Effect of Parathyroidectomy on Metabolic Homeostasis in Primary Hyperparathyroidism

Primary Hyperparathyroidism: An Analysis Amid the Co-Occurrence of Type 2 Diabetes Mellitus

BACKGROUND

Apart from classical elements in primary hyperparathyroidism (PHPT), non-classical complications, including type 2 diabetes mellitus (T2DM), are reported in some patients, but currently, they do not represent a parathyroidectomy (PTx) indication.

OBJECTIVE

to explore the latest data regarding glucose profile, particularly, T2DM and metabolic syndrome (MetS) in PHPT, including post-PTx.

METHODS

PubMed-based review included English-published original studies between January 2020 and December 2024 (n = 20).

RESULTS

Studied population: 764,485 subjects (female-to-male ratio of 1.26:1; 23,931 were PHPT patients vs. 740,502 controls). T2DM prevalence (n = 13; N = 763,645 patients; 55.92% females): 4-60% (higher vs. controls); for the largest study (N = 699,157) of 31.3%. Age-based analysis: higher T2DM prevalence at >50 vs. <50 years (14.4% vs. 2.6%, p < 0.001), but not all studies agreed. Concurrent vitamin D deficiency as a contributor to a higher risk had limited evidence. The association MetS-PHPT (n = 2) had no clear conclusion. Post-PTx showed the following: lower glycaemia, fasting insulin, insulin resistance (HOMA-IR) improvement, and reduced rate (but not all studies agreed). PHPT patients with prediabetes might represent the population sub-group with the highest post-PTx benefit.

CONCLUSIONS

The panel of PHPT-T2DM interplay remains heterogeneous. Data regarding post-PTx improvement of glucose disorders are still conflicting, recent findings suggested that surgery has beneficial effects, especially in patients with confirmed pre-existing prediabetes. Patients with the normocalcemic variant seemed to be less affected by the glucose-related disturbances, but further studies are needed. A better understanding of the intricate relationship between PHPT and glucose metabolism anomalies will help in providing optimal management to reduce the overall disease burden.

Chapter 3: Impact of primary hyperparathyroidism

At present, primary hyperparathyroidism is most often discovered in an asymptomatic patient, but can sometimes be revealed by a renal or bone complications. In all cases, a full work-up is recommended, with assessment of renal function (glomerular filtration rate), 24-hour calciuria, screening for risk factors for lithiasis, and renal and urinary tract imaging (ultrasound or CT scan) to look for stones or nephrocalcinosis. Bone densitometry, with measurements of the spine, femur and radius, is the recommended reference test for demineralization. Standard X-rays of the spine or other imaging techniques are recommended for the detection of asymptomatic vertebral fracture. Neurocognitive manifestations, reduced quality of life or cardiovascular manifestations should not be routinely screened for, as they are not currently consensual criteria for surgical indications.

Turning Points in Cross-Disciplinary Perspective of Primary Hyperparathyroidism and Pancreas Involvements: Hypercalcemia-Induced Pancreatitis, MEN1 Gene-Related Tumors, and Insulin Resistance

We aimed to provide an in-depth analysis with respect to three turning points in pancreas involvement in primary hyperparathyroidism (PHP): hypercalcemia-induced pancreatitis (HCa-P), MEN1 (multiple endocrine neoplasia)-related neuroendocrine tumors (NETs), and insulin resistance (IR). This was a comprehensive review conducted via a PubMed search between January 2020 and January 2024. HCa-P (n = 9 studies, N = 1375) involved as a starting point parathyroid NETs (n = 7) or pancreatitis (n = 2, N = 167). Case report-focused analysis (N = 27) showed five cases of pregnancy PHP-HCa-P and three reports of parathyroid carcinoma (female/male ratio of 2/1, ages of 34 in women, men of 56). MEN1-NET studies (n = 7) included MEN1-related insulinomas (n = 2) or MEN1-associated PHP (n = 2) or analyses of genetic profile (n = 3), for a total of 877 MEN1 subjects. In MEN1 insulinomas (N = 77), the rate of associated PHP was 78%. Recurrence after parathyroidectomy (N = 585 with PHP) was higher after less-than-subtotal versus subtotal parathyroidectomy (68% versus 45%, p < 0.001); re-do surgery was 26% depending on surgery for pancreatic NETs (found in 82% of PHP patients). MEN1 pathogenic variants in exon 10 represented an independent risk factor for PHP recurrence. A single pediatric study in MEN1 (N = 80) revealed the following: a PHP rate of 80% and pancreatic NET rate of 35% and 35 underlying germline MEN1 pathogenic variants (and 3/35 of them were newly detected). The co-occurrence of genetic anomalies included the following: CDC73 gene variant, glucokinase regulatory protein gene pathogenic variant (c.151C>T, p.Arg51*), and CAH-X syndrome. IR/metabolic feature-focused analysis identified (n = 10, N = 1010) a heterogeneous spectrum: approximately one-third of adults might have had prediabetes, almost half displayed some level of IR as reflected by HOMA-IR > 2.6, and serum calcium was positively correlated with HOMA-IR. Vitamin D deficiency was associated with a higher rate of metabolic syndrome (n = 1). Normocalcemic and mildly symptomatic hyperparathyroidism (n = 6, N = 193) was associated with a higher fasting glucose and some improvement after parathyroidectomy. This multilayer pancreas/parathyroid analysis highlighted a complex panel of connections from pathogenic factors, including biochemical, molecular, genetic, and metabolic factors, to a clinical multidisciplinary panel.

Changes in bone turnover markers and bone mineral density after radiofrequency ablation for mild primary hyperparathyroidism: a prospective cohort study

Background

The application of radiofrequency ablation (RFA) is becoming increasingly widespread in the treatment of primary hyperparathyroidism (PHPT). However, the effect of RFA treatment on the skeleton in mild PHPT remains unclear. Therefore, the aim of this study was to investigate the change in bone turnover markers and bone mineral density (BMD) before and 2 years after RFA in patients with mild PHPT.

Methods

In this open-label, prospective study, 81 patients with mild PHPT including 36 treated with RFA and 45 observed without intervention (OBS), along with 81 age-matched healthy controls, were enrolled from November 2018 to September 2021 at Gansu Provincial Hospital. The main outcome measures were levels of serum calcium, serum intact parathyroid hormone (iPTH), and bone turnover markers, including bone-specific alkaline phosphatase (ALP), C-terminal cross-linking telopeptides of type I collagen (β-CTx), and osteocalcin (OC). BMD (femoral neck and lumbar spine) was measured with dual-energy X-ray absorptiometry, and spine radiographs were obtained for vertebral fracture assessment. Paired and unpaired two-tailed t-tests and Spearman rank correlation coefficient were used for statistical analyses.

Results

Normalized outcomes for both iPTH and calcium levels were achieved in 32 of 36 (88.9%) patients with mild PHPT treated with RFA. There was a significant treatment effect of RFA on bone turnover biomarkers compared with OBS before the treatment (P=0.04) and at the end of follow-up or (P=0.03). BMD of the lumbar spine increased by 1.8% (P=0.03) and remained stable in the femoral neck (P=0.17) after RFA. However, there was an obvious treatment effect of RFA on BMD compared with OBS (P 0.04). The only compartment with a T-score increase in the RFA group was the lumbar spine in (P<0.001). There was no difference in fracture frequency between groups during the follow-up period.

Conclusions

RFA can improve serum bone turnover markers in patients with mild PHPT and can be expected to increase BMD in the L1-L4 vertebrae and preserve BMD in the femoral neck. Whether RFA can reduce fracture risk in the long-term is a clinical concern for patients with mild PHPT.

Parathyroidectomy Improves Bone Density in Women With Primary Hyperparathyroidism and Preoperative Osteopenia

CONTEXT

Osteoporosis and/or bone fractures are indications of parathyroidectomy in primary hyperparathyroidism (PHPT), especially in women. However, the benefit of surgery in patients with osteopenia remains unclear.

OBJECTIVE

To evaluate bone mineral density (BMD) and bone remodeling biomarkers changes 1 year after parathyroidectomy in women with PHPT.

DESIGN

In the prospective, monocentric, observational prospective cohort with primary hyperparathyroidism patients (CoHPT) cohort, women operated for sporadic PHPT since 2016 with ≥1 year follow-up were included. BMD (dual-X ray absorptiometry) and bone remodeling biomarkers [cross-linked C-telopeptide (CTX), procollagen type 1 N-terminal propeptide (P1NP), and bone-specific alkaline phosphatases] were assessed before and 1 year after parathyroidectomy.

SETTING

Referral center.

PATIENTS

A total of 177 women with PHPT (62.5 ± 13.3 years, 83.1% menopausal, 43.9% osteopenic, and 45.1% osteoporotic) were included.

INTERVENTION

Parathyroidectomy.

MAIN OUTCOME MEASURE

BMD change between before and 1 year after parathyroidectomy.

RESULTS

Parathyroidectomy resulted in significant increase in BMD and decrease in serum bone remodeling biomarker concentrations. In the 72 patients with baseline osteopenia, mean BMD significantly increased at the lumbar spine [+0.05 g/cm2 (95% confidence interval [CI], 0.03-0.07)], the femoral neck [+0.02 g/cm2 (95% CI 0.00-0.04)], the total hip [+0.02 g/cm2 (95% CI 0.01-0.02)], and the forearm [+0.01 (95% CI 0.00-0.02)], comparable to osteoporotic patients. Among osteopenic patients, those with individual BMD gain (>0.03 g/cm2) at ≥1 site had higher preoperative serum CTX, P1NP, and urine calcium concentrations than those without improvement.

CONCLUSION

Parathyroidectomy significantly improved BMD and remodeling biomarkers in women with osteopenia, thereby supporting the benefit of parathyroidectomy in these patients. Preoperative serum CTX and P1NP concentrations could be useful to predict expected BMD gain.