HIGH ALTITUDE MEDICINE & BIOLOGY Volume 9, Number 3, 2008 © Mary Ann Liebert, Inc. DOI: 10.1089/ham.2007.1075 Case Report Acute Mountain Sickness in a Subject with Metabolic Syndrome at High Altitude Giacomo Strapazzon, 1 Annalisa Cogo, 2 and Andrea Semplicini 1 Abstract Strapazzon, Giacomo, Annalisa Cogo, and Andrea Semplicini. Acute mountain sickness in a subject with meta- bolic syndrome at high altitude. High Alt. Med. Biol. 9:245–248, 2008.—Visitors at high altitude are increasing in age and comorbidities, which can lead to a failure in acclimatization. We describe the development of acute mountain sickness (AMS) in a 44-year-old man with metabolic syndrome and the time- and altitude-dependent correlation between the development of AMS and blood pressure and heart rate changes. Our observations support a dominant role of endothelial dysfunction in the pathogenesis of AMS and suggest new behavioral indications. Key words: altitude sickness; blood pressure; metabolic syndrome; obesity; vascular endothelium 245 Introduction V ISITORS AT HIGH ALTITUDE are increasing in age and co- morbidities. It has been suggested that hypertensive pa- tients should not climb to an altitude higher than 3000 m (Ponchia, 2000; Ponchia et al., 2006), because long-lasting hy- poxia increases blood pressure in healthy volunteers due to sympathoadrenal system activation (Wolfel et al., 1994; Mazzeo et al., 1998; Kanstrup et al., 1999; Calbet, 2003; Hansen and Sander, 2003; Hainsworth et al., 2007). However, it has been shown that patients with metabolic syndrome (MS), which is characterized by hypertension, abdominal obesity, and lipid and glucose abnormalities, tolerate chronic exposure to moderate altitude with favorable effects on car- diovascular and metabolic variables and without physical problems (Schobersberger et al., 2003). Here we describe the development of AMS in a 44-year- old man with MS during high altitude ascent. Case Report A group of 14 European and Nepal lowlanders (mean age 42  10 yr, range 27–56) trekked in Khumbu valley (Nepal) to an altitude of 5050 m. During trekking, arterial blood pres- sure (BP) and heart rate (HR) were measured in sitting po- sition according to ESH/ESC guidelines, and signs and symptoms of AMS and high altitude pulmonary edema (HAPE) were monitored according to the Consensus Con- ference of Lake Louise Score (LLS) (Roach et al., 1993) after night rest. All subjects gave informed consent to the clinical monitoring and the institutional committee approved it. The group included a 44-yr-old man who had climbed to the same place 10 years before, staying there for 10 days and developing mild AMS for 3 days with moderate head- ache, vomit, and mild weakness. Before departure he re- ported no cardiovascular diseases and normal BP. He was on a high-salt diet, moderate alcohol assumption (alcohol less than 208 g/month), and sedentary lifestyle. His phys- ical examination was normal, BMI 27.5 kg/m 2 , abdominal circumference 92 cm, blood pressure 135/92 mmHg, and heart rate 85 beats per minute (bpm). EKG, chest X-ray, and liver and kidney ultrasound examination were unre- markable, and fasting blood tests showed only impaired fasting glucose (117 mg/dL), low HDL cholesterol (39 mg/dL), and high triglycerides (159 mg/dL). The clinical diagnosis was MS, according to the AHA/NHLBI state- ment (Grundy et al., 2005). At day 3 of trekking, after a night at 3450-m altitude, his 1 Department of Clinical and Experimental Medicine, University of Padova, Italy. 2 Sport Biomedical Study Centre, University of Ferrara, Ferrara, Italy.