Genetic Testing for Hypertriglyceridemia in Academic Lipid Clinics: Implications for Precision Medicine-Brief Report

BACKGROUND

Severe hypertriglyceridemia is often caused by variants in genes of triglyceride metabolism. These variants include rare, heterozygous pathogenic variants (PVs), or multiple common, small-effect single nucleotide polymorphisms that can be quantified using a polygenic risk score (PRS). The role of genetic testing to examine PVs and PRS in predicting risk for pancreatitis and severity of hypertriglyceridemia is unknown.

METHODS

We examined the relationship of PVs and PRSs associated with hypertriglyceridemia with the highest recorded plasma triglyceride level and risk for acute pancreatitis in 363 patients from 3 academic lipid clinics who underwent genetic testing (GBinsight's Dyslipidemia Comprehensive Panel). Categories of hypertriglyceridemia included: normal triglyceride (<200 mg/dL), moderate (200-499 mg/dL), severe (500-999 mg/dL), or very severe (≥1000 mg/dL).

RESULTS

PVs and high PRSs were identified in 37 (10%) and 59 (16%) individuals, respectively. Patients with both had increased risk for very severe hypertriglyceridemia compared with those with neither genetic risk factor. Risk for acute pancreatitis was also increased in individuals with both genetic risk factors (odds ratio, 5.1 [P=0.02] after controlling for age, race, sex, body mass index, and highest triglyceride level), but not in individuals with PV or high PRS alone.

CONCLUSIONS

The presence of both PV and high PRS significantly increased risk for very severe hypertriglyceridemia and acute pancreatitis, whereas PV or PRS alone only modestly increased risk. Genetic testing may help identify patients with hypertriglyceridemia who have the greatest risk for developing pancreatitis and may derive the greatest benefit from novel triglyceride-lowering therapies.

Management of Mild-to-Moderate Hypertriglyceridemia

OBJECTIVE

Hypertriglyceridemia is highly prevalent globally and its prevalence is rising with international increases in the incidence of obesity and diabetes. This review examines current management and future therapies METHODS: For this review, hypertriglyceridemia is defined as mild-to-moderate triglyceride elevation, a fasting or non-fasting triglyceride level >150 mg/dL and <500 mg/dL. We reviewed scientific studies published over the last 30 years and current professional society recommendations regarding evaluation and treatment of hypertriglyceridemia.

RESULTS

Genetics, lifestyle, and other environmental factors impact triglyceride levels. In adults with mild-to-moderate hypertriglyceridemia, clinicians should routinely assess and treat secondary treatable causes (diet, physical activity, obesity, metabolic syndrome, and reduction or cessation of medications that elevate triglyceride levels). Since atherosclerotic cardiovascular disease (ASCVD) risk is the primary clinical concern, statins are usually first-line treatment. Patients with triglyceride levels between >150 mg/dL and <500 mg/dL whose LDL-C is treated adequately with statins (at "maximally tolerated" doses, per some statements) and have either prior cardiovascular disease or diabetes mellitus plus at least 2 additional cardiovascular disease risk factors should be considered for added icosapent ethyl treatment to further reduce their cardiovascular disease risk. Fibrates, niacin, and other approved agents or agents under development are also reviewed in detail.

CONCLUSION

The treatment paradigm for mild-to-moderate hypertriglyceridemia is changing based on data from recent clinical trials. Recent trials suggest that the addition of icosapent ethyl to background statin therapy may further reduce ASCVD risk in patients with moderate HTG, though a particular TG goal has not been identified.

Pharmacotherapy of obesity in complex diseases

More than 40% of adults in the United States suffer from obesity. Obesity is inextricably linked to many chronic illnesses like type-2 diabetes mellitus, hypertension, hyperlipidemia, heart disease, sleep apnea, stroke, and cancers. When used in combination with lifestyle modifications, pharmacotherapy has a vital role in treating obesity and improves short-term and long-term outcomes. A growing number of physicians are now interested in obesity medicine, and many of them are seeking guidance on how to treat complex patients with co-morbidities. This review provides a practical guide to the use of anti-obesity medications across various obesity-related comorbidities. It provides a general review of the currently approved anti-obesity medications and effective combinations. It discusses the highlights of the major trials and recent studies assessing the benefits of anti-obesity medications in comorbid conditions such as type-2 diabetes mellitus, psychiatric disorders, cardiovascular diseases, hypertension, renal diseases, and liver diseases. This review briefly examines the aspects of recognizing and addressing iatrogenic weight gain; discusses the precautions and prescribing considerations of anti-obesity medications, including side effects and possible dose adjustments in various comorbid conditions; and provides an expert opinion on an individualized choice of the best anti-obesity medication.

The impact of lipid-lowering medications on coronary artery plaque characteristics

Atherosclerosis is the predominant cause of coronary artery disease. The last several decades have witnessed significant advances in lipid-lowering therapies, which comprise a central component of atherosclerotic cardiovascular disease prevention. In addition to cardiovascular risk reduction with dyslipidemia management, some lipid-based therapies show promise at the level of the atherosclerotic plaque itself through mechanisms governing lipid accumulation, plaque stability, local inflammation, endothelial dysfunction, and thrombogenicity. The capacity of lipid-lowering therapies to modify atherosclerotic plaque burden, size, composition, and vulnerability should correlate with their ability to reduce disease progression. This review discusses plaque characteristics, diagnostic modalities to evaluate these characteristics, and how they are altered by current and emerging lipid-lowering therapies, all in human coronary artery disease.

Fracture Rates in Men With Non-Metastatic Prostate Cancer on Androgen Deprivation Therapy With or Without Anti-Osteoporosis Treatment

Introduction: Androgen deprivation therapy (ADT) decreases bone mineral density and increases osteoporotic fracture (OsteoFx) risk. Hypothesis: To assess OsteoFx incidence most predictive of future OsteoFx among men with prostate cancer on ADT. Methods: 4370 electronic medical records were reviewed of adult men with prostate cancer on cancer therapy +/- anti-osteoporotic therapy (Anti-OsteoRx) from 2011–2019. Cancer therapy included ADT (anti-androgens, GnRH agonists & antagonists, orchiectomy) and supplemental cancer therapy (SupplRx) (prostatectomy, brachytherapy, radiation, immunotherapy, and chemotherapy). Anti-OsteoRx included bisphosphonates, denosumab, and parathyroid hormone analogs. Patients with other cancers within 5 years of initial visit, metastasis or traumatic fractures were excluded. Retrospective analysis was done to determine baseline characteristics, type and duration of ADT, Anti-OsteoRx, SupplRx, and OsteoFx incidence. Results: Fracture rate subgroups: • ADT only - Anti-OsteoRx 37/ 374 fractured (9.89%) • ADT only + Anti-OsteoRx 10/52 fractured (19.23%) • ADT + SupplRx + Anti-OsteoRx 2/19 fractured (10.53%) • ADT + SupplRx + Anti-OsteoRx 13/170 fractured (7.65%) Comparing fracture rates between subgroups: • Comparing ADT only +/- Anti-OsteoRx, statistical significance was observed with higher fracture rate in patients taking Anti-OsteoRx (19.23% vs. 9.89%, p &lt; 0.044) • Comparing ADT + SupplRx +/- Anti-OsteoRx, no significant difference in fracture rates due to small number of fractures Comparing combined subgroups: • ADT +/- SupplRx + Anti-OsteoRx 12/71 (16.9%) fractured • ADT +/- SupplRx - Anti-OsteoRx 50/544 (9.19%) fractured • Statistically significant between groups fracture rates was observed (p= 0.042) in patients treated with Anti-OsteoRX. Discussion: Patients receiving Anti-OsteoRx, regardless of their prostate cancer therapies, had higher rates of fractures (16.9 vs. 9.19%, p= 0.042) due to their being selected for therapy based on greater clinical risks. The Anti-OsteoRx group had a higher percentage of glucocorticoid listed as a historical medication (26.8 vs.15.3% vs, p= 0.023), glucocorticoids administered (50.7 vs. 30.3% p=0.001), and anticonvulsants and proton-pump inhibitor use (45.1 vs. 26.5%, p= 0.002). Conclusion: Higher fracture rates were observed in patients on Anti-OsteoRx that could be related to their being selected for treatment based on risk factors known to be associated with osteoporosis. Limited Anti-OsteoRx use in our study is possibly related to lack of standardized guidelines for prevention of osteoporotic fractures in prostate cancer patients. OsteoFx risk assessment utilizing CRF, DXA, and FRAX may prevent fractures in these high-risk patients. Further long-term prospective studies to address these unresolved queries are warranted.

Clinical Risk Factors for Osteoporotic Fractures in Men With Non-Metastatic Prostate Cancer on Androgen Deprivation Therapy With or Without Anti-Osteoporosis Treatment

Introduction: Androgen deprivation therapy (ADT) decreases bone mineral density and increases osteoporotic fracture (OsteoFx) risk.

Hypothesis: To assess OsteoFx clinical risk factors (CRF) most predictive of future OsteoFx among men with prostate cancer on ADT.

Methods: 4370 electronic medical records were reviewed of adult men with prostate cancer on cancer therapy +/- anti-osteoporosis therapy (Anti-OsteoRx) from 2011–2019. Cancer therapy included ADT (anti-androgens, GnRH agonists & antagonists, orchiectomy) and supplemental cancer therapy (SupplRx) (prostatectomy, brachytherapy, radiation, immunotherapy, and chemotherapy). Anti-OsteoRx included bisphosphonates, denosumab, and parathyroid hormone analogs. Patients with other cancers within 5 years of initial visit, metastasis, and traumatic fractures were excluded. Retrospective analysis was done to determine baseline characteristics, type and duration of ADT, Anti-OsteoRx, SupplRx, and osteoporosis CRF.

Results: 615 men on ADT +/- SupplRx +/- Anti-OsteoRx were included in the study. 10.08% had OsteoFx irrespective of SupplRx or Anti-OsteoRx. Comparing the OsteoFx group to the non-fracture group, the following CRF were found to be statistically significant (p <0.05): age at prostate cancer diagnosis (75.10 +/- 11.80 vs 71.59 +/- 9.80 y), diabetes mellitus (DM) (33.9 vs 19%), pre-existing comorbidities affecting bone (PreCo) (41.9 vs 24.8%), steroid use (11.3 vs 4.0%), and anti-convulsant and proton-pump inhibitor (med) use (45.2 vs 26.8%).

9.89% of 374 men on ADT only without (wo) Anti-OsteoRx fractured. Statistically significant CRF for OsteoFx were age (76.86 +/- 10.55 vs 73.02 +/- 10.06 y), DM (40.5 vs 19.6%), PreCo (45.9 vs. 26.4%), and med use (48.6 vs. 25.5%).

In the following subgroups there were no statistically significant difference in CRF:•7.64% of 170 men on ADT + SupplRx wo Anti-OsteoRx •19.23% of 52 men on ADT only + Anti-OsteoRx •10.52% of 19 men on ADT + SupplRx + Anti-OsteoRx

To increase statistical power, patients on ADT +/- SupplRx were assessed:•Among 71 men on ADT +/- SupplRx + Anti-OsteoRx, there were no statistically significant differences in CRF•Among the 544 men on ADT +/- SupplRx wo Anti-OsteoRx, significant CRF for OsteoFx were age (75.16 + 11.70 vs 71.37 + 9.85 y), DM (38 vs 19.4%), PreCo (38 vs 24.1%), steroid use (12 vs 3.8%), and med use (48 vs 24.3%)

Discussion:

Men with prostate cancer requiring ADT have a higher incidence of osteoporosis defined by DXA prior to initiating ADT compared to age-matched cohorts (Hussain et al). Our study revealed ADT with CRF is associated with OsteoFx irrespective of SupplRx or Anti-OsteoRx. Limitations include inability to evaluate efficacy of Anti-OsteoRx due to insufficient power.

Conclusion: OsteoFx risk assessment utilizing CRF, FRAX, DXA with timely intervention may prevent OsteoFx in these high-risk patients.

The clinical black, white, and gray lessons

PURPOSE OF REVIEW

This review examines recent contradictory large, well-controlled randomized control trials assessing the effects of omega-3 fatty acids and colchicine on cardiovascular (CV) outcomes.

RECENT FINDINGS

The Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) and Statin Residual Risk Reduction with Epanova in high Cardiovascular Risk patients with Hypertriglyceridemia (STRENGTH) trial assessed the CV outcomes using high-dose omega-3 fatty acids in statin-treated patients with moderate hypertriglyceridemia and high-risk for CV disease with differing results. Similarly, Colchicine Cardiovascular Outcomes trial, (COLCOT) second Low Dose Colchicine (LoDoCo2), and Colchicine in patients with Acute Coronary Syndrome (COPS) assessed the CV outcomes using low-dose colchicine in patients with coronary artery disease with inconsistent results. These contradictory findings among studies assessing similar questions with the same drug or a drug within the same class challenge the scientific validity and clinical applicability of the derived conclusions.

SUMMARY

A comprehensive review revealed many differences between the trials, which could have contributed to observed divergent results. Consistent findings across multiple trials help strengthen the evidence for specific endpoints or sub-populations, and these findings must be included in guidelines. Large prospective cohort studies with diligent study protocols are warranted in the future to resolve unanswered dilemmas.

How I treat statin-associated side effects in an outpatient setting

Dyslipidemia promotes atherosclerosis and causes cardiovascular diseases. Statins are potent lipid-lowering medications with a cardiovascular mortality benefit. They are generally safe and well tolerated but sometimes can be associated with side effects of variable severity. The most common side effect is statin-associated muscle symptoms. Uncommon side effects include new-onset diabetes mellitus and elevation in liver enzymes. These effects can lead to noncompliance and premature discontinuation of the medication. Hence, it is crucial to identify patients with true statin-associated side effects (SASE) to ensure optimal statin use. The appropriate evaluation of the patient before starting statins and proactive utilization of available diagnostic tests to rule out alternate etiologies mimicking adverse effects are essential for accurate diagnosis of SASE. In patients with true SASE, timely intervention with modified statin or non-statins is beneficial. Herein, we discuss key clinical trial data on statins and non-statins, and describe our center's approach toward patients with SASE.

Cardiovascular outcomes with glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Background

Glucagon-like peptide-1 receptor agonists (GLP1RAs) are relatively newer anti-hyperglycemic agents, which have demonstrated cardiovascular benefits in patients with type 2 diabetes mellitus.

Design

We performed a meta-analysis of randomized controlled trials to evaluate the cardiovascular outcomes of GLP1RAs compared to placebo in type 2 diabetes mellitus patients. We performed an additional subgroup analysis to evaluate the role of GLP1RAs in patients with chronic kidney disease.

Methods

MEDLINE, Cochrane and ClinicalTrials.gov databases were searched from inception to 15 July 2019. The authors extracted relevant information from articles and independently assessed the study quality.

Results

Compared to placebo, GLP1RAs demonstrated a significant reduction in all-cause mortality (odds ratio (OR) 0.88, 95% confidence interval (CI) 0.82–0.95; P &lt; 0.001), cardiovascular mortality (OR 0.88, 95% CI 0.81–0.96; P = 0.004), primary composite endpoint (OR 0.86, 95% CI 0.80–0.91; P &lt; 0.001) and non-fatal stroke (OR 0.86, 95% 0.77–0.95; P = 0.004). There was no statistical difference in non-fatal myocardial infarction (OR 0.92, 95% CI 0.83–1.01; P = 0.09). In subgroup analyses of patients with estimated glomerular filtration rate less than 60 ml/min/1.73 m2 and less than 30 ml/min/1.73 m2, there was no significant difference in the primary composite endpoint.

Conclusions

GLP1RAs demonstrated a significant reduction in all-cause mortality, cardiovascular mortality, primary composite endpoint and non-fatal stroke in patients with type 2 diabetes mellitus. There was no significant difference in the primary composite endpoint in patients with type 2 diabetes mellitus and chronic kidney disease.

SUN-474 An Unusual Case of Poorly Differentiated Thyroid Carcinoma with an Excellent Prognosis

Background: Poorly differentiated thyroid carcinoma (PDTC) is a rare and aggressive subtype with morphological/behavioral features between differentiated thyroid carcinoma (DTC) and anaplastic thyroid carcinoma (ATC).

Clinical case: A 43-year-old female presented with 3 cm right thyroid mass noted on US neck. FNA biopsy showed undifferentiated carcinoma, large cell type. Additional immune-stains were suggestive of ATC. Pre-surgery non-stimulated thyroglobulin (NSTG) was 311 (RR 0–55 ng/dl). Pathology post-total thyroidectomy with bilateral level VI lymph node dissection showed a 3.2 x 2.5 x 2.5 cm carcinoma with vascular and capsular invasion. Most of the mass consisted of very atypical pleomorphic cells, mitosis was difficult to find. The tumor did not show the widely invasive-destructive pattern commonly seen in ATC. An adjacent differentiated component showed predominantly follicular pattern and was described as dedifferentiated follicular carcinoma. All lymph nodes were negative for metastatic disease. Post-surgery NSTG was &lt;0.2 (RR &lt;0.1ng/ml as athyreotic), stimulated TG was 2.22 with negative TG antibodies. Four months later, she received 193.5 mCi radioactive iodine (RAI) therapy. The post-therapy scan showed no Iodine-131 avid uptake in neck or distant metastasis. Neck imaging and TG levels done periodically showed no structural or biochemical evidence of recurrence. Currently the patient is cancer-free for 14 years since diagnosis with no need for additional therapies.

Discussion: PDTC accounts for 1–15% of all thyroid cancers. Although PDTC is rare, it is a clinically significant histological diagnosis as it represents the main cause of death from non-anaplastic follicular cell-derived thyroid carcinoma. The Turin proposal published in 2007 suggested three criteria for the diagnosis of PDTC which included the pattern of growth and high-grade features. PDTC presents more frequently with locally invasive extra-thyroidal disease, metastasis to regional lymph nodes and distant organs compared to DTC. Despite the capacity to have RAI uptake, there has been no evidence of significant improvement in survival due to tumor heterogeneity in differentiation. Recent data suggest that age more than 45 years, tumor size more than 4cm, extra-thyroidal extension, higher pathological T stage, positive margins, and distant metastasis predict worse prognosis.

Conclusion: Our patient showed an excellent response to therapy in spite of having PDTC with positive margins. We hypothesize that this could be likely due to young age at the time of diagnosis, early detection of tumor while it was localized in the thyroid without distant metastasis as well as heterogeneity in the tumor with differentiated cells that are responsive to RAI. We conclude that with early detection, timely surgery, and adjuvant therapy, excellent prognosis can be achieved in patients with PDTC.

SAT-128 An Uncommon Case of Squamous Cell Carcinoma of the Vulva with Metastasis to the Thyroid Gland

Background: Distant metastasis from Squamous Cell Carcinoma (SCC) of the Vulva is very rare and typically associated with poor outcomes. In the literature, there have been no reported cases of vulvar SCC with metastasis to the thyroid, which augments the uniqueness of the case we are presenting.

Clinical Case: A 29-year-old female was hospitalized for abdominal pain & altered mental status. Labs showed calcium 21 (RR 8.5-10.5 mg/dL) with iPTH 4.3 (RR 12-88 pg/mL). Imaging revealed an 8.6 x 7.2 cm right thyroid mass (solid with cystic internal components, hyperechoic to isoechoic, wider than tall, lobulated margins, punctate echogenic foci occupying nearly the entire right lobe, minimal vascularity), mildly effacing the trachea. There were also extensive lesions consistent with systemic metastasis involving the left hilar lymph nodes, pre-tracheal lymph nodes, right hepatic lobe, head of pancreas, retroperitoneal lymph nodes, right inferior pubic ramus, proximal right humerus, left humerus, proximal femur & frontal lobe of the brain. Hypercalcemia of malignancy from an unknown cancer was diagnosed. FNA biopsy of the thyroid mass was consistent with atypia of undetermined significance. Liver biopsy showed evidence of high grade carcinoma with non-calcitonin producing neuroendocrine differentiation. Labs showed serum serotonin 11 (RR 56-244 ng/mL), CA 19-9 &lt; 0.8 (RR 0-35 U/mL), alpha-fetoprotein 2.12 (RR 0-9 ng/mL), CEA 20.97 (RR 0-2.9 ng/mL), PTHrP 33 (RR 14-27 pg/mL), 1,25OH Vit D 18 (RR 18-72 pg/mL), chromogranin A 189 (RR 25-140 pg/mL), & calcitonin &lt; 2 (RR &lt; 5 pg/mL). A vaginal lesion was discovered on exam & biopsy showed squamous cells with cytopathic effect of Herpes Simplex Virus (confirmed with immunohistochemical stain). Subsequent biopsy of the brain & core needle biopsy of the thyroid showed morphology similar to a concurrent biopsy of a vulvar lesion also found on exam: poorly differentiated SCC. The patient was diagnosed with vulvar SCC with extensive metastasis. Her hospital course was complicated by atrial fibrillation, acute respiratory failure, & sepsis. She, unfortunately, passed away from her severe morbidities.

Discussion: Metastasis to the thyroid is an infrequent occurrence. It is commonly encountered in breast, lung & renal cell carcinomas. It can occur due to direct spread from adjacent tissues or by lymphatic or hematogenous spread. Thyroid gland metastasis is more commonly seen in patients with aggressive or widespread carcinomas, especially by hematogenous route, due to the thyroid’s extensive vascularity.

Conclusion: Thyroid gland metastasis, particularly due to vulvar SCC, is a rare entity with a poor prognosis. In patients with extensive poorly differentiated carcinoma such as our patient, it is of utmost importance to identify suspicious thyroid nodules and perform comprehensive diagnostic testing to facilitate timely intervention for improved outcomes.

SUN-205 Pseudo-Cushing Syndrome Secondary to Malnutrition and Gluco-Toxicity Mimicking Type 1 Diabetes Mellitus

Background: Pseudo-Cushing Syndrome (PCS) is an under-recognized clinical entity that is a reversible consequence of alterations in cortisol production. We present a case of a patient with presumed type 1 Diabetes Mellitus (DM) who was found to have PCS secondary to malnutrition. Once the nutritional status normalized, the patient’s glycemic control remarkably improved and became well-controlled on metformin alone.

Clinical case: A 54-year-old female with poorly controlled insulin-dependent DM for 10 years was referred for concern for adrenal insufficiency after an ACTH came back elevated in the setting of intractable nausea, vomiting and considerable weight loss over 1 year. Prior HbA1c was 16.2% (RR 4.4–6.7). On exam her vitals were normal, body mass index (BMI) was 15 kg/m². Workup confirmed an elevated ACTH of 100 pg/ml (RR 6–50 pg/ml), however, random PM cortisol was unexpectedly elevated at 26.58 ug/dL (RR 4.46 – 22.7). 8 AM labs for ACTH and cortisol were similarly elevated at 91 pg/ml and 28.33 ug/dl, respectively. She had no evidence of classic Cushingoid features. Subsequent low dose dexamethasone suppression test and 24-hour urine free cortisol were negative. Over 18 months, with optimization of her insulin therapy, BMI improved to 19 kg/m², ACTH and cortisol started to downtrend spontaneously. After 30 months, her BMI improved to 20 kg/m². Repeat blood work showed A1C 6.5%, ACTH and cortisol completely normalized to 42 pg/dl and 8 ug/dL, respectively. After being adherent to insulin for a few years, her gluco-toxicity state resolved. A month prior to following up, she self-discontinued insulin due to hypoglycemia but continued on metformin. Currently she continues to remain off insulin.

Discussion: PCS is a challenging diagnosis to recognize and differentiate from Cushing Disease (CD) especially due to overlap in biochemical profile. It is important to be aware of this clinical condition to avoid misdiagnosis, delay in treatment or over-treatment. Common etiologies causing PCS include depression, chronic alcoholism, obesity, physical stress, malnutrition, eating disorders, uncontrolled DM, obstructive sleep apnea. PCS occurs due to chronic activation of the hypothalamic-pituitary-adrenal axis, it is usually mild and resolves with treatment of underlying etiology. In our case, first-line screening tests could differentiate between PCS and CD hence she did not require late-night salivary cortisol testing or corticotropic-releasing hormone testing.

Conclusion: In our patient, PCS occurred secondary to malnutrition and severe gluco-toxicity which mimicked insulin-dependent type 1 DM. Interestingly, once her nutritional status and insulin compliance improved, cortisol levels normalized, gluco-toxicity state resolved and she no longer required exogenous insulin therapy.

MON-343 The Mystery of Recurrent PTH-Independent Hypercalcemia with Severe Hypophosphatemia

Background

The differential diagnoses for PTH independent hypercalcemia with hypophosphatemia are broad. Careful history with systematic evaluation for possible etiologies is necessary for accurate diagnosis and timely therapeutic intervention.

Clinical Case

A 72-year old female was referred to our clinic for evaluation of hypercalcemia with low iPTH level. Review of lab workup over the past two years showed frequent occurrences of mild hypercalcemia, low iPTH and moderate to severe hypophosphatemia. She denied use of calcium, vitamin D, Vitamin A or herbal supplements and over the counter (OTC) medications. Age-appropriate cancer screening was up to date. She had no clinical evidence of granulomatous diseases or malabsorption syndrome. Labs revealed corrected calcium (cCa) 9.9 (8.5-10.5 mg/dL), iPTH 6.36 (12-88 pg/mL), phosphate 1.5 (2.5-4.5 mg/dl), magnesium 1.6 (1.8-2.7 mg/dl), 25-OH Vit D 30 (30-100 ng/mL), PTHrP 12 (14-27 pg/mL), 1,25 OH Vit D 32 (18-72 pg/ml), TSH 1.8 (03-5.6 uIU/mL), GFR 49 (>90 mL/min/1.73 m²) and bicarbonate 30 (23-31 mEq/L). FGF23, 1-mg ODST and SPEP were normal. 24-hour urine phosphate was 3 mg/24h, ruling out renal phosphate wasting.

Two months later, she developed myalgia and generalized weakness. Labs showed cCa 11.3mg/dl, iPTH 3.79 pg/ml, phosphate <1 mg/dl, magnesium 1.2 mg/dl, bicarbonate 33 mEq/L. She was hospitalized for severe hypophosphatemia. Here, she revealed she was intermittently taking a “milky” antacid obtained from Mexico, for her GERD. She required IV phosphate and magnesium replacement and her mineral abnormalities normalized within 24 hours. She was advised to stop use of OTC antacids and provided daily phosphate and magnesium supplementation. 4 weeks later, she developed recurrent hypercalcemia 10.4 mg/dl, hypophosphatemia 1.1 mg/dl and alkalosis with bicarbonate 35 mEq/L, which corrected with supervised phosphate and magnesium supplementation and restricted access to home OTC medications.

Discussion

Milk-alkali syndrome, characterized by the triad of hypercalcemia, metabolic alkalosis and renal failure, has been classically associated with ingestion of large amounts of milk and absorbable alkali. Once a common cause of hypercalcemia, its incidence declined rapidly with advent of new therapies for PUD. Recently, this syndrome, now described as calcium-alkali syndrome (CAS) has re-emerged due to use of high dose calcium carbonate supplements and OTC antacids, with a prevalence of 9-12% among hospitalized patients with hypercalcemia.

We hypothesize our patient’s mineral abnormalities are explained by CAS. High doses of calcium from antacids can bind phosphate in the gut, leading to poor phosphate absorption and hypophosphatemia.

Conclusion

CAS is emerging as a frequent cause of hospital admissions for hypercalcemia. Severe hypophosphatemia can be a rare manifestation. Primary therapy is withdrawal of offending agent.

SAT-498 Use of Cinacalcet for PTHrP-Mediated Hypercalcemia of Malignancy in Penile Squamous Cell Carcinoma

Background: PTHrP-mediated hypercalcemia accounts for 80% of hypercalcemia of malignancy (HCM), and is traditionally treated with bisphosphonates or hemodialysis. We report a patient with penile squamous cell carcinoma (SCC) and bisphosphonate resistant PTHrP-mediated HCM that responded to calcimimetic therapy. Clinical Case: A 75-year-old man with metastatic penile SCC was admitted with altered sensorium. He had no prior history of hypercalcemia or fractures. His exam was significant for disorientation and hypovolemia. Labs revealed an elevated ionized calcium [iCa] of 1.65 mmol/L [0.95-1.32 mmol/L], phosphorus 2.6 mg/dl [2.5-4.6 mg/dL], magnesium 1.8 mg/dl [1.6-2.7 mg/dL], appropriately low intact PTH 8.1 pg/ml [8.0-85.0 pg/mL], 25-hydroxy vitamin D of 24 ng/ml [30-100 ng/mL], TSH 3.3 uIU/mL [0.350-4.940 uIU/mL], elevated PTHrP level 47 pg/ml [14-27 pg/mL], 1, 25-dihydroxy vitamin D 25 pg/ml [18 - 64 pg/mL], and serum immunofixation negative for paraproteins. Due to concomitant SIADH, intravenous (IV) fluids were used cautiously. He received IV zoledronic acid (ZA) 4mg on Day 2, following which iCa normalized in two days. One month later, the patient was readmitted with pneumonia. On Day 7, he was noted to have an elevated iCa of 1.4 mmol/L. On Day 8 of admission, he was given a second dose of IV ZA 4mg and iCa normalized 48 hours later. However, his hospital course was complicated by recurrences of hypercalcemia on day 14 (iCa 1.41 mmol/L) and day 24 (iCa 1.41 mmol/L) requiring 2 additional doses of IV ZA 4mg (Days 14 and 24) resulting in brief normalization of iCa. On day 26, iCa increased to 1.36 with further ZA unable to be administered due to worsening creatinine clearance. Use of IV fluids was limited due to worsening hyponatremia. Denosumab or calcitonin were not available in the inpatient formulary. Prior to considering hemodialysis, the patient was started on a trial of oral cinacalcet 30mg daily on Day 28. Within 24 hrs of initiation of cinacalcet, iCa normalized. On Day 40 hemodialysis was initiated. iCa increased to 1.36 on Day 43 requiring 60 mg of cinacalcet daily. Throughout the remainder of the patient’s hospitalization, further titration of cinacalcet was required with 90 mg twice daily prescribed on Day 54 resulting in normalization of iCa. On day 60, iCal was again found to be abnormal with a repeat PTHrP level of 1318 pg/ml. iCal levels continued to trend up until day 64, when the patient had a cardiac arrest and expired. Conclusion: Cinacalcet is an allosteric activator of the calcium sensing receptor. The mechanism of effect on PTHrP-mediated HCM is still under investigation, but in murine models, increased calcitonin secretion appears to play a role. The use of cinacalcet for HCM has been described in only four prior case reports. Further studies are needed to further elucidate the role of cinacalcet as a therapeutic option in HCM.

SUN-508 Intravenous Bisphosphonates Induced Renal Injury with Nephrotic Range Proteinuria in a Patient with Severe Hypercalcemia Secondary to Parathyroid Carcinoma

Background: Bisphosphonates is a known therapeutic option for PTH dependent hypercalcemia. We report a patient who developed nephrotic range proteinuria after treatment with Bisphosphonates for severe hypercalcemia in parathyroid carcinoma (PTHCa). Clinical Case: A 43 year old male with PTHCa presented with corrected serum calcium (Sr Ca) of 16.1 [8.5-10.5 mg/dl] and iPTH of 1116 [6.0-65.0 pg/mL]. He had undergone two surgeries for the parathyroid mass 7 years prior to presentation at another hospital and was lost to follow up for 5 years. At admission he was treated with IV fluids, calcitonin and IV Pamidronate [IVP] 90mg with improvement in calcium within 1-2 day. Imaging showed a 1.7cm mediastinal mass. Subsequently he had frequent hospitalizations due to recurrence of hypercalcemia. He was started on cinacalcet and was unable to tolerate it due to severe nausea. Hence, he received almost weekly bisphosphonate infusions, 6 doses of IVP and 2 doses of IV zoledronic acid (ZA) in 3 months. He then underwent surgery to removal the mediastinal mass which was lymphoid tissue only. He had persistent high iPTH (1206 pg/ml) and Sr Ca 17.4 mg/dl. He received 3 cycles of chemotherapy with transient improvement in Sr Ca, with subsequent recurrence of hypercalcemia. As there was no structural disease noted on imaging, he was treated medically. During the subsequent 6 month after surgery, patient received further 8 doses of IVP 90mg and 3 doses of IV ZA 4mg. Repeat imaging 4 months later, showed a new mediastinal mass, 2.6 cm invading trachea for which he had another surgery. Post-surgery, iPTH was low (84.6 pg/ml) and he developed hypocalcemia. However, hypercalcemia recurred and he was noted to have proteinuria with progressive worsening serum creatinine from baseline 1.3 [0.6-1.4 mg/dl] to 4.1 mg/dl. This was seen after 14 doses of IVP 90mg and 5 doses of ZA over a period of 9 months. 24-hour urine protein was 12gm/24hr. Workup for proteinuria including Hepatitis panel, HIV, RPR, ANA, C3/C4, SPEP were unremarkable. Renal US showed markedly echogenic kidneys suggesting medical renal disease. Patient declined renal biopsy. Bisphosphonate induced focal segmental glomerulosclerosis [FSGS] with nephrotic range proteinuria was diagnosed after exclusion of other etiologies. Conclusion: In experimental models, bisphosphonates especially Pamidronate has shown to cause kidney injury in a dose-dependent pattern. It is a rare complication with very few cases reported in the literature and most of them in breast cancer patients. We are reporting the same in a patient with PTHCa. Multiple mechanisms have been proposed to cause nephrotic range proteinuria including collapsing FSGS, mitochondrial apoptosis in podocytes and/or proximal tubular cells by IVP and ATN by ZA. In patients requiring large and frequent dose of bisphosphonates monitoring for proteinuria may help in early detection.