1. No category

BRIEF OBSERVATION
Hiking in Suicidal Patients: Neutral Effects on Markers
of Suicidality
Daniel Neunhäuserer, MD, PhD,a Josef Sturm, MSc, PhD,b Mira M. Baumgartlinger, MD,a David Niederseer, MD, PhD, BSc,a
Eveline Ledl-Kurkowski, MD, PhD,a Eva Steidle, MSc,a Martin Plöderl, MD,b Clemens Fartacek, MSc,b Karl Kralovec, MD,b
Reinhold Fartacek, MD,b Josef Niebauer, MD, PhD, MBAa
a
Department of Sports Medicine, Prevention and Rehabilitation, Paracelsus Medical University Salzburg, Institute of Sports Medicine of the
State of Salzburg, Sports Medicine of the Olympic Center Salzburg-Rif, Salzburg, Austria; bDepartment for Suicide Prevention, University
Clinic for Psychiatry, Paracelsus Medical University Salzburg, Salzburg, Austria.
ABSTRACT
BACKGROUND: Regular physical activity promotes physical and mental health. Psychiatric patients are
prone to a sedentary lifestyle, and accumulating evidence has identified physical activity as a supplemental
treatment option.
METHODS: This prospective, randomized, crossover study evaluated the effects of hiking in high-risk
suicidal patients (n ¼ 20) who performed 9 weeks of hiking (2-3 hikes/week, 2-2.5 hours each) and a
9-week control period.
RESULTS: All patients participated in the required 2 hikes per week and thus showed a compliance of
100%. Regular hiking led to significant improvement in maximal exercise capacity (hiking period
D: þ18.82 0.99 watt, P < .001; control period: P ¼ .134) and in aerobic capability at 70% of the
individual heart rate reserve (hiking period D: þ8.47 2.22 watt; P ¼ .010; control period: P ¼ .183).
Cytokines, associated previously with suicidality (tumor necrosis factor-a, interleukin-6, S100), remained
essentially unchanged.
CONCLUSIONS: Hiking is an effective and safe form of exercise training even in high-risk suicidal patients.
It leads to a significant improvement in maximal exercise capacity and aerobic capability without
concomitant deterioration of markers of suicidality. Offering this popular mode of exercise to these patients
might help them to adopt a physically more active lifestyle.
Ó 2013 Elsevier Inc. All rights reserved. The American Journal of Medicine (2013) -, --KEYWORDS: Depression; Endurance training; Hiking; Hopelessness; Physical exercise training; Suicide prevention
Psychiatric patients tend to lead a less active lifestyle and
do not comply with recommendations of regular physical
activity.1,2 Because exercising in green space has been
shown to induce beneficial effects on mental and physical
well-being,3,4 we designed a hiking program for high-risk
suicidal patients and set out to assess its feasibility and
effectiveness, as well as its impact on cytokines, which
Funding: None.
Conflict of Interest: None.
Authorship: All authors had access to the data and played a role in
writing this manuscript.
Requests for reprints should be addressed to Josef Niebauer, MD, PhD,
MBA, Department of Sports Medicine, Prevention and Rehabilitation,
Paracelsus Medical University, Lindhofstr. 20, 5020 Salzburg, Austria.
E-mail address: [email protected]
0002-9343/$ -see front matter Ó 2013 Elsevier Inc. All rights reserved.
http://dx.doi.org/10.1016/j.amjmed.2013.05.008
have been associated with suicidality in depression,
schizophrenia, and bipolar disorder.5-9
MATERIALS AND METHODS
This is a prospective, randomized, controlled, 9-week,
crossover exercise training study in 20 high-risk suicidal
patients (female, 14; male, 6). After baseline assessment,
randomization allowed half of the patients to start with the
9-week hiking program followed by a 9-week control
period (Hike-Control group) and vice versa (Control-Hike
group).
The main inclusion criterion was high-risk suicidality,
defined as at least 1 suicide attempt in the past and a current
Beck Hopelessness Scale score of >26. Of the 167 patients
in our outpatient clinic who were invited to an informative
event, 23 (female, 16; male, 7) met the inclusion criteria,
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The American Journal of Medicine, Vol -, No -,
gave written informed consent, and were subsequently
recruited.
Patients were expected to participate in at least 2 of 3
supervised hikes per week. During each hike (2-2.5 hours),
exercise intensity was controlled by heart rate monitors,
which were set to 70% of the individual heart rate reserve.10
All hiking routes had the
following in common:
-
2013
heart rate (70% of heart rate reserve). Moreover, during the
hiking period, exercise capacity significantly increased
(D: þ8.47 2.22 watt; P ¼ .01), whereas during the
control period no significant changes were observed
(D: 3.82 1.83 watt; P ¼ .183).
Cytokines
Tumor necrosis factor-a remained
essentially unchanged during the
Hiking is a feasible and well-accepted
hiking period (11.83 3.24 pg/mL
form of physical exercise training in
to 11.88 1.97 pg/mL; P ¼ .93)
patients with high-risk suicidality.
and decreased significantly during
the control period (11.94 2.29
Both maximal exercise capacity and
pg/mL to 10.87 2.81 pg/mL;
At the start, crossover, and end
aerobic capability increase with regular
P < .05). No significant changes
of the study, anthropometric data,
hiking.
were observed for interleukin-6 or
exercise capacity, and cytokines
Systemic training effects were induced
S100 during either period (inter(tumor necrosis factor-a, interleukin-6: hiking period: 2.38 without
concomitant
increase
in
leukin-6, S100) were assessed.
1.19 pg/mL to 1.93 0.93 pg/mL,
cytokines
previously
associated
with
Data are presented as mean P ¼ .12; control period: 1.98 suicidality.
standard deviation and were
0.91 pg/mL to 2.07 1.09 pg/mL,
tested for normal distribution by
P ¼ .78; S100: hiking period:
ShapiroeWilk. Data of the hiking
0.06 0.03 mg/L to 0.07 0.04 mg/L, P ¼ .32; control
and the control period were compared by paired t tests.
period: 0.07 0.05 mg/L to 0.07 0.04 mg/L, P ¼ .73;
Comparisons between groups were tested by 1-way analysis
Figure 3).
of variance. A P value <.05 was considered statistically
significant. The protocol was approved by the Ethical
Committee of the State of Salzburg and registered with
DISCUSSION
Clinical-Trial.gov under the ID of NCT01152086.
This is the first study to investigate the effects of a regular
hiking program in high-risk suicidal patients. The main
RESULTS
findings are as follows:
Baseline characteristics are shown in Figure 1. Of the 20
Moderate hiking emerged as a feasible and highly
patients, 17 completed the study (13 women, 4 men) and 3
accepted form of exercise training in otherwise rather
patients dropped out early: 1 because of complications after
sedentary patients with high-risk suicidality.
shoulder surgery, 1 because of lack of time, and 1 because
Regular moderate hiking improves maximal exercise caof an acute suicidal crisis. During the hiking period, all
pacity and aerobic capability.
patients participated in the required number of hikes (Hike Moderate hiking induced systemic training effects without
Control group: 18.2 5.0 hikes; Control-Hike group:
increasing cytokines previously associated with deterio18.6 4.1 hikes).
rated suicidality.
CLINICAL SIGNIFICANCE
Altitude difference: 200 to 300 m
Distance: 6 to 8 km
Hiking time: 2 to 2.5 hours
Alpine terrain without dangerous drops or cliffs
Exercise Capacity
Moderate hiking resulted in a highly significant improvement in maximal exercise capacity (D: þ18.82 0.99 watt,
P < .001), which remained essentially unchanged during the
control period (D: 7.88 5.31 watt; P ¼ .134; Figure 2).
Physical work capacity at a heart rate of 130 beats/min
(physical work capacity 130) significantly improved during
hiking compared with the control period (after hiking:
1.15 0.36 watt/kg; after control period: 1.04 0.36 watt/kg;
P < .05). Furthermore, a significant increase also was observed when watts achieved at a heart rate of 150 beats/min
(physical work capacity 150) were compared (after hiking:
1.57 0.45 watt/kg; after control: 1.44 0.39 watt/kg;
P < .05). Patients also showed highly significant improvement in aerobic capability at their individual training
Recommendations of regular physical activity are not
met by the general population and even less by suicidal
patients, despite all the known beneficial effects it exerts
on general and mental well-being.11 One way to overcome
this discrepancy between knowledge and behavior is to
identify forms of exercise training that appeal to a large
number of people, can be performed almost everywhere,
and are effective with regard to improvement of exercise
capacity. Hiking might qualify as such a sport, and patients in this study showed impeccable compliance, which
resulted in an increased maximal exercise capacity and
aerobic capability. The natural environment and group
dynamics might have positively influenced patients’
motivation.3,4,12
Recent studies suggest tumor necrosis factor-a,
interleukin-6, and S100B as potential markers for the
Neunhäuserer et al
Hiking Intervention in Suicidal Patients
3
300
250
[watt]
200
150
100
50
begin
end
hiking period
begin
end
control period
Figure 2 Maximal physical exercise capacity (watt) assessed
during cycle ergometry before and after the hiking and control
periods, respectively. Box plots depict the 25th and 75th percentiles, median (band in box), standard deviation (whiskers),
and outliers (open circles).
Figure 1 Baseline characteristics. ACE ¼ angiotensin-converting enzyme; BMI ¼ body mass index; MAOI ¼ monoamine
oxidase inhibitor; NSAID ¼ nonsteroidal anti-inflammatory
drug; PPI ¼ proton-pump inhibitor; SD ¼ standard deviation;
SNRI ¼ serotoninenorepinephrine reuptake inhibitor; SSRI ¼
selective serotonin reuptake inhibitor; TCA ¼ tricyclic
antidepressant.
prediction of suicidality in high-risk patients.5-8 Janelidze
et al5 reported increased levels of tumor necrosis factor-a
and interleukin-6 in suicide attempters compared with
nonsuicidal depressed patients or healthy controls. Because
it is known that acute bouts of exercise lead to an increase of
these proinflammatory markers, it could be speculated that
hiking could worsen suicidality.13 We found unaltered
levels of tumor necrosis factor-a during the hiking period
and reduced levels during the control period, for which no
valid explanation could be found. Interleukin-6 was not
altered pathologically at baseline or during the study course.
Falcone et al8 reported significantly higher serum S100B
levels in patients with psychosis or mood disorders, which
correlated with the severity of suicidal ideation independently of the psychiatric diagnosis. High-risk suicidal patients in this study did not show increased levels of S100 at
baseline. Furthermore, no significant alterations were found
after the hiking period, although patients showed highly
significant improvement in suicidal ideation.14 A comparison between both studies is limited by the fact that different
assays were used.
These results nicely dovetail our previous findings that
patients reported significant improvement of their mental
well-being after the hiking period, which was associated
with a reduction of suicide ideation.14 Therefore, this
moderate hiking program represents an exercise training
regimen capable of inducing positive physical and mental
effects without causing an increase of proinflammatory cytokines that might be associated with an adverse outcome
with regard to suicidality.
CONCLUSIONS
This moderate hiking program has been found to be a
feasible, effective, and well-tolerated form of exercise
training even in high-risk suicidal patients. This is of great
interest because offering hiking to suicidal patients might
help them to become physically more active and mentally
more balanced. Tailoring exercise training to patients’
needs and preferences might lead to a higher rate of
long-term compliance and thus a lifelong physically active
lifestyle.
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The American Journal of Medicine, Vol -, No -,
B
TNF-α
[μg/L]
[pg/ml]
S100
begin end begin end
hiking period control period
C
2013
IL-6
[pg/ml]
A
-
begin end begin end
hiking period control period
begin end begin end
hiking period control period
Figure 3 Blood markers associated with suicidality obtained before and after the hiking or control period: S100 (cytoplasmic Ca2þ
binding protein) (A), tumor necrosis factor-a (B), and interleukin-6 (C). Box plots depict the 25th and 75th percentiles, median (band in
box), standard deviation (whiskers), and outliers (open circles). IL ¼ interleukin; TNF ¼ tumor necrosis factor.
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