Levine, Michael A.

Diabetes mellitus (DM) and periodontitis share a complex, bidirectional relationship, with each condition exacerbating the other. Diabetes, particularly when poorly controlled, significantly increases the risk, severity, and progression of periodontitis. The biological mechanisms involved are complex and numerous. Hyperglycemia in diabetes is linked to oral microbial dysbiosis, which is in turn associated with increased inflammation, epithelial barrier dysfunction, impaired neutrophil and macrophage function, altered T-cell profiles, and cytokine imbalance, collectively fostering chronic inflammation and immune dysregulation. Moreover, diabetes alters bone metabolism, promoting osteoclastogenesis and reducing reparative bone regeneration by limiting coupled bone formation through an effect on growth factor production, mesenchymal stems cells, and osteoblasts. Conversely, periodontitis is strongly linked to poor glycemic control. Clinical studies and longitudinal meta-analyses report consistent positive associations, while randomized controlled trials show that periodontal therapy reduces HbA1c by ~0.43%. Emerging evidence suggests that periodontitis and oral preclinical dysbiosis contribute to diabetogenesis, although causality remains uncertain. Periodontitis may drive metabolic dysfunction through several biological mechanisms. The dysbiotic oral microbiome and subsequent periodontitis may promote systemic inflammation and subsequent insulin resistance and glucose intolerance. Moreover, oral dysbiosis may deplete nitrate-reducing taxa and impair nitric oxide pathways, which has relevance to both periodontal and cardiometabolic health. Accordingly, periodontal treatment in diabetic populations has shown potential health care savings. Nevertheless, trials assessing the influence of periodontitis treatment on systemic outcomes consistently show significant treatment heterogeneity, which requires explication in future studies. This review underscores the systemic implications of periodontitis in diabetes and highlights the value of integrating periodontal care into diabetes management. A better understanding of the shared pathophysiology between these diseases supports interdisciplinary approaches and points toward novel preventive and therapeutic strategies targeting inflammation, microbial balance, and host response modulation to jointly benefit periodontal and cardiometabolic health.

Abstract Disclosure: D.S. Ali: None. Z. Chung: None. L. Kamel: None. S. Björnsdottir: Shire. B.L. Clarke: Shire, Takeda, Ascendis, Calcilytix. S. Hahner: None. L.C. Hofbauer: Amgen Inc, Ascendis, UCB, Ascendis, Amolyte. P. Houillier: None. S.W. Ing: Amgen Inc, Radius Health, Inc, Takeda, AscendAlexion, Amolyt, Ascendis, Calcilytix, Kyowa Kirin. M.A. Levine: Takeda, Amolyt, Calcilytix. M. Mannstadt: Takeda, Amolyt, Calcilytix. L. Rejnmark: Takeda, Amolyt, Ascendis, Calcilytix. D.M. Shoback: Amolyt, Ascendis, member of the advisory board (PARADIGHM). M. Brandi: Takeda, Eli Lilly & Company, Calcilytix, Kyowa Kirin, UCB, Abiogen, Alexion, Amolyt, Amorphical, Bruno Farmaceutici, CoGeDi, Echolight. A.A. Khan: Takeda, Amgen Inc, Alexion, Ascendis, Amolyt, Calcilytix. Background: Hypoparathyroidism (HypoPT) is a rare endocrine disorder that requires close evaluation and follow up during pregnancy to minimize maternal and fetal complications. The primary objectives of this study are to evaluate the use of rhPTH (1-84) during pregnancy by analyzing data from the PARADIGHM disease registry, and to compare maternal and neonatal outcomes among patients who continued PTH therapy during pregnancy versus those on conventional therapy (CT). Methods: We performed a retrospective analysis of data in the PARADIGHM registry. Maternal and neonatal outcomes in women treated with rhPTH (1-84) were compared to women who received CT. Results: We analyzed 39 pregnancies of 32 women. Of those, 4 women (6 pregnancies) used rhPTH (1-84) either before or during pregnancy and 28 women (33 pregnancies) continued CT during pregnancy. The mean (SD) maternal age at enrollment was 31.7 (5.6) years. Postsurgical HypoPT was the most common etiology (68.8%). The mean gestational age at delivery was 36 (2.4) weeks (PTH-treated) vs 38.3 (3.3) weeks (CT) (p=0.162). Preterm delivery rates were higher in the PTH-treated group (50% vs. 27%, p=0.591), but this was not statistically significant. Two women had pre-eclampsia, one in each group (PTH-treated and CT). In the PTH-treated group, one pregnancy resulted in a stillbirth, and one infant was born with congenital anomalies (16.7% each). Conclusions: The safety of rhPTH (1-84) use in pregnancy cannot be determined at this time. The PTH-treated group exhibited trends towards higher rates of preterm delivery, but the rates of stillbirth, and congenital anomalies were low and comparable in both groups of women. Larger studies are necessary to determine the optimal approach to manage women with HypoPT during pregnancy. Presentation: Sunday, July 13, 2025

Abstract Context Chronic hypoparathyroidism is conventionally treated with oral calcium and active vitamin D to reach and maintain targeted serum calcium and phosphorus levels, but some patients remain inadequately controlled. Objective To assess long-term safety and efficacy of recombinant human parathyroid hormone (1-84) (rhPTH(1-84)) treatment. Methods This was an open-label extension study at 12 US centers. Adults (n = 49) with chronic hypoparathyroidism were included. The intervention was rhPTH(1-84) for 6 years. The main outcome measures were safety, biochemical measures, oral supplement doses, bone indices. Results Thirty-eight patients (77.6%) completed the study. Throughout 72 months, mean albumin-adjusted serum calcium was within 2.00 to 2.25 mmol/L (8.0-9.0 mg/dL). At baseline, 65% of patients with measurements (n = 24/37) were hypercalciuric; of these, 54% (n = 13/24) were normocalciuric at month 72. Mean serum phosphorus declined from 1.6 ± 0.19 mmol/L at baseline (n = 49) to 1.3 ± 0.20 mmol/L at month 72 (n = 36). Mean estimated glomerular filtration rate was stable. rhPTH(1-84)-related adverse events were reported in 51.0% of patients (n = 25/49); all but 1 event were mild/moderate in severity. Mean oral calcium supplementation reduced by 45% ± 113.6% and calcitriol by 74% ± 39.3%. Bone turnover markers declined by month 32 to a plateau above pretreatment values; only aminoterminal propeptide of type 1 collagen remained outside the reference range. Mean bone mineral density z score fell at one-third radius and was stable at other sites. Conclusion 6 years of rhPTH(1-84) treatment was associated with sustained improvements in biochemical parameters, a reduction in the percentage of patients with hypercalciuria, stable renal function, and decreased supplement requirements. rhPTH(1-84) was well tolerated; no new safety signals were identified.

Abstract Context The ketogenic diet is associated with progressive skeletal demineralization, hypercalciuria, and nephrolithiasis. Acute hypercalcemia has been described as a newly recognized complication of this treatment. Objective To describe the clinical characteristics of acute hypercalcemia in children on the ketogenic diet through analysis of the presentation, response to treatment, and natural history in a large cohort of patients. Design A multicenter case series was performed including children who developed acute hypercalcemia while treated with the ketogenic diet. Information on clinical presentation, treatment, and course of this complication was collated centrally. Results There were 14 patients (median (range) age 6.3 (0.9 to 18) years) who developed hypercalcemia 2.1 (range, 0.2-12) years after starting the ketogenic diet. All had low levels of parathyroid hormone and levels of 1,25-dihydroxyvitamin D were low in all except one. Seven (50%) had impaired renal function at presentation. All except the 2 oldest had low alkaline phosphatase levels for age. Once normocalcemia was achieved, hypercalcemia recurred in only 2 of these patients over observation of up to 9.8 years. One patient discontinued the ketogenic diet prior to achieving normocalcemia while 4 more stopped the diet during follow-up after resolution of hypercalcemia. Conclusions Ketotic hypercalcemia can occur years after starting the ketogenic diet, especially in the setting of renal impairment. The mechanism is unknown but appears to be due to reduced osteoblast activity and impaired bone formation. We recommend close attention to optimizing bone health in these children, and screening for the development of ketotic hypercalcemia.

Abstract PARADIGHM is an actively recruiting, prospective, observational registry (NCT01922440/EUPAS16927). The primary objective is to evaluate the safety and effectiveness of recombinant human parathyroid hormone, rhPTH(1-84), treatment in patients with chronic hypoparathyroidism (HypoPT) under routine clinical care. The secondary objective is to characterize the clinical course of chronic HypoPT under conditions of routine clinical practice. At enrollment, registry inclusion criteria are patients having a HypoPT diagnosis >6 months and receiving conventional therapy (CT; eg, calcium supplements and active vitamin D), rhPTH(1-84) plus CT, or rhPTH(1-84). We present baseline characteristics of patients as of a June 30 2019 data cut. Baseline was defined as the value entered at the time of enrollment (Visit 1). Baseline symptom data exclude patients who initiated rhPTH(1-84) prior to enrollment (n=68) and are herein presented as two groups: those subsequently prescribed with rhPTH(1-84) after enrollment or those treated with CT. All data are summarized descriptively. Patient data from 64 centers in Europe and North America were analyzed. In the analysis population (n=737), 587 patients (79.6%) were female, 620 (84.1%) were white, and the mean (SD) age was 49.1 (16.45) years. The mean (SD) BMI was 19.3 (5.73) kg/m2 and 30.0 (7.72) kg/m2 in patients aged <18 (n=25) and ≥18 (n=587) years, respectively. The primary cause of HypoPT was thyroid surgery (n=547 [74.2%]; of these, 281 [60.0%] underwent surgery for thyroid cancer). Endocrinologists were the prescribing specialists for most patients (n=660 [89.6%]). Vitamin D and analogs were prescribed for 90.1% of patients (calcitriol, 74.2%, native vitamin D, 47.4%, alfacalcidol, 7.9%,), calcium for 81.0% (calcium carbonate, 57.9%, calcium citrate, 27.1%), and thyroid hormones for 71.2% (levothyroxine, 73.4%; liothyronine, 5.8%). Symptoms reported at enrollment for the rhPTH(1-84) (n=66) and the CT groups (n=603), respectively, included fatigue (53.0%, 39.3%), paresthesia (48.5%, 29.2%), muscle twitching (48.5%, 21.1%), muscle cramping (40.9%, 33.0%), headaches (33.3%, 17.6%), anxiety (28.8%, 20.1%), muscle pain (28.8%, 19.2%), tetany (28.8%, 12.1%), and brain fog (27.3%, 16.3%). The baseline data for the overall population appear to be representative of patients with chronic HypoPT. Baseline data suggest that at enrollment patients prescribed rhPTH(1-84) after enrollment appear to have an increased burden of disease than patients receiving CT based on symptoms. PARADIGHM will be a valuable resource of real-world longitudinal data for patients with chronic HypoPT.

Abstract Context Conventional hypoparathyroidism treatment with oral calcium and active vitamin D is aimed at correcting hypocalcemia but does not address other physiologic defects caused by PTH deficiency. Objective To evaluate long-term safety and tolerability of recombinant human PTH (1-84) [rhPTH(1-84)]. Design Open-label extension study; 5-year interim analysis. Setting 12 US centers. Patients Adults (N = 49) with chronic hypoparathyroidism. Intervention(s) rhPTH(1-84) 25 or 50 µg/d initially, with 25-µg adjustments permitted to a 100 µg/d maximum. Main Outcome Measure(s) Safety parameters; composite efficacy outcome was the proportion of patients with ≥50% reduction in oral calcium (or ≤500 mg/d) and calcitriol (or ≤0.25 µg/d) doses, and albumin-corrected serum calcium normalized or maintained compared with baseline, not exceeding upper limit of normal. Results Forty patients completed 60 months of treatment. Mean albumin-corrected serum calcium levels remained between 8.2 and 8.7 mg/dL. Between baseline and month 60, levels ± SD of urinary calcium, serum phosphorus, and calcium-phosphorus product decreased by 101.2 ± 236.24 mg/24 hours, 1.0 ± 0.78 mg/dL, and 8.5 ± 8.29 mg2/dL2, respectively. Serum creatinine level and estimated glomerular filtration rate were unchanged. Treatment-emergent adverse events (AEs) were reported in 48 patients (98.0%; hypocalcemia, 36.7%; muscle spasms, 32.7%; paresthesia, 30.6%; sinusitis, 30.6%; nausea, 30.6%) and serious AEs in 13 (26.5%). At month 60, 28 patients (70.0%) achieved the composite efficacy outcome. Bone turnover markers increased, peaked at ∼12 months, and then declined to values that remained above baseline. Conclusion Treatment with rhPTH(1-84) for 5 years demonstrated a safety profile consistent with previous studies and improved key biochemical parameters.

ABSTRACT Normal vitamin D homeostasis is critical for optimal health; nevertheless, vitamin D deficiency is a worldwide public health problem. Vitamin D insufficiency is most commonly due to inadequate cutaneous synthesis of cholecalciferol and/or insufficient intake of vitamin D, but can also arise as a consequence of pathological states such as obesity. Serum concentrations of 25(OH)D (calcidiol) are low in obesity, and fail to increase appropriately after vitamin D supplementation. Although sequestration of vitamin D in adipose tissues or dilution of ingested or cutaneously synthesized vitamin D in the large fat mass of obese patients has been proposed to explain these findings, here we investigate the alternative mechanism that reduced capacity to convert parent vitamin D to 25(OH)D due to decreased expression of CYP2R1, the principal hepatic vitamin D 25-hydroxylase. To test this hypothesis, we isolated livers from female mice of 6 to 24 weeks of age, weaned onto either a normal chow diet or a high-fat diet, and determined the abundance of Cyp2r1 mRNA using digital droplet-quantitative PCR. We observed a significant (p < 0.001) decrease in Cyp2r1 mRNA in the liver of high-fat diet–fed mice relative to lean-chow–fed female mice. Moreover, there was a significant (p < 0.01) relationship between levels of Cyp2r1 mRNA and serum 25(OH)D concentrations as well as between Cyp2R1 mRNA and the ratio of circulating 25(OH)D3 to cholecalciferol (p < 0.0001). Using linear regression we determined a curve with 25(OH)D3/cholecalciferol versus normalized Cyp2R1 mRNA abundance with an R2 value of 0.85. Finally, we performed ex vivo activity assays of isolated livers and found that obese mice generated significantly less 25(OH)D3 than lean mice (p < 0.05). Our findings indicate that expression of CYP2R1 is reduced in obesity and accounts in part for the decreased circulating 25(OH)D. © 2019 American Society for Bone and Mineral Research.

Bone atrophy and its related fragility fractures are frequent, late side effects of radiotherapy in cancer survivors and have a detrimental impact on their quality of life. In another study, we showed that parathyroid hormone 1‐34 and anti‐sclerostin antibody attenuates radiation‐induced bone damage by accelerating DNA repair in osteoblasts. DNA damage responses are partially regulated by the ubiquitin proteasome pathway. In the current study, we examined whether proteasome inhibitors have similar bone‐protective effects against radiation damage. MG132 treatment greatly reduced radiation‐induced apoptosis in cultured osteoblastic cells. This survival effect was owing to accelerated DNA repair as revealed by γH2AX foci and comet assays and to the up‐regulation of Ku70 and DNA‐dependent protein kinase, catalytic subunit, essential DNA repair proteins in the nonhomologous end‐ joining pathway. Administration of bortezomib (Bzb) reversed the loss of trabecular bone structure and strength in mice at 4 wk after focal radiation. Histomorphometry revealed that Bzb significantly increased the number of osteoblasts and activity in the irradiated area and suppressed the number and activity of osteoclasts, regardless of irradiation. Two weeks of Bzb treatment accelerated DNA repair in bone‐lining osteoblasts and thus promoted their survival. Meanwhile, it also inhibited bone marrow adiposity. Taken together, we demonstrate a novel role of proteasome inhibitors in treating radiation‐induced osteoporosis.—Chandra, A., Wang, L., Young, T., Zhong, L., Tseng, W.‐J., Levine, M. A., Cengel, K., Liu, X. S., Zhang, Y., Pignolo, R. J., Qin, L. Proteasome inhibitor bortezomib is a novel therapeutic agent for focal radiation‐induced osteoporosis. FASEB J. 32, 52‐62 (2018). www.fasebj.org