Evaluation of Strontium Interference in Calcium Measurement Procedures and Content in Supplements as Measured by ICP-MS.

BACKGROUND: Bone health supplements containing strontium are available without prescription, however, the effects of strontium interference on clinical laboratory calcium measurement procedures are unknown. METHODS: To evaluate strontium interference on total calcium measurements, plasma pools with exogenously added strontium were measured by 3 total calcium measurement procedures. For ionized calcium measurements, whole blood pools prepared with exogenously added strontium were measured by 2 ionized calcium measurement procedures. An inductively coupled plasma mass spectrometry assay (ICP-MS) was validated for research measurements of strontium content in commercially available supplements. RESULTS: Exogenous strontium addition to plasma caused positive bias for total calcium measurements. Strontium concentrations of 1.0 mg/dL (0.114 mmol/L), 2.5 mg/dL (0.284 mmol/L), and 5.0 mg/Dl (0.568 mmol/L) resulted in mean biases of 1.9% to 3.5%, 4.9% to 9.0%, and 10.8% to 19.2%, respectively, for total calcium measurement procedures. Biases for ionized calcium measurements were less than 4.5% for a strontium concentration of 5.0 mg/dL (0.568 mmol/L). An in-house-developed ICP-MS assay for strontium in commercially available supplements exhibited within-laboratory and within-run coefficients of variation of less than 3%, and a linear response was obtained over the assay analytical measurement range of 10 to 100 000 ng/mL (0.0001 to 1.141 mmol/L). Strontium recovery for the ICP-MS assay was 97.1% to 105.3%. The largest amount of strontium measured in dietary supplements was 395 mg in a 1054 mg tablet. CONCLUSIONS: Some dietary supplements contain larger amounts of strontium than indicated on the product label. High concentrations of strontium may cause significant interference for total calcium measurement procedures, but ionized calcium measurement procedures are not significantly affected.

Outbreak of Severe Hypoglycemia After Ingestion of a Male Enhancement Supplement - Virginia, August-November 2019.

In August 2019, the Virginia Poison Center (VPC) and the Blue Ridge Poison Center (BRPC) were contacted concerning patients experiencing repeated episodes of marked hypoglycemia following ingestion of a male enhancement supplement tablet marketed as "V8" in convenience stores in central Virginia. Over the following 3 months, the Virginia Department of Agriculture and Consumer Services (VDACS) and the Virginia Department of Health (VDH) conducted an investigation and identified 17 patients meeting the case definition (severe hypoglycemia within 48 hours of consuming an over-the-counter male enhancement supplement in a man with no history of use of insulin or other medication used to control blood glucose). Analysis of the V8 tablets revealed that most contained glyburide, a sulfonylurea oral hypoglycemic used in the treatment of diabetes and associated with prolonged hypoglycemia following overdose (1). To stem this outbreak, V8 was removed from stores when found, and public service announcements were released. The public health implications of V8 use include the potential for substantial morbidity from hypoglycemic episodes and the potential for mortality if health care services are not accessed in a timely manner when hypoglycemia occurs. The presence of V8 in the market poses a serious threat to public health because of its potentially life-threatening adverse effects.

Severe Systemic Lead Toxicity Resulting From Extra-Articular Retained Shrapnel Presenting as Jaundice and Hepatitis: A Case Report and Review of the Literature.

INTRODUCTION: Despite greater than 60,000 nonfatal firearm injuries per year in the United States, retained shrapnel is a relatively rare cause of systemic lead toxicity with less than 100 cases reported in the medical literature since 1867. While intra-articular retained shrapnel as a cause of lead toxicity is well-described, extra-articular fragments are less well known to cause symptomatic disease. CASE REPORT: A 31-year-old man initially presented with abdominal pain, constipation, jaundice, and elevated liver transaminases approximately 3 weeks after suffering a left lower extremity injury during athletic activity. The patient was found to have steatohepatitis after extensive inpatient and outpatient gastroenterological workup to include upper and lower endoscopy, liver ultrasound, and biopsy of the liver to confirm the diagnosis. Imaging was incidentally notable for retained gunshot in the left flank and large shell fragment containing seroma in the left thigh. The patient was initially discharged with improved pain, but later presented to a primary care clinic with weight loss and continued pain. This was followed by a subsequent progression to diffuse weakness, ultimately resulting in an inability to ambulate. The patient was readmitted to a tertiary care medical center, 3 months after the initial presentation. Physical exam was then notable for 70-lb weight loss from initial admission and diffuse peripheral weakness with global muscle atrophy. Following a broad differential workup, he was found to have a blood lead level of 129 µg/dL, and hemoglobin of 7.7 g/dL with basophilic stippling on peripheral smear. The patient was transferred to the intensive care unit for chelation therapy with dimercaprol and calcium ethylenediaminetetraacetic acid. Lead levels initially decreased, but rose when patient was transitioned to oral therapy with succimer. Surgery was consulted for removal of multiple retained fragments, which were analyzed by the Joint Pathology Center and found to contain lead. The patient's motor function gradually improved on oral chelation and he was discharged to a subacute rehabilitation facility. CONCLUSION: This complex case describes a rare cause for a relatively common clinical presentation, jaundice and hepatitis, and reinforces the importance of longitudinal follow up and reassessment of a patient with an unknown illness and worsening clinical condition. Diagnosis of systemic lead toxicity is challenging because of its protean clinical manifestations, and relative rarity with the advent of strict environmental lead controls and decrease in lead-based paint and industrial products. Furthermore, extra-articular lead remains a rare cause of systemic toxicity, and the surgical standard of care has been to not remove these fragments in gunshot victims. This case adds to a small amount of evidence that lead screening may be of value in selected patients with extra-articular retained shrapnel, especially those with seroma and osteophyte formation in the wound.