Associations between social network properties and metabolic syndrome and the mediating effect of physical activity: findings from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort

Associations between dimensions of the social environment and cardiometabolic risk factors: Systematic review and meta-analysis

Aim

The social environment (SE), including social contacts, norms and support, is an understudied element of the living environment which impacts health. We aim to comprehensively summarize the evidence on the association between the SE and risk factors of cardiometabolic disease (CMD).

Methods

We performed a systematic review and meta-analysis based on studies published in PubMed, Scopus and Web of Science Core Collection from inception to 16 February 2021. Studies that used a risk factor of CMD, e.g., HbA1c or blood pressure, as outcome and social environmental factors such as area-level deprivation or social network size as independent variables were included. Titles and abstracts were screened in duplicate. Study quality was assessed using the Newcastle-Ottawa Scale. Data appraisal and extraction were based on the study protocol published in PROSPERO. Data were synthesized through vote counting and meta-analyses.

Results

From the 7521 records screened, 168 studies reported 1050 associations were included in this review. Four meta-analyses based on 24 associations suggested that an unfavorable social environment was associated with increased risk of cardiometabolic risk factors, with three of them being statistically significant. For example, individuals that experienced more economic and social disadvantage had a higher "CVD risk scores" (OR = 1.54, 95%CI: 1.35 to 1.84). Of the 458 associations included in the vote counting, 323 (71%) pointed towards unfavorable social environments being associated with higher CMD risk.

Conclusion

Higher economic and social disadvantage seem to contribute to unfavorable CMD risk factor profiles, while evidence for other dimensions of the social environment is limited.

Social isolation and risk of disability in older adults: Effect modification of metabolic syndrome

PURPOSE

Delaying the onset of disabilities is a social challenge, especially in an aging society. Social isolation (SI) and metabolic syndrome (MetS) can coexist and pose the risks of disability onset. However, their interaction is not proven in older adults. Therefore, this study investigated whether SI combined with MetS exacerbates disability onset in older adults.

MATERIALS AND METHODS

A total of 3,738 community-dwelling older adults underwent a health check-up. After baseline assessments, we followed them up to assess disability incidence for five years. SI was defined as a condition in which two or more of the following measures were met: domestic isolation, less social contact, and social disengagement. MetS was defined according to the criteria of the International Diabetes Federation. We used Cox proportional hazard regression used to identify the interaction effect of SI and MetS on the risk of disability onset after adjusting for potential confounding factors.

RESULTS

Multivariate Cox proportional hazard regression showed a significant interaction effect of SI and MetS on disability onset. In the subgroup analysis stratified by MetS status, SI was identified as a risk factor for disability onset only in the MetS group, but not in the non-MetS group.

CONCLUSIONS

This five-year longitudinal study showed that the co-occurrence of SI and MetS increased the risk of disability onset in older adults. This indicates that the assessment of MetS in socially isolated older adults is important for healthcare providers to delay the onset of disabilities.

Psychosocial Determinants of Knee Osteoarthritis Progression: Results from the Promoting Independence in Our Seniors with Arthritis Study

BACKGROUND

Knee osteoarthritis (OA) is a common cause of physical disability among older adults. While established risk factors for knee OA include age and increased body weight, few studies have examined psychosocial risk factors or progression of knee OA.

METHODS

The Promoting Independence in our Seniors with Arthritis study recruited participants aged 65 years and over from orthopedic outpatients and community engagement events. Participants were invited to annual visits during which knee OA symptoms were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS), social network using the 6-item Lubben Social Network Scale and anxiety and depression using the Hospital Anxiety and Depression scale. Knee OA worsening was defined by a 5% reduction in mean KOOS scores at the last visit compared to the first visit.

RESULTS

Data were available from 148 participants, mean age 66.2±6.5 years and 74.1% female, of whom 28 (18.9%) experienced OA worsening over a median follow-up period of 29 months. Univariate analyses revealed that age, sex, height, grip strength, and social network were associated with OA worsening. Social network remained statistically significantly associated with OA worsening after adjustment for age and sex difference (odds ratio=0.924; 95% confidence interval, 0.857-0.997). The relationship between social network and OA worsening were attenuated by both depression and handgrip strength at baseline.

CONCLUSION

Psychological status and muscle strength may be modifiable risk factors for social network which may in turn prevent knee OA worsening and should be targeted in future intervention studies.

Association between social networks and symptoms of post-traumatic stress during the pandemic: Cohort study in South Korea

BACKGROUND

This study estimated the association between pre-pandemic social network properties and symptoms of posttraumatic stress during the coronavirus disease 2019 (COVID-19) pandemic in South Korea.

METHODS

We conducted four online mental health surveys during COVID-19 (from March 14, 2020, to December 11, 2021) among individuals enrolled in a community-based cohort study (previously recruited from 2013 to 2018). Among 4060 people interviewed at the pre-pandemic baseline, 2652 individuals (men = 951, women = 1701) who responded to at least one of the four surveys conducted were included. At baseline, each individual's social network, including size and average closeness, was measured in an egocentric way. Post Traumatic Stress Disorder Checklist for DSM-5 (PCL-5) was measured at each survey point. A generalized linear model and a generalized linear mixed model were used after stratified by sex.

RESULTS

Among men, network size was negatively associated with total PCL-5 score (b = -0.42, SE = 0.16, p = 0.002). The magnitude of the association increased over time and was maximal by the 4th survey (b = -0.65, SE = 0.31, p = 0.037). Among women, average closeness was negatively associated with the total PCL-5 score (b = -1.16, SE = 0.37, p = 0.002). In analyses disaggregated by symptom clusters, social networks were associated explicitly with symptoms of intrusion and mood but not with avoidance and arousal symptoms.

CONCLUSION

In this cohort of adults followed for more than a year during the outbreak of COVID-19 in South Korea, social networks established before the onset of the COVID-19 pandemic had a protective association against developing symptoms of PTSD during the first two years of the pandemic.

Subjective Happiness, Frequency of Laughter, and Hypertension: A Cross-Sectional Study Based on the Japan Gerontological Evaluation Study (JAGES)

In recent years, positive psychological factors, such as subjective happiness and laughter, have been reported to be associated with cardiovascular disease. In this study, we examined the relationship of hypertension with subjective happiness and frequency of laughter using the data from the Japan Gerontological Evaluation Study (JAGES). Of the 138,294 respondents, 26,368 responded to a version of the self-administered questionnaire that included a question about the frequency of laughter in the JAGES 2013. In total, 22,503 (10,571 men and 11,932 women) were included in the analysis after excluding those with missing responses regarding a history of hypertension, frequency of laughter, and subjective happiness. The prevalence of hypertension in this study was 10,364 (46.1%). Multivariate logistic regression analysis showed that age, female sex, obesity, infrequent chewing, former and current drinker, seeing three to five friends, and the absence of hobbies were positively associated with hypertension. However, infrequent laughter/high level of subjective happiness, frequent laughter/high level of subjective happiness, being underweight, and current smoker were negatively associated with hypertension. As per the findings of this study, it was determined that subjective happiness was negatively associated with hypertension. Therefore, this study suggests that having more opportunities to feel happiness may be important in preventing hypertension.

Knowledge of stroke risk factors and warning symptoms among adults with type 2 diabetes in Addis Ababa, Ethiopia, 2021: an institution-Based cross-sectional study

BACKGROUND

Stroke is a global public health concern with type 2 diabetes being one of the common risk factors. Knowledge of stroke risk factors and warning symptoms among type 2 diabetes patients is largely unknown in developing countries like Ethiopia. The inability to recognize stroke warning symptoms accurately is an important cause of delay in seeking medical attention. We investigated knowledge of stroke risk factors and warning symptoms among adults with type 2 diabetes and the factors associated with these variables.

METHODS

This was an institution-based cross-sectional study. We enrolled 470 adult type 2 diabetes patients using a systematic random sampling method from four government-managed hospitals in Addis Ababa from 1 to 30 February 2021. The Stroke Recognition Questionnaire was adapted to measure the knowledge of stroke risk factors and warning symptoms. Sociodemographic characteristics, source of information, and reaction to stroke were also measured. Data were analyzed using SPSS version 25 and linear regression analysis was used to determine factors independently associated with knowledge of stroke risk factors and warning symptoms.

RESULT

The mean age of the participants was 50.6 ± 12.9 years. The mean score of knowledge of stroke risk factors and warning symptoms was 67.2% and 63.9%, respectively. Higher educational level (B = 2.007, 95% CI = 1.101, 2.914, P < 0.001), knowing someone diagnosed with stroke (B = 3.328, 95% CI = 2.734, 3.922, P < 0.001), and living with others (B = 2.28, 95% CI = 1.606, 2.954, P < 0.001) were independently associated with knowledge of stroke risk factors. Younger age (B = - 0.021, 95% CI= -0.038, 0.005, P = 0.01), higher educational level (B = 1.873, 95% CI = 1.017, 2.730, P < 0.001), and knowing someone diagnosed with stroke (B = 3.64, 95% CI = 3.079, 4.200, P < 0.001) were independently associated with knowledge of warning symptoms of stroke.

CONCLUSION

The mean score of knowledge of stroke risk factors and warning symptoms was 67.2% and 63.9%, respectively. Younger age, higher educational level, and living with other people are predictors of better knowledge of stroke risk factors and warning symptoms in this study. Future educational interventions should target type 2 diabetes adults with advancing age and the involvement of their family members.

Support Needs and Coping Strategies in Non-Alcoholic Fatty Liver Disease (NAFLD): A Multidisciplinary Approach to Potential Unmet Challenges beyond Pharmacological Treatment

Non-alcoholic fatty liver disease (NAFLD) is the most frequently occurring chronic liver disease, affecting approximately 25–30% of the adult general population worldwide. NAFLD reflects excess hepatic accumulation of fat in the absence of increased alcohol intake, and, due to its close association with obesity, is frequently referred to as the ‘hepatic manifestation’ of metabolic syndrome. Indeed, a high percentage of individuals with NAFLD present with a combination of the cardio-metabolic comorbidities that are associated with the metabolic syndrome. In addition to its well-established link with the metabolic syndrome and increased risk for cardiovascular disease, NAFLD has also been associated with certain mental health issues (e.g., depression and stress). Although this link is now being increasingly recognized, there are still unmet needs regarding the holistic management of patients with NAFLD, which could further contribute to feelings of social isolation and loneliness. The latter conditions are also increasingly reported to pose a substantial risk to overall health and quality of life. To date, there is limited research that has explored these issues among patients with NAFLD, despite existing data which indicate that perceived loneliness and isolation may pose an additional health risk. Notably, many features associated with NAFLD have been related to these concepts, such as perceived stigma, fatigue, stress, and confusion regarding this diagnosis. As such, this review aimed to assess such potential problems faced by patients with NAFLD, and to explore the possibility of unmet support needs which could lead to perceived social isolation. Moreover, the importance of a compassionate approach towards such patients is discussed, together with potential coping strategies. Future research directions and the need for a multidisciplinary approach are also highlighted.

Association of social network properties with resilience and depression among community-based Korean population

We aimed to determine how the properties of social networks relate to resilient-related status. This cross-sectional study used baseline data from the Cardiovascular and Metabolic Disease Etiology Research Center cohort and included 11,132 participants. Ego-centric social network size and intimacy were used to reflect social network properties. Resilient-related status was operationally defined based on the participant's response to the Life Experience Survey and the Back Depression Inventory Ⅱ. Participants were categorized into three groups: reference (no negative life event; no depression), resilient (with negative life event; but no depression), and depression (no/with negative life event; with depression). Multinomial logistic regression models were used to estimate the association of social networks on the resilient-related status after adjusting for all covariates. Social network size was positively associated with the resilient group for both sex (male: OR = 1.01 [95% CI = 0.96 to 1.05], female: OR = 1.07 [95% CI = 1.03 to 1.11]), whereas intimacy showed a negative association (male: OR = 0.91 [95% CI = 0.82 to 1.01], female: OR = 0.84 [95% CI = 0.76 to 0.92]). Additionally, as each social network property increased, the likelihood of being categorized as belonging to the depression group decreased, regardless of age and sex.

Effect of a Community Gerontology Program on the Control of Metabolic Syndrome in Mexican Older Adults

Background: Metabolic syndrome (MS) is highly prevalent in older adults; it constitutes a risk factor for cognitive deterioration, frailty, and Alzheimer’s disease. For this reason, the WHO has pointed out the importance of the implementation of community programs for the training of healthy aging. The aim of this study was to evaluate the effect of a community gerontology program framed in active aging on the control of metabolic syndrome in older adults. Methods: An experimental study was carried out in a convenience sample of 80 older adults diagnosed with MS according to the ATPIII criteria, comprising (1) experimental group (EG), n = 40; (2) control group (CG), n = 40. During a 6-month period, the EG participated in a supervised community gerontology program, and the CG was assessed monthly. Results: A statistically significant decrease was observed in the number of components for the diagnosis of MS. In this regard, of the total of participants with a diagnosis of MS in EG, only 28% maintained the diagnosis of MS (ATPIII ≥ 3 criteria), in contrast to 83% of the CG participants (p < 0.0001). Conclusions: Our findings suggest that health self-care training within the framework of active aging is effective for the control of MS in older adults.

Association Between Social Network and Cognitive Function: A Cross-Sectional Assessment From the Cardiovascular and Metabolic Diseases Etiology Research Center Cohort (2013-2018)

BACKGROUND

This study aimed to investigate how social networks are associated with cognitive function in the middle-aged and elderly Korean population.

METHODS

A total of 7,704 individuals over the age of 50 were included from the baseline recruitment of the Cardiovascular and Metabolic Diseases Etiology Research Center cohort from the years 2013 to 2018. Egocentric social network characteristics including network size, intimacy, and frequency of face-to-face meetings were measured as exposures, and the Korean version of Mini-Mental State Examination (K-MMSE) score was measured to reflect general cognitive function as an outcome. We also stratified the analysis by income level into tertiles, with income caps of 42,000 thousand won and 72,000 thousand won. A general linear regression model was used, adjusting for age, gender, socioeconomic factors, lifestyle factors, depressive symptoms, and study settings.

RESULTS

Social network properties were positively associated with cognitive function in both men and women. However, the specific estimates varied according to gender and income level. In men, frequency was most significantly associated with cognitive function (standardized β = 0.093, p-value <0 .0001). In women, the strength of the association with cognitive function was found in size (standardized β = 0.055, p-value = 0.001). The effect modification of income level could be seen in the association between frequency and cognitive function. The strongest association between frequency and cognitive function was found in the middle income group in men (standardized β = 0.114, p-value = 0.0063), and the low income group in women (standardized β = 0.076, p-value = 0.0039).

CONCLUSION

There were positive associations between social network properties (i.e., size, intimacy, and frequency of face-to-face meetings) and cognitive function. The degree of association varied according to social network properties, gender, and income level. Overall, among social network properties, social network size was an important factor in the cognition of women, whereas frequency was important in the cognition of men.

Loneliness: An Immunometabolic Syndrome

Loneliness has been defined as an agonizing encounter, experienced when the need for human intimacy is not met adequately, or when a person’s social network does not match their preference, either in number or attributes. This definition helps us realize that the cause of loneliness is not merely being alone, but rather not being in the company we desire. With loneliness being introduced as a measurable, distinct psychological experience, it has been found to be associated with poor health behaviors, heightened stress response, and inadequate physiological repairing activity. With these three major pathways of pathogenesis, loneliness can do much harm; as it impacts both immune and metabolic regulation, altering the levels of inflammatory cytokines, growth factors, acute-phase reactants, chemokines, immunoglobulins, antibody response against viruses and vaccines, and immune cell activity; and affecting stress circuitry, glycemic control, lipid metabolism, body composition, metabolic syndrome, cardiovascular function, cognitive function and mental health, respectively. Taken together, there are too many immunologic and metabolic manifestations associated with the construct of loneliness, and with previous literature showcasing loneliness as a distinct psychological experience and a health determinant, we propose that loneliness, in and of itself, is not just a psychosocial phenomenon. It is also an all-encompassing complex of systemic alterations that occur with it, expanding it into a syndrome of events, linked through a shared network of immunometabolic pathology. This review aims to portray a detailed picture of loneliness as an “immunometabolic syndrome”, with its multifaceted pathology.

Introduction to Mediation Analysis and Examples of Its Application to Real-world Data

Traditional epidemiological assessments, which mainly focused on evaluating the statistical association between two major components-the exposure and outcome-have recently evolved to ascertain the in-between process, which can explain the underlying causal pathway. Mediation analysis has emerged as a compelling method to disentangle the complex nature of these pathways. The statistical method of mediation analysis has evolved from simple regression analysis to causal mediation analysis, and each amendment refined the underlying mathematical theory and required assumptions. This short guide will introduce the basic statistical framework and assumptions of both traditional and modern mediation analyses, providing examples conducted with real-world data.

The Mediterranean lifestyle (MEDLIFE) index and metabolic syndrome in a non-Mediterranean working population

BACKGROUND & AIMS

The Mediterranean lifestyle (MEDLIFE), as an overall lifestyle pattern, may be associated with a lower prevalence of metabolic syndrome. We assessed the association of a validated MEDLIFE index with metabolic syndrome and its components in a non-Mediterranean working population.

METHODS

A cross-sectional analysis was conducted at baseline among 249 US career firefighters in Feeding America's Bravest 2016-2018. The MEDLIFE index consisted of 26 items on food consumption, dietary habits, physical activity, rest, and social interactions that scored 0 or 1 point. Thus, total scores could range from 0 to 26 points. Multivariable logistic regression models were used to determine the associations across tertiles of MEDLIFE adherence with metabolic syndrome and each of its individual components. Multivariable linear models further assessed each component as a continuous outcome.

RESULTS

The prevalence of metabolic syndrome was 17.7%. Participants with higher MEDLIFE adherence (T3: 11-17 points) had 71% lower odds of having metabolic syndrome compared to those with lower MEDLIFE adherence (T1: 2-7 points) (OR = 0.29; 95%CI: 0.10 to 0.90, p for trend = 0.04). Furthermore, significant inverse associations were found for T3 versus T1 on abdominal obesity (OR = 0.42; 95%CI: 0.18 to 0.99, p for trend = 0.07) and hypertriglyceridemia (OR = 0.24; 95%CI: 0.09 to 0.63, p for trend = 0.002). Significant inverse associations for continuous outcomes included total-cholesterol (total-c), low-density lipoprotein (LDL) cholesterol, and total-c:high-density lipoprotein (HDL) cholesterol (p for trend <0.05).

CONCLUSION

Higher adherence to traditional Mediterranean lifestyle habits, as measured by a comprehensive MEDLIFE index, was associated with a lower prevalence of metabolic syndrome and a more favorable cardiometabolic profile in a non-Mediterranean working population. Future studies employing the MEDLIFE index in other populations are warranted to support this hypothesis.