Ralf Nass
University of Virginia
EndocrinologyGhrelinDiabetes mellitusHormoneMedicine
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Publications 40
#1Chiara Fabris (UVA: University of Virginia)H-Index: 3
#2Ralf Nass (UVA: University of Virginia)H-Index: 18
Last. Marc D. Breton (UVA: University of Virginia)H-Index: 28
view all 10 authors...
OBJECTIVE Insulin dosing in type 1 diabetes (T1D) is oftentimes complicated by fluctuating insulin requirements driven by metabolic and psychobehavioral factors impacting individuals’ insulin sensitivity (IS). In this context, smart bolus calculators that automatically tailor prandial insulin dosing to the metabolic state of a person can improve glucose management in T1D. RESEARCH DESIGN AND METHODS Fifteen adults with T1D using continuous glucose monitors (CGMs) and insulin pumps completed two ...
2 CitationsSource
#1Chiara Fabris (UVA: University of Virginia)H-Index: 3
#2Leon S. Farhy (UVA: University of Virginia)H-Index: 20
Last. Marc D. Breton (UVA: University of Virginia)H-Index: 6
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Aims:In type 1 diabetes (T1D), repeated hypoglycemic episodes may reduce hormonal defenses and increase the risk for severe hypoglycemia. In this work, we investigate the effect of a structured hyper/hypoglycemic metabolic challenge on the postintervention glucose variability in T1D subjects studied at home.Methods:Thirty T1D subjects using insulin pump were monitored with blood glucose meters (SMBG) during a 1-month observation period. After 2 weeks of monitoring, participants were admitted at ...
#1Min YuH-Index: 4
#2David E. BrunsH-Index: 32
Last. Michael O. Thorner (UVA: University of Virginia)H-Index: 71
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BACKGROUND: In the immediate postoperative period following resection of growth hormone (GH)-secreting pituitary tumors, serum concentrations of GH have limited ability to predict remission of acromegaly. Since many actions of GH actions are mediated by insulin-like growth factor-1 (IGF-I), we aimed to determine the rates of fall of IGF-I during 72 h after surgical resection of pituitary tumors. METHODS: We studied patients who were undergoing pituitary surgery for acromegaly. IGF-I was measured...
2 CitationsSource
#1Bruce D. Gaylinn (Duke University)H-Index: 26
#2Leon S. Farhy (Duke University)H-Index: 20
Last. Michael O Thorner (Duke University)H-Index: 1
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1 CitationsSource
#1Ralf NassH-Index: 18
#2Alexander Nikolayev (Eli Lilly and Company)H-Index: 8
Last. Michael O. ThornerH-Index: 71
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Background: Acyl-ghrelin is a 28-amino acid peptide released from the stomach. Ghrelin O-acyl transferase (GOAT) attaches an 8-carbon medium-chain fatty acid (MCFA) (octanoate) to serine 3 of ghrelin. This acylation is necessary for the activity of ghrelin. Animal data suggest that MCFAs provide substrate for GOAT and an increase in nutritional octanoate increases acyl-ghrelin. Objectives: To address the question of the source of substrate for acylation, we studied whether the decline in ghrelin...
3 CitationsSource
Background: Ghrelin is a 28-amino acid peptide released from the stomach. Ghrelin is found in the circulation in two forms: acyl- and desacyl-ghrelin. Acyl- and desacyl-ghrelin concentrations increase at night, when cortisol concentrations are low. Acute ghrelin administration increases ACTH and cortisol concentrations and a feedback loop between the ghrelin and ACTH-cortisol axis has been postulated. A previous study showed that exogenously induced hypercortisolism for 5 days decreased plasma g...
3 CitationsSource
Background: Acyl-ghrelin is thought to have both orexigenic effects and to stimulate GH release. A possible cause of the anorexia of aging is an age-dependent decrease in circulating acyl-ghrelin levels. Objectives: The purpose of the study was to compare acyl-ghrelin and GH concentrations between healthy old and young adults and to examine the relationship of acyl-ghrelin and GH secretion in both age groups. Methods: Six healthy older adults (age 62–74 y, body mass index range 20.9–29 kg/m2) an...
22 CitationsSource
#1Ralf NassH-Index: 18
#2Kristin D. HelmH-Index: 1
Last. William S. EvansH-Index: 45
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1 CitationsSource
Growth hormone (GH) and/or ghrelin mimetics represent potential treatment and/or prevention options for musculoskeletal impairment associated with aging. Use of improvement in muscle function as an outcome in studies of GH and ghrelin mimetics is complicated by the lack of a standardized definition for clinically meaningful efficacy of this end point. Based on preliminary study results, the use of ghrelin mimetics may be more suitable for use in this age group than GH itself. There are still sev...
9 CitationsSource
#1Ralf Nass (UVA: University of Virginia)H-Index: 18
#2Michael O. Thorner (UVA: University of Virginia)H-Index: 71
Frailty is one of the key features of aging and it is associated with a loss of function, an increased risk of falls, and ultimately loss of the ability to live independently. Based on the demographic shift of the older population, as a result of the aging of the baby boomers, interventions to slow or delay the development of frailty will be of increasing importance. One of the physiologic correlates of frailty is the cachexia of aging. The underlying mechanism of the cachexia of aging is cytoki...