In postmenopausal female subjects with type 2 diabetes mellitus, vertebral fractures are independently associated with cortisol secretion and sensitivity

The degree of cortisol secretion is associated with diabetes mellitus and hypertension in patients with nonfunctioning adrenal tumors

BACKGROUND

Similarly to cortisol-secreting adrenal tumors, also non-functioning adrenal tumors (NFAT) may be associated with an increased cardiovascular risk. We assessed in NFAT patients: (i) the association between hypertension (HT), diabetes mellitus (DM), obesity (OB), dyslipidemia (DL) and cardiovascular events (CVE) and cortisol secretion; (ii) the cut-off of the cortisol secretion parameters for identifying NFAT patients with a worse cardiometabolic profile.

PATIENTS AND METHODS

In 615 NFAT patients (with cortisol levels after 1 mg overnight dexamethasone suppression test, F-1mgDST < 1.8 µg/dL [50 nmol/L]) F-1mgDST and adrenocorticotroph hormone (ACTH) levels and data on HT, DM, OB, DL and CVEs prevalence were retrospectively collected.

RESULTS

HT, DM and HT plus DM were associated with F-1mgDST levels (area under the ROC curve: 0.588 ± 0.023, 0.610 ± 0.028, 0.611 ± 0.033, respectively, p < 0.001 for all comparisons) but not with ACTH. The cut-off for identifying patients with either HT or DM or HT plus DM was set at ≥ 1.2 µg/dL (33 nmol/L). As compared with patients with F-1mgDST < 1.2 µg/dL (n = 289), patients with F-1mgDST 1.2-1.79 µg/dL (33-49.4 nmol/L) (n = 326) had lower ACTH levels (17.7 ± 11.9 vs 15.3 ± 10.1 pg/mL, respectively, p = 0.008), older age (57.5 ± 12.3 vs 62.5 ± 10.9 years, respectively, p < 0.001), and higher prevalence of HT (38.1% vs 52.5% respectively p < 0.001), DM (13.1% vs 23.3%, respectively, p = 0.001), HT plus DM (8.3% vs 16.9%, respectively, p < 0.002) and CVE (3.2% vs 7.3%, respectively, p = 0.028). F-1mgDST 1.2-1.79 µg/dL was associated with either HT (odd ratio, OR, 1.55, 95% confidence interval, 95% CI 1.08-2.23, p = 0.018) or DM (OR 1.60, 95% CI 1.01-2.57, p = 0.045) after adjusting for age, gender, OB, DL, and DM (for HT) or HT (for DM), and with the presence of HT plus DM (OR 1.96, 95% CI 1.12-3.41, p = 0.018) after adjusting for age, gender, OB and DL.

CONCLUSIONS

In NFAT patients, F-1mgDST 1.2-1.79 µg/dL seems to be associated with a higher prevalence of HT and DM and a worse cardiometabolic profile, even if the poor accuracy of these associations suggests caution in interpreting these results.

Validation of the clinical consensus recommendations on the management of fracture risk in postmenopausal women with type 2 diabetes

BACKGROUND AND AIMS

Bone fragility is recognized as a complication of type 2 diabetes (T2D). However, the fracture risk in T2D is underestimated using the classical assessment tools. An expert panel suggested the diagnostic approaches for the detection of T2D patients worthy of bone-active treatment. The aim of the study was to apply these algorithms to a cohort of T2D women to validate them in clinical practice.

METHODS AND RESULTS

The presence of T2D-specific fracture risk factors (T2D ≥ 10 years, ≥1 T2D complications, insulin or thiazolidinedione use, poor glycaemic control) was assessed at baseline in 107 postmenopausal T2D women. In all patients at baseline and in 34 patients after a median follow-up of 60.2 months we retrospectively evaluated bone mineral density and clinical and morphometric vertebral fractures. No patient was treated with bone-active drug. Following the protocols, 34 (31.8%) and 73 (68.2%) patients would have been pharmacologically and conservatively treated, respectively. Among 49 patients without both clinical fractures and major T2D-related risk factors, who would have been, therefore, conservatively followed-up without vertebral fracture assessment, only one showed a prevalent vertebral fracture (sensitivity 90%, negative predictive value 98%). The two patients who experienced an incident fracture would have been pharmacologically treated at baseline.

CONCLUSIONS

The clinical consensus recommendations showed a very good sensitivity in identifying T2D postmenopausal women at high fracture risk. Among those with treatment indication as many as 13% of patients experienced an incident fracture, and, conversely, among those without treatment indication no incident fractures were observed.

Bone health in Duchenne muscular dystrophy: clinical and biochemical correlates

PURPOSE

An increased fracture risk is commonly reported in Duchenne muscular dystrophy (DMD). Our aim was to investigate bone mineral density (BMD) and bone turnover, including sclerostin, and their association with markers of cardiac and respiratory performance in a cohort of DMD subjects.

METHODS

In this single center, cross sectional observational study, lumbar spine (LS) BMD Z-scores, C-terminal telopeptide of procollagen type I (CTX) and osteocalcin (BGP), as bone resorption and formation markers, respectively, and sclerostin were assessed. Left ventricular ejection fraction (LVEF) and forced vital capacity (FVC) were evaluated. Clinical prevalent fractures were also recorded.

RESULTS

Thirty-one patients [median age = 14 (12-21.5) years] were studied. Ambulant subjects had higher LS BMD Z-scores compared with non-ambulant ones and subjects with prevalent clinical fractures [n = 9 (29%)] showed lower LS BMD Z-scores compared with subjects without fractures. LS BMD Z-scores were positively correlated with FVC (r = 0.50; p = 0.01), but not with glucocorticoid use, and FVC was positively associated with BGP (r = 0.55; p = 0.02). In non-ambulant subjects, LS BMD Z-scores were associated with BMI (r = 0.54; p = 0.02) and sclerostin was associated with age (r = 0.44; p = 0.05). Age, BMI, FVC and sclerostin were independently associated with LS BMD Z-score in a stepwise multiple regression analysis. Older age, lower BMI, FVC and sclerostin were associated with lower LS BMD Z-scores.

CONCLUSION

In a cohort of DMD patients, our data confirm low LS BMD Z-scores, mainly in non-ambulant subjects and irrespective of the glucocorticoid use, and suggest that FVC and sclerostin are independently associated with LS BMD Z-scores.

Management of bone fragility in type 2 diabetes: Perspective from an interdisciplinary expert panel

AIM

Bone fragility is increasingly recognized as a relevant complication of type 2 diabetes (T2D) and diabetic patients with fragility fractures have higher mortality rates than non diabetic individuals or diabetic patients without fractures. However, current diagnostic approaches for fracture risk stratification, such as bone mineral density measurement or the use of risk assessment algorithms, largely underestimate fracture risk in T2D patients. A multidisciplinary expert panel was established in order to in order to formulate clinical consensus recommendations on bone health assessment and management of fracture risk in patients with T2D.

DATA SYNTHESIS

The following key questions were addressed: a) which are the risk factors for bone fragility in T2D?, b) which diagnostic procedures can be currently used to stratify fracture risk in T2D patients?, c) which are the effects of antidiabetic treatments on bone?, and d) how to prevent and treat bone fragility in T2D patients? Based on the available data members of this panel suggest that the stratification of fracture risk in patients with diabetes should firstly rely on the presence of a previous fragility fracture and on the individual risk profile, with the inclusion of T2D-specific risk factors (namely T2D duration above 10 yrs, presence of chronic T2D complications, use of insulin or thiazolidinediones and persistent HbA1c levels above 8% for at least 1 year). Two independent diagnostic approaches were then suggested in the presence or the absence of a prevalent fragility fracture, respectively.

CONCLUSIONS

Clinical trials in T2D patients at risk for fragility fractures are needed to determine the efficacy and safety of available antiresorptive and anabolic agents in this specific setting.

Prediction of hypertension, diabetes and fractures in eucortisolemic women by measuring parameters of cortisol milieu

PURPOSE

Cortisol secretion, peripheral activation, and sensitivity seem to be associated with hypertension (HY), type 2 diabetes (T2D), and fragility fractures (FX) even in eucortisolemic subjects. The aim of the present study was to determine the cutoff(s) of the parameters of cortisol secretion and peripheral activation for predicting the presence of HY, T2D, and FX (comorbidities).

METHODS

In 206 postmenopausal females (157 with ≥1 comorbidities and 49 without any), we assessed the ratio between 24-h urinary free cortisol and cortisone (R-UFF/UFE, cortisol activation index), cortisol after 1 mg-overnight-dexamethasone (F-1mgDST, cortisol secretion index), and the GC receptor N363S single-nucleotide polymorphism (N363S-SNP, cortisol sensitivity index).

RESULTS

The cutoffs for F-1mgDST and R-UFF/UFE were set at 0.9 μg/dL (area under the curve, AUC 0.634 ± 0.43, p = 0.005) and 0.17 (AUC 0.624 ± 0.5, p = 0.017), respectively, predicted the presence of ≥1 comorbidities. The presence of F-1mgDST > 0.9 μg/dL plus R-UFF/UFE > 0.17 showed 82.1% specificity for predicting the presence of ≥1 comorbidities, while the simultaneous presence of F-1mgDST ≤ 0.9 μg/dL and R-UFF/UFE ≤ 0.17 showed 88% sensitivity for predicting the absence of comorbidities. The F-1mgDST > 0.9 μg/dL or R-UFF/UFE > 0.17 was associated with 2.8 and 2.1-fold increased risk of having ≥1 comorbidities, respectively. The F-1mgDST ≤ 0.9 μg/dL plus R-UFF/UFE ≤ 0.17 or F-1mgDST > 0.9 μg/dL plus R-UFF/UFE > 0.17 was associated with 2.8-fold reduced or 4.9-fold increased risk of having ≥1 comorbidities regardless of age, BMI, and N363S-SNP.

CONCLUSIONS

F-1mgDST > 0.9 μg/dL and R-UFF/UFE > 0.17 may be used for predicting the presence of ≥1 among HY, T2D, and fragility FX.

Unilateral primary aldosteronism as an independent risk factor for vertebral fracture

CONTEXT

Primary aldosteronism (PA) is known to increase vertebral fracture (VF), although the detailed mechanism remains to be elucidated. We hypothesized that the PA subtype is associated with VF.

OBJECTIVE

To evaluate whether unilateral PA is associated with the prevalence of VF.

DESIGN

This was a retrospective cross-sectional study in a single referral centre.

PATIENTS

We identified 210 hypertensive patients whose clinical data were available for case-detection results. One hundred and fifty-two patients were diagnosed with PA using captopril challenge tests.

MEASUREMENTS

We measured the prevalence of VF, according to PA subtype.

RESULTS

One hundred thirteen patients with PA were subtype classified by adrenal vein sampling. Of these, 37 patients had unilateral PA, 76 patients had bilateral PA, 58 patients had non-PA; 39 patients with PA were not subtype-classified. Patients with PA had a higher prevalence of VF (29%, 44/152) than those with non-PA (12%, 7/58; P = .011). Moreover, unilateral PA had a higher prevalence of VF (46%, 17/37) than bilateral PA (20%, 15/76; P = .021). There was no significant difference in the prevalence of VF between bilateral PA and non-PA. Unilateral PA was an independent risk factor for VF after adjusting for age and sex (OR: 3.16, 95% confidence interval: 1.12-8.92; P = .017). Among patients with unilateral PA, serum cortisol concentrations after 1-mg dexamethasone suppression test were higher in those with VF (1.32 ± 0.67 g/dL) than those without (0.96 ± 0.33 g/dL; P = .048).

CONCLUSIONS

Unilateral PA is an independent risk factor for VF.

Hypogonadism, Type-2 Diabetes Mellitus, and Bone Health: A Narrative Review

One of the complications from chronic hyperglycemia and insulin resistance due to type 2 diabetes mellitus (T2DM) on the hypothalamic-pituitary-gonadal axis in men is the high prevalence of hypogonadotropic hypogonadism (HH). Both T2DM and hypogonadism are associated with impaired bone health and increased fracture risk but whether the combination results in even worse bone disease than either one alone is not well-studied. It is possible that having both conditions predisposes men to an even greater risk for fracture than either one alone. Given the common occurrence of HH or hypogonadism in general in T2DM, a significant number of men could be at risk. To date, there is very little information on the bone health men with both hypogonadism and T2DM. Insulin resistance, which is the primary defect in T2DM, is associated with low testosterone (T) levels in men and may play a role in the bidirectional relationship between these two conditions, which together may portend a worse outcome for bone. The present manuscript aims to review the available evidences on the effect of the combination of hypogonadism and T2DM on bone health and metabolic profile, highlights the possible metabolic role of the skeleton, and examines the pathways involved in the interplay between bone, insulin resistance, and gonadal steroids.

Pathophysiology and Management of Type 2 Diabetes Mellitus Bone Fragility

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone fragility fractures compared to nondiabetic subjects. This increased fracture risk may occur despite normal or even increased values of bone mineral density (BMD), and poor bone quality is suggested to contribute to skeletal fragility in this population. These concepts explain why the only evaluation of BMD could not be considered an adequate tool for evaluating the risk of fracture in the individual T2DM patient. Unfortunately, nowadays, the bone quality could not be reliably evaluated in the routine clinical practice. On the other hand, getting further insight on the pathogenesis of T2DM-related bone fragility could consent to ameliorate both the detection of the patients at risk for fracture and their appropriate treatment. The pathophysiological mechanisms underlying the increased risk of fragility fractures in a T2DM population are complex. Indeed, in T2DM, bone health is negatively affected by several factors, such as inflammatory cytokines, muscle-derived hormones, incretins, hydrogen sulfide (H2S) production and cortisol secretion, peripheral activation, and sensitivity. All these factors may alter bone formation and resorption, collagen formation, and bone marrow adiposity, ultimately leading to reduced bone strength. Additional factors such as hypoglycemia and the consequent increased propensity for falls and the direct effects on bone and mineral metabolism of certain antidiabetic medications may contribute to the increased fracture risk in this population. The purpose of this review is to summarize the literature evidence that faces the pathophysiological mechanisms underlying bone fragility in T2DM patients.

Cortisol Secretion, Sensitivity, and Activity Are Associated With Hypertension in Postmenopausal Eucortisolemic Women

CONTEXT

Previous data suggest a possible association between type 2 diabetes (T2D) and fragility fractures (FX) with the degree of glucocorticoid suppressibility (GCS) and peripheral activation or sensitivity even in persons without hypercortisolemia.

OBJECTIVE

To investigate whether the degree of GCS, GC sensitivity, and peripheral activation in persons without overt or mild hypercortisolism are associated with hypertension and with the number of the possible consequences of cortisol excess among patients with T2D, fragility FX, and hypertension.

DESIGN

Case-control study.

SETTING

Outpatient clinic.

PATIENTS

A total of 216 postmenopausal women without hypercortisolemia (age, 50 to 80 years; 108 with hypertension); 68 and 99 patients had fragility FX and T2D, respectively.

MAIN OUTCOME MEASURES

We assessed 24-hour urinary free cortisol (UFF), cortisone (UFE), their ratio (R-UFF/UFE), (F-1mgDST), and the GC receptor N363S single-nucleotide polymorphism (N363S-SNP).

RESULTS

Hypertension was associated with F-1 mgDST [odds ratio (OR), 3.3; 95% CI, 1.5 to 7.5; P = 0.004) and R-UFF/UFE (OR, 101.7; 95% CI, 2.6 to 4004.1; P = 0.014), regardless of age, body mass index, and presence of the N363S single nucleotide polymorphism and of T2D. The progressive increase in the number of possible consequences of cortisol excess was significantly associated with F-1mgDST levels (R2 = 0.125; P = 0.04), R-UFF/UFE (R2 = 0.46; P = 0.02), and the prevalence of N363S heterozygous variant (T = 0.46; P = 0.015), after adjustment for age.

CONCLUSIONS

In postmenopausal women without hypercortisolemia, hypertension is associated with GCS and GC peripheral activation. The number of possible consequences of cortisol excess (among patients with hypertension, T2D, and fragility FX) is associated with GCS, GC peripheral activation, and the prevalence of the N363S heterozygous variant.

DIAGNOSIS OF ENDOCRINE DISEASE: Evaluation of bone fragility in endocrine disorders

An underlying disease affecting bone health is present in up to 40% and 60% of osteoporotic post-menopausal women and men respectively. Among the disorders leading to a secondary form of osteoporosis, the endocrine diseases are highly represented. A frequent finding in patients affected with an endocrine-related forms of bone disease is that the skeletal fragility is partially independent of the bone density, since the fracture risk in these patients is related more to a reduction of bone quality than to a decrease of bone mass. As a consequence, bone mineral density evaluation by dual-X-ray Absorptiometry may be inadequate for establishing the risk of fracture in the setting of the endocrine-related forms of osteoporosis. In the recent years several attempts to non-invasively estimating bone quality have been done. Nowadys, some new tools are available in the clinical practice for optimizing the fracture risk estimation in patients with endocrine disorders. The aim of this review is to summarise the evidences regarding the role of the different imaging tools for evaluating bone density and bone quality in the most frequent forms of endocrine-related osteoporosis, such as obesity, diabetes, acromegaly, thyrotoxicosis, primary hyperparathyroidism, hypercortisolism and hypogonadism. For each of these disorders, data regarding both the current available tools and the future possible new techniques for assessing bone fragility in patients with endocrine diseases are reported.

Autonomous cortisol secretion in adrenal incidentalomas

Adrenal incidentalomas (AI) are one of the most frequent reasons for consultation in Endocrinology, as they are present in 3-10% of the general population. Up to 20% of them may have autonomous cortisol secretion (ACS), a term that refers to AI carriers with biochemical evidence of excess cortisol, but without the "specific" clinical signs of Cushing's syndrome. As ACS is associated with an increased risk of diabetes, obesity, high blood pressure (HBP), osteoporosis, cardiovascular events, and global mortality; its correct identification is of great importance. There are different laboratory assays to detect ACS, but all of them have some limitations. The dexamethasone suppression test is the most accepted for screening. However, there is no consensus on the cutoff point that should be used. Low levels of ACTH and DHEA-S and high urinary free cortisol are also associated with ACS, but in isolation they are of little value to establish the diagnosis. Considering its clinical implications and the lack of consensus in the diagnosis and in which is the most appropriate management of these patients, this review offers a quick reference guide of ACS, presenting an exhaustive review of the topic: its definition, epidemiology, diagnosis, clinical implications, treatment, and follow-up.

Fracture risk in women with type II diabetes. Results from a historical cohort with fracture follow-up

PURPOSE

To examine the independent association between type II diabetes and fracture risk in a population of predominantly postmenopausal women referred to a specialist clinic for osteoporosis evaluation.

METHODS

Type II diabetes associated fracture risk were evaluated among to 229 patients with type II diabetes in a cohort of 6285 women followed on average (until major osteoporotic fracture (MOF), death or end of study) for 5.8 years. Information of fracture risk factors was obtained from a clinical database and from national registries.

RESULTS

An elevated fracture risk was present. Prevalent fractures (43.7 vs. 33.2%, p = 0.0010) and prevalent MOF (26.2 vs. 20.5% p = 0.038) were more common among patients with type II diabetes. The unadjusted incident fracture risk was increased with a higher relative risk of 42%. An elevated MOF hazard ratio was present (HR = 1.726, p = 0.0006). Adjustment for prevalent osteoporosis and other possible confounders did not change this finding (HR = 1.558, p = 0.0207).

CONCLUSIONS

An association between type II diabetes and an increased risk of MOF primarily driven by an increased hip fracture risk was documented. This finding was independent of the presence of osteoporosis. Clinicians need to be aware of and adjust for these findings when evaluating patients with diabetes. Additional research examining pathophysiological mechanisms are needed.

MECHANISMS IN ENDOCRINOLOGY: Endogenous subclinical hypercortisolism and bone: a clinical review

In recent years, the condition of subclinical hypercortisolism (SH) has become a topic of growing interest. This is due to the fact that SH prevalence is not negligible (0.8-2% in the general population) and that, although asymptomatic, this subtle cortisol excess is not harmless, being associated with an increased risk of complications, in particular of osteoporosis and fragility fractures. As specific symptoms of hypercortisolism are absent in SH, the SH diagnosis relies only on biochemical tests and it is a challenge for physicians. As a consequence, even the indications for the evaluation of bone involvement in SH patients are debatable and guidelines are not available. Finally, the relative importance of bone density, bone quality and glucocorticoid sensitivity in SH is a recent field of research. On the other hand, SH prevalence seems to be increased in osteoporotic patients, in whom a vertebral fracture may be the presenting symptom of an otherwise asymptomatic cortisol excess. Therefore, the issue of who and how to screen for SH among the osteoporotic patients is widely debated. The present review will summarize the available data regarding the bone turnover, bone mineral density, bone quality and risk of fracture in patients with endogenous SH. In addition, the role of the individual glucocorticoid sensitivity in SH-related bone damage and the problem of diagnosing and managing the bone consequences of SH will be reviewed. Finally, the issue of suspecting and screening for SH patients with apparent primary osteoporosis will be addressed.

Analysis of BCLI, N363S and ER22/23EK Polymorphisms of the Glucocorticoid Receptor Gene in Adrenal Incidentalomas

CONTEXT

Patients with adrenal incidentalomas (AI) may experience detrimental consequences due to a minimal cortisol excess sustained by adrenal adenoma. SNPs of the glucocorticoid receptor gene (NR3C1) modulate individual sensitivity to glucocorticoids and may interfere with the clinical presentation.

OBJECTIVE

To compare the frequency of N363S, ER22/23EK and BclI SNPs in patients with AI with the general population and to evaluate whether these SNPs are linked to consequences of cortisol excess.

SETTING

Multicentric, retrospective analysis of patients referred from 2010 to 2014 to 4 centers (Orbassano, Milano, Messina [Italy] and Zagreb [Croatia]).

PATIENTS

411 patients with AI; 153 males and 258 females and 186 from blood donors.

MAIN OUTCOMES MEASURES

All patients and controls were genotyped for BclI, N363S and ER22/23EK and SNPs frequency was associated with clinical and hormonal features.

RESULTS

SNP frequency was: SNP frequency was: N363S 5.4% (MAF 0.027), BclI 54.7% (MAF 0.328), ER22/23EK 4.4% (MAF 0.022), without any significant difference between patients and controls. N363S was more frequent in hypertensive patients (p = 0.03) and was associated with hypertension (p = 0.015) in patients with suppressed cortisol after the 1-mg DST.

CONCLUSIONS

Our results demonstrate that SNPs of the glucocorticoid receptor gene do not play a pathogenetic role for AI. The impact of any single SNP on the phenotypic expression of minimal cortisol excess is limited and their analysis does not provide additional data that may be exploited for patient management.

Bone mineral density and intervertebral disc height in type 2 diabetes

BACKGROUND

Studies of the effect of type 2 diabetes (T2D) on bone mineral density (BMD have produced conflicting results, possibly due to failure to adjust for potential confounding factors. Nonetheless, T2D has consistently been associated with increased fracture risk, suggesting that other factors might play a role.

OBJECTIVE

This study assesses the relationship between T2D and BMD at the femoral neck and spine in diabetic and non-diabetic subjects, after adjusting for multiple covariates which may affect BMD. Intervertebral disc height was also investigated in view of its possible relation to fracture risk.

METHODS

A cross-sectional study of 100 patients with T2DM of at least 5 years duration and 86 non-diabetic subjects was carried out.

RESULTS

There were no significant differences in T scores in either the spine or femoral neck after adjustment for potential confounding variables between T2D subjects and controls. Diabetic patients had a statistically lower intervertebral disc height between the 2nd and 3rd lumbar vertebrae (D3) after adjustment for potential confounders (p=0.004). Urinary albumin:creatinine ratio, total cholesterol, LDL-cholesterol and cigarette smoking were independently associated with lower height of D3 in diabetic subjects.

CONCLUSIONS

There is no significant independent association between T2D and BMD. However we found a novel association of significantly lower disc height in patients with T2D. This may contribute to the increased vertebral fracture risk in subjects with T2D. Further studies are needed to investigate the relationship of disc height, T2D and fracture risk.