Battillo DJ, Remchak MME, Shah AM, Malin SK. Impact of Insulin-Induced Relative Hypoglycemia on Vascular Insulin Sensitivity and Central Hemodynamics in Prediabetes.
J Clin Endocrinol Metab 2024:dgae152. [PMID:
38491968 DOI:
10.1210/clinem/dgae152]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 03/05/2024] [Accepted: 03/07/2024] [Indexed: 03/18/2024]
Abstract
CONTEXT
Relative hypoglycemia (RH) is linked to sympathetic responses that can alter vascular function in individuals with type 2 diabetes. However, less is known about the role of RH on hemodynamics or metabolic insulin sensitivity in prediabetes.
OBJECTIVE
Determine if RH alters peripheral endothelial function or central hemodynamics to a greater extent in those with prediabetes (PD) versus normoglycemia (NG).
METHODS
Seventy adults with obesity were classified using ADA criteria as PD (n=34 (28F); HbA1c=6.02±0.1%) or NG (n=36 (30F); HbA1c=5.4±0.0%). Brachial artery endothelial function, skeletal muscle capillary perfusion, and aortic waveforms were assessed at 0 and 120min of a euglycemic clamp (40 mU/m2/min, 90 mg/dl). Plasma nitrate/nitrite and endothelin-1 (ET-1) were measured as surrogates of nitric oxide-mediated vasodilation and vasoconstriction, respectively. RH was defined as the drop in glucose (%) from fasting to clamp steady state.
RESULTS
There were no differences in age, weight, or VO2max between groups. PD had higher HbA1c (P<0.01) and a greater drop in glucose in response to insulin (14 vs. 8%; P=0.03). Further, heart rate (HR) increased in NG compared to PD (P<0.01), while forward wave (Pf) decreased in PD (P=0.04). Insulin also tended to reduce arterial stiffness (cfPWV) in NG versus PD (P=0.07), despite similar increases in pre-occlusion diameter (P=0.02), blood flow (P=0.02), and lower augmentation index (AIx75) (P≤0.05).
CONCLUSION
Compared with NG, insulin-induced RH corresponded with a blunted rise in HR and drop in Pf during insulin infusion in adults with PD, independent of changes in peripheral endothelial function.
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