This Article Full Text Full Text (PDF) All Versions of this Article: 91/3/851    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Petrova, M. Articles by Teff, K. L. Search for Related Content PubMed PubMed Citation Articles by Petrova, M. Articles by Teff, K. L. Related Collections Cardiovascular Endocrinology Metabolism

Prolonged (48-Hour) Modest Hyperinsulinemia Decreases Nocturnal Heart Rate Variability and Attenuates the Nocturnal Decrease in Blood Pressure in Lean, Normotensive Humans

Monell Chemical Senses Center (M.P.), Philadelphia, Pennsylvania 19104; and Department of Medicine (R.T.) and Monell Chemical Senses Center and Department of Medicine (K.L.T.), University of Pennsylvania, Philadelphia, Pennsylvania 19104

Address all correspondence and requests for reprints to: Dr. Karen Teff, Monell Chemical Senses Center, 3500 Market Street, Philadelphia, Pennsylvania 19104. E-mail: kteff{at}pobox.upenn.edu.

Context: Heart rate variability (HRV), an index of cardiac vagal activity, is decreased in individuals with metabolic disease. The relationship between decreased HRV and metabolic disease is unclear.

Objective: The objective of this study was to determine whether experimentally induced glucose intolerance decreases HRV in a circadian relevant manner in healthy individuals.

Design: This was a within-subject, randomized design study with subjects infused for 48 h with saline (50 ml/h) or 15% glucose (200 mg/m²·min). HRV was evaluated using time domain measurements taken over the 48-h period. Blood pressure and heart rate were monitored, and blood samples were taken.

Setting: This study was performed at the General Clinical Research Center of the Hospital of the University of Pennsylvania.

Patients: Sixteen healthy subjects (eight men and eight women; 18–30 yr old; mean body mass index, 21.7 ± 1.6 kg/m²) were studied.

Results: After glucose infusion, mean plasma glucose was increased by 16.8% (P < 0.0001), and plasma insulin was increased by 99.4% (P < 0.0001) compared with after saline infusion. Significant decreases in homeostasis model assessment indicated a decrease in insulin sensitivity (saline, 0.52 + 0.13; glucose, 0.34 + 0.12; P < 0.0001). The nocturnal root mean square successive difference, an index of cardiac vagal activity, was significantly decreased (P < 0.01), and nocturnal HR (P < 0.001) and blood pressure were significantly elevated (saline, 107.4 ± 2.7; glucose, 112.5 ± 3.3 mm Hg; P < 0.05) compared with the saline control. The change in homeostasis model assessment due to glucose infusion was significantly correlated with the change in root mean square successive difference (r = 0.48; P < 0.01).

Conclusions: Prolonged mild hyperinsulinemia disrupts the circadian rhythm of cardiac autonomic activity. Early changes in the neural control of cardiac activity may provide a potential mechanism mediating the pathophysiological link between impaired glucose tolerance and cardiovascular disease.

This article has been cited by other articles:

				A. Pletinck, F. Verbeke, L. Van Bortel, C. Dequidt, D. Vijt, W. Van Biesen, and R. Vanholder Acute central haemodynamic effects induced by intraperitoneal glucose instillation Nephrol. Dial. Transplant., December 1, 2008; 23(12): 4029 - 4035. [Abstract] [Full Text] [PDF]

				K. L. Teff Visceral Nerves: Vagal and Sympathetic Innervation JPEN J Parenter Enteral Nutr, September 1, 2008; 32(5): 569 - 571. [Abstract] [Full Text] [PDF]

				M. L. Jehn, D. J. Brotman, and L. J. Appel Racial Differences in Diurnal Blood Pressure and Heart Rate Patterns: Results From the Dietary Approaches to Stop Hypertension (DASH) Trial Arch Intern Med, May 12, 2008; 168(9): 996 - 1002. [Abstract] [Full Text] [PDF]