Objective It was hypothesized that psychophysiological insomniacs, who have been shown to have elevated heart rate, body temperature, and whole body metabolic rate, would also have increased low frequency and decreased high frequency power in the spectral analysis of their heart period data. Method Groups of 12 objectively defined insomniacs and age-, sex-, and weight-matched controls with normal sleep were evaluated on sleep and EKG measures over a 36-hour sleep laboratory stay. Results Heart period was decreased (ie, heart rate was increased) and its SD was decreased in all stages of sleep in the insomniacs compared with the controls. Spectral analysis revealed significantly increased low frequency power and decreased high frequency power in insomniacs compared with controls across all stages of sleep. Conclusions Because increased low frequency spectral power is an indicator of increased sympathetic nervous system activity, these data imply that chronic insomniacs could be at increased risk for the development of disorders, such as coronary artery disease, that are related to increased sympathetic nervous system activity.

Heart Rate Variability in Insomniacs and Matched Normal Sleepers

Autonomic imbalance, hypertension, and cardiovascular risk

Corcoran Lecture. Sympathetic hyperactivity and coronary risk in hypertension.

Sympathetic Overactivity in Hypertension*: A Moving Target

https://www.onlinejacc.org/content/accj/44/2/415.full.pdf

Platelet indexes in relation to target organ damage in high-risk hypertensive patients: A substudy of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT)☆

Twenty-three 50-year-old men with untreated, essential hypertension had elevated plasma concentrations of the platelet release product beta-thromboglobulin (BTG) compared to 14 age-matched control men (p less than 0.01). BTG correlated with arterial plasma adrenaline concentrations in the hypertensive (r = 0.44, p less than 0.05), normotensive (r = 0.73, p less than 0.01) and combined group (r = 0.51, p less than 0.01). Significant correlations (p less than 0.05) between BTG and cholesterol (LDL + VLDL fraction) were observed both in the hypertensive and the normotensive group. In the hypertensive group arterial adrenaline correlated with cholesterol (LDL + VLDL) (p less than 0.05). These findings are consistent with increased platelet activity in middle-aged men with essential hypertension, and may indicate that plasma adrenaline influence platelet function. The risk factors for coronary artery disease (blood pressure, lipid status, stress as evidenced by catecholamine release and platelet function) were positively related. Measurement of arterial instead of venous adrenaline is essential for the demonstration of the associations presented.

Ivar Eide

Papers

Increased β‐Thromboglobulin in Essential Hypertension: Interactions between Arterial Plasma Adrenaline, Platelet Function and Blood Lipids