Identification of direct and indirect social network effects in the pathophysiology of insulin resistance in obese human subjects

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.

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.

The effects of glucagon-like peptide-1 receptor agonists on glycemic control and anthropometric profiles among diabetic patients with non-alcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials

This study was undertaken to assess the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs), mainly liraglutide and exenatide, on glycemic control and anthropometric profiles to see if they are effective in treating patients with non-alcoholic fatty liver disease (NAFLD) and type-2 diabetes mellitus (T2DM). We searched PubMed, Embase, Scopus, Web of Science (WOS), and Cochrane Library databases to identify all the randomized clinical trials (RCTs) up to August 23, 2020. Heterogeneity of the included studies was evaluated using Cochrane's Q test and the I² statistic. Moreover, a random-effects model was used to pool the weighted mean differences (WMDs) and their 95% confidence intervals (CIs). Nine articles (12 studies) comprising a total of 780 participants aged 40-56 were finally selected. GLP-1RAs intake significantly reduced body mass index (BMI) (WMD -1.57, 95%CI; -2.74, -0.39), waist-circumference (WC) (WMD -4.14, 95%CI; -7.09, -1.19), body weight (WMD -4.20, 95%CI; -8.15, -0.25) among the body mass indices. Additionally, GLP-1RAs leads to lower postprandial plasma glucose (PPG) levels (WMD -25.73 mg/dl, 95%CI; -32.71, -18.75). We also found that GLP-1RAs intake has no significant effect on the waist-hip ratio (WHR) (WMD -0.01, 95%CI; -0.03, 0.02), fasting blood glucose (FBG) (WMD -2.12 mg/dl, 95%CI; -6.23, 1.96), hemoglobin A1c (HbA1c) (WMD -0.08%, 95%CI; -0.21, 0.04), and homeostatic model assessment for insulin resistance (HOMA-IR) levels (WMD -0.31, 95%CI; -0.69, 0.07). GLP-1RAs therapy showed a greater reduction in BMI, body weight, WC, and PPG, but not in WHR, HOMA-IR, FBG, and HbA1c compared with other therapies in patients with T2DM and NAFLD.

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

INTRODUCTION

Social isolation and loneliness are positively associated with metabolic syndrome. However, the mechanisms by which social isolation affects metabolic syndrome are not well understood.

RESEARCH DESIGN AND METHODS

This study was designed as a cross-sectional study of baseline results from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort. We included 10 103 participants (8097 community-based low-risk participants, 2006 hospital-based high-risk participants) from the CMERC Cohort. Participants aged 65 years or older were excluded. Multiple imputation by chained equations was applied to impute missing variables. The quantitative properties of social networks were assessed by measuring the 'size of social networks'; qualitative properties were assessed by measuring the 'social network closeness'. Metabolic syndrome was defined based on the National Cholesterol Education Program Adult Treatment Panel III criteria. Multivariate logistic regression analyses were conducted to assess association between social network properties and metabolic syndrome. The mediating effects of physical inactiveness, alcohol consumption, cigarette smoking and depressive symptoms were estimated. Age-specific effect sizes were estimated for each subgroup.

RESULTS

A smaller social network was positively associated with higher prevalences of metabolic syndrome in all subgroups, except the high-risk male subgroup. There was no clear association between social network closeness and metabolic syndrome. In community-based participants, an indirect effect through physical activity was detected in both sexes; however, in hospital-based participants, no indirect effects were detected. Cigarette smoking, alcohol consumption and depression did not mediate the association. Age-specific estimates showed that the indirect effect through physical activity had a greater impact in older participants.

CONCLUSIONS

A smaller social network is positively associated with metabolic syndrome. This trend could be partially explained by physical inactivity, especially in older individuals.

Prevalence of insulin resistance and identifying HOMA1-IR and HOMA2-IR indexes in the Middle Black Sea region of Turkey

Background

Insulin resistance (IR) is one of the most important etiological risk factors in the development of diabetes. However, there is no clear data regarding the prevalence of IR in the country.

Objective

This study evaluates the prevalence of IR and identifies the optimal threshold values for the HOMA indexes in Turkey.

Methods

This cross-sectional, population-based survey includes 2013 participants aged 20–84 years. The values of the anthropometric measurements and laboratory analysis were recorded. The 90^th percentile in the non-obese and non-diabetic population was accepted as cut-off values for IR.

Results

The optimal threshold values for IR were 2.46 in HOMA1-IR and 1.40 in HOMA2-IR. Using the HOMA2-IR method, the overall prevalence of IR was 33.2%. The IR prevalence was higher in women (35.6%) compared to men (30.1%) [p=0.008]. There was a higher IR prevalence in men living in urban areas (p=0.001), not in women. The multivariate logistic regression analysis showed that gender, serum glucose level, serum levels of triglycerides and high-density lipoprotein cholesterol, bodymass index and income status were associated with insulin resistance.

Conclusion

The cut-off values of HOMA1-IR and HOMA2-IR were determined in this study and we believe that these findings will be helpful to clinicians in the fight against health problems such as diabetes.

Association of ghrelin dynamics with beta cell function in Japanese subjects with normal glucose tolerance

BACKGROUND

Ghrelin is involved in feeding regulation and energy metabolism and is also known to inhibit insulin secretion (β). However, few clinical studies have demonstrated the relationship between β and ghrelin dynamics. This study tested the hypothesis that, in oral glucose tolerance tests (OGTT), ghrelin dynamics are associated with β.

METHODS

Subjects were 1145 healthy individuals <40 years old who tested normal on the 75-g OGTT. The following indicators and the ghrelin suppression ratio (GSR) during OGTT were calculated: insulin sensitivity (SI) [1/homoeostasis model assessment of insulin resistance, insulin sensitivity index-Matsuda and 1/fasting insulin (1/FIRI)]; and β [Stumvoll first-phase index (Stumvoll-1), Stumvoll second-phase index and insulinogenic index]. From nine combinations of SI and β, combinations that produce hyperbolic relationships were identified.

RESULTS

Stumvoll-1 and 1/FIRI showed a hyperbolic relationship in nonobese subjects, and the product of Stumvoll-1 and 1/FIRI was used as the disposition index (DI). When analyzed by BMI quartiles, post-loading glucose and insulin levels at each time point increased from Q1 (low BMI) through Q4 (high BMI), whereas the DI, ghrelin levels at each time point, and GSR decreased from Q1 to Q4. On multivariate and bivariate analysis, GSR and DI were positive and independent, and fasting ghrelin and FIRI were negatively and independently correlated.

CONCLUSIONS

Ghrelin dynamics were associated with beta cell function in subjects with normal glucose tolerance. Glucose intolerance in obesity may be due not only to insulin resistance but also to impaired beta cell function associated with abnormalities of ghrelin dynamics.

Weight and weight control behaviors of Latinas and their social ties

OBJECTIVE

Shared behaviors have been implicated in the clustering of obesity among socially connected people. This study determined how weight and weight control behaviors of participants and their social ties are related and how these factors are associated with weight change in participants.

METHOD

Adult Latinas participating in a lifestyle intervention completed an egocentric network measure of weight and weight control behaviors. Participant weight was objectively measured at baseline and 12 months. Multivariable regression models determined the relationship between weight and weight control behaviors of participants and their social ties.

RESULTS

Participants and their social ties shared similarities in weight control behaviors and weight change. Participants who reported social ties that had lost weight were more likely to eat small portions and low-fat foods, but those with social ties that had gained weight were more likely to use herbal supplements. Participants who reported more social ties who exercised, drank liquid meal replacements, took herbal supplements, and self-weighed were more likely to lose weight whereas those with fewer social ties that exercised were more likely to gain weight. Weight loss and weight gain by social ties predicted participant weight loss and weight gain, respectively.

CONCLUSIONS

Given that weight and weight control behaviors of Latinas reflect that of their social ties, targeting existing social networks for lifestyle interventions may more effectively improve and sustain health-promoting behaviors and outcomes. (PsycINFO Database Record

Incident Type 2 Diabetes Risk is Influenced by Obesity and Diabetes in Social Contacts: a Social Network Analysis

BACKGROUND

Obesity and diabetes family history are the two strongest risk factors for type 2 diabetes (T2D). Prior work shows that an individual's obesity risk is associated with obesity in social contacts, but whether T2D risk follows similar patterns is unknown.

OBJECTIVE

We aimed to estimate the relationship between obesity or diabetes in an individual's social contacts and his/her T2D risk. We hypothesized that obesity and diabetes in social contacts would increase an individual's T2D risk.

DESIGN

This was a retrospective analysis of the community-based Framingham Offspring Study (FOS).

PARTICIPANTS

FOS participants with T2D status, height and weight, and at least one social contact were eligible for this study (n = 4797 at Exam 1). Participants' interpersonal ties, cardiometabolic and demographic variables were available at eight exams from 1971 to 2008, and a T2D additive polygenic risk score was measured at the fifth exam.

MAIN MEASURES

Primary exposures were T2D (fasting glucose ≥ 7 mmol/L or taking diabetes medications) and obesity status (BMI ≥ 30 kg/m(2)) of social contacts at a prior exam. Primary outcome was incident T2D in participants.

KEY RESULTS

Incident T2D was associated with having a social contact with diabetes (OR 1.32, p = 0.004) or with obesity (OR 1.21, p = 0.004). In stratified analyses, incident T2D was associated with diabetes in siblings (OR 1.64, p = 0.001) and obesity in spouses (OR 1.54, p = 0.0004). The associations between diabetes and obesity in social contacts and an individual's incident diabetes risk were stronger in individuals with a high diabetes genetic risk score.

CONCLUSIONS

T2D and obesity in social contacts, particularly siblings and spouses, were associated with an individual's risk of incident diabetes even after accounting for parental T2D history. Assessing risk factors in an individual's siblings and spouses can inform T2D risk; furthermore, social network based lifestyle interventions involving spouses and siblings might be a novel T2D prevention approach.

Income differences in social control of eating behaviors and food choice priorities among southern rural women in the US: A qualitative study

The role of social influences on rural women's food choice is not well understood. Rural adults experience high rates of obesity and poor diet quality prompting exploration of how social factors influence food choice in this population. Semi-structured qualitative interviews were conducted with 20 women in rural North Central Florida. Women were purposively sampled and stratified by race and income. Lower income was defined as household income at or below 185% of the federal poverty level (FPL). Women at or below 185% poverty level (BPL) experienced direct social control of their eating behaviors, which occurred when social network members explicitly regulated or otherwise sanctioned eating behaviors or food choices. Women above 185% of the federal poverty level (APL) internalized social norms and self-regulated their eating behaviors to maintain healthy habits. APL women described choosing foods for health reasons whereas BPL women offered a variety of reasons including taste, convenience, family history, price, health, and routine. Findings suggest that women in different income groups have different social influences working to help them regulate eating behaviors as well as diverse priorities influencing their food choices. Future interventions to promote healthy eating may be more effective by incorporating social network members and framing intervention messages so they are consistent with priorities.

Liraglutide for the treatment of type 2 diabetes mellitus: a meta-analysis of randomized placebo-controlled trials

INTRODUCTION

Liraglutide has been widely used in the treatment of type 2 diabetes mellitus (T2DM), however, the results of a number of randomized placebo-controlled trials on the effects of liraglutide for the treatment of T2DM have varied. The purpose of this study was to assess the effects of liraglutide versus placebo for the treatment of T2DM.

METHODS

We searched randomized controlled trials comparing liraglutide and placebo for the treatment of T2DM in the following databases: MEDLINE; EMBASE; Cochrane Library Central Register of Controlled Trials; and Clinical Trials Gov (through August 2014). The standard mean difference (SMD) was calculated for the continuous data and a χ (2) test was used to evaluate heterogeneity.

RESULTS

Initially, 103 articles were retrieved through the literature search and 11 studies met the requirements for the meta-analysis. The effects of liraglutide on lowering glycosylated hemoglobin, fasting plasma glucose, reducing weight, lowering blood pressure, and the prevalence of adverse events were significantly different from placebo (P < 0.0001, SMD = -0.96, 95% CI = [-1.20, -0.73]; P < 0.0001, SMD = -0.72, 95% CI = [-0.99, -0.45]; P = 0.004, SMD = -0.24, 95% CI = [-0.40, -0.07]; P = 0.021, SMD = -0.15, 95% CI = [-0.27, -0.02], and P = 0.007, respectively).

CONCLUSION

Liraglutide had greater hypoglycemic, weight-reducing and systolic blood pressure-lowering effects than placebo. However, there were more adverse events in the treatment with liraglutide. It is suggested that additional well-designed, large, studies be conducted to further support the use of liraglutide and provide objective guidance for clinical application of liraglutide.