overnight sampling) was associated positively with subcutaneous adipose tissue and, with body mass index standard deviation score, accounted for 92% of its variability, whereas log peak GH and body mass index standard deviation score accounted for 88% of visceral adipose tissue variability and log peak GH for 34% of the intramyocellular lipid variability. Log mean cortisol was independently associated with log homeostasis model assessment of insulin resistance, LDL, and HDL and explained 49-59% of the variability. Our data indicate that lower peak GH and higher UFC in overweight girls are associated with visceral adiposity, insulin resistance, and lipids.

Protein metabolism in glucocorticoid excess: study in Cushing's syndrome and the effect of treatment

How protein metabolism is perturbed during chronic glucocorticoid excess is poorly understood. The aims were to investigate the impact of chronic glucocorticoid excess and restoration of eucortisolemia in Cushing's syndrome (CS) on whole body protein metabolism. Eighteen subjects with CS and 18 normal subjects (NS) underwent assessment of body composition using DEXA and whole body protein turnover with a 3-h constant infusion of l-[(13)C]leucine, allowing calculation of rates of leucine appearance (leucine R(a)), leucine oxidation (L(ox)), and leucine incorporation into protein (LIP). Ten subjects with CS were restudied after restoration of eucortisolemia. Percentage FM was greater (43.9 +/- 1.6 vs. 33.8 +/- 2.4%, P = 0.002) and LBM lower (52.7 +/- 1.6 vs. 62.1 +/- 2.3%, P = 0.002) in CS. LBM was significantly correlated (r(2) > 0.44, P < 0.005) to leuceine R(a), L(ox), and LIP in both groups. After correcting for LBM, leucine R(a) (133 +/- 5 vs. 116 +/- 5 micromol/min, P = 0.02) and L(ox) (29 +/- 1 vs. 24 +/- 1 micromol/min, P = 0.01) were greater in CS. FM significantly correlated (r(2) = 0.23, P < 0.05) with leucine R(a) and LIP, but not L(ox) in CS. In multiple regression, LBM was an independent determinant of all three indexes of leucine turnover, FM of leucine R(a), and LIP and CS of L(ox). Following restoration of eucortisolemia, L(ox) was reduced (Delta-7.5 +/- 2.6 micromol/min, P = 0.02) and LIP increased (Delta+15.2 +/- 6.2 micromol/min, P = 0.04). In summary, whole body protein metabolism in CS is influenced by changes in body composition and glucocorticoid excess per se, which increases protein oxidation. Enhanced protein oxidation is a likely explanation for the reduced protein mass in CS. Successful treatment of CS reduces protein oxidation and increases protein synthesis to prevent ongoing protein loss.

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.