Dual-energy X-ray absorptiometry DEXA

Routinely assess acromegaly complications, including blood pressure, glucose tolerance, fasting lipid profile, cardiac evaluations (if clinically indicated), colonoscopy, dual-energy x-ray absorptiometry (DEXA) scan (hypogonadal only), evaluation of residual pituitary function, and evaluation of sleep apnea. 

Hologic Dexa QDR 4000 used for Dual-energy X-ray absorptiometry (DEXA)... 

Bone mineral density (BMD) is measured using dual energy X-ray absorptiometry (DEXA) usually at the neck of femur (on the hip). The World Health Organization defines a diagnosis of osteoporosis if the BMD is 2.5 standard deviations or more below the young adult female mean value. This difference is known as the T-score. Patients are considered to have osteopenia if the T-score is between -1 and -2.5. 

Patients can undergo a dual-energy X-ray absorptiometry (DEXA) scan to confirm the diagnosis of osteoporosis. Osteoporosis is defined as having a bone mineral density which is at least 2.5 standard deviations below the peak bone mass when measured by a DEXA scan (e.g. a T-score -2.5 SD or below). 

A bone mineral density (BMD) test measures the density of minerals (such as calcium) using X-ray, computed tomography (CT) or ultrasound. Dual-energy X-ray absorptiometry (DEXA) is the most accurate way to measure BMD. DEXA can measure as little as 2% of bone loss per year it is fast, uses low doses of radiation, but is more expensive than ultrasound. 

DEXA, dual-energy x-ray absorptiometry ECG, electrocardiogram GH, growth hormone HbAlc, glycosylated hemoglobin Alc. 

APV, amprenavir ATV, atazanavir CNS, central nervous system CVD, cardiovascular disease D/C, discontinue ddC, zalcitabine ddl, didanosine DEXA, dual-energy x-ray absorptiometry d4T, stavudine EFV, efavirenz HDL, high-density lipoprotein HIV, human immunodeficiency virus HTN, hypertension IDV, indinavir LDL, low-density lipoprotein LPV/r, lopinavir+ ritonavir MRI, magnetic resonance imaging NNRTI, nonnucleoside reverse transcriptase inhibitor NRTI, nucleoside reverse transcriptase inhibitor NVP, nevirapine PI, protease inhibitor RTV, ritonavir SQV, saquinavir TDF, tenofovir disoproxil fumarate TG, triglyceride TPV/r, tipranivir + ritonavir ZDV, zidovudine. 

Two imaging systems, dual energy X-ray absorptiometry scanning (DEXA) and magnetic resonance imaging (MRI), allow for longitudinal studies of whole body composition. DEXA measures bone mineral density and content, fat content, and lean content in anesthetized mice. Echo MRI from Echo Medical System, Houston, TX, is used to measure whole body composition parameters such as total body fat, lean mass, body fluids, and total body water in live mice without the need for anesthesia or sedation (15). The MRI technology is more rapid, less than a minute to scan one mouse, than DEXA which takes about 5 min per mouse. 

Abbreviations CLA, conjugated linoleic add BMI, body mass index BC, body composition % BF, percentage of body fat M, men W, women DEXA, dual energy X-ray absorptiometry TOBEC, total body electrical conductivity BIS, bioimpedance spectroscopy NR, not reported SAD, sagittal abdominal diameter. 

U = untrained (no previous resistance training in the last 3 months) T = trained (undergoing some form of resistance training prior to study). ° DEXA = dual-energy x-ray absorptiometry HW = hydrostatic weighing SF = skin-fold thickness TOBC = total body electrical conductivity. 

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