1,721,160 research outputs found
Evaluation of renal glucose uptake with [18F]FDG-PET: Methodological advancements and metabolic outcomes
No full textBackground/purpose: Studying renal glucose metabolism non-invasively in humans is an unmet need. Positron emission tomography (PET) is the current gold standard for measuring regional tissue glucose uptake rates, but the most widely used glucose analog ([18F]FDG) is not a good substrate for sodium-glucose cotransporters (SGLTs). As a consequence, [18F]FDG spills over into the urine and [18F]FDG-PET considerably underestimates published rates of whole renal glucose uptake obtained using the arterial-venous difference technique. Our aim was to assess whether [18F]FDG-PET can be used in the study of renal glucose metabolism in humans.
Methods: We measured individual [18F]FDG radioactivity in the urine and estimated intraluminal [18F]FDG radioactivity concentration; these values were used to correct renal [18F]FDG-PET data acquired ~90 min from tracer injection under fasting conditions and during an insulin clamp in 9 lean and 16 obese subjects.
Results: We found that the corrected glucose uptake is consistently higher in the medulla than cortex and that both cortical and medullary glucose uptake are higher in lean than obese participants under both fasting and insulinized conditions. Moreover, cortical but not medullary glucose uptake is increased from the fasting to the insulinized condition.
Conclusion: The data show for the first time that [18F]FDG-PET can still provide relevant physiological information on regional renal glucose uptake on the condition that [18F]FDG uptake is corrected for tubular radioactivity
Clinical and subclinical autoimmune thyroid disorders insystemic sclerosis
No full textObjective: Several studies have reported the association of systemic sclerosis (SSc) with thyroidautoimmune disorders, but most of them have neither an appropriate control group nor include acomplete thyroid work-up.Design: The aim of our study was to evaluate the prevalence of thyroid disorders in a large number ofpatients with SSc using a complete clinical evaluation.Methods: Thyroid-stimulating hormone (TSH), free triiodothyronine, free thyroxine, antithyroglobulinand antithyroid-peroxidase (AbTPO) autoantibodies, thyroid ultrasonography and blood flow and fineneedle aspirationwere performed in 202 SSc patients versus 404 gender- and age-matched controls fromthe general population, with similar iodine intake, to evaluate the prevalence of clinical and subclinicalthyroid disorders.Results: Odds ratio (OR) for female SSc versus controls was: for subclinical hypothyroidism, 3.2(95% CI)Z1.8–5.7); for clinical hypothyroidism, 14.5 (95% CIZ2.3–90.9); for AbTPO positivity,2.7 (95% CIZ1.8–4.1); for hypoechoic pattern, 3.2 (95% CIZ2.2–4.7); for thyroidautoimmunity, 3.7 (95% CIZ2.6–5.4); for thyroid volume !6 ml, 1.8 (95% CIZ1.2–2.7).OR for thyroid autoimmunity in male SSc versus controls was 10.8 (95% CIZ2.2–52.4). Meanvalues of TSH in female SSc, and of AbTPO in female and male SSc were higher (P!0.01) thanin controls. We observed three cases of Graves’ disease in female SSc versus zero in controls(PZ0.0140), and two cases of papillary thyroid cancer in SSc patients.Conclusions: Thyroid function, AbTPO and ultrasonography should be tested as part of theclinical profile in SSc patients. Females, subjects with positive AbTPO and hypoechoic and smallthyroid should have thyroid function follow-up and appropriate treatment in due course
Normal beta-cell function
No full textThis chapter provides an account of the basic methods and main concepts concerning the physiology of in vitro insulin secretion in humans, including a brief mention of the role of insulin clearance. For each topic we will provide, when available, quantitative information and discuss its relevance to overall glucose homeostasis
Book Review Hypertension and Co-existing Disease By Francisco Leyva and Andrew Coats. 240 pp., illustrated. Malden, Mass., Blackwell Science, 2000. $99. 0-632-05073-X
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Hiperglicemia postprandial, factor emergente de riesgo cardiovascular en la diabetes tipo 2 (2)
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