In a recent study published in PLoS One, researchers assess population-attributable risk variables for cause-specific and all-cause mortality due to type 2 diabetes.
Study: Age-specific population attributable risk factors for all-cause and cause-specific mortality in type 2 diabetes: An analysis of a 6-year prospective cohort study of over 360,000 people in Hong Kong. Image Credit: Montri Thipsorn / Shutterstock.com
An overview of type 2 diabetes
Type 2 diabetes is related to premature mortality with increasing prevalence among both young and elderly individuals. By controlling for modifiable risk factors and managing comorbidities, a considerable number of premature deaths in patients with type 2 diabetes can be prevented.
As both the incidence of risk factors and the robustness of their relationships with mortality change by age, there may be significant age-related variation with respect to the contribution of risk variables to the mortality burden in a population. In patients with type 2 diabetes, the leading risk factors associated with cause-specific and all-cause mortality across different age cohorts remain unknown.
About the study
In the present study, researchers analyze age-specific relationships and population-attributable fractions (PAFs) of risk variables for cause-specific and all-cause mortalities among type 2 diabetes patients.
The team conducted a prospective cohort study utilizing information obtained from a Hong Kong-wide diabetic complication screening program. All individuals with diabetes were considered eligible participants of the Risk Assessment and Management Program for Diabetes Mellitus (RAMP-DM).
People with type 2 diabetes who were eligible for the present study were participants of the RAMP-DM between January 1, 2000, and December 31, 2019, and were at least 18 years old at the time of evaluation. The study was scheduled for September 2021, and the analysis was conducted from September 2021 to March 2022.
At the metabolic evaluation and complication screening, the team collected data related to demographic, lifestyle, disease history, laboratory tests, anthropometric measures, and medication usage. A total of eight risk factors were measured at baseline, including three prevalent comorbidities of chronic kidney disease (CKD), cardiovascular disease (CVD), and all-site cancer, as well as five modifiable risk variables including suboptimal HbA1c control, suboptimal blood pressure control, suboptimal low-density lipoprotein cholesterol (LDL-C) control, present smoking habits, and suboptimal weight.
The study cohort included 360,202 individuals with type 2 diabetes. The mean age at baseline was 61.4 years, while 188,872 participants were male. About 17% of the study cohort reported CVD, 14% had CKD, and 4.3% experienced all-site cancer.
In terms of LDL-C, HbA1c, and systolic blood pressure (SBP)/diastolic blood pressure (DBP), 54%, 50.2%, and 33.5% of individuals did not meet the recommended treatment targets, respectively. The current smoking prevalence among the participants was 13.4%.
The distribution of risk variables differed between age groups. Younger adults, for example, reported a lower number of CKD, CVD, and cancer cases than older people.
Younger individuals were also more likely to be current smokers, have suboptimal LDL-C and HbA1c control, and have optimal SBP/DBP control. Younger individuals also exhibited higher average body-mass index (BMI) values and were more likely to be obese as compared to older individuals. However, no discernible age-related trend in the incidence of suboptimal weight was observed.
The absolute mortality risk rose with increasing age at baseline. The crude all-cause death rate was ten times greater among individuals aged 75 years or older than among those between 18 and 54 years of age.
All risk variables were remarkably associated with an elevated risk of death from all causes, except the inconsiderable correlation with suboptimal LDL-C control. In general, the higher mortality risk correlated with suboptimal weight was greater in those with a low BMI as compared to individuals with a high BMI. When categorized by age, correlations between most risk variables and all-cause mortality were highest in the youngest age group and weakened as age increased.
Taken together, CVD, cancer, and pneumonia were responsible for over 60% of all deaths. Suboptimal LDL-C management was associated with an increased risk of CVD-related mortality and renal illness, as well as a decreased risk of mortality due to pneumonia, cancer, and digestive disorders.
Age-related gradients were also observed for the connections between risk variables and several specific causes of mortality, with the associations more significant among younger than older individuals.
Although the absolute mortality risk due to type 2 diabetes is lower among younger than older individuals, modifiable risk variables and major comorbidities were correlated with a higher comparative mortality risk among younger people.
The current study highlighted the significance of early management of modifiable risk variables, particularly blood pressure, to prevent premature mortality among young individuals with type 2 diabetes and reduce the CKD mortality risk of CKD in older age groups.
- Wu, H., Lau, E. S. H., Yang, A., et al. (2023) Age-specific population attributable risk factors for all-cause and cause-specific mortality in type 2 diabetes: An analysis of a 6-year prospective cohort study of over 360,000 people in Hong Kong. PLOS Medicine 20(1). doi:10.1371/journal.pmed.1004173