Impaired flow-mediated vasodilation of the brachial artery in patients with primary hyperparathyroidism improves after parathyroidectomy.

OBJECTIVE: The endothelium is a newly recognised target tissue of parathyroid hormone (PTH). It is not clear whether hyperparathyroidism affects endothelial function and whether parathyroidectomy (Ptx) has an influence on arterial vessel wall properties. We studied brachial flow-mediated vasodilation (FMD) and brachial and carotid intima-media thickness (IMT) in patients with primary hyperparathyroidism (pHPT) before and after Ptx and in healthy controls. METHODS: 19 patients with pHPT (mean+SEM, age 45+/-4.7 years, PTH 238+/-52 ng/l) were studied. Diabetes, hypertension and vascular disease were excluded. Twenty healthy volunteers matched for age, sex and blood pressure served as controls. Enddiastolic diameter, FMD and nitroglycerine-induced (NMD) dilation of the brachial artery were measured by a multigate pulsed doppler system (echo-tracking), IMT was determined using automatic analysis of the M-line signal. Healthy volunteers where studied on one occasion, patients were studied at baseline and 6 months after Ptx. RESULTS: Six months after Ptx PTH had decreased to normal, blood pressure levels remained unchanged. Endothelium dependent FMD at baseline was impaired in patients compared to controls (4.7+/-1.2 vs. 18.2+/-3.7%, P<0.01), however, FMD improved significantly after Ptx (16.7+/-3.0%, P<0.01). Nitroglycerine-induced dilation, IMT and artery diameter were not different between groups and did not change after Ptx. CONCLUSIONS: Impaired endothelium dependent vasodilation in patients with primary hyperparathyroidism improves after successful parathyroidectomy. Endothelial dysfunction associated with primary hyperparathyroidism occurs without detectable structural wall alterations of the brachial artery and appears therefore to be an early and reversible arterial alteration.

Studies on flow-mediated vasodilation and intima-media thickness of the brachial artery in patients with primary hyperparathyroidism.

The endothelium is a newly recognized target organ of parathyroid hormone (PTH) and may contribute to its effects on vascular tone and blood pressure regulation. Flow-mediated vasodilation (FMD), brachial and carotid intima-media thickness (IMT) were studied in patients with primary hyperparathyroidism (pHPT) and controls to evaluate endothelial function and structural arterial vessel wall alterations. Sixteen patients with pHPT (mean +/- SEM, age 44 +/- 5 years; PTH 229 +/- 72 ng/L; serum calcium 3.0 +/- 0.06 mmol/L; serum phosphate 2.0 +/- 0.2 mg/L) and 16 normocalcemic control subjects matched for age, sex, and blood pressure were included. Diabetes, hypertension, and vascular disease were excluded in both groups. End-diastolic diameter, flow-mediated (FMD) and nitroglycerin-mediated (NMD) dilation of the brachial artery were measured by a multigate pulsed Doppler system (echo-tracking). IMT was determined using automatic analysis of the M-line signal. Endothelium-dependent FMD was impaired in patients compared to controls (4.6 +/- 1.6% v 19.2 +/- 3.9%, P < .001). NMD (23.8 +/- 3.1% v. 22.4 +/- 2.8%, P = NS), carotid and brachial IMT (0.60 +/- 0.04 mm v 0.64 +/- 0.06 mm, P = NS, and 0.46 +/- 0.04 mm v 0.47 +/- 0.08 mm, P = NS, respectively) and artery diameters were not different. Endothelium-dependent vasodilation is impaired in patients with primary hyperparathyroidism despite normal IMT. Endothelial dysfunction may contribute to increased cardiovascular morbidity and mortality in pHPT.

Therapeutic and interventional endoscopy for gastrointestinal bleeding.

INTRODUCTION: Gastrointestinal (GI) bleeding remains a common clinical problem encountered by every emergency room and trauma physician. Endoscopy remains the main approach to the diagnosis and therapy of GI bleeding. OBJECTIVES: To present the modern endoscopic approach for GI bleeding. METHODS: Narrative review based on our expertise and inclusion of classic articles dealing with interventional and therapeutic GI endoscopy. RESULTS: GI hemorrhage is now classified as upper, middle, and lower GI bleeding. Upper GI bleeding is defined as hemorrhage originating from the oropharynx to the ligament of Treitz (or papilla of Vater), middle GI bleeding occurs distal to the papilla of Vater to the terminal ileum, and lower GI bleeding is defined as bleeding distal to the ileocecal valve, including the entire colon and anorectum. Endoscopic methods used to diagnosed and treat GI bleeding include esophagogastroduodenoscopy, duodenoscopy, capsule endoscopy, double- and single-balloon enteroscopy, spiral enteroscopy, and colonosocopy. CONCLUSIONS: This is the first review paper dedicated to endoscopic therapy for bleeding involving any part of the luminal GI tract (i.e., esophagus, stomach, small bowel, and colon). Modern endoscopy permits the investigation and treatment of the majority of conditions affecting the entire hollow GI tract.