A UK Biobank analysis followed more than 3,600 adults with type 2 diabetes to examine how diet, sleep, physical activity, and social habits relate to major cardiovascular events and survival.
Study: Mediterranean lifestyle and risk of adverse cardiovascular events, all-cause and cardiovascular mortality among individuals with type 2 diabetes. Image Credit: Guillermo Dario / Shutterstock
In a recent study published in the journal eClinicalMedicine, researchers investigated associations between adherence to a Mediterranean lifestyle and the risk of major adverse cardiovascular events (MACE) and mortality in adults with type 2 diabetes (T2D).
Global T2D prevalence is projected to rise by 62% from 2021 to 2050, affecting more than 1.27 billion individuals. Cardiovascular disease (CVD) remains the major complication, with T2D patients facing up to a 2.5-fold higher risk of MACE, including heart failure (HF), ischemic stroke (IS), myocardial infarction (MI), revascularization, and CVD mortality. Adherence to healthy dietary patterns, such as the Mediterranean diet (MD), may reduce the risk of MACE and CVD mortality in T2D patients.
Adequate sleep, regular physical activity, and optimal social connections have been associated with a lower risk of MACE in people with T2D. Furthermore, higher scores on the Mediterranean Lifestyle Index (MEDLIFE), a validated tool for assessing adherence to a Mediterranean lifestyle, have been associated with reduced CVD risk in the general population. However, evidence in the T2D population, especially in non-Mediterranean cohorts, remains scarce.
About the study
In the present study, researchers examined associations between adherence to the MEDLIFE and the risk of MACE, CVD mortality, and all-cause mortality in a non-Mediterranean T2D population. The study included adults aged 40–70 years from the United Kingdom Biobank (UKB) cohort, who had T2D at baseline and completed at least two dietary assessments. MD adherence was examined at baseline using repeated 24-hour dietary assessments collected with the Oxford WebQ questionnaire.
The UK Biobank touchscreen questionnaire collected information on physical activity, sedentary behavior, social habits, rest, and other lifestyle factors. The MEDLIFE comprised 25 items across three blocks: 1) Mediterranean food intake, 2) Mediterranean dietary habits, and 3) conviviality, rest, physical activity, and social habits. Because some components of the original MEDLIFE were unavailable in UKB, including olive oil and sofrito consumption, snacking outside meals, and eating with company, the researchers used a modified version of the index. The study’s primary outcomes included the incidence of MACE, CVD mortality, and all-cause mortality.
MACE was a composite of IS, MI, revascularization procedures, HF, and CVD death. Hazard ratios (HRs) were computed for the association between MEDLIFE scores and outcomes using Cox proportional hazard models. Model 1 was adjusted for sex, education, deprivation index, ethnicity, assessment region, and family CVD history. Model 2 was additionally adjusted for body mass index, smoking, mineral or vitamin supplement use, and total energy intake.
Model 3 was further adjusted for CVD medications and intermediate conditions (hypertension, prevalent MACE, and cancer). Model 4, which was the primary analytic model, underwent additional adjustment for T2D prognostic factors: age at diagnosis, medications, duration of T2D, and glycemic control. Secondary analyses explored associations between individual MEDLIFE blocks and outcomes, as well as between MEDLIFE and individual MACE components.
Findings
The study included 3,612 individuals with T2D, with an average age of 59.8 years. About 34% of participants were female. The mean MEDLIFE scores were 8.8 for females and 8.4 for males. Participants in the highest MEDLIFE quartile were more likely to be female, older, non-smokers, and more educated than those in the lowest quartile. Overall, 737 incident MACE, 645 all-cause deaths, and 171 CVD deaths were recorded over the follow-up.
Higher MEDLIFE adherence was associated with a reduced risk of MACE and mortality. The HR for MACE was 0.73 for participants in the highest quartile compared with those in the lowest quartile. The HRs for all-cause and CVD deaths were 0.74 and 0.49, respectively, in the highest quartile relative to the lowest quartile. Each two-point increase in the MEDLIFE score was associated with 12%, 21%, and 9% lower risks of MACE, CVD mortality, and all-cause mortality, respectively.
Each MEDLIFE block contributed to the overall pattern of associations, although the specific outcomes associated with each block differed. There was a 10% lower risk of MACE and a 23% lower risk of CVD deaths associated with each two-point increase in the scores of Mediterranean food consumption and Mediterranean dietary habits blocks, respectively. Each two-point increase in the third MEDLIFE block was associated with 14%–25% lower risks of all outcomes. The direction of associations across individual MACE components remained consistent, although none reached statistical significance, with the association for HF approaching significance. Subgroup analyses identified interactions with educational level and T2D medication use, with higher MEDLIFE adherence associated with lower MACE risk among participants taking T2D medication and those with lower educational attainment. Sensitivity analyses were broadly consistent, although the association with CVD mortality was no longer statistically significant after excluding participants with prevalent MACE at baseline.
The observational design cannot establish causality, and self-reported lifestyle data, the modified MEDLIFE score, potential residual confounding, changes in lifestyle that were not assessed during follow-up, and the UK Biobank volunteer population may limit interpretation and generalizability.
Conclusions
Taken together, greater MEDLIFE adherence was associated with progressively lower risk of MACE, all-cause mortality, and CVD deaths among individuals with T2D. These associations persisted after adjustment for T2D prognostic factors, underscoring MEDLIFE’s potential across the clinical spectrum of diabetes. The authors suggest that MEDLIFE may provide an accessible and promising tool for T2D management.
