title: Long-term, intermittent, insulin-induced hypoglycemia produces marked obesity without hyperphagia or insulin resistance: a model for weight gain with intensive insulin therapy.
abstract: A major side effect of insulin treatment of diabetes is weight gain, which limits patient compliance and may pose additional health risks. Although the mechanisms responsible for this weight gain are poorly understood, it has been suggested that there may be a link to the incidence of recurrent episodes of hypoglycemia. Here we present a rodent model of marked weight gain associated with weekly insulin-induced hypoglycemic episodes in the absence of diabetes. Insulin treatment caused a significant increase in both body weight and fat mass, accompanied by reduced motor activity, lowered thermogenesis in response to a cold challenge, and reduced brown fat uncoupling protein mRNA. However, there was no effect of insulin treatment on total food intake nor on hypothalamic neuropeptide Y or proopiomelanocortin mRNA expression, and insulin-treated animals did not become insulin-resistant. Our results suggest that repeated iatrogenic hypoglycemia leads to weight gain, and that such weight gain is associated with a multifaceted deficit in metabolic regulation rather than to a chronic increase in caloric intake.
authors.affiliation: Behavioral Neuroscience, University at Albany, 1400 Washington Ave., Albany, NY 12222, USA. emcnay@albany.edu
authors.forename: Ewan C
authors.initials: EC
authors.lastname: McNay
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Teske
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Kotz
authors.forename: Ambrose
authors.initials: A
authors.lastname: Dunn-Meynell
authors.forename: Barry E
authors.initials: BE
authors.lastname: Levin
authors.forename: Rory J
authors.initials: RJ
authors.lastname: McCrimmon
authors.forename: Robert S
authors.initials: RS
authors.lastname: Sherwin
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D006963:Hyperphagia / Q000150:complications; D007003:Hypoglycemia / Q000139:chemically induced* / Q000150:complications*; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects; D007328:Insulin / Q000008:administration & dosage / Q000009:adverse effects*; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D009765:Obesity / Q000139:chemically induced / Q000209:etiology* / Q000473:pathology; D010507:Periodicity; D051381:Rats; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D013997:Time Factors; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin