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.

Prevalence of less severe hypercortisolism in fractured patients admitted in an outpatient clinic for metabolic bone diseases

PURPOSE

To evaluate the prevalence of less severe hypercortisolism (LSH) in fractured patients, and its association with hypertension, hyperglicemia, dyslipidemia, and obesity.

METHOD

From July 2015 to October 2018 we enrolled all fractured patients admitted in our outpatient center for metabolic bone diseases, after exclusion of patients with secondary osteoporosis apart from diabetes and taking drugs known to affect bone metabolism. In all enrolled patients we collected data regarding gonadal status, history of diabetes, high blood pressure, dyslipidemia, and measured blood pressure, lipid profile, fasting glycaemia. Bone mass was measured with DXA at lumbar spine and femoral neck and the presence of fractures was evaluated with X-ray of thoracic and lumbar spine. All patients performed twice, 1 mg overnight dexametasone suppression test (DST) and, as confirmatory, 2day low-dose DST for diagnosing hypercortisolism.

RESULTS

We enrolled 101 fractured patients (75 females, 26 males), aged 65 ± 10.3 years. Five out of 101 (5.0%) patients were diagnosed as LSH. Fifty-five (54.5%) out of 101 were hypertensive, 57 (56.4%) dyslipidemic, 17 (16.8%) hyperglicaemic, 28(27.7%) obese patients. LSH tended to be associated to blood hypertension [5/5 vs 50/96 (Fisher exact test, p = 0.06) hypertensive patients]. Four out five LSH patients were hypogonadic.

CONCLUSIONS

Our study confirms that a nonnegligible percentage of fractured subjects actually presents an unrecognized hypercortisolism. Accordingly, regardless of age, we suggest to screen for hypercortisolism all patients with established osteoporosis and in particular hypertensive subjects.

Normocalcemic primary hyperparathyroidism: an update

Normocalcemic primary hyperparathyroidism (NPHPT) is diagnosed in the setting of elevated PTH concentrations with consistently normal albumin-adjusted and ionized serum calcium levels, in absence of secondary causes for elevated PTH concentrations. In order to confirm persistence of the hyperparathyroid state, PTH levels should be elevated on at least two occasions over a 3 to 6 months period. The prevalence of NPHPT depends on the population studied. Data from different studies are often not comparable; indeed, different criteria have been used to exclude secondary hyperparathyroidism. Notwithstanding such limits, the prevalence of NPHPT in studies including ionized calcium dosage was between 0.5% and 0.7%. Available data suggest that patients with NPHPT are likely to have more skeletal, kidney and metabolic complications compared to healthy subjects, but almost all studies suffer from possible misclassification of patients due to lack of ionized calcium dosage. The management of NPHPT is controversial in part due to lack of solid data about the natural history. However, surgical treatment is currently performed more frequently than in the past, although studies do not show, so far, a clear benefit from intervention.

MEN1 gene mutation with parathyroid carcinoma: first report of a familial case

BACKGROUND

The occurrence of parathyroid carcinoma in multiple endocrine neoplasia type I (MENI) is rare and the 15 cases of malignant parathyroid tumor reported so far have been associated with MENI in individuals and not with multiple members within a family.

METHODS

We report on a 61-year-old male, operated for a 7.3 cm parathyroid carcinoma infiltrating the esophagus. In his brother, a 4.6 cm parathyroid carcinoma was diagnosed histologically, while in the daughter, neck ultrasonography revealed 2 extrathyroidal nodules, yet to be excised.

RESULTS

Screening of the MEN1 gene identified a known germline heterozygous missense mutation (c.1252G>A; p.D418N) in exon 9, in all affected subjects.

CONCLUSIONS

The occurrence of parathyroid carcinoma in more than one affected member of a single MEN1 family represents the first reported familial case. This suggests that additional constitutional genetic mutations may contribute to the variation in malignant potential and clinical behavior of parathyroid tumors in MEN1.

Vitamin D status in primary hyperparathyroidism: effect of genetic background

Primary hyperparathyroidism (PHPT) is associated with hypovitaminosis D as assessed by serum total 25-hydroxyvitamin D (TotalD) levels. The aim of this study is to evaluate whether this is also the case for the calculated bioavailable 25-hydroxyvitamin D (BioD) or free 25-hydroxyvitamin D (FreeD), and whether the vitamin D status is influenced by genetic background. We compared vitamin D status of 88 PHPT patients each with a matched healthy family member sharing genetic background, i.e., first-degree relative (FDR), or not, namely an in-law relative (ILR). We compared TotalD and vitamin D-binding protein (DBP), using the latter to calculate BioD and FreeD. We also genotyped two common DBP polymorphisms (rs7041 and rs4588) likely to affect the affinity for and levels of vitamin D metabolites. TotalD was lower (p < 0.001) in PHPT (12.3 ± 6.6 ng/mL) than either family member group (FDR: 19.4 ± 12.1 and ILR: 23.2 ± 14.1), whether adjusted for DBP or not. DBP levels were also significantly lower (p < 0.001) in PHPT (323 ± 73 mg/L) versus FDR (377 ± 98) or ILR (382 ± 101). The differences between PHPT and control groups for TotalD, BioD, and FreeD were maintained after adjustment for season, gender, and serum creatinine. 25-hydroxyvitamin D, evaluated as total, free, or bioavailable fractions, is decreased in PHPT. No difference was seen between first-degree relative and in-law controls, suggesting that neither genetic nor non-genetic background greatly influences the genesis of the hypovitaminosis D seen in PHPT.

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.

Increased prevalence of the GCM2 polymorphism, Y282D, in primary hyperparathyroidism: analysis of three Italian cohorts

CONTEXT

Glial cells missing-2 (GCM2) is key for parathyroid gland organogenesis. Its persistent expression in the adult parathyroid raises the possibility that overactive forms play a role in the evolution of parathyroid hyperactivity or tumorigenesis. A GCM2 c.844T → G; p.Y282D missense variant has been described within a transactivation inhibitory domain (amino acids 263-352).

OBJECTIVE

The aims of the study were to 1) assess the frequency of Y282D in Italian primary hyperparathyroidism (PHPT) and control (C) populations, 2) test for association of 282D with PHPT and its phenotypic features, and 3) compare the transactivation potency of GCM2 282D relative to wild-type Y282.

SUBJECTS AND METHODS

Subjects included a large southern Italian cohort (310 PHPT and 433 C) and 2 replication cohorts from northern Italy. Association of 282D with PHPT was tested in all cohorts and with phenotypic features in the larger PHPT cohort. An in vitro GCM promoter-luciferase reporter assay was conducted in HEK293 cells.

RESULTS

282D was significantly increased in the PHPT group, with a minor allele frequency of 0.066 compared with 0.029 in the C group (P = .0008), in the discovery cohort and was more prevalent in the replication cohorts. Combined analysis (510 PHPT and 665 C) yielded a likelihood ratio of 2.27 (95% confidence interval = 1.50-3.42; P < .0001). The 282D variant was not associated with serum calcium, phosphate, creatinine, or PTH levels or with bone mineral density, fractures, or renal stones in the PHPT group. The 282D variant had significantly greater transcriptional activity than the wild-type Y282 (17× basal vs 12× basal; P < 0.05).

CONCLUSION

The higher frequency of GCM2 282D in PHPT and enhanced transcriptional activity of this variant supports the notion that it could contribute causally to parathyroid tumorigenesis.

Long-term follow-up in adrenal incidentalomas: an Italian multicenter study

CONTEXT

The long-term consequences of subclinical hypercortisolism (SH) in patients with adrenal incidentalomas (AIs) are unknown.

SETTING AND PATIENTS

In this retrospective multicentric study, 206 AI patients with a ≥5-year follow-up (median, 72.3 mo; range, 60-186 mo) were enrolled.

INTERVENTION AND MAIN OUTCOME MEASURES

Adrenocortical function, adenoma size, metabolic changes, and incident cardiovascular events (CVEs) were assessed. We diagnosed SH in 11.6% of patients in the presence of cortisol after a 1 mg-dexamethasone suppression test >5 μg/dL (138 nmol/L) or at least two of the following: low ACTH, increased urinary free cortisol, and 1 mg-dexamethasone suppression test >3 μg/dL (83 nmol/L).

RESULTS

At baseline, age and the prevalence of CVEs and type 2 diabetes mellitus were higher in patients with SH than in patients without SH (62.2 ± 11 y vs 58.5 ± 10 y; 20.5 vs 6%; and 33.3 vs 16.8%, respectively; P < .05). SH and type 2 diabetes mellitus were associated with prevalent CVEs (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1-9.0; and OR, 2.0; 95% CI, 1.2-3.3, respectively), regardless of age. At the end of the follow-up, SH was diagnosed in 15 patients who were without SH at baseline. An adenoma size >2.4 cm was associated with the risk of developing SH (sensitivity, 73.3%; specificity, 60.5%; P = .014). Weight, glycemic, lipidic, and blood pressure control worsened in 26, 25, 13, and 34% of patients, respectively. A new CVE occurred in 22 patients. SH was associated with the worsening of at least two metabolic parameters (OR, 3.32; 95% CI, 1.6-6.9) and with incident CVEs (OR, 2.7; 95% CI, 1.0-7.1), regardless of age and follow-up.

CONCLUSION

SH is associated with the risk of incident CVEs. Besides the clinical follow-up, in patients with an AI >2.4 cm, a long-term biochemical follow-up is also required because of the risk of SH development.

Bilateral and unilateral adrenal incidentalomas: biochemical and clinical characteristics

OBJECTIVE

The possible different prevalence of arterial hypertension (AH), type 2 diabetes mellitus (T2DM), dyslipidaemia (DL) and vertebral fractures (FX) between patients with bilateral and unilateral adrenal incidentalomas (BAI and UAI, respectively) with and without subclinical hypercortisolism (SH) is unknown. In this study we compared the prevalence of AH, T2DM, DL and FX in BAI and UAI patients in relation to SH.

DESIGN

Prospective study.

METHODS

In 175 UAI and 38 BAI patients, we evaluated BMI, spinal and femoral bone mineral density (LS and FN BMD, respectively) and the presence of AH, T2DM, DL and FX. SH was diagnosed in the presence of 2 of the following: urinary free cortisol levels >193 nmol/24 h, serum cortisol levels after 1 mg dexamethasone suppression test >83 nmol/l or ACTH levels <2.2 pmol/l.

RESULTS

Age, BMI and cortisol secretion were comparable, while FN BMD was lower in BAI than in UAI patients (-0.45±0.86 vs 0.09±1.07, P=0.004). The prevalence of SH, AH, T2DM, and DL was comparable, while the prevalence of FX was higher in BAI than in UAI (52.6 vs 28%, P=0.007). The presence of FX was associated with BAI (odds ratio (OR) 2.6, 95% confidence interval (95% CI) 1.2-5.6, P=0.016), after adjusting for SH (OR 1.77, 95% CI 0.85-3.7, P=0.12), BMI (OR 1.06, 95% CI 0.98-1.13, P=0.1), age (OR 1.07, 95% CI 1.04-1.11, P=0.0001) and LS BMD (OR 1.31, 95% CI 1.03-1.67, P=0.03).

CONCLUSION

BAI patients have an increased FX risk than UAI ones. Further studies should investigate the causes of bone involvement in BAI patients.

Carboxyl-terminal parathyroid hormone fragments: biologic effects

Carboxyl-terminal PTH fragments (C-PTH), are generated by both direct secretion from parathyroids in relation to serum calcium levels and catabolism of PTH operated by the Kupffer cells in the liver. These molecular fragments have been till recently regarded as inert byproducts of PTH metabolism, since they do not interact with the PTH/PTH-related peptide (rP) receptor, which mediates the classical hormone actions. Current findings instead indicate that C-PTH would interact with a putative C-PTH receptor. This way, C-PTH seem to exert specific effects on calcium homeostasis and bone metabolism, opposite to those of the synthetic agonist of PTH/PTHrP receptor (i.e. PTH 1-34). In vitro and in vivo data actually indicate that C-PTH, by interacting with specific receptors, could have an anti-calcemic action, as well as a pro-apoptotic effect on both osteocytes and osteoclasts. This in turn could result in a reduced activity of the latter cells, with a consequent inhibition of bone resorption.

Subclinical hypercortisolism: correlation between biochemical diagnostic criteria and clinical aspects

OBJECTIVE

Subclinical hypercortisolism (SH) has been associated with increased prevalence of hypertension, type 2 diabetes mellitus, dyslipidaemia, central obesity, osteoporosis and vertebral fractures. We aimed to investigate the accuracy of different SH diagnostic criteria in predicting the presence of complications.

DESIGN

This was a retrospective study.

PATIENTS

We evaluated data from 231 patients (120 women and 111 men) affected with adrenal incidentalomas (AI).

MEASUREMENTS

We studied the accuracy of different SH diagnostic criteria (cortisol after 1 mg overnight dexamethasone suppression test - 1mg-DST - at different cut-off such as 49.7, 82.8, 137.9 nmol/l, elevated urinary free cortisol, reduced adrenal corticotroph hormone (ACTH) levels alone or various combination of these parameters) in predicting the concomitant presence of the following three complications: hypertension, type 2 diabetes and vertebral fractures.

RESULTS

The criterion characterized by the presence of two of 1mg-DST >82.8 nmol/l, elevated UFC and reduced ACTH struck the best balance between sensitivity and specificity, reaching a good accuracy in predicting the cluster of complications (61.9%; 77.1% and 75.8%, respectively). The presence of this cluster was associated with this criterion (OR 4.75, 95%CI 1.8-12.7, P = 0.002) regardless of gonadal status, body mass index (BMI) and age.

CONCLUSIONS

The SH criterion characterized by the presence of two of 1mg-DST >82.8 nmol/l, elevated UFC and reduced ACTH seems the best in predicting the presence of chronic manifestations of subtle cortisol excess.

Role of adrenal gland scintigraphy in patients with subclinical hypercortisolism and incidentally discovered adrenal mass

BACKGROUND

The role of adrenal scintigraphy (AS) in the diagnosis of subclinical hypercortisolism (SH) in adrenal incidentaloma (AI) is debated.

AIM

To evaluate the possible role of AS in identifying SH in AI patients.

SUBJECTS AND METHODS

In the retrospective phase (2000-2004), 102 AI patients [71 females (F)/31 males (M)] referred to our center were reevaluated for SH. In the prospective phase (2005-2006), 42 patients (32F/10M) with suspected SH were evaluated performing AS and biochemical assessment of cortisol secretion. We report data of the prospective phase of the study. In these patients AS was performed at baseline; the difference between the uptake of the affected and the controlateral gland [mean Delta uptake (MDeltau)] was calculated. Cortisol secretion was evaluated in 3 different occasions. Patients were considered affected with SH if they presented at least twice 2 of the following criteria: urinary free cortisol >193 nmol/l, cortisol after 1 mg dexamethasone suppression test >83 nmol/l, ACTH levels <2.2 pmol/l.

RESULTS

MDeltau was higher in patients with SH (no.=27, 5/22 M/F) than in patients without SH (83.7+/-12.5 vs 54.7+/-24.1%, p<0.001), and directly correlated with UFC (beta=0.387, p=0.015) and was predictive of SH (odds ratio 1.12, 95% confidence interval 1.03-1.22, p=0.009) regardless of age, body mass index, and diameter of the mass. A 75% MDeltau cut-off has 86.7% specificity and 81.5% sensitivity in diagnosing SH.

CONCLUSIONS

AS is not recommended as screening test in AI patients, but it can be useful to exclude the presence of a subtle cortisol excess in patients with unclear biochemical diagnosis of SH.