Format

Send to:

Choose Destination
See comment in PubMed Commons below
Diabetes. 2009 Feb;58(2):448-52. doi: 10.2337/db08-1224. Epub 2008 Nov 18.

Small decrements in systemic glucose provoke increases in hypothalamic blood flow prior to the release of counterregulatory hormones.

Author information

  • 1Department of Internal Medicine, Division of Endocrinology, Yale University School of Medicine, New Haven, Connecticut, USA. kathleen.page@yale.edu

Abstract

OBJECTIVE:

The hypothalamus is the central brain region responsible for sensing and integrating responses to changes in circulating glucose. The aim of this study was to determine the time sequence relationship between hypothalamic activation and the initiation of the counterregulatory hormonal response to small decrements in systemic glucose.

RESEARCH DESIGN AND METHODS:

Nine nondiabetic volunteers underwent two hyperinsulinemic clamp sessions in which pulsed arterial spin labeling was used to measure regional cerebral blood flow (CBF) at euglycemia ( approximately 95 mg/dl) on one occasion and as glucose levels were declining to a nadir of approximately 50 mg/dl on another occasion. Plasma glucose and counterregulatory hormones were measured during both study sessions.

RESULTS:

CBF to the hypothalamus significantly increased when glucose levels decreased to 77.2 +/- 2 mg/dl compared with the euglycemic control session when glucose levels were 95.7 +/- 3 mg/dl (P = 0.0009). Hypothalamic perfusion was significantly increased before there was a significant elevation in counterregulatory hormones.

CONCLUSIONS:

Our data suggest that the hypothalamus is exquisitely sensitive to small decrements in systemic glucose levels in healthy, nondiabetic subjects and that hypothalamic blood flow, and presumably neuronal activity, precedes the rise in counterregulatory hormones seen during hypoglycemia.

PMID:
19017765
[PubMed - indexed for MEDLINE]
PMCID:
PMC2628619
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk