Exploratory multivariate analysis of the effect of fatty fish consumption and medicinal use on heart rate and heart rate variability data

Abstract

The overall aim of the present study was to explore the relationship between medicinal use and fatty fish consumption on heart rate variability (HRV) and heart rate (HR) in a group of forensic inpatients on a variety of medications. A total of 49 forensic inpatients, randomly assigned to a fish group (n = 27) or a control group (n = 22) were included in the present study. Before and by the end of the food intervention period HR and HRV were measured during an experimental test procedure. An additional aim of this paper is to show how multivariate data analysis can highlight differences and similarities between the groups, thus being a valuable addition to traditional statistical hypothesis testing. The results indicate that fish consumption may have a positive effect on both HR and HRV regardless of medication, but that the influence of medication is strong enough to mask the true effect of fish consumption. Without correcting for medication, the fish group and control group become indistinguishable (p = 0.0794, Cohen’s d = 0.60). The effect of medication is demonstrated by establishing a multivariate regression model that estimates HR and HRV in a recovery phase based on HR and HRV data recorded during psychological tests. The model performance is excellent for HR data, but yields poor results for HRV when employed on participants undergoing the more severe medical treatments. This indicates that the HRV behavior of this group is very different from that of the participants on no or lower level of medication. When focusing on the participants on a constant medication regime, a substantial improvement in HRV and HR for the fish group compared to the control group is indicated by a principal component analysis and t-tests (p = 0.00029, Cohen’s d = 2.72). In a group of psychiatric inpatients characterized by severe mental health problems consuming different kinds of medication, the fish diet improved HR and HRV, indices of both emotional regulation and physical health.

The effects of diet on levels of physical activity during winter in forensic inpatients – A randomized controlled trial

“…This study is one of a series of papers from a parallel group randomized controlled trial investigating the effects of a long-term fatty fish intervention on mental health (1,2,14,16,22). The intervention period took place in a secure facility between September 2008 and February 2009.…”

Short-Term Intake of Yellowstripe Scad versus Salmon Did Not Induce Similar Effects on Lipid Profile and Inflammatory Markers among Healthy Overweight Adults despite Their Comparable EPA+DHA Content

“…Eating fish on a regular basis can be beneficial for our health in many ways. For example, fish could help to reduce the risk of cardiovascular disease (CVD) and improve the chances of survival following a heart attack, as displayed in several observational studies [ 3 , 4 , 5 ], although not all agree [ 6 ]. Researchers believe that the heart health benefit of fish is more promising in those fish rich in omega-3 fatty acids, which is attributed to the ability of fish to ameliorate hypertriglyceridemia [ 7 , 8 ] and resolve inflammatory processes [ 9 ].…”

Fatty Fish Intervention and Psychophysiological Responses to Mental Workload in Forensic Inpatients

“…In contrast, the control group, receiving a diet without fatty fish, showed increased resting heart rate (Hansen, Olson, et al, 2014) as well as increased sleep latency from pretest to posttest (Hansen, Dahl, et al, 2014). In a hypothesis-generating study using principal component analysis and partial least squares (Grung et al, 2015), a question related to the importance of a resting HRV recovery (i.e., a post-stress) measure as an index of physiological cost and mental health was also raised. As this study was a hypothesis-generating study, no conclusions were drawn.…”

“…As this study was a hypothesis-generating study, no conclusions were drawn. In order to follow up, Grung et al’s (2015) hypothesis-testing is needed. This will generate knowledge about the recovery measure, which may also have important implications with regard to stress resilience.…”