Myokines represent important regulators of muscle metabolism. Our study aimed to explore the effects of a cyclical ketogenic reduction diet (CKD) vs. a nutritionally balanced reduction diet (RD) combined with regular resistance/aerobic training in healthy young males on serum concentrations of myokines and their potential role in changes in physical fitness. Twenty-five subjects undergoing regular resistance/aerobic training were randomized to the CKD (n = 13) or RD (n = 12) groups. Anthropometric and spiroergometric parameters, muscle strength, biochemical parameters, and serum concentrations of myokines and cytokines were assessed at baseline and after 8 weeks of intervention. Both diets reduced body weight, body fat, and BMI. Muscle strength and endurance performance were improved only by RD. Increased musclin (32.9 pg/mL vs. 74.5 pg/mL, p = 0.028) and decreased osteonectin levels (562 pg/mL vs. 511 pg/mL, p = 0.023) were observed in RD but not in the CKD group. In contrast, decreased levels of FGF21 (181 pg/mL vs. 86.4 pg/mL, p = 0.003) were found in the CKD group only. Other tested myokines and cytokines were not significantly affected by the intervention. Our data suggest that changes in systemic osteonectin and musclin levels could contribute to improved muscle strength and endurance performance and partially explain the differential effects of CKD and RD on physical fitness.

(1) Background: C1q TNF-related protein 3 (CTRP3) is an adipokine with anti-inflammatory and cardioprotective properties. In our study, we explored changes in serum CTRP3 and its gene expression in epicardial (EAT) and subcutaneous (SAT) adipose tissue in patients with and without coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM) undergoing elective cardiac surgery. (2) Methods: SAT, EAT, and blood samples were collected at the start and end of surgery from 34 patients: (i) 11 without CAD or T2DM, (ii) 14 with CAD and without T2DM, and (iii) 9 with both CAD and T2DM. mRNA levels of CTRP3 were assessed by quantitative reverse transcription PCR. Circulating levels of CTRP3 and other factors were measured using ELISA and Luminex Multiplex commercial kits. (3) Results: Baseline plasma levels of TNF-α and IL6 did not differ among the groups and increased at the end of surgery. Baseline circulating levels of CTRP3 did not differ among the groups and decreased after surgery. In contrast, baseline CTRP3 mRNA levels in EAT were significantly decreased in CAD/T2DM group, while no differences were found for TNF-α and IL6 gene expression. (4) Conclusions: Our data suggest that decreased EAT mRNA levels of CTRP3 could contribute to higher risk of atherosclerosis in patients with CAD and T2DM.

Aims: Obesity is one of the strongest risk factors for the development of atrial fibrillation (AF), and its reduction is associated with the alleviation of AF burden. The HOBIT-AF study aimed to evaluate the impact of complex weight loss interventions on AF recurrence rate in obese individuals after catheter ablation (CA). Methods and results: The HOBIT-AF was a randomized controlled trial with a 15-month treatment period (3–18 months post CA) involving complex weight-reducing interventions in the active arm. The primary outcome was the change in AF/atrial tachycardia (AT) burden assessed from baseline and the final 14-day Holter monitoring. A total of 167 individuals (aged 59 years, body mass index of 35.6 kg/m2) were randomized into the active (n = 85) and control group (n = 82). At the end of the treatment period, a mean reduction of 6.8 ± 7.0% of the initial body weight accompanied by improvement of metabolic parameters was achieved in the active group. The AF/AT burden change was 0.6 ± 2.5% (95% CI: −4.2–5.5%) in the active group and −0.9 ± 1.8% (95% CI: −4.5–3.0%) in the control group. The AF/AT recurrence-free survival during the 3–18-month follow-up period was comparable between groups (70.4% vs. 69.6%). Conclusion: HOBIT-AF trial showed that despite the beneficial effect of body weight reduction on metabolic profile of obese patients with predominantly paroxysmal AF after CA, no reduction in AF/AT recurrence was observed in comparison with control patients. This may be likely due to low AF burden after previous CA, limiting further improvement.