Impact of a short-term Mediterranean diet intervention on plasma metabolites: a pilot study.

BACKGROUND: Dietary habits significantly influence the risks of type 2 diabetes and cardiovascular disease. Through metabolomics, we've previously measured plasma metabolites to gauge dietary quality, introducing a healthy dietary metabolic signature (HDMS) linked to a decreased risk of future type 2 diabetes and coronary artery disease. OBJECTIVES: To assess the impact of a 6-day dietary intervention on plasma metabolites and the HDMS. METHODS: Fifty-nine Swedish participants (71% women, mean age 69 years) underwent a 6-day Mediterranean diet (MD) intervention in Italy's Cilento region. All meals, crafted from local recipes and ingredients, were provided. Metabolite profiling pre- and post-intervention was conducted with a UHPLC-QTOF. Alterations in metabolite levels and the HDMS were examined using paired T-test. RESULTS: The MD intervention notably enhanced the HDMS across participants (mean increase: 1.3 standard deviations (SD), 95% CI 1.1-1.4, p = 6E-25). Out of 109 metabolites, 66 exhibited significant alterations (fdr adjusted p < 0.05). Among the 10 most significant changes, increases were observed in several diet related metabolites such as pipecolate, hippurate, caffeine, homostachydrine, acylcarnitine C11:0, acetylornithine, beta-carotene and 7-methylguanine. The most significant decreases manifested in piperine and 3-methylhistidine. CONCLUSIONS: The HDMS, which is linked to a healthy diet and inversely associated with cardiometabolic disease, was significantly improved by the 6-day Mediterranean diet intervention. Notably, metabolite markers previously shown to be indicative of the intake of vegetables, fruits, grains, and legumes increased, while markers previously associated with red meat consumption decreased. These findings highlight the potential of short-term dietary interventions to induce significant changes in plasma metabolite profiles.

The impact of prediabetes and diabetes on endothelial function in a large population-based cohort.

BACKGROUND: Diabetes and prediabetes are well-recognized risk factors for cardiovascular disease (CVD) and are marked by vascular endothelial dysfunction (ED). However, there is a scarcity of thorough population-based studies examining ED in individuals with diabetes/prediabetes free from manifest CVD. Here, we examined the association between ED assessed by reactive hyperaemia index (RHI) in the finger and diabetes/prediabetes in a large middle-aged population cohort. METHODS: Within the Malmö Offspring Study, following the exclusion of participants <30 years and participants with prevalent CVD, 1384 participants had complete data on all covariates. The RHI was calculated using pulse amplitude tonometry. ED was defined as RHI < 1.67. Multivariable logistic and linear regression models were conducted to investigate associations between ED and RHI with diabetes and prediabetes. RESULTS: The study population had a mean age of 53.6 ± 7.6 years (53% women). In study participants with manifest diabetes (n = 121) and prediabetes (n = 514), ED was present in 42% and 25% respectively, compared to 23% in those with normal glucometabolic status. In multivariable logistic regression analyses, prevalent diabetes was significantly associated with ED (OR 1.95; 95%CI 1.57-3.39; p = 0.002), as well as with lower RHI (ß-coeff. -0.087; p = 0.002). However, prediabetes showed no association with neither ED nor RHI. CONCLUSION: In a population free from CVD, vascular endothelial dysfunction was primarily associated with manifest diabetes, but not with prediabetes, implying that finger ED may develop when diabetes is established, rather than being an early sign of glucose intolerance. Further research is needed to explore whether addressing glucose intolerance could potentially delay or prevent vascular ED onset.

What is the context?Diabetes and prediabetes are known to increase the risk of cardiovascular disease (CVD) through a condition called vascular endothelial dysfunction (ED). However, there is a lack of comprehensive studies on ED in individuals with diabetes/prediabetes who do not already have CVD. In this study, we investigated the association between ED, assessed using the reactive hyperaemia index (RHI) in a finger, and diabetes/prediabetes in a large group of middle-aged individuals.What is new?We conducted this study within the Malmö Offspring Study, involving 1384 participants who were over 30 years old and did not have pre-existing CVD. The average age of the participants was 53 years, with 53% being women. Among those with diagnosed diabetes (121 individuals) and prediabetes (5141 individuals), 42% and 25% respectively showed signs of ED, compared to 23% in those with normal glucose metabolism. In our analyses, we found that established diabetes was significantly associated with ED, as well as with lower finger RHI values. However, prediabetes did not show any significant association with either ED or RHI.What is the impact? In a healthy population without pre-existing CVD, vascular endothelial dysfunction was predominantly linked to diagnosed diabetes, rather than prediabetes. This suggests that ED may develop once diabetes is established, rather than being an early indicator of glucose intolerance. Further research is necessary to investigate whether addressing glucose intolerance could potentially delay or prevent the onset of vascular ED.