Mifepristone reduces insulin resistance in patient volunteers with adrenal incidentalomas that secrete low levels of cortisol : a pilot study

Background: Incidental adrenal masses are commonly detected during imaging for other pathologies. 10% of the elderly population has an ‘adrenal incidentaloma’, up to 20% of these show low-grade autonomous cortisol secretion and 60% of patients with autonomous cortisol secretion have insulin resistance. Cortisol excess is known to cause insulin resistance, an independent cardiovascular risk marker, however in patients with adrenal incidentalomas it is unknown whether their insulin resistance is secondary to the excess cortisol and therefore potentially reversible. In a proof of concept study we examined the short-term effects of glucocorticoid receptor (GR) antagonism in patients with an adrenal incidentaloma to determine whether their insulin resistance was reversible. Methodology/Principal Findings: In a prospective open-label pilot study, six individuals with adrenal incidentalomas and autonomous cortisol secretion were treated with mifepristone (a GR antagonist) 200 mg twice daily and studied for 4 weeks on a Clinical Research Facility. Insulin resistance at four weeks was assessed by insulin resistance indices, lnHOMA-IR and lnMatsuda, and AUC insulin during a 2-hour glucose tolerance test. Biochemical evidence of GR blockade was shown in all individuals and across the group there was a significant reduction in insulin resistance: lnHOMA-IR (1.0vs0.6; p = 0.03), lnHOMA-%beta (4.8vs4.3; p = 0.03) and lnMatsuda (1.2vs1.6; p = 0.03). Five out of six individuals showed a reduction in insulin AUC .7237 pmol/l.min, and in two patients this showed a clinically significant cardiovascular benefit (as defined by the Helsinki heart study). Conclusions: Short-term GR antagonism is sufficient to reduce insulin resistance in some individuals with adrenal incidentalomas and mild cortisol excess. Further assessment is required to assess if the responses may be used to stratify therapy as adrenal incidentalomas may be a common remediable cause of increased cardiovascular risk

Reference interval for albumin‐adjusted calcium based on a large UK population

Context: Primary hyperparathyroidism is a common condition and results in hypercalcaemia, especially in older women. Thus, it is critical to obtain a robust estimate for the upper limit of the reference interval for albumin‐adjusted serum calcium in the general population. The current reference interval in use in the UK (Pathology Harmony range, 2.20 to 2.60 mmol/L) was based on a consensus. Objectives: To establish a reference interval for albumin‐adjusted serum calcium in men and women. Design: Cross‐sectional study of men and women who did not have chronic kidney disease or vitamin D deficiency; outliers were identified statistically and then rejected and then a 99% reference interval was calculated. Patients: 502 524 men and women aged 40 to 69 years from the UK Biobank Study. Measurements: Serum total calcium, albumin, 25‐hydroxyvitamin D, estimated glomerular function (eGFR). Results: We developed an equation for albumin‐adjusted serum calcium and applied it to 178 377 men and women who did not have chronic kidney disease or vitamin D deficiency. We identified 2962 (1.7%) as outliers, and when excluded, we report a 99% reference interval of 2.19 to 2.56 mmol/L (8.76 to 10.24 mg/dL). We found that for older (55‐69 years) and younger women (40‐55 years) the upper limits were 2.59 mmol/L and 2.57 mmol/L and that for all men, the upper limit was 2.55 mmol/L. Conclusions: We have established an upper limit of the reference range for older women that would identify all high outliers (2.60 mmol/L and above). The upper limit for young women and for men is lower, at 2.57 and 2.55 mmol/L respectively. The current reference interval in use has to be updated and improved based on these findings. These upper limits may prove helpful for identifying hypercalcaemic disorders like primary hyperparathyroidism in clinical practice

Effect of age and gender on serum periostin: Relationship to cortical measures, bone turnover and hormones

Periostin is an extracellular matrix protein, and in bone is expressed most highly in the periosteum. It increases bone formation through osteoblast differentiation, cell adhesion, Wnt signalling and collagen cross-linking. We hypothesised that serum periostin would be high at times of life when cortical modeling is active, in early adulthood and in older age, and that it would correlate with cortical bone measures, bone turnover and hormones that regulate cortical modeling. We conducted a cross-sectional observational study of 166 healthy men and women at three skeletal stages; the end of longitudinal growth (16–18 years), peak bone mass (30–32 years) and older age (over 70 years). We measured serum periostin with a new ELISA optimised for human serum and plasma which recognises all known splice variants (Biomedica). We measured the distal radius and distal tibia with HR-pQCT, and measured serum PINP, CTX, sclerostin, PTH, IGF-1, estradiol and testosterone. Periostin was higher at age 16–18 than age 30–32 (1253 vs 842 pmol/l, p < 0.001), but not different between age 30–32 and over age 70. Periostin was inversely correlated with tibia cortical thickness and density (R − 0.229, − 0.233, both p = 0.003). It was positively correlated with PINP (R 0.529, p < 0.001), CTX (R 0.427, p < 0.001) and IGF-1 (R 0.440, p < 0.001). When assessed within each age group these correlations were only significant at age 16–18, except for PINP which was also significant over age 70. We conclude that periostin may have a role in IGF-1 driven cortical modeling and consolidation in young adults, but it may not be an important mediator in older adults

Normocalcemic hyperparathyroidism : study of its prevalence and natural history

Context Normocalcemic hyperparathyroidism (NPHPT) is characterized by persistently normal calcium levels and elevated parathyroid hormone (PTH) values, after excluding other causes of secondary hyperparathyroidism. The prevalence of the disease varies greatly and the data on the natural history of this disease are sparse and inconclusive. Objectives The objectives of this study are to describe the prevalence of NPHPT and its natural history in a referral population and to compare the variability of serum calcium with a group of patients with primary hyperparathyroidism (PHPT). Design A retrospective study was conducted over 5 years. Setting The setting for this study was a metabolic bone referral center. Patients A total of 6280 patients were referred for a bone mineral density measurement (BMD). Main Outcome Measures The prevalence and natural history of NPHPT and variability of calcium were the main outcome measures. Results We identified NPHPT patients using data from the day of the BMD measurement. We excluded patients with low estimated glomerular filtration rate (eGFR) or vitamin D, or with no measurements available. Based on the evaluation of their medical files, we identified 11 patients with NPHPT (prevalence 0.18%). Only 4 patients had consistent normocalcemia throughout their follow-up, with only 2 also having consistently high PTH. None had consistently normal eGFR or vitamin D. Intermittent hypercalcemia was present in 7 of the 11 NPHPT patients. The mean adjusted calcium was found to be significantly lower in the NPHPT group compared with the PHPT group but higher than the control group. PTH was similar for NPHPT and PHPT. These 2 groups had similar variability in serum calcium. Conclusions NPHPT patients often have episodes of hypercalcemia. We believe that NPHPT is a mild form of PHPT

Normocalcaemic hyperparathyroidism (NPHPT) and primary hyperparathyroidism (PHPT): Least significant change (LSC) for adjusted serum calcium

Introduction: The least significant change (LSC) is a term used in individuals in order to evaluate whether one measurement has changed significantly from the previous one. It is widely used when assessing bone mineral density (BMD) scans. To the best of our knowledge, there no such estimate available in the literature for patients with disorders of calcium metabolism. Our aim was to provide an estimate of the least significant change for albumin-adjusted calcium in patients with normocalcaemic hyperparathyroidism (NPHPT) and primary hyperparathyroidism (PHPT). Methods: We used the within subject standard deviation calculated in a population of NPHPT and PHPT patients and multiplied it by 2.77. Results: The LSC for NPHPT and PHPT were found to be 0.25 and 0.24 mmol/L respectively (1.00 and 0.96 mg/dL). In clinical practice, the value of 0.25 mmol/L could be used. Discussion: The least significant change given, could be used in two ways in these patients. First, it gives a range to which values are expected. This can provide some reassurance for the patient and the physician in cases of intermittent hypercalcaemia. Moreover, it can be a marker of whether an individual has an actual significant change of his calcium after parathyroid surgery

Antiresorptive versus anabolic therapy in managing osteoporosis in people with type 1 and type 2 diabetes

Diabetes is characterized by hyperglycemia, but the two main types, type 1 diabetes (T1D) and type 2 diabetes (T2D), have distinct pathophysiology and epidemiological profiles. Individuals with T1D and T2D have an increased risk of fractures, particularly of the hip, upper arm, ankle, and nonvertebral sites. The risk of fractures is higher in T1D compared to T2D. The diagnosis of osteoporosis in individuals with T1D and T2D follows similar criteria as in the general population, but treatment thresholds may differ. Antiresorptive therapies, the first-line treatment for osteoporosis, are effective in individuals with T2D. Observational studies and post hoc analyses of previous trials have indicated that antiresorptive drugs, such as bisphosphonates and selective estrogen receptor modulators, are equally effective in reducing fracture risk and increasing bone mineral density (BMD) in individuals with and without T2D. Denosumab has shown similar effects on vertebral fracture risk but increases the risk of nonvertebral fractures. Considering the low bone turnover observed in T1D and T2D, anabolic therapies, which promote bone formation and resorption, have emerged as a potential treatment option for bone fragility in this population. Data from observational studies and post hoc analyses of previous trials also showed similar results in increasing BMD and reducing the risk of fractures in people with or without T2D. However, no evidence suggests that anabolic therapy has greater efficacy than antiresorptive drugs. In conclusion, there is an increased risk of fractures in T1D and T2D. Reductions in BMD cannot solely explain the relationship between T1D and T2D and fractures. Bone microarchitecture and other factors play a role. Antiresorptive and anabolic therapies have shown efficacy in reducing fracture risk in individuals with T2D, but the evidence is more robust for antiresorptive drugs. Evidence in T1D is scant. Further research is needed to fully understand the underlying mechanisms and optimize management strategies for bone fragility in T1D and T2D. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Microarchitecture of bone predicts fractures in older women

High-resolution peripheral quantitative CT (HRpQCT) provides more detailed information than older methods. A new study shows that radial and tibial HRpQCT measurements are associated with incident fracture in postmenopausal women. However, it is unclear whether HRpQCT improves fracture risk prediction enough to justify its use in clinical practice