Primary Aldosteronism and Bone Metabolism: A Systematic Review and Meta-Analysis

Increased risk of osteoporotic fractures and osteoporosis in patients with Addison's disease in Sweden: A nationwide population-based cohort study

BACKGROUND

The risk of major osteoporotic fractures (MOFs) and osteoporosis in patients with autoimmune Addison's disease (AAD) is unclear.

OBJECTIVE

To investigate the risk of MOF in patients with AAD and the possible correlation with adrenal hormone replacement doses.

METHODS

Swedish national health registers were used to identify 1869 subjects with AAD and 16,844 matched controls. The primary outcome was MOF, and the secondary outcome was treatment with osteoporosis medications. Marginal Cox models were used to compare time-to-event outcomes. The study period spanned from 1 July 2005 until 31 December 2020. Individuals at risk were followed from inclusion until censored or the end of the study period.

RESULTS

A total of 77 patients with AAD (7.1/1000 person-years [PY]), and 387 matched controls (3.9/1000 PY) were diagnosed with MOF. The risk of MOF was higher in patients with AAD compared to matched controls, with an adjusted hazard ratio (aHR) of 1.82 (95% confidence interval [CI], 1.41-2.35) and increased in both male and female patients, with aHR of 2.51 (95% CI, 1.56-4.02) and 1.65 (95% CI, 1.22-2.24), respectively. Patients with AAD had an increased risk of treatment with osteoporosis medications: aHR 3.25 (95% CI, 2.71-3.99), compared to controls. No significant differences in MOF rates were observed between patients treated with intermediate or high doses of glucocorticoids compared to low doses (p = 0.967 and p = 0.580, respectively). Similarly, stratification by mineralocorticoid dose (<0.10 vs. ≥0.10 mg/day) showed no significant association regarding MOF (p = 0.915).

CONCLUSIONS

The risk of MOF is increased in patients with AAD without any apparent correlation to adrenal hormone replacement doses.

Mild autonomous cortisol secretion leads to reduced volumetric BMD at lumbar spine in patients with primary aldosteronism

Objectives

Glucocorticoid cosecretion is more common in primary aldosteronism (PA) than previously thought. Chronic subtle cortisol excess in patients with mild autonomous cortisol secretion (MACS) negatively affects bone health. This study aimed to evaluate the impact of MACS on bone density and turnover markers in PA patients.

Methods

Patients with PA and MACS (n = 50), confirmed by a 1-mg dexamethasone suppression test (DST) with a cortisol cutoff of ≥1.8 µg/dL without symptoms of overt Cushing, were compared to age- and sex-matched patients with PA without MACS (non-MACS, n = 50). Lumbar volumetric bone mineral density (vBMD) was extracted by a novel convolutional neural network (CNN)-based framework (SpineQ software v1.0) applied to routine CT data, incorporated into the diagnostic protocol for PA. Additionally, bone turnover markers-including osteocalcin, bone-specific alkaline phosphatase, N-terminal propeptide of type I collagen, and carboxy-terminal crosslinked telopeptide of type I collagen were evaluated between the groups.

Results

Median cortisol after DST was 1.1 µg/dL (30.3 nmol/L) [IQR: 0.5 µg/dL (13.8 nmol/L)] in the non-MACS group and 2.5 µg/dL (69.0 nmol/L) [IQR: 1.4 µg/dL (38.5 nmol/L)] in the MACS group (p < 0.001). Patients with MACS had significantly lower vBMD values compared to the non-MACS group (106.4 mg/cm³ vs. 116.6 mg/cm³, p = 0.038). Cortisol after DST negatively correlated with vBMD (Spearman's r=-0.33, p=0.00042). No significant differences in bone turnover markers were found, and classifications based on visible lesions on CT or PA-lateralization via adrenal venous sampling did not reveal any significant differences in these markers (p > 0.05 for all comparisons).

Conclusion

Despite non-significant differences in bone turnover markers between patients with PA with or without MACS, CT scans revealed significantly reduced vBMD in PA and MACS patients, indicating compromised bone health and vBMD significantly negatively correlated with cortisol post DST. Thus, opportunistic evaluation of vBMD in routine CT screenings could aid in the early detection of bone alterations in MACS and help mitigate potential long-term adverse effects on bone health.

Hip fractures in patients with primary aldosteronism - a Swedish nationwide study

In this large population-based matched cohort study, patients with primary aldosteronism were at increased risk of hip fracture, particularly subgroups traditionally considered at higher risk of osteoporosis such as women, patients older than 56 years at diagnosis, patients with established cardiovascular disease at diagnosis, and patients treated with MRA.

PURPOSE

Previous studies suggest that primary aldosteronism (PA) is associated with dysregulated bone homeostasis. The aim of this study was to evaluate the incidence of hip fractures in patients with PA.

METHODS

We studied a nationwide cohort of 2419 patients with PA (1997-2019) and 24 187 age and sex matched controls from the general population. Hip fractures were identified by ICD codes in the Swedish National Patient Register. We estimated hazard ratios (HRs) for incident hip fractures, adjusted for prior fractures, socioeconomic factors, diabetes, osteoporosis, hyperparathyroidism, and cardiovascular disease (CVD). Pairwise subgroup comparisons were performed by age (18-56 and > 56 years), sex, CVD at baseline, and treatment for PA.

RESULTS

During a mean follow up of 8 ± 5 years, 64 (2.6%) patients had a hip fracture after being diagnosed with PA, compared to 401 (1.7%) controls. After adjustments, PA was associated with a 55% increased risk of hip fracture compared to controls (HR 1.55 [1.18-2.03]). HRs were increased in women (HR 1.76 [95% CI 1.24-2.52]), patients aged > 56 years (HR 1.62 [95% CI 1.21-2.17]), and patients with CVD at diagnosis (HR 2.15 [95% CI 1.37-3.37]). PA patients treated with adrenalectomy did not have higher risk than controls (HR 0.84 [95% CI 0.35-2.0]), while patients treated with mineralocorticoid receptor antagonists (MRA) retained a greater risk (HR 1.84 [95% CI 1.20-2.83]).

CONCLUSION

PA is associated with increased hip fracture risk, especially in women, patients diagnosed after the age of 56 years and patients with established CVD at diagnosis. Also, patients treated with MRA seem to have an increased risk of hip fractures, while adrenalectomy may be protective.

Moderate salt restriction in primary aldosteronism improves bone metabolism through attenuation of urinary calcium and phosphate losses

Accumulating evidence links osteoporosis and dietary salt consumption. Primary aldosteronism (PA) is a model disease with increased dietary salt intake and constitutes an independent risk factor for osteoporosis. We, thus, assessed whether a short-term moderate reduction in salt intake in PA results in detectable osteoanabolic effects. Forty-one patients with PA on stable mineralocorticoid receptor antagonist therapy were subjected to a 12-week salt restriction. Serum and urinary electrolytes, markers of bone turnover, and a 15 steroids plasma profile were registered. After 12 weeks, urinary calcium and phosphate decreased, while plasma testosterone, serum phosphate, and bone alkaline phosphatase (BAP) all increased significantly. Longitudinal changes in BAP were independently correlated with changes in serum phosphate, parathyroid hormone, and urinary calcium in multivariate analysis. Salt restriction in PA limits urinary calcium and phosphate losses and may confer favorable osteoanabolic effects. Our findings suggest that salt restriction should be considered in patients with PA to improve bone health.

Epidemiology and diagnosis of primary aldosteronism. What have we learned from the SPAIN-ALDO registry?

PURPOSE

To summarize the available data on the prevalence, clinical repercussion, and diagnosis of primary aldosteronism (PA) and to discuss the SPAIN-ALDO registry's findings, which is the largest PA patient registry in Spain.

METHODS

A comprehensive review of the literature focused on the prevalence, clinical presentation and diagnosis of PA was performed.

RESULTS

PA is the most common cause of secondary arterial hypertension. In addition, PA patients have a higher cardio-metabolic risk than patients with essential arterial hypertension matched by age, sex, and blood pressure levels. However, despite its high prevalence and associated metabolic and cardiovascular complications, PA remains largely under-recognized, with less than 2% of people in at-risk populations ever tested. The diagnostic investigation is a multistep process, including screening, confirmatory testing, and subtype differentiation of unilateral from bilateral PA forms. Data from the SPAIN-ALDO registry have shed light on the cardiometabolic impact of PA and about the limitations in the PA diagnosis of these patients in Spain.

CONCLUSIONS

The most common cause of secondary hypertension is PA. One of the most challenging aspects of the diagnosis is the differentiation between unilateral and bilateral PA because adrenal venous sampling is a difficult procedure that should be performed in experienced centers. Data from the SPAIN-ALDO registry have provided important information on the nationwide management of this pathology.

Follow-up care and assessment of comorbidities and complications in patients with primary aldosteronism: The clinical practice guideline of the Taiwan Society of aldosteronism

Primary aldosteronism (PA) is the most common form of endocrine hypertension, characterized by excess aldosterone production that leads to an increased risk of cardiovascular events and target organ damage. Both adrenalectomy and medical treatment have shown efficacy in improving clinical outcomes and comorbidities associated with PA, including a specific subtype of PA with autonomous cortisol secretion (ACS). Understanding the comorbidities of PA and establishing appropriate follow-up protocols after treatment are crucial for physicians to enhance morbidity and mortality outcomes in patients with PA. Additionally, the screening for hypercortisolism prior to surgery is essential, as the prognosis of patients with coexisting PA and ACS differs from those with PA alone. In this review, we comprehensively summarize the comorbidities of PA, encompassing cardiovascular, renal, and metabolic complications. We also discuss various post-treatment outcomes and provide insights into the strategy for glucocorticoid replacement in patients with overt or subclinical hypercortisolism. This clinical practice guideline aims to equip medical professionals with up-to-date information on managing concurrent hypercortisolism, assessing treatment outcomes, and addressing comorbidities in patients with PA, thereby improving follow-up care.

Sex-specific association of low-renin hypertension with metabolic and musculoskeletal health in Korean older adults

Introduction

Low-renin hypertension (LRH) accounts for approximately one-third of patients with hypertension and are more prevalent in women and the older adult population. Previous study has found a link between the renin-angiotensin-aldosterone system (RAAS) and sex hormones. However, there are insufficient data on the relationship between LRH and metabolic or musculoskeletal outcomes in older adults.

Methods and materials

Among the 343 participants from a population-based cohort study conducted between May 2018 and August 2019, a total of 256 (86 men older than 50 years and 170 postmenopausal women) were included. The presence of LRH was defined as plasma renin activity (PRA) <1 ng/mL/h and systolic blood pressure (BP) ≥130 or diastolic BP ≥80 mmHg based on the 2017 ACC/AHA guidelines. Individuals with missing data, and those who had used medications that could affect PRA within the past six months were excluded. Bone mineral density (BMD), trabecular bone score (TBS), and appendicular lean mass (ALM) index were assessed using dual-energy X-ray absorptiometry; degraded TBS was defined as partially degraded to degraded levels (≤1.350). Muscle function was assessed according to the Asian Working Group for Sarcopenia guidelines. PRA was measured using radioimmunoassay.

Results

The median age was 66 [61-72] years, and the body mass index (BMI) was 24.7 [23.0-26.4] kg/m2. Individuals with LRH, accounting for 34.8%, had lower diabetes mellitus; more dyslipidemia; and poorer muscle function, BMD, and TBS than those in the non-LRH group. In addition, PRA was positively correlated with C-peptide, HOMA-IR, TBS, and ALM index. After adjusting for covariates including age and BMI, LRH was negatively associated with femur neck T-score (adjusted β = -0.30, 95% CI [-0.55 to -0.05], p = 0.021) and the presence of LRH was significantly associated with degraded TBS in women (adjusted odds ratio = 3.00, 95% CI [1.36-6.58], p = 0.006).

Conclusion

Our findings suggest that LRH can influence clinical features and metabolic risk in older adults. Notably, LRH in postmenopausal women was linked to lower femur neck T-scores and degraded TBS, indicating sex-specific effects of LRH on bone health. Larger prospective studies are required to elucidate how changes in the RAAS affect metabolic and musculoskeletal outcomes in older adults.

The Influence of Hyponatremia and Hypokalemia on the Risk of Fractures in Various Anatomical Regions among Adult Trauma Patients: A Propensity Score-Matched Analysis

BACKGROUND

Hyponatremia and hypokalemia are common electrolyte imbalances in trauma patients and have been identified to be risk factors for a fall. In addition, hyponatremia was reported to be related to osteoporosis and fragility fractures, while the association between hypokalemia and osteoporosis has only been reported in rare case reports. This study investigated the impact of hyponatremia and hypokalemia on the incidence of fractures in various body regions of adult trauma patients, using the propensity score-matched patient cohort to reduce the influence of patients' baseline characteristics.

METHODS

The study analyzed data from 11,173 hospitalized adult trauma patients treated from 1 January 1998, to 31 December 2022. The study included 1968 patients with hyponatremia and 9205 without, and 1986 with hypokalemia and 9187 without. Different 1:1 propensity score-matched cohorts were generated to create the 1903 pairings of patients with or without hyponatremia, 1977 pairings of patients with or without hypokalemia, and 380 pairing of patients with both hyponatremia and hypokalemia vs. normal control patients. Analysis was conducted on the incidence of fracture in various anatomic regions.

RESULTS

Hyponatremic patients had increased odds of thoracic vertebral fracture [odds ratio (95% confidence interval) 1.63 (1.10-2.42), p = 0.014], pelvic fracture [2.29 (1.12-4.67), p = 0.019], and femoral fracture [1.28 (1.13-1.45), p < 0.001] but decreased odds of radial and patella fractures. Hypokalemic patients showed no significant differences in fracture risk except for a decreased likelihood of radial fractures. The patients with both hyponatremia and hypokalemia showed a decreased likelihood of radial fractures and patella fractures.

CONCLUSION

Hyponatremia may have a greater impact on the occurrence of bone fractures than hypokalemia in trauma patients who have suffered a fall. Electrolyte abnormalities should be taken into account while assessing the risk of fractures in trauma patients.

Proteomic Analysis Based on TMT Regarding the Therapeutic Action of Rhizoma Drynariae on Rats in an Osteoporosis Model

BACKGROUND

Primary osteoporosis has increasingly become one of the risk factors affecting human health, and the clinical effect and action mechanism of traditional Chinese medicine in the treatment of primary osteoporosis have been widely studied. Previous studies have confirmed that in traditional Chinese medicine (TCM), Drynaria rhizome has a role in improving bone density. In this study, a tandem mass tag (TMT)-based proteomic analysis was conducted to derive potential targets for Drynaria rhizome treatment in postmenopausal osteoporosis.

METHODS

The model group (OVX) and experimental group (OVXDF) for menopausal osteoporosis were established using the universally acknowledged ovariectomy method, and the OVXDF group was given 0.48g/kg Rhizoma Drynariae solution by gavage for 12 weeks. After 12 weeks, femurs of rats selected for this study were examined with a bone mineral density (BMD) test, Micro-CT, ELISABiochemical testing, hematoxylin and eosin (HE) staining, and immunohistochemistry. A certain portion of the bone tissue was studied with a TMT-based proteomic analysis and functional and pathway enrichment analysis. Finally, key target genes were selected for Western blotting for validation.

RESULTS

The comparison of the OVXDF and OVX groups indicated that Drynaria rhizome could improve bone density. In the TMT-based proteomic analysis, the comparison of these two groups revealed a total of 126 differentially expressed proteins (DEPs), of which 62 were upregulated and 64 were downregulated. Further, by comparing the differential genes between the OVXDF and OVX groups and between the OVX and SHAM groups, we concluded that the 27 differential genes were significantly changed in the rats selected for the osteoporosis model after Drynaria rhizome intragastric administration. The gene ontology (GO) enrichment analysis of DEPs showed that molecular function was mainly involved in biological processes, such as glucose metabolism, carbohydrate metabolism, immune responses, and aging. A Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of DEPs revealed that multiple differential genes were enriched in the estrogen and peroxisome proliferator-activated receptor (PPAR) signaling pathways. Relationships with nitrogen metabolism, glycerophospholipid metabolism, secretion systems, and tumor diseases were also observed. Western blotting was consistent with the analysis.

CONCLUSIONS

We used TMT-based proteomics to analyze the positive effects of TCM Drynaria rhizome, which can regulate related proteins through the unique roles of multiple mechanisms, targets, and pathways. This treatment approach can regulate oxidative stress, improve lipid metabolism, reduce the inflammatory response mechanism, and improve bone density. These benefits highlight the unique advantages of TCM in the treatment of primary osteoporosis.

Cross-Disciplinary Approach of Adrenal Tumors: Insights into Primary Aldosteronism-Related Mineral Metabolism Status and Osteoporotic Fracture Risk

Our objective was to overview the novel aspects in the field of adrenal gland neoplasms, namely, the management of bone status with respect to primary aldosteronism (PA). In the current narrative review, a PubMed study was conducted from inception until June 2023. The inclusion criteria were: human (clinically relevant) studies of any study design (at least 10 patients per study); English papers; and the following combination of key words within the title and/or abstract: "aldosterone" AND "bone", "skeleton", "osteoporosis", "fracture", "calcium", "parathyroid", "DXA", "osteocalcin", "P1NP", "alkaline phosphatase", "bone marker", "trabecular bone score", or "FRAX". The exclusion criteria were in vitro or animal studies, reviews, and case reports/series. We screened 1027 articles and finally included 23 studies (13 of case-control type, 3 cross-sectional, 5 prospective, 1 observational cohort, and 1 retrospective study). The assessments provided in these studies were as follows: nine studies addressed Dual-Energy X-ray Absorptiometry (DXA), another study pointed out a bone microarchitecture evaluation underlying trabecular bone score (TBS), and seven studies investigated the bone turnover markers (BTMs) profile. Moreover, 14 studies followed the subjects after adrenalectomy versus medical treatment, and 21 studies addressed secondary hyperparathyroidism in PA patients. According to our study on published data during a period of almost 40 years (n = 23, N = 3965 subjects aged between 38 and 64, with a mean age 56.75, and a female-to-male ratio of 1.05), a higher PTH in PA versus controls (healthy persons or subjects with essential hypertension) is expected, secondary hyperparathyroidism being associated in almost half of the adults diagnosed with PA. Additionally, mineral metabolism anomalies in PA may include lower serum calcium and higher urinary calcium output, all these three parameters being reversible under specific therapy for PA, regardless medical or surgical. The PA subgroup with high PTH seems at higher cardiovascular risk, while unilateral rather than bilateral disease was prone to this PTH anomaly. Moreover, bone mineral density (BMD) according to central DXA might show a higher fracture risk only in certain adults, TBS being a promising alternative (with a still unknown perspective of diabetes' influence on DXA-TBS results in PA). However, an overall increased fracture prevalence in PA is described in most studies, especially with respect to the vertebral site, the fracture risk that seems correctable upon aldosterone excess remission. These data recommend PA as a cause of secondary osteoporosis, a treatable one via PA intervention. There is still an area of debate the way to address BMTs profile in PA, the case's selection toward specific bone evaluation in every day practice, and further on, the understanding of the potential genetic influence at the level of bone and mineral complications in PA patients.

The prevalence of primary and secondary hyperparathyroidism and its cardiometabolic implications in primary aldosteronism

BACKGROUND

The aim of this study was to analyze the prevalence of primary and secondary hyperparathyroidism in patients with primary aldosteronism (PA), and its implication on cardiovascular and metabolic outcomes.

METHODS

A retrospective study of patients with PA (exposed cohort, N.=44) and all hypertensive (EH) patients with adrenal lesions without PA nor other adrenal hypersecretion (non-exposed cohort, N.=41) on follow-up at our center between 2016 and 2020.

RESULTS

The mean age of patients with PA and EH was 55.1±14.13 and 66.3±10.93 (P<0.001), and 50% of PA and 39.0% of EH were women (P=0.309). At diagnosis, the prevalence of primary hyperparathyroidism in PA was of 18.2%, and all were normocalcemic hyperparathyroidism cases. Globally, no differences were found in the prevalence of primary hyperparathyroidism compared to EH (18.2% vs. 29.3%, P=0.229), but hypercalcemic primary hyperparathyroidism was significantly more prevalent in EH patients than in PA (22.0% vs. 0%, P=0.001). There were 47.7% (N.=21) cases of secondary hyperparathyroidism in patients with PA (4 due to chronic kidney disease (CKD) and vitamin D deficiency, and 17 due to vitamin D deficiency alone). The cardiometabolic profile of patients with PA and hyperparathyroidism (N.=29) was similar to of those patients without hyperparathyroidism (N.=15) at diagnosis and after a median follow-up of 3.6 years (interquartile range 1.1-5.9).

CONCLUSIONS

Although primary and secondary hyperparathyroidism are common in patients with PA, their prevalence was similar than the observed in EH patients. Primary hyperparathyroidism is usually mild in PA, appearing as normocalcemic forms. No negative implications of the hyperparathyroidism in the cardiometabolic profile of PA were observed.

Bilateral co-secretory lesions presenting with coexisting Cushing syndrome and primary aldosteronism: a case report

BACKGROUND

There is an increasing number of cases of aldosterone- and cortisol-producing adenomas (A/CPAs) reported in the context of primary aldosteronism (PA). Most of these patients have PA complicated with subclinical Cushing's syndrome; cases of apparent Cushing's syndrome (CS) complicated with aldosteronism are less reported. However, Co-secretory tumors were present in the right adrenal gland, a cortisol-secreting adenoma and an aldosterone-producing nodule (APN) were present in the left adrenal gland, and aldosterone-producing micronodules (APMs) were present in both adrenal glands, which has not been reported. Here, we report such a case, offering profound insight into the diversity of clinical and pathological features of this disease.

CASE PRESENTATION

The case was a 45-year-old female from the adrenal disease diagnosis and treatment centre in West China Hospital of Sichuan University. The patient presented with hypertension, moon-shaped face, central obesity, fat accumulation on the back of the neck, disappearance of cortisol circadian rhythm, ACTH < 5 ng/L, failed elevated cortisol inhibition by dexamethasone, orthostatic aldosterone/renin activity > 30 (ng/dL)/(ng/mL/h), and plasma aldosterone concentration > 10 ng/dL after saline infusion testing. Based on the above, she was diagnosed with non-ACTH-dependent CS complicated with PA. Adrenal vein sampling showed no lateralization for cortisol and aldosterone secretion in the bilateral adrenal glands. The left adrenocortical adenoma was removed by robot-assisted laparoscopic resection. However, hypertension, fatigue and weight gain were not alleviated after surgery; additionally, purple striae appeared in the lower abdomen, groin area and inner thigh, accompanied by systemic joint pain. One month later, the right adrenocortical adenoma was also removed. CYP11B1 were expressed in the bilateral adrenocortical adenomas, and CYP11B2 was also expressed in the right adrenocortical adenomas. APN existed in the left adrenal gland and APMs in the adrenal cortex adjacent to bilateral adrenocortical adenomas. After another surgery, her serum cortisol and plasma aldosterone returned to normal ranges, except for slightly higher ACTH.

CONCLUSIONS

This case suggests that it is necessary to assess the presence of PA, even in CS with apparent symptoms. As patients with CS and PA may have more complicated adrenal lesions, more data are required for diagnosis.

Associations Between Aldosterone-Renin-Ratio and Bone Parameters Derived from Peripheral Quantitative Computed Tomography and Impact Microindentation in Men

Components of the renin-angiotensin-aldosterone system (RAAS) are present on bone cells. One measure of RAAS activity, the aldosterone-renin-ratio (ARR), is used to screen for primary aldosteronism. Associations between ARR and bone mineral density are conflicting. This study investigated associations between ARR and peripheral quantitative computed tomography (pQCT) and impact microindentation (IMI). Male participants (n = 431) were from the Geelong Osteoporosis Study. "Likely" primary aldosteronism was defined as ARR ≥ 70 pmol/mIU. Another group, "possible" primary aldosteronism, was defined as either ARR ≥ 70 pmol/mIU or taking a medication that affects the RAAS, but not a beta blocker, and renin < 15 mU/L. Using pQCT, images at 4% and 66% of radial (n = 365) and tibial (n = 356) length were obtained. Using IMI measurements, bone material strength index (BMSi; n = 332) was determined. Associations between ARR or likely/possible primary aldosteronism and IMI or pQCT-derived bone parameters were tested using median regression. ARR and aldosterone values were not associated with any of the pQCT-derived bone variables in either unadjusted or adjusted analyses. Men with likely primary aldosteronism (n = 16), had lower adjusted total bone area (radial 66% site, - 12.5%). No associations were observed for men with possible primary aldosteronism (unadjusted or adjusted). No associations with BMSi were observed (p > 0.05). There were no associations between ARR or aldosterone and pQCT-derived bone parameters. Men with likely primary aldosteronism had lower bone area, suggesting clinically high levels of ARR may have a negative impact on bone health.

New Insights in the Pathophysiology, Epidemiology, and Response to Treatment of Osteoporotic Vertebral Fractures

CONTEXT

Vertebral fractures (VFs) make up an important but challenging group of fractures often caused by osteoporosis. Osteoporotic fractures pose unique diagnostic challenges in generally requiring imaging for diagnosis. The objective of this narrative mini-review is to provide an overview of these recent advances in our knowledge of VF pathophysiology and epidemiology with particular focus on endocrine diseases, prevention, and treatment.

EVIDENCE ACQUISITION

We searched PubMed on May 23, 2022, for studies of VFs in humans. Results were limited to papers available as full-text publications in English, published from 2020 and onward. This yielded 3457 citations. This was supplemented by earlier publications selected to add context to the recent findings.

EVIDENCE SYNTHESIS

Studies addressed VF risk in hyperthyreosis, hyperparathyroidism, acromegaly, Cushing syndrome, primary aldosteronism, and diabetes. For pharmaceutical treatment, new studies or analyses were identified for romosozumab and for weekly teriparatide. Several studies, including studies in the immediate pipeline, were intervention studies with vertebroplasty or kyphoplasty, including combination with stem cells or pharmaceuticals.

CONCLUSIONS

Endocrinologists should be aware of the high likelihood of osteoporotic VFs in patients with endocrine diseases. Though licensed treatments are able to substantially reduce the occurrence of VFs in patients with osteoporosis, the vast majority of recent or ongoing randomized controlled trials in the VF area focus on advanced invasive therapy of the fracture itself.

Aldosterone-producing adenoma is associated with urolithiasis in primary aldosteronism

Primary aldosteronism (PA) is associated with urolithiasis as it causes hypercalciuria and hypocitraturia. However, the influence of different subtypes of PA on urinary stone formation remains unclear. This study aimed to evaluate the association between aldosterone-producing adenoma (APA) and the burden of urolithiasis in patients with PA. In the present study, we enrolled 312 patients with PA from a prospectively maintained database, of whom 179 had APA. Clinical, biochemical, and imaging data (including the presence, volume, and density of urinary stones on abdominal computed tomography) were compared between groups, with employment of propensity score matching (PSM) analysis to balance possible confounding factors. Kaplan-Meier analysis was used to estimate the acute renal colic event during follow-up. After PSM for age, sex, serum calcium, phosphate, blood urea nitrogen, creatinine, and uric acid, the APA and non-APA groups had 106 patients each. Patients with APA had higher serum intact parathyroid hormone (iPTH) (79.1 ± 45.0 vs 56.1 ± 30.3, P < 0.001) and a higher prevalence of urolithiasis (27.4% vs 12.3%, P = 0.006) than non-APA patients. During follow-up, a higher incidence of acute renal colic events was noted in the APA group than the non-APA group (P = 0.011); this association remained significant (P = 0.038) after adjustment for age and sex in Cox-regression analysis. Our data suggest that APA is associated with a heavier burden of urolithiasis and higher incidence of renal colic events compared to the non-APA subtype of PA.

Evaluating the clinical and mechanistic effects of eplerenone and amiloride monotherapy, and combination therapy with cinacalcet, in primary hyperparathyroidism: A placebo-controlled randomized trial

OBJECTIVES

Human physiology and epidemiology studies have demonstrated complex interactions between the renin-angiotensin-aldosterone system, parathyroid hormone and calcium homeostasis. Several of these studies have suggested that aldosterone inhibition may lower parathyroid hormone (PTH) levels. The objective of this study was to assess the effect of 4 weeks of maximally tolerated mineralocorticoid receptor antagonist therapy with eplerenone on PTH levels in patients with primary hyperparathyroidism (P-HPT) when compared to amiloride and placebo. We also investigated the synergistic effect of these interventions when combined with cinacalcet for an additional 2 weeks.

DESIGN

Randomized, double-blinded, three parallel-group, placebo-controlled trial.

PATIENTS

Patients with P-HPT.

RESULTS

Most patients were women (83%) and White (76%). Maximally tolerated doses of eplerenone and amiloride induced significant reductions in blood pressure and increases in renin and aldosterone production; however, despite these physiologic changes, neither intervention induced significant changes in PTH or calcium levels when compared to the placebo. Both eplerenone and amiloride therapy induced significant reductions in procollagen type 1 N-terminal propeptide levels when compared to placebo. When cinacalcet therapy was added, PTH and calcium levels were markedly reduced in all groups; however, there was no significant difference in PTH or serum calcium reductions between groups.

CONCLUSIONS

Although maximally tolerated therapy with eplerenone and amiloride induced expected changes in renin, aldosterone and blood pressure, there were no meaningful changes in PTH or serum calcium levels in P-HPT patients. These results suggest that inhibition of aldosterone action does not have a clinically meaningful role in medical therapy for P-HPT.

The Entity of Connshing Syndrome: Primary Aldosteronism with Autonomous Cortisol Secretion

Connshing syndrome (CoSh) (adrenal-related synchronous aldosterone (A) and cortisol (C) excess) represents a distinct entity among PA (primary hyperaldosteronisms) named by W. Arlt et al. in 2017, but the condition has been studied for more than 4 decades. Within the last few years, this is one of the most dynamic topics in hormonally active adrenal lesions due to massive advances in steroids metabolomics, molecular genetics from CYP11B1/B2 immunostaining to genes constellations, as well as newly designated pathological categories according to the 2022 WHO classification. In gross, PA causes 4-10% of all high blood pressure (HBP) cases, and 20% of resistant HBP; subclinical Cushing syndrome (SCS) is identified in one-third of adrenal incidentalomas (AI), while CoSh accounts for 20-30% to 77% of PA subjects, depending on the tests used to confirm autonomous C secretion (ACS). The clinical picture overlaps with PA, hypercortisolemia being mild. ACS is suspected in PA if a more severe glucose and cardiovascular profile is identified, or there are larger tumours, ACS being an independent factor risk for kidney damage, and probably also for depression/anxiety and osteoporotic fractures. It seems that one-third of the PA-ACS group harbours mutations of C-related lines like PRKACA and GNAS. A novel approach means we should perform CYP11B2/CYP11B1 immunostaining; sometimes negative aldosteronoma for CYP11B1 is surrounded by micronodules or cell clusters with positive CYP11B1 to sustain the C excess. Pitfalls of hormonal assessments in CoSh include the index of suspicion (check for ACS in PA patients) and the interpretation of A/C ratio during adrenal venous sample. Laparoscopic adrenalectomy is the treatment of choice. Post-operative clinical remission rate is lower in CoSh than PA. The risk of clinically manifested adrenal insufficiency is low, but a synthetic ACTH stimulating testing might help to avoid unnecessary exposure to glucocorticoids therapy. Finally, postponing the choice of surgery may impair the outcome, having noted that long-term therapy with mineralocorticoids receptors antagonists might not act against excessive amounts of C. Awareness of CoSh improves management and overall prognosis.

Different roles of the RAAS affect bone metabolism in patients with primary aldosteronism, Gitelman syndrome and Bartter syndrome

BACKGROUND

Components of the RAAS may influence bone metabolism. Different roles of the RAAS are found in patients with primary aldosteronism (PA), Gitelman syndrome (GS) and Bartter syndrome (BS). We collected inpatient medical records including 20 patients with Gitelman syndrome (GS group), 17 patients with Bartter syndrome (BS group) and 20 age-matched patients with primary aldosteronism (PA group). We found the following results. (1) PA patients had significantly higher serum magnesium, potassium, plasma aldosterone, serum parathyroid hormone, urinary calcium and BMI (p<0.05) while significantly lower serum calcium and phosphorus (P < 0.05) than GS and BS patients. (2) Total hip and femoral neck bone mineral density (BMD) in PA patients were significantly lower than those in GS and BS patients (P<0.05). (3) GS patients had lower serum magnesium and urinary calcium than BS patients (P < 0.05). (4) Compared with BS patients, the vertebral BMD in GS patients were significantly higher (P < 0.05). So we believe higher aldosterone and PTH levels may be the reason that PA patients have lower hip BMD. Lower urinary calcium and inactivation of the NCC gene (Na-Cl cotransporter) in GS patients may have protective effects on vertebral bone mineral density.

CONCLUSIONS

With persistence disordered RAAS, PA patients have lower BMD, especially hip BMD as compared with GS and BS patients. We presumed the lower renin and higher aldosterone level may be the reason. With the same level of renin and aldosterone, BS patients have lower vertebrate BMD than GS patients. Decreased urinary calcium excretion may be the reason.

Bone and mineral metabolism in patients with primary aldosteronism: A systematic review and meta-analysis

PURPOSE

Patients with primary aldosteronism (PA) tend to exhibit a high prevalence of osteoporosis (OP) that may vary by whether PA is unilateral or bilateral, and responsive to PA treatment. To explore relationships between bone metabolism, PA subtypes, and treatment outcomes, we performed a systematic review and meta-analysis.

METHODS

The PubMed, Embase, and Cochrane databases were searched for clinical studies related to PA and bone metabolism markers. Articles that met the criteria were screened and included in the systematic review; the data were extracted after evaluating their quality. R software (ver. 2022-02-16, Intel Mac OS X 11.6.4) was used for the meta-analysis.

RESULTS

A total of 28 articles were subjected to systematic review, of which 18 were included in the meta-analysis. We found that PA patients evidenced a lower serum calcium level (mean difference [MD] = -0.06 mmol/L, 95% confidence interval [CI]: -0.10 ~ -0.01), a higher urine calcium level (MD = 1.29 mmol/24 h, 95% CI: 0.81 ~ 1.78), and a higher serum parathyroid hormone (PTH) level (MD = 2.16 pmol/L, 95% CI: 1.57 ~ 2.75) than did essential hypertension (EH) subjects. After medical treatment or adrenal surgery, PA patients exhibited a markedly increased serum calcium level (MD = -0.08 mmol/L, 95% CI: -0.11 ~ -0.05), a decreased urine calcium level (MD = 1.72 mmol/24 h, 95% CI: 1.00 ~ 2.44), a decreased serum PTH level (MD = 2.67 pmol/L, 95% CI: 1.73 ~ 3.62), and an increased serum 25-hydroxyvitamin D (25-OHD) level (MD = -6.32 nmol/L, 95% CI: -11.94 ~ -0.70). The meta-analysis showed that the ser um PTH level of unilateral PA patients was significantly higher than that of bilateral PA patients (MD = 0.93 pmol/L, 95% CI: 0.36 ~ 1.49) and the serum 25-OHD lower than that of bilateral PA patients (MD = -4.68 nmol/L, 95% CI: -7.58 ~ 1.77). There were, however, no significant differences between PA and EH patients of 25-OHD, or BMD of femoral neck and lumbar spine. BMDs of the femoral neck or lumbar spine did not change significantly after treatment. The meta-analytical results were confirmed via sensitivity and subgroup analyses.

CONCLUSION

Excess aldosterone was associated with decreased serum calcium, elevated urinary calcium, and elevated PTH levels; these effects may be enhanced by low serum 25-OHD levels. The risks of OP and fracture might be elevated in PA patients, especially unilateral PA patients, but could be reduced after medical treatment or adrenal surgery. In view, however, of the lack of BMD changes, such hypothesis needs to be tested in further studies.

Risk Factors Associated With Lower Bone Mineral Density in Primary Aldosteronism Patients

PURPOSE

The association between primary aldosteronism (PA) and lower bone mineral density (BMD) has raised a concern, but the contributing factors remain unclear. We aim to explore the risk factors for lower BMD in PA patients.

METHODS

We analyzed and compared the data of 60 PA patients with 60 matched essential hypertension (EH) patients. BMD, bone metabolites, and several oxidative stress and inflammation indicators-including C-reactive protein (CRP), superoxide dismutase (SOD), total bilirubin (TBIL), mean platelet volume (MPV), etc.-were assessed and compared in PA and EH patients. Bivariate correlation analysis and multivariate linear regression analysis were performed to explore the factors associated with BMD in PA patients.

RESULTS

The BMD measured by quantitative computed tomography in PA patients was lower than that in EH patients (141.9 ± 34.0 vs. 158.9 ± 55.9 g/cm³, p = 0.047), especially in patients less than 50 years old. BMD was independently negatively associated with age (standardized β = -0.581, p < 0.001), serum phosphorus (standardized β = -0.203, p = 0.008), urinary calcium excretion (standardized β = -0.185, p = 0.031), and MPV (standardized β = -0.172, p = 0.043) and positively associated with SOD (standardized β = 0.205, p = 0.011) and TBIL (standardized β = 0.212, p = 0.015).

CONCLUSIONS

The PA patients showed a lower BMD than the EH patients, which was associated with age, serum phosphorus, urinary calcium excretion, MPV, SOD, and TBIL. These variables might be potential markers for the assessment of bone loss and efficacy of treatments in PA patients.

The activity of the renin-angiotensin-aldosterone system before and after parathyroidectomy in patients with primary hyperparathyroidism

Background. The relationships between renin-angiotensin-aldosterone system (RAAS) and elevated parathyroid hormone levels in primary hyperparathyroidism (PHPT) is being actively discussed. But the way how parathyroid hormone interacts with renin and aldosterone currently is not clear. Materials and methods. Forty patients aged 18 to 70 years with a confirmed diagnosis of PHPT were involved in the study. All patients were tested for the main parameters of phosphorus-calcium metabolism and the RAAS parameters (plasma renin, plasma aldosterone) before and 2 weeks after parathyroidectomy. Results. Sixty percent of patients had any cardiovascular disease (CVD) and hypertension was the most common. Patients CVD in comparison with patients without CVD were older (61 and 41 years, respectively; p0.001), had a higher body mass index (28.9 and 21.9 kg/m2, respectively; p0.001) and had a lower aldosterone-to-renin ratio ARR (1.78 and 5.42, respectively; p=0.030). Patients with hypertension were older than patients with normal blood pressure (63 and 41 years, respectively; p0.001), had a higher body mass index (28.1 and 23.5 kg/m2, respectively; p=0.005), a lower ARR (1.46 and 5.82, respectively; p=0.001), as well higher levels of plasma renin (109.2 and 20.3 pg/ml, respectively; p=0.007) and serum total calcium (2.84 and 2.71 mmol/l, respectively; p=0.041). Correlation analysis showed that in patients with PHPT and CVD, the concentration of aldosterone is associated with the level of 24-hour urinary calcium (r=0.829, p=0.042), and in patients with symptomatic PHPT and CVD, the level of aldosterone correlated with the level of ionized calcium (r=-0.812, p=0.05). We found no significant differences between the levels of renin, aldosterone and ARR before and 2 weeks after parathyroidectomy. However, in the postoperative period, there were no differences in the levels of renin and ARR among patients with hypertension and without hypertension. Conclusion. In our study we found that the levels of plasma renin and serum total calcium were higher in patients with PHPT and hypertension compared to patients with normal blood pressure. Also, we found the associations between plasma aldosterone and levels of ionized calcium and 24-hour urinary calcium. But the relationships between RAAS parameters and parameters of phosphorus-calcium metabolism need further investigations.

Spironolactone Attenuates Methylglyoxal-induced Cellular Dysfunction in MC3T3-E1 Osteoblastic Cells

BACKGROUND

Methylglyoxal (MG) is associated with the pathogenesis of age- and diabetes-related complications. Spironolactone is a competitive antagonist of aldosterone that is widely employed in the treatment of hypertension and heart failure. This study examined the effects of spironolactone on MG-induced cellular dysfunction in MC3T3-E1 osteoblastic cells.

METHODS

MC3T3-E1 cells were treated with spironolactone in the presence of MG. The mitochondrial function, bone formation activity, oxidative damage, inflammatory cytokines, glyoxalase I activity, and glutathione (GSH) were measured.

RESULTS

Pretreatment of MC3T3-E1 osteoblastic cells with spironolactone prevented MG-induced cell death, and improved bone formation activity. Spironolactone reduced MG-induced endoplasmic reticulum stress, production of intracellular reactive oxygen species, mitochondrial superoxides, cardiolipin peroxidation, and inflammatory cytokines. Pretreatment with spironolactone also increased the level of reduced GSH and the activity of glyoxalase I. MG induced mitochondrial dysfunction, but markers of mitochondrial biogenesis such as mitochondrial membrane potential, adenosine triphosphate, proliferator-activated receptor gamma coactivator 1α, and nitric oxide were significantly improved by treatment of spironolactone.

CONCLUSION

Spironolactone could prevent MG-induced cytotoxicity in MC3T3-E1 osteoblastic cells by reduction of oxidative stress. The oxidative stress reduction was explained by spironolactone's inhibition of advanced glycation end-product formation, restoring mitochondrial dysfunction, and anti-inflammatory effect.