Daily Endocrinology Research Analysis
Three studies reshape endocrine diagnostics and bone risk management: a blinded diagnostic accuracy study shows the seated saline suppression test performs poorly for confirming primary aldosteronism; age-, sex-, and race-specific thyroid function reference intervals from NHANES challenge one-size-fits-all cutoffs; and a nationwide Swedish cohort reveals chronic hypoparathyroidism increases vertebral but lowers femur fracture risk and is undertreated for osteoporosis.
Summary
Three studies reshape endocrine diagnostics and bone risk management: a blinded diagnostic accuracy study shows the seated saline suppression test performs poorly for confirming primary aldosteronism; age-, sex-, and race-specific thyroid function reference intervals from NHANES challenge one-size-fits-all cutoffs; and a nationwide Swedish cohort reveals chronic hypoparathyroidism increases vertebral but lowers femur fracture risk and is undertreated for osteoporosis.
Research Themes
- Diagnostic accuracy and pathways in endocrine hypertension
- Population-specific reference intervals in thyroid disease
- Fracture risk patterns and treatment gaps in endocrine bone disorders
Selected Articles
1. Confirmatory Testing for Primary Aldosteronism : A Study of Diagnostic Test Accuracy.
In a blinded diagnostic accuracy study of 156 adults with positive PA screening, the seated saline suppression test showed poor discrimination (AUC 62.1%) with overlapping post-infusion aldosterone between responders and nonresponders and equivocal likelihood ratios across common cutoffs, indicating a high false-negative rate.
Impact: This high-quality negative study challenges a widely used confirmatory test for PA and suggests current diagnostic pathways may miss treatable cases.
Clinical Implications: Clinicians should de-emphasize SSST for confirming PA and consider alternative approaches (e.g., repeat screening under standardized conditions, other suppression tests, or earlier subtype evaluation) to avoid missed diagnoses.
Key Findings
- Post-SSST aldosterone overlapped between treatment responders and nonresponders; AUC 62.1% (95% CI, 45.1% to 79.1%).
- Positive and negative likelihood ratios were equivocal across aldosterone cutoffs 140–300 pmol/L.
- Results were consistent after accounting for treatment differences, hypokalemia, and assay type; high false-negative rate implied.
Methodological Strengths
- Blinded diagnostic accuracy design with treatment response as reference standard
- Pre-registered study and robust sensitivity analyses addressing assay and clinical factors
Limitations
- Study population enriched for high-risk PA with few nonresponders
- Single regional center may limit generalizability
Future Directions: Head-to-head comparisons of confirmatory tests, development of prediction models integrating biochemical and imaging data, and evaluation of pathways that bypass confirmatory testing for selected patients.
BACKGROUND: Confirmatory testing to verify the diagnosis of primary aldosteronism (PA) in patients who have an abnormal screening result is of uncertain benefit. OBJECTIVE: To perform a blinded assessment of the seated saline suppression test (SSST). DESIGN: Diagnostic test accuracy study. (ClinicalTrials.gov: NCT04422756). SETTING: The regional Endocrine Hypertension Clinic in Calgary, Alberta, Canada. PARTICIPANTS: 156 adults with a positive screening result for PA. INTERVENTION: The SSST was done by administering 2 L of 0.9% sodium chloride intraveno
2. Bone pain in fibrous dysplasia does not rely on aberrant sensory nerve sprouting or neuroma formation.
Using an FD mouse model and first-in-kind analysis of human FD bone biopsies, the authors show that bone pain in fibrous dysplasia is not linked to disorganized sensory nerve sprouting or neuroma formation; innervation is preserved and sensory fibers are sparse and perivascular within lesions.
Impact: This work overturns a prevailing hypothesis about the origin of FD bone pain and redirects mechanistic and therapeutic research toward non-neuropathic drivers.
Clinical Implications: Analgesic strategies targeting aberrant nerve sprouting or neuromas are unlikely to benefit FD; investigations should prioritize vascular, inflammatory, or osteoclast/osteocyte signaling pathways underlying pain.
Key Findings
- FD (EF1α-GsαR201C) mice exhibit pain-related behaviors and altered nociceptive responses not correlating with skeletal disease burden.
- Skeletal innervation pattern is preserved; sensory fibers within lesions are sparse and mainly perivascular.
- First series of human FD bone biopsies shows few, organized sensory fibers despite rich vascularization, arguing against neuroma/sprouting as pain drivers.
Methodological Strengths
- Integrated mouse behavioral phenotyping with detailed innervation mapping
- First systematic human biopsy analysis corroborating animal findings
Limitations
- Mechanistic pathways for non-neuropathic pain were not delineated
- Mouse model may not capture full spectrum of human FD heterogeneity
Future Directions: Probe vascular, immune, and bone cell signaling in FD pain; test targeted anti-inflammatory or bone remodeling modulators; longitudinal human imaging–biomarker studies correlating pain with microenvironmental changes.
Bone pain is a major symptom of many skeletal disorders. Fibrous dysplasia (FD) is a genetic disease with mono or polyostotic skeletal phenotype due to the post-zygotic occurrence of the causative Gsα mutation. Bone pain in FD often associates with skeletal deformities and fractures or nerve impingement by the pathological tissue. However, even in the absence of complications, FD patients often complain of a chronic pain that does not correlate with their disease burden. Multiple hypotheses have been made to explain this pain. However, its pathogenetic mechanisms remain, as yet, largely unexplored. In this study, we first demonstrate that the FD mouse model EF1α-GsαR201C develops behavioral impairments and altered response to nociceptive stimuli that, as in FD patients, do not correlate with their skeletal disease burden, thus providing a reliable model to study bone pain in FD. Then, we show that in EF1α-GsαR201C mice, the overall pattern of skeletal innervation is preserved and that within FD lesions, sensory fibers are variably and focally distributed, mainly at perivascular sites. Finally, we provide the first analysis of a series of human FD bone biopsies showing that, within the lesional tissue, sensory nerve fibers are few despite the rich vascular network and appear to be well-organized. These data show that, albeit sensory nerve fibers are found within FD lesions, bone pain in humans and functional impairment in mice are not associated to pathological sensory nerve sprouting or formation of neuromas in the Gsα-mutated skeleton. Little is known about the mechanisms causing the chronic and untreatable bone pain that associate with fibrous dysplasia (FD) of bone. We demonstrate that FD-related pain can be reproduced in EF1α-GsαR201C mice and provide a fine tracing of innervation of mouse FD lesions. We also characterize for the first time the sensory innervation in human FD biopsies. Our study reveals that, contrarily to long-standing beliefs, FD bone pain does not associate with haphazard growth of sensory nerve fibers or
3. Increased risk of vertebral fractures and reduced risk of femur fractures in patients with chronic hypoparathyroidism: a nationwide cohort study in Sweden.
In 1,915 Swedish patients with chronic hypoparathyroidism versus 15,838 controls, overall MOF risk was not elevated, but vertebral fractures were more common and femur fractures less common; osteoporosis was diagnosed more often yet osteoporosis medications were prescribed less frequently.
Impact: This large, registry-based study refines fracture risk profiles in chronic hypoparathyroidism and uncovers a treatment gap, informing targeted screening and therapy.
Clinical Implications: Consider vertebral fracture surveillance (imaging, risk assessment) in hypoPT, while recognizing lower hip fracture risk; address undertreatment by aligning osteoporosis therapy with individual risk and bone quality.
Key Findings
- No increased risk of major osteoporotic fracture overall (HR 0.93; 95% CI 0.69–1.26).
- Higher vertebral fracture risk (HR 1.55; 95% CI 1.12–2.14) and lower femur fracture risk (HR 0.70; 95% CI 0.50–0.98).
- Osteoporosis diagnoses more frequent (HR 1.54) but osteoporosis medications less frequently prescribed (HR 0.69).
Methodological Strengths
- Large, nationwide matched cohort using multiple Swedish registries
- Adjusted analyses with fracture subtype resolution and interaction testing
Limitations
- Observational design with potential residual confounding
- Definition based on active vitamin D treatment may miss untreated hypoPT or misclassify severity
Future Directions: Evaluate vertebral imaging strategies and anti-fracture therapies tailored to hypoPT; mechanistic studies on site-specific fracture risk and bone quality; intervention studies to close treatment gaps.
Patients with chronic hypoparathyroidism (hypoPT) have reduced bone remodeling, leading to increased bone density and abnormalities in microarchitecture and bone strength. Whether these patients have an increased fracture risk remains unclear. This study aimed to evaluate the risk of major osteoporotic fracture (MOF), osteoporosis diagnoses, and osteoporosis medication use in patients with chronic hypoPT in Sweden. Subtypes of fractures were also assessed. Using the Swedish National Patient Register, the Prescribed Drug Register, and the Total Population Register, we identified 1915 patients with chronic hypoPT treated with active vitamin D between 1997 and 2018, and 15 838 matched controls. After adjustment, patients with chronic hypoPT did not have a higher risk of MOF compared to controls (HR 0.93; 95% CI: 0.69-1.26). However, they had a higher risk of vertebral fractures (HR 1.55; 95% CI: 1.12-2.14) and a lower risk of femur fractures (HR 0.70; 95% CI: 0.50-0.98) compared to controls. They were more often diagnosed with osteoporosis (HR 1.54; 95% CI: 1.21-1.95) but less frequently prescribed osteoporosis medication (HR 0.69; 95% CI: 0.54-0.88) compared to controls. No difference in the MOF risk was observed between females and males (p for interaction = 0.872) or between patients with surgical and non-surgical chronic hypoPT (p for interaction = 0.072). In this large Swedish cohort, chronic hypoPT was not associated with an increased risk of MOF. Vertebral fracture risk was higher, while the femur fracture risk was lower compared to controls. Despite higher prevalence of osteoporosis diagnoses, these patients received less frequently osteoporosis medications.