Abstract

AIMS: To evaluate the effect of an intensive lifestyle intervention (ILI) on the structural and functional cardiac substrate of atrial fibrillation (AF) in overweight or obese people with metabolic syndrome (Mets). METHODS AND RESULTS Participants of the PREvención con DIeta MEDiterranea-Plus trial (n = 6874) were randomized 1:1 to an ILI programme based on an energy-reduced Mediterranean diet, increased physical activity, and cognitive-behavioural weight management or to a control intervention of low-intensity dietary advice. A core echocardiography lab evaluated left atrial (LA) strain, function, and volumes in 534 participants at baseline, 3-year, and 5-year follow-ups. Mixed models were used to evaluate the effect of the ILI on LA structure and function. In the subsample, the baseline mean age was 65 years [standard deviation (SD) 5 years], and 40% of the participants were women. The mean weight change after 5 years was -3.9 kg (SD 5.3 kg) in the ILI group and -0.3 kg (SD 5.1 kg) in the control group. Over the 5-year period, both groups experienced a worsening of LA structure and function, with increases in LA volumes and stiffness index and decreases in LA longitudinal strain, LA function index, and LA emptying fraction over time. Changes in the ILI and control groups were not significantly different for any of the primary outcomes {LA emptying fraction: -0.95% [95% confidence interval (CI) -0.93, -0.98] in the control group, -0.97% [95% CI -0.94, -1.00] in the ILI group, Pbetween groups = 0.80; LA longitudinal strain: 0.82% [95% CI 0.79, 0.85] in the control group, 0.85% [95% CI 0.82, 0.89] in the ILI group, Pbetween groups = 0.24} or any of the secondary outcomes. CONCLUSION In overweight or obese people with Mets, an ILI had no impact on the underlying structural and functional LA substrate measurements associated with AF risk. This study evaluated whether an intervention-modifying lifestyle had an effect on the parts of the heart involved in the development of atrial fibrillation (AF), a common problem of the heart rhythm. This intervention was implemented in people who had excessive body weight and the metabolic syndrome (Mets), which is a combination of several cardiovascular risk factors. The lifestyle intervention included promoting a Mediterranean diet low in calories and increasing exercise to facilitate weight loss, and this intervention was compared with a control intervention to follow a healthy diet. We performed repeated studies of the heart structure and function with imaging over a period of 5 years. During the 5 years of the study, both study groups (intervention and control) showed changes in their heart consistent with ageing. However, these changes were not different in those who were receiving the lifestyle intervention. Also, participants who lost more weight, adhered better to the study diet, or did more physical activity, overall did not show any differences in their heart compared with those who did not achieve their lifestyle goals.In conclusion, a lifestyle intervention focusing on weight loss, better diet, and more exercise was not effective in improving parts of the heart potentially involved with the risk of AF.In people with metabolic syndrome, a weight control lifestyle intervention, based on an energy-reduced Mediterranean diet and physical activity, had no effect on the structural and functional cardiac substrate of atrial fibrillation.

Abstract

BACKGROUND & AIMS Continuous glucose monitoring (CGM) provides data on short-term glycemic variability (GV). GV is associated with adverse outcomes in individuals with diabetes. Whether GV is associated with cardiometabolic risk in individuals without diabetes is unclear. We systematically reviewed the literature to assess whether GV is associated with cardiometabolic risk markers or outcomes in individuals without diabetes. METHODS Searches were performed in PubMed/Medline, Embase and Cochrane from inception through April 2022. Two researchers were involved in study selection, data extraction and quality assessment. Studies evaluating GV using CGM for ≥24 h were included. Studies in populations with acute and/or critical illness were excluded. Both narrative synthesis and meta-analyzes were performed, depending on outcome. RESULTS Seventy-one studies were included; the majority were cross-sectional. Multiple measures of GV are higher in individuals with compared to without prediabetes and GV appears to be inversely associated with beta cell function. In contrast, GV is not clearly associated with insulin sensitivity, fatty liver disease, adiposity, blood lipids, blood pressure or oxidative stress. However, GV may be positively associated with the degree of atherosclerosis and cardiovascular events in individuals with coronary disease. CONCLUSION GV is elevated in prediabetes, potentially related to beta cell dysfunction, but less clearly associated with obesity or traditional risk factors. GV is associated with coronary atherosclerosis development and may predict cardiovascular events and type 2 diabetes. Prospective studies are warranted, investigating the predictive power of GV in relation to incident disease. GV may be an important risk measure also in individuals without diabetes.

Abstract

PURPOSE To assess the prospective association between metabolic syndrome (MetS), its components, and incidence of thyroid disorders by conducting a systematic review and meta-analysis. METHODS A systematic search was performed in Ovid Medline, Embase.com, and Cochrane CENTRAL from inception to February 22, 2023. Publications from prospective studies were included if they provided data on baseline MetS status or one of its components and assessed the incidence of thyroid disorders over time. A random effects meta-analysis was conducted to calculate the odds ratio (OR) for developing thyroid disorders. RESULTS After full-text screening of 2927 articles, seven studies met our inclusion criteria. Two of these studies assessed MetS as an exposure (N = 71,727) and were included in our meta-analysis. The association between MetS at baseline and incidence of overt hypothyroidism at follow-up yielded an OR of 0.78 (95% confidence interval [CI]: 0.52-1.16 for two studies, I2 = 0%). Pooled analysis was not possible for subclinical hypothyroidism, due to large heterogeneity (I2 = 92.3%), nor for hyperthyroidism, as only one study assessed this association. We found evidence of an increased risk of overt (RR: 3.10 (1.56-4.64, I2 = 0%) and subclinical hypothyroidism (RR 1.50 (1.05-1.94), I2 = 0%) in individuals with obesity at baseline. There was a lower odds of developing overt hyperthyroidism in individuals with prediabetes at baseline (OR: 0.68 (0.47-0.98), I2 = 0%). CONCLUSIONS We were unable to draw firm conclusions regarding the association between MetS and the incidence of thyroid disorders due to the limited number of available studies and the presence of important heterogeneity in reporting results. However, we did find an association between obesity at baseline and incidence of overt and subclinical hypothyroidism.

Abstract

BACKGROUND Subclinical hypothyroidism (SCH) is a common endocrine subclinical disorder, the main adverse consequences of which are the development of clinical hypothyroidism and the promotion of ischemic heart disease. Metabolic syndrome (MetS) is a collection of metabolic problems. The goal of this meta-analysis was to evaluate the relationship between MetS and SCH. METHODS Suitable publications were identified using PubMed, Embase, and the Cochrane Library. The meta-analysis included only studies in English that reported odds ratio (OR) data for MetS and SCH. Two researchers combined data using a random-effects model. OR and 95% confidence intervals (CIs) were used to present the results. RESULTS MetS was associated with an elevated risk of developing SCH (OR 2.56, 95% CI 1.44-4.55). However, the individual components of MetS were not associated with the risk of SCH. Subgroup analysis revealed that different definitions of MetS had varying effects on SCH. Sensitivity analysis confirmed that our results were robust. CONCLUSIONS This meta-analysis indicates that patients with MetS have an increased risk of SCH, while there is no significant association between the five individual components of MetS and the risk of SCH. SYSTEMATIC REVIEW REGISTRATION https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023454415.

Abstract

BACKGROUND Obesity and metabolic syndrome (MetS) have become urgent worldwide health problems, predisposing patients to unfavorable myocardial status and thyroid dysfunction. Low-carbohydrate diet (LCD) and time-restricted eating (TRE) have been confirmed to be effective methods for weight management and improving MetS, but their effects on the myocardium and thyroid are unclear. METHODS We conducted a secondary analysis in a randomized clinical diet-induced weight-loss trial. Participants (N = 169) diagnosed with MetS were randomized to the LCD group, the 8 h TRE group, or the combination of the LCD and TRE group for 3 months. Myocardial enzymes and thyroid function were tested before and after the intervention. Pearson's or Spearman's correlation was assessed between functions of the myocardium and thyroid and cardiometabolic parameters at baseline. RESULTS A total of 162 participants who began the trial were included in the intention-to-treat (ITT) analysis, and 57 participants who adhered to their assigned protocol were involved in the per-protocol (PP) analysis. Relative to baseline, lactate dehydrogenase, creatine kinase MB, hydroxybutyrate dehydrogenase, and free triiodothyronine (FT3) declined, and free thyroxine (FT4) increased after all 3 interventions (both analyses). Creatine kinase (CK) decreased only in the TRE (- 18 [44] U/L, P < 0.001) and combination (- 22 [64] U/L, P = 0.003) groups (PP analysis). Thyrotropin (- 0.24 [0.83] μIU/mL, P = 0.011) and T3 (- 0.10 ± 0.04 ng/mL, P = 0.011) decreased in the combination group (ITT analysis). T4 (0.82 ± 0.39 μg/dL, P = 0.046), thyroglobulin antibodies (TgAb, 2 [1] %, P = 0.021), and thyroid microsomal antibodies (TMAb, 2 [2] %, P < 0.001) increased, while the T3/T4 ratio (- 0.01 ± 0.01, P = 0.020) decreased only in the TRE group (PP analysis). However, no significant difference between groups was observed in either analysis. At baseline, CK was positively correlated with the visceral fat area. FT3 was positively associated with triglycerides and total cholesterol. FT4 was negatively related to insulin and C-peptide levels. TgAb and TMAb were negatively correlated with the waist-to-hip ratio. CONCLUSIONS TRE with or without LCD confers remarkable metabolic benefits on myocardial status and thyroid function in subjects with MetS. TRIAL REGISTRATION ClinicalTrials.gov, NCT04475822.