Value of sestamibi scans in tertiary hyperparathyroidism.

OBJECTIVES: To determine the value of preoperative Tc-sestamibi scans and the incidence of ectopic glands in tertiary hyperparathyroidism. DESIGN: Prospective, non-randomized analysis of a consecutive cohort of surgical patients from the Medical College of Georgia Thyroid/Parathyroid Center. MATERIALS AND METHODS: A consecutive series of patients with tertiary hyperparathyroidism undergoing parathyroidectomy was analyzed. Demographic data, preoperative Tc-sestamibi scintigraphy results, location of diseased glands, pre- and postoperative calcium, and parathyroid hormone levels were collected. RESULTS: Twenty-one patients underwent parathyroidectomy for tertiary hyperparathyroidism between March 2004 and September 2006. Of these 21 patients, 3 were re-operative cases for persistent hypercalcemia and each was found to have a single diseased gland. Of the 18 patients undergoing first time surgery, 15 had four-gland hyperplasia, 2 patients had single adenomas, and 1 patient had a double adenoma. Nine of the 21 patients (43%) had ectopic glands (2 of these patients had 2 ectopic glands each). The overall sensitivity of the preoperative Tc-sestamibi scintigraphy was 76% and was not significantly different when comparing patients with ectopic glands (78%) and those without (75%). CONCLUSIONS: Tc sestamibi scintigraphy has high positive predictive value and sensitivity in patients with tertiary hyperparathyroidism. Sestamibi scanning is particularly valuable in this patient population since the incidence of ectopic glands may be higher than previously recognized.

Hyperthyroidism: a secondary cause of isolated systolic hypertension.

Isolated systolic hypertension is the most common form of hypertension, especially among patients 50 years or older. What is not appreciated is that there are secondary causes of isolated systolic hypertension. Hyperthyroidism increases systolic blood pressure by decreasing systemic vascular resistance, increasing heart rate, and raising cardiac output. Potential cardiovascular consequences of hyperthyroidism include atrial arrhythmias (especially atrial fibrillation), pulmonary hypertension, left ventricular hypertrophy, and heart failure. The prevalence of hypertension is greater among hyperthyroid patients than euthyroid patients. Whether there is a blunted nocturnal decline in ambulatory blood pressure among hyperthyroid patients is more controversial. Treatment is associated with a reduction in systolic blood pressure, heart rate, and cardiac output.

Significant differential effects of alendronate, estrogen, or combination therapy on the rate of bone loss after discontinuation of treatment of postmenopausal osteoporosis. A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Combination therapy with alendronate and estrogen for 2 years increases bone mineral density at the spine and hip more than does therapy with either agent alone. Changes in bone mineral density after discontinuation of therapy have not been compared directly. OBJECTIVE: To determine the rate of bone loss when therapy with alendronate, estrogen, or both agents is discontinued. DESIGN: Double-blind, placebo-controlled discontinuation trial. SETTING: 18 U.S. centers. PATIENTS: 244 postmenopausal, hysterectomized women 44 to 77 years of age. INTERVENTION: 2 years of therapy with alendronate, 10 mg/d (n = 92); conjugated estrogen, 0.625 mg/d (n = 143); alendronate and conjugated estrogen (n = 140); or placebo (n = 50). At year 3, women were allocated into five groups: Twenty-eight women continued to take placebo and 44 women continued to take combination therapy, but 50 women taking alendronate, 81 taking conjugated estrogen, and 41 taking combination therapy were switched to placebo. MEASUREMENTS: Bone mineral density and biochemical markers of bone turnover. RESULTS: Women taking alendronate or combination therapy who were switched to placebo for year 3 of the study maintained bone mass. Bone mineral density in these women was 4.1% (CI, 2.6% to 5.7%) and 6.6% (CI, 5.0% to 8.2%) higher, respectively, at the spine (P < 0.001 for both treatment comparisons) and 3.5% (CI, 2.3% to 4.6%) and 3.0% (CI, 1.8% to 4.2%) higher, respectively, at the trochanter (P < 0.001 for both treatment comparisons) than that in women previously taking estrogen who were switched to placebo. In contrast, women who were taking estrogen and were switched to placebo during year 3 experienced a 4.5% decrease at the spine (95% CI, -5.0% to -4.0%) and a 2.4% decrease at the trochanter (CI, -2.7% to -2.1%) (P < 0.001 for both changes). Compared with women who took placebo for 3 years, women who took estrogen for 2 years and were then switched to placebo had a bone mineral density that was 2.9% higher (CI, 1.2% to 4.6%) at the spine (P < 0.05) and 2.9% higher (CI, 1.6% to 4.2%) at the trochanter (P < 0.001). Changes in biochemical markers during year 3 did not differ among the groups that discontinued active treatment. CONCLUSIONS: Accelerated bone loss is seen after withdrawal of estrogen therapy but not after withdrawal of alendronate or combination therapy. The differential effects after withdrawal of therapy should be considered in the management of postmenopausal osteoporosis.

Glucose-dependent insulinotropic peptide stimulates proliferation and TGF-beta release from MG-63 cells.

Glucose-dependent insulinotropic peptide (GIP) is known to modulate alkaline phosphatase activity and collagen type I message in osteoblastic-like cells. GIP effects on cell proliferation are not known. We report that GIP dose dependently stimulated 3H-thymidine incorporation in the osteoblastic-like cell line MG-63. Furthermore, GIP increased message and secretion of transforming growth factor beta (TGF-beta), an agent known to regulate osteoblastic proliferation and differentiation. However, when GIP was added to MG-63 cells concurrently with a TGF-beta neutralizing antibody, there was no effect on 3H-thymidine incorporation in these cells. These data demonstrate that GIP stimulates osteoblastic-like cell proliferation but that this effect is not mediated by TGF-beta.

Primary ovarian lymphoma manifesting with severe hypercalcemia.

OBJECTIVE: To describe a case of primary ovarian lymphoma manifesting with severe hypercalcemia. METHODS: We report the occurrence of a substantially increased serum calcium level in a 74-year-old female patient who presented with progressive weakness, volume depletion, confusion, slurred speech, cardiac abnormalities, and renal insufficiency. The patient's clinical course is reviewed, and the results of laboratory and imaging studies leading to the underlying diagnosis are presented. RESULTS: Initial evaluation revealed hemodynamic instability, disorientation, cardiac rhythm abnormalities, high levels of blood urea nitrogen and creatinine, and a serum calcium level of 18 mg/dL. A cranial computed tomographic scan showed no evidence of pronounced atrophy or stroke. Aggressive rehydration was initiated, and a permanent pacemaker was inserted. A suppressed level of parathyroid hormone and a high serum 1,25-dihy-droxyvitamin D concentration were found, but no evidence of granulomatous disease, infection, or overt malignant lesion was detected. The patient showed clinical improvement and was dismissed from the hospital, but the hypercalcemic state recurred soon thereafter. A computed tomographic scan of the abdomen and pelvis revealed a pelvic mass, which was diagnosed as ovarian lymphoma after surgical removal. The serum calcium and 1,25-dihy-droxyvitamin D levels normalized postoperatively. CONCLUSIONS: Primary ovarian lymphoma can be a cause of, and can manifest solely as, a severe and symptomatic increase in the serum calcium level, which is mediated by an increased serum concentration of 1,25-dihy-droxyvitamin D. It should be considered in the differential diagnosis of unexplained nonparathyroid hypercalcemia.

Optimal use of intraoperative PTH levels in parathyroidectomy.

OBJECTIVES/HYPOTHESIS: Localization and the intraoperative parathyroid hormone assay (IOPTH) have facilitated minimally invasive parathyroidectomy. The precise algorithm governing use of IOPTH has been debated. Numerous authors advocate acquisition of a so-called pre-excision (P-E) baseline level (obtained after dissection of the adenoma, but prior to excision) in addition to a preincision baseline, to guard against spurious elevation in the baseline that might confuse interpretation of postexcision levels. We sought to clarify the optimal timing of PTH level determination. STUDY DESIGN: Consecutive single-surgeon case series with planned data collection from patients undergoing parathyroid surgery at a university hospital. METHODS: Demographic data and intraoperative laboratory and surgical findings from patients undergoing parathyroidectomy were prospectively gathered and analyzed. Attention was paid to the value of P-E and 5-minute postexcision levels and their impact on intraoperative decision-making. RESULTS: One hundred twelve patients underwent parathyroidectomy. Thirty were for secondary or tertiary hyperparathyroidism and were excluded. Seventy-nine (96.3%) of the 82 patients with primary hyperparathyroidism were rendered eucalcemic. In no case did the P-E value change what was otherwise destined to be a successful result. In 65.3% of cases, operative time was conserved as the procedure was correctly stopped after the 5-minute level, without the need to wait until the 10-minute postexcision level was reported. CONCLUSIONS: Pre-excision baseline IOPTH levels, although logical in their original proposal, appear to play little role in determining the completeness of an exploration. A 5-minute postexcision level adds value in nearly two thirds of cases by allowing earlier termination of the operation.