Smoking, physical inactivity, and other lifestyle factors increase the risk of multimorbidity

By Pooja Toshniwal PahariaReviewed by Benedette Cuffari, M.Sc.Jul 31 2023

In a recent study published in PLoS ONE, researchers examine a wide range of lifestyle variables in the context of multimorbidity of chronic non-communicable illnesses.

Study: Lifestyle factors related to prevalent chronic disease multimorbidity: A population-based cross-sectional study. Image Credit: Amorn Suriyan / Shutterstock.com

What is multimorbidity?

Multimorbidity is a global health concern involving the coexistence of multiple chronic conditions in the same person. Importantly, multimorbidity is linked to cardiovascular disease, respiratory illnesses, type 2 diabetes, and cancer, thus leading to higher healthcare costs and increased mortality.

Lifestyle medicine aims to improve clinical care by reducing symptoms, increasing medication effectiveness, and encouraging disease remission. Understanding the prevalence and specificity of lifestyle-associated risk factors for multimorbidity linked to chronic diseases would help determine future clinical treatment recommendations.

About the study

In the present population-based study, researchers evaluate the association between exercise, nutrition, substance abuse, stress, relationships, and sleep to multimorbidity. For the purposes of the current study, multimorbidity was defined as the presence of two or more chronic respiratory diseases, including airflow obstruction and asthma, as well as cardiovascular disease, diabetes mellitus type 2 (T2D), and cancer.

The study used the Lifelines Cohort Study data of 79,345 adults living in the northern parts of the Netherlands. Odds ratios (OR) were calculated using multivariate logistic regression modeling, which adjusted for factors such as age, gender, body mass index (BMI), socioeconomic position, educational attainment, and household income.

Baseline data were obtained between December 2006 and December 2013 if they contained all lifestyle variables and multimodality outcomes required to determine multimorbidity.

Pre-bronchodilator spirometry was used to measure airflow restriction. Asthma was considered present if diagnosed by a clinician or if the patient took asthma medications and reported two or more symptoms of wheezing and dyspnea at rest and upon waking up.

Prevalent T2D cases were defined as those who self-documented T2D or diabetes with missing type data and those who used diabetic medication or had fasting blood glucose (FG) of at least 7.0 mmol/L or glycated hemoglobin (HbA1c) less than 6.5%.

The Lifelines Diet Score (LLDS) was used to assess diet quality, whereas the Food Frequency Questionnaire (FFQ) was used to analyze diet during the preceding month. According to the Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH), the Lifelines Physical Activity Score (LLPAS) assessed physical activity.

Acute stress was assessed using the List of Threatening Experiences (LTE), Dutch version, while chronic stress was assessed using the Long-term Difficulties Inventory (LDI). Total self-reported sleep for every 24 hours was classified using the American National Sleep Foundation's age-specific parameters.

Study findings

About 28% of research participants had a single chronic condition, 5% with multimorbidity, and 4.3% with two chronic diseases. When compared to the single- and no-disease groups, the multimorbidity group was older and more likely to be overweight or obese. Inadequate sleep was common, with 22% of individuals with multimorbidity patients reporting insufficient or slightly inappropriate sleep periods.

The most frequent ailment was chronic respiratory disease at 22%, followed by CVD, T2D, and cancer at 11%, 3.0%, and 2.3%, respectively. The most common multimorbidity combination was generated by the two most common chronic illnesses of respiratory disease and cardiovascular disease. Taken together, 4.7% of study participants with a mean age of 54 years had multimorbidity and tended to live less healthy lives.

Individuals with multimorbidity reported more physical inactivity, inadequate sleep, and chronic stress with ORs of 1.2, 1.7, and 2.1, respectively. Multimorbid individuals were current smokers, watched television, and consumed less alcohol.

No association was observed between food quality and morbidity.

Conclusions

The study findings indicate that inadequate sleep and chronic stress should be considered when developing supportive lifestyle programs for people with multimorbidity. Physical inactivity and smoking were also identified as key lifestyle factors among people with multiple chronic diseases.  

Additional research is needed to assess the impact of every lifestyle component on disease prognosis, devise lifestyle therapies for multimorbid patients, and examine the influence of lifestyle interventions on clinical outcomes and life quality.