Can loneliness lead to diabetes? New research reveals the role of physical activity and BMI

This is evident from a recent study published in the journal Nutrientsresearchers evaluate the mediating effects of physical activity, body mass index (BMI), and diet quality on the association between loneliness and diabetes.

Study: The association between loneliness and diabetes is mediated by physical activity and BMI, but not by diet quality. Image credits: asylsun / Shutterstock.com

Background

Loneliness, a subjective emotional state, is associated with an increased risk of diabetes and cardiovascular disease. Some of the underlying mechanisms contributing to this increased risk include depression, decreased cognitive performance, and nursing home admission.

Loneliness worsens health through several pathways, including diet quality, physical activity, alcoholic beverages, smoking and sleep patterns. Psychological factors such as perceived stress and depression have inconsistent effects on this association, which may be influenced by unhealthy dietary behavior and obesity. Thus, additional research is needed to examine the mediating pathways between loneliness and obesity, to support the development of effective health interventions.

About the study

In the current study, researchers examine whether physical activity, BMI, and diet quality mediate the relationship between loneliness and diabetes among white and African American adults aged 36 to 77 in the United States.

The study involved 1,713 individuals who participated in follow-up visits of the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study between 2013 and 2017 and had complete information on explanatory, predictive, and outcome variables. . The HANDLS study was conducted in 2004 and included 3,720 individuals to evaluate the impact of socioeconomic factors on health disparities between white and African American residents of Baltimore.

Participants were classified as non-diabetic, pre-diabetic, or diabetic based on fasting blood glucose levels, medications, and self-reports. The three-item scale from the University of California Los Angeles (UCLA) measures loneliness based on a lack of companionship, feeling left out, and social isolation.

The 2010 Healthy Eating Index (HEI) scores were based on participants’ responses to two 24-hour dietary recalls obtained using the United States Department of Agriculture (USDA) automated multiple-pass method (AMPM) to assess quality of the diet.

All participants received food notebooks and other tools to estimate portion size. Food items were coded using the USDA Food and Nutrient Database for Dietary Studies (FNDDS).

Physical activity was assessed using the Baecke questionnaire and mediation analysis was performed using the Hayes PROCESS macro model. Covariates included age, gender, race, education, household income, and alcohol consumption.

Findings of the study

The average age of participants was 57, with 59% female, 39% white, and 38% with an income below the poverty line. Within the study cohort, 16% and 24% were classified as pre-diabetic and diabetic, respectively. About 14% of participants often felt the absence of a companion; however, only 8% reported feelings of social isolation.

Of the participants, 24%, 26% and 51% were normal weight, overweight and obese, respectively. Prediabetes and diabetes were reported more frequently among white and African American individuals, respectively.

Whites were more likely to report feeling left out than African American adults. Feeling lonely showed significant but inverse correlations with diet quality and physical activity.

Through the PROCESS Macro Model, nine direct pathways linking loneliness to diabetes have been identified, with loneliness influencing diet quality, BMI or physical activity and consequently contributing to diabetes risk.

The risk of poor diet quality increased as people felt lonely. Age, female gender, higher education level and income that was 125% above the poverty line were significantly related to better diet quality. Relatively speaking, being younger, male, or having more years of education increases the likelihood of higher physical activity levels.

Physical activity was a predictive factor that significantly contributed to variations in BMI values. Higher BMI values ​​were significantly associated with younger age, being female, having an income greater than 125% poverty status, and consuming fewer alcoholic beverages.

High BMI values ​​were found to significantly increase the risk of diabetes in a dose-dependent manner, with greater increases in BMI leading to a higher risk of diabetes. Physical activity and BMI had a significant and indirect influence on the effect of loneliness on diabetes risk. Race or poverty status significantly influenced the effect of loneliness on diabetes.

Conclusions

Feeling lonely had significant but inverse associations with exercise and diet quality, consistent with previous research.

The development of mental disorders such as depression and loneliness is often multi-faceted, as the chronic inflammation associated with various diseases, including diabetes, exhibits the same pathology as depression. Additionally, poor mental health often leads to low-quality diets high in processed foods and low in fruits and vegetables, in addition to poor sleep habits and increased mental distress.

The complex interplay between lifestyle and genetic factors on loneliness and diabetes highlights the importance of developing targeted intervention programs that can improve both mental and physical health outcomes.