Energy expenditure of genuine laughter

Association of laughter and social communication with oral frailty among residents in Fukushima: a cross-sectional study

Oral frailty (OF) is a form of frailty. Laughter and social communication such as talking and participating in community activities, contribute to extending healthy life expectancy by reducing stress and increasing physical activity. However, limited research exists on the association between laughter and social communication and OF. This cross-sectional study aimed to explore the association of laughter and social communication with the risk of developing OF using the eight-item OF Index among Fukushima residents. In 2020-2021, 916 residents aged 60-79 were surveyed regarding OF and psychosocial factors. Binomial logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for psychosocial factors associated with the OF prevalence. The OF prevalence was 41.5%. The sex- and age-adjusted ORs (95% CIs) for psychosocial factors associated with OF prevalence were 0.38 (0.26-0.57) for daily laughter, 0.51 (0.35-0.76) for laughter 1-5 times/week, 0.42 (0.20-0.89) for daily talking, 0.40 (0.22-0.72) for participating in community activities more than once/week, and 0.29 (0.20-0.43) for no depressive symptoms. After multivariate adjustment, only daily laughter and no depressive symptoms were associated with OF. As a public health strategy, increasing laughter and social communication frequencies, along with reducing depressive symptoms, may enhance healthy life expectancy through improved frailty.

Effect of laughter exercise versus 0.1% sodium hyaluronic acid on ocular surface discomfort in dry eye disease: non-inferiority randomised controlled trial

OBJECTIVE

To assess efficacy and safety of laughter exercise in patients with symptomatic dry eye disease.

DESIGN

Non-inferiority randomised controlled trial.

SETTING

Recruitment was from clinics and community and the trial took place at Zhongshan Ophthalmic Center, Sun Yat-sen University, the largest ophthalmic centre in China, between 18 June 2020 to 8 January 2021.

PARTICIPANTS

People with symptomatic dry eye disease aged 18-45 years with ocular surface disease index scores ranging from 18 to 80 and tear film break-up time of eight seconds or less.

INTERVENTIONS

Participants were randomised 1:1 to receive laughter exercise or artificial tears (0.1% sodium hyaluronic acid eyedrop, control group) four times daily for eight weeks. The laughter exercise group viewed an instructional video and participants were requested to vocalise the phrases "Hee hee hee, hah hah hah, cheese cheese cheese, cheek cheek cheek, hah hah hah hah hah hah" 30 times per five minute session. Investigators assessing study outcomes were masked to group assignment but participants were unmasked for practical reasons.

MAIN OUTCOME MEASURES

The primary outcome was the mean change in the ocular surface disease index (0-100, higher scores indicating worse ocular surface discomfort) from baseline to eight weeks in the per protocol population. The non-inferiority margin was 6 points of this index score. Main secondary outcomes included the proportion of patients with a decrease from baseline in ocular surface disease index score of at least 10 points and changes in dry eye disease signs, for example, non-invasive tear break up time at eight weeks.

RESULTS

299 participants (mean age 28.9 years; 74% female) were randomly assigned to receive laughter exercise (n=149) or 0.1% sodium hyaluronic acid (n=150). 283 (95%) completed the trial. The mean change in ocular surface disease index score at eight weeks was -10.5 points (95% confidence interval (CI) -13.1 to -7.82) in the laughter exercise group and -8.83 (-11.7 to -6.02) in the control group. The upper boundary of the CI for difference in change between groups was lower than the non-inferiority margin (mean difference -1.45 points (95% CI -5.08 to 2.19); P=0.43), supporting non-inferiority. Among secondary outcomes, the laughter exercise was better in improving non-invasive tear break up time (mean difference 2.30 seconds (95% CI 1.30 to 3.30), P<0.001); other secondary outcomes showed no significant difference. No adverse events were noted in either study group.

CONCLUSIONS

The laughter exercise was non-inferior to 0.1% sodium hyaluronic acid in relieving subjective symptoms in patients with dry eye disease with limited corneal staining over eight weeks intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04421300.

Laughter as medicine: A systematic review and meta-analysis of interventional studies evaluating the impact of spontaneous laughter on cortisol levels

OBJECTIVES

Laughter as an expression of humor has been recognized as good medicine for centuries. The health benefits of humor-induced well-being remain unclear and thus we conducted a systematic review and meta-analysis of interventional studies to evaluate the impact of spontaneous laughter on stress response as measured by cortisol levels.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE/PubMed, EMBASE, PsycINFO, Scopus, and Clinicaltrials.gov.

ELIGIBILITY CRITERIA

Interventional studies, which could be either randomized placebo-controlled trials (RCTs) or quasi-experimental studies, conducted in adults that compared any spontaneous laughter intervention to a controlled setting and reported changes in cortisol levels were selected.

DATA EXTRACTION AND SYNTHESIS

We examined the impact of laughter on percentage change in cortisol levels by calculating pooled estimates of the absolute differences between arithmetic means before and after interventions as compared to control using random-effects model.

RESULTS

Eight studies (315 participants; mean age 38.6) met our inclusion criteria; four were RCTs and four were quasi-experiment studies. Five studies evaluated the impact of watching a humor/comedy video, two studies evaluating laughter sessions administered by a trained laughter therapist, and one study evaluating a self-administered laughter program. Pooling these data showed a significant reduction in cortisol levels by 31.9% (95%CI -47.7% to -16.3%) induced by laughter intervention compared to control group with no evidence of publication bias (P = 0.66). Sensitivity analyses demonstrated that even a single laughter session induced a significant reduction of 36.7% in cortisol (95%CI -52.5% to -20.8%). In addition, analyses including the four RCTs reinforced these results by demonstrating a significant reduction in cortisol levels promoted by laughter as compared to the placebo arm [-37.2% (95%CI -56.3% to -18.1%)].

CONCLUSIONS

Current evidence demonstrates that spontaneous laughter is associated with greater reduction in cortisol levels as compared with usual activities, suggesting laughter as a potential adjunctive medical therapy to improve well-being.

TRIAL REGISTRATION

Registration number: CRD42021267972.

Laughter yoga as an enjoyable therapeutic approach for glycemic control in individuals with type 2 diabetes: A randomized controlled trial

BACKGROUND

Laughter has been reported to have various health benefits. However, data on the long-term effects of laughter interventions on diabetes are limited. This study aimed to investigate whether laughter yoga can improve glycemic control among individuals with type 2 diabetes.

METHODS

In a single-center, randomized controlled trial, 42 participants with type 2 diabetes were randomly assigned to either the intervention or the control group. The intervention consisted of a 12-week laughter yoga program. Hemoglobin A1c (HbA1c), body weight, waist circumference, psychological factors, and sleep duration were evaluated at baseline and week 12.

RESULTS

Intention-to-treat analysis showed that participants in the laughter yoga group experienced significant improvements in HbA1c levels (between-group difference: -0.31%; 95% CI -0.54, -0.09) and positive affect scores (between-group difference: 0.62 points; 95% CI 0.003, 1.23). Sleep duration tended to increase in the laughter yoga group with a between-group difference of 0.4 hours (95% CI -0.05, 0.86; P = 0.080). The mean attendance rate for laughter yoga program was high (92.9%).

CONCLUSIONS

A 12-week laughter yoga program is feasible for individuals with type 2 diabetes and improves glycemic control. These findings suggest that having fun could be a self-care intervention. Further studies with larger numbers of participants are warranted to better evaluate the effects of laughter yoga.

CLINICAL TRIAL REGISTRATION

http://www.chinadrugtrials.org.cn, identifier UMIN000047164.

Physiological linkage during shared positive and shared negative emotion

Physiological linkage refers to the degree to which peoples' physiological responses change in coordinated ways. Here, we examine whether and how physiological linkage relates to incidents of shared emotion, distinguished by valence. Past research has used an "overall average" approach and characterized how physiological linkage over relatively long time periods (e.g., 10-15 min) reflects psychological and social processes (e.g., marital satisfaction, empathy). Here, we used a "momentary" approach and characterized whether physiological linkage over relatively short time periods (i.e., 15 s) reflects shared positive emotion, shared negative emotion, or both, and whether linkage during shared emotions relates to relational functioning. Married couples (156 dyads) had a 15-min conflict conversation in the laboratory. Using behavioral coding, each second of conversation was classified into 1 of 4 emotion categories: shared positive emotion, shared negative emotion, shared neutral emotion, or unshared emotion. Using a composite of 3 peripheral physiological measures (i.e., heart rate, skin conductance, finger pulse amplitude), we computed momentary in-phase and antiphase linkage to represent coordinated changes in the same or opposite direction, respectively. We found that shared positive emotion was associated with higher in-phase and lower antiphase linkage, relative to the other 3 emotion categories. Greater in-phase physiological linkage during shared positive emotion was also consistently associated with higher-quality interactions and relationships, both concurrently and longitudinally (i.e., 5 to 6 years later). These findings advance our understanding of the nature of physiological linkage, the emotional conditions under which it occurs, and its possible associations with relational functioning. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

La risa contagiosa como vocalización provocadora de expresiones faciales y electromiográficas relacionadas con emociones positivas en los oyentes

A pesar de su relevancia para la comprensión de la expresión emocional vocal, el estudio de la risa contagiosa se encuentra en sus primeras etapas de investigación y aún no se ha establecido su naturaleza ni la de las respuestas que esta provoca. Teniendo esto en cuenta, el propósito de este estudio fue determinar si los estímulos acústicos de risa contagiosa, además de generar conductas de risa o sonrisa, provocan en los oyentes las expresiones faciales, electromiográficas y cardíacas de una emoción positiva. Para esto, se contó con la participación de 60 universitarios de ambos sexos con edades entre los 18 y los 30 años en un diseño experimental intrasujeto con mediciones en la condición de línea de base y en exposiciones a diferentes estímulos de risa contagiosa, donde se verificaron tres hipótesis en las que se comparó expresiones faciales de alegría (medidas con el software FaceReader), amplitud electromiográfica (emg) del músculo cigomático mayor (medida con el módulo emg-100 del Biopac) e intervalos R-R como indicadores de frecuencia cardíaca (medidos con el módulo ecg-100 del Biopac) entre las diferentes condiciones. Como resultado, se encontraron diferencias significativas en los porcentajes de las expresiones faciales de alegría y amplitud emg del cigomático al comparar las condiciones de línea de base y estímulos de risa más contagiosa, y de risas más y menos contagiosas; no obstante, no se encontraron diferencias significativas en los intervalos R-R en ninguna de las condiciones comparadas. Como conclusión, se comprobó la naturaleza emocional positiva de la risa/sonrisa provocada por estímulos de risa contagiosa y la proporcionalidad entre la intensidad de las expresiones faciales y las respuestas emg elicitadas por esta risa y el grado de contagio percibido de la misma.

A comparison of the cardiovascular effects of simulated and spontaneous laughter

OBJECTIVES

Laughter has long been regarded as beneficial for health, but the mechanisms are not clearly understood. The current study aimed to compare the acute cardiovascular effects of spontaneous and simulated laughter.

DESIGN

A mixed factorial experiment was performed to examine changes in cardiovascular variables in response to experimental tasks across conditions.

INTERVENTIONS

A sample of 72 participants were randomised to one of three 6 min interventions. Participants in the simulated laughter condition were asked to generate fake laughter, the spontaneous laughter condition viewed a humorous video, and the control condition watched a non-humorous documentary. This was followed by a laboratory stress task.

MAIN OUTCOMES MEASURES

Heart rate and heart rate variability (as indexed by rMSSD) were monitored continuously throughout the experiment using ECG.

RESULTS

The simulated laughter condition had a significantly higher heart rate (p < .001, η_p² = .26) and lower rMSSD (p < .001, η_p² = .13) during the laughter task compared to the other two conditions. Follow-up hierarchical regressions indicated that the difference in heart rate was due to the fact that the simulated condition produced more laughter. The difference in rMSSD, however, was unique to the simulated condition even when controlling for the amount of laughter. The simulated laughter condition had a significantly lower mean HR during the stress task but this was not significant after controlling amount of laughter produced.

CONCLUSIONS

Laughter leads to increased heart rate and reduced heart rate variability, which is similar to the effects of exercise. This finding is more pronounced in simulated laughter.

Evaluation of a Laughter-based Exercise Program on Health and Self-efficacy for Exercise

Background

Despite health benefits of physical activity (PA) and risks of physical inactivity, many older adults do not accumulate sufficient levels of PA to achieve associated health benefits. Lack of PA enjoyment may be a barrier to PA participation. Combining simulated laughter and PA for strength, balance, and flexibility is a potential solution for helping older adults maintain independence in activities of daily living through enjoyable participation in PA.

Purpose of the study

The purpose of this study is to assess whether combining simulated laughter exercises with a moderate-intensity strength, balance, and flexibility PA program (i.e., LaughActive) increases participation in PA, health, and self-efficacy for PA among older adults residing in 4 assisted living facilities (ALFs).

Design and methods

The 12-week wait list control pilot study used pre- and 6-week post-intervention comparisons within and between groups identified by paired sample t-test results among those who participated in twice-weekly LaughActive classes (n = 27).

Results

Significant improvements (p < .05-.10) were observed in mental health (SF-36v2), aerobic endurance (2-minute step test), and self-efficacy for exercise (OEE).

Implications

PA programs that elicit positive emotions through simulated laughter have the potential to improve health, physical performance, and self-efficacy for PA among older adults and may positively influence participant adherence.

Laughter and MIRTH (Methodical Investigation of Risibility, Therapeutic and Harmful): narrative synthesis

OBJECTIVE

To review the beneficial and harmful effects of laughter.

DESIGN

Narrative synthesis.

DATA SOURCES AND REVIEW METHODS

We searched Medline (1946 to June 2013) and Embase (1974 to June 2013) for reports of benefits or harms from laughter in humans, and counted the number of papers in each category.

RESULTS

Benefits of laughter include reduced anger, anxiety, depression, and stress; reduced tension (psychological and cardiovascular); increased pain threshold; reduced risk of myocardial infarction (presumably requiring hearty laughter); improved lung function; increased energy expenditure; and reduced blood glucose concentration. However, laughter is no joke-dangers include syncope, cardiac and oesophageal rupture, and protrusion of abdominal hernias (from side splitting laughter or laughing fit to burst), asthma attacks, interlobular emphysema, cataplexy, headaches, jaw dislocation, and stress incontinence (from laughing like a drain). Infectious laughter can disseminate real infection, which is potentially preventable by laughing up your sleeve. As a side effect of our search for side effects, we also list pathological causes of laughter, among them epilepsy (gelastic seizures), cerebral tumours, Angelman's syndrome, strokes, multiple sclerosis, and amyotrophic lateral sclerosis or motor neuron disease.

CONCLUSIONS

Laughter is not purely beneficial. The harms it can cause are immediate and dose related, the risks being highest for Homeric (uncontrollable) laughter. The benefit-harm balance is probably favourable. It remains to be seen whether sick jokes make you ill or jokes in bad taste cause dysgeusia, and whether our views on comedians stand up to further scrutiny.

Humor theories and the physiological benefits of laughter

There are 3 main theories used to explain the functions of humor: (1) the relief theory, (2) the incongruity theory, and (3) the superiority theory. While these theories focus on the specific role that humor plays for people in situations such as dealing with misfortune, making sense of rule violations, and bonding with others, we propose that underlying each of these theories are the physiological benefits of laughter. We draw on findings from empirical studies on laughter to demonstrate that these physiological benefits occur regardless of the theory that is used to explain the humor function. Findings from these studies have important implications for nurse practitioners working in hospice settings, long-term care facilities, nursing homes, and hospitals.