A retrospective review of the effectiveness of recombinant human TSH as a preparation for radioiodine thyroid remnant ablation.

UNLABELLED: Radioiodine remnant ablation (RRA) is frequently used after a thyroidectomy for differentiated thyroid carcinoma because it has been reported to reduce the number of local recurrences and to increase overall survival. Although the traditional method of preparation for RRA is thyroid hormone withdrawal, several physicians at our medical center have offered the option of having RRA after preparation by recombinant human thyroid-stimulating hormone (thyrotropin; TSH) over the past 2 y. During this same time period, other patients at our center were prepared for RRA by hormone withdrawal. METHODS: We took this opportunity to retrospectively review the rate of complete remnant ablation in patients having RRA after hormone withdrawal compared with those having RRA after recombinant human TSH. Only patients who had RRA after January 1, 1999, and follow-up diagnostic studies at our medical center, were included in the analysis. A successful ablation was defined as no visible radioiodine uptake on the follow-up diagnostic scans, performed with 185 MBq (5 mCi) (131)I. The 2 groups had comparable patient and tumor characteristics and received similar ablative activities of (131)I. RESULTS: We found that 84% of those prepared by recombinant human TSH, and 81% of those prepared by hormone withdrawal, had complete resolution of visible thyroid bed uptake after RRA (P = not significant). CONCLUSION: Given the biases that exist in retrospective studies, we cannot yet recommend RRA preparation by recombinant human TSH for routine use. However, these preliminary findings are favorable enough to support the design of a prospective randomized trial comparing RRA success rates after preparation by either thyroid hormone withdrawal or recombinant human TSH.

Medical versus surgical treatment of type 2 diabetes: the search for level 1 evidence.

Data from observational and nonrandomized comparative studies have shown a dramatic effect of bariatric surgery on type 2 diabetes mellitus (T2DM), including in nonobese patients. However, a relative paucity of level 1 evidence is available to define the exact role of surgery as a treatment modality for T2DM, especially in less obese subjects. Performing randomized clinical trials in this field, however, poses significant and specific challenges for the study design. We have addressed such challenges in a carefully designed randomized controlled trial comparing glycemic control with optimal medical management versus Roux-en-Y gastric bypass in overweight to mildly obese patients with T2DM mellitus (body mass index 26-35 kg/m(2)). The present report describes the rationale and design of the Weill Cornell Medical College study. In addition to glycemic endpoints, however, clinical trials should also investigate the effect of surgery on cardiovascular risk or T2DM-specific morbidity. Addressing these endpoints would entail large, randomized clinical trials with prolonged period of observation and ideally a multicenter study design. Such a multisite trial poses substantial logistical and financial challenges, which would predictably delay rather than accelerate progress of research in this field. A consortium of centers performing independent small and medium size randomized clinical trials may provide a more realistic and feasible approach. In this paper, we present an overview of on-going randomized clinical trials in this field and propose a worldwide consortium of randomized controlled trials (WORLDCoRDS) using the Weill Cornell Medical College protocol. The aim of this consortium is to standardize research in T2DM surgery and timely accumulate homogeneous data that can help assess the effects of GI surgery on cardiovascular risk and T2DM-related mortality and morbidity.

Increased PTH and 1.25(OH)(2)D levels associated with increased markers of bone turnover following bariatric surgery.

The objective of this study was to characterize changes in metabolic bone parameters following bariatric surgery. Seventy-three obese adult patients who underwent either gastric banding (GB), Roux-en-Y gastric bypass (RYGB), or biliopancreatic diversion with duodenal switch (BPD/DS) were followed prospectively for 18 months postoperatively. Changes in the calcium-vitamin D axis (25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)(2)D), calcium, parathyroid hormone (PTH)), markers of bone formation (osteocalcin, bone-specific alkaline phosphatase) and resorption (urinary N-telopeptide (NTx)), as well as bone mineral density (BMD) were assessed at 3-month intervals during this time period. Bariatric surgery resulted in significant and progressive weight loss over 18 months. With supplementation, 25OHD levels increased 65.3% (P < 0.0001) by 3 months, but leveled off and decreased <30 ng/ml by 18 months. PTH initially decreased 21.4% (P = 0.01) at 3 months, but later approached presurgery levels. 1,25(OH)(2)D increased significantly starting at month 12 (50.3% increase from baseline, P = 0.008), and was positively associated with PTH (r = 0.82, P = 0.0001). When stratified by surgery type, median PTH and 1,25(OH)(2)D levels were higher following combined restrictive and malabsorptive operations (RYGB and BPD/DS) compared to GB. Bone formation/resorption markers were increased by 3 months (P < 0.05) and remained elevated through 18 months. Radial BMD decreased 3.5% by month 18, but this change was not significant (P = 0.23). Our findings show that after transient improvement, preoperative vitamin D insufficiency and secondary hyperparathyroidism persisted following surgery despite supplementation. Postoperative secondary hyperparathyroidism was associated with increased 1,25(OH)(2)D levels and increased bone turnover markers.

"Metabolic" surgery for treatment of type 2 diabetes mellitus.

OBJECTIVE: To discuss the potential contribution of "metabolic" surgery in providing optimal management of patients with type 2 diabetes mellitus (T2DM). METHODS: A literature search was performed with use of PubMed, and the clinical experience of the authors was also considered. RESULTS: Bariatric-or, more appropriately, metabolic-surgical procedures have been shown to provide dramatic improvement in blood glucose levels, blood pressure, and lipid control in obese patients with T2DM. In these patients, metabolic surgery involves a low risk of short-term mortality and a significant long-term survival advantage, whereas the diagnosis of diabetes is associated with significant long-term mortality. Experimental studies in animals and clinical trials suggest that gastrointestinal bypass procedures can control diabetes and associated metabolic alterations by mechanisms independent of weight loss. As a result, the use of bariatric surgery and experimental gastrointestinal manipulations to treat T2DM is increasing, even among less obese patients. Although body mass index (BMI) currently is the most important factor for identifying candidates for bariatric surgery, evidence shows that a specific cutoff BMI value cannot accurately predict successful surgical outcomes. Furthermore, BMI appears limited in defining the risk profile for patients with T2DM. CONCLUSION: Current BMI-based criteria for performance of bariatric surgery are not adequate for determining eligibility for operative treatment in patients with diabetes. Large clinical trials, comparing bariatric surgery versus optimal medical care of patients with T2DM, should be given priority in order to define the role of surgery in the management of diabetes. Recognizing the need to work as a multidisciplinary team that includes endocrinologists and surgeons is an initial step in addressing the issues and opportunities that surgery offers to diabetes care and research.